ASCE - Proceedings

Select this Article FREE		Proceedings Information ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)1 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This is the general conference information, including title, notices, and committee acknowledgements.

Select this Article FREE		Student and Younger Members Photo Contest ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)2 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This is the winning photograph in the 15th Annual EWRI Student and Younger Member Photo contest. There are details of the contest and a description of the winning photo.

Select this Article		Emerging Micro‐Pollutants in the Environment: Sorption and Mobility of Sulfonamide Antibiotics—A Potential Threat to Groundwater Contamination (First Place) Sudarshan Tanaji Kurwadkar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)3 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Veterinary antibiotics used in livestock operations have been identified as one of the major sources of antibiotics in the environment. Antibiotics, such as sulfonamides, used in feedlots are excreted in a partially metabolized form in the urine and fecal material of livestock animals. The current practice of land application of untreated lagoon waste from livestock operations has a serious potential to contaminate groundwater. This paper intends to elucidate some of the key aspects of the mobility of sulfonamides, such as sulfachloropyridazine (SCPD) and sulfamerazine (SMRZ), in the environment. To achieve this objective, column studies were performed for SCPD and SMRZ in three soils: Missouri loam, North Carolina loamy sand, and Iowa sandy loam. A pulse containing a suite of eight antibiotics was injected instantaneously and the filtrate was analyzed for antibiotics concentrations. In all three soils, based on the initial soil pH, both SCPD and SMRZ were observed to be highly mobile at high pH value; however, significant retardation was observed at lower pH. Enhanced mobility of these compounds observed at high pH was due to the cumulative effect of the anionic form of antibiotics, the polar nature of soil material, and the increased solubility observed at high pH value. Conversely, severe attenuation of these compounds observed at lower pH values was due to the increased interaction of cationic and neutral forms of antibiotics with soil material. The recoveries and the sorption experiment performed for SCPD and Iowa sandy loam indicated that the mobility of sulfonamides, in general, is contingent upon the alkalinity of the soil. Considerable decrease in the sorption coefficient was observed at high pH value.

Select this Article		Biodegradation of Pyrene in Soil Microcosms: Identification of a Toxic Intermediate (Second Place) Yanna Liang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)4 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Pyrene is a polycyclic aromatic hydrocarbon (PAH) compound that was a regulated pollutant that limited the rate of bioremediation of wood preservative contaminated soil at the Champion International Superfund Site in Libby, Montana. The half‐life of pyrene in soil at field scale may extend beyond one year depending on environmental conditions. The environmental fate of pyrene and other PAHs affected by naturally occurring soil microbes is important in the development of monitoring and bioremediation strategies, and in protecting drinking water supplies originating from groundwater resources threatened by leaching of PAHs. Mycobacterium sp. KMS was isolated from vadose zone soil at the Libby site and was shown to transform more than 60% of ¹⁴C pyrene added to soil microcosms to carbon dioxide within 38 days at 28°C. In this study, Pyrene fate was monitored in four soil matrices: an uncontaminated Kidman soil, a site boundary soil (BD), the BD soil with the addition of Mycobacterium sp. KMS, and mercuric chloride poisoned BD soil. The amount of extractable pyrene was relatively constant over the experimental period in Kidman and poisoned soil microcosms, whereas the amount of extractable pyrene decreased with time in BD soil and decreased rapidly in the inoculated BD soil. High‐performance Liquid Chromatography (HPLC), Liquid Chromatography Mass Spectrometry (LC/MS) and Nuclear Magnetic Resonance (NMR) spectroscopy analyses showed the formation of a major metabolite, pyrene‐4,5‐dione (PYRQ) in the BD soil microcosms with and without Mycobacterium sp. KMS inoculation. PYRQ was also identified in solvent extracts of site soil. PYRQ demonstrated a response in the aqueous Microtox® toxicity assay. It can be further degraded in inoculated and uninoculated BD soil, but it accumulates in other systems. The production of PYRQ and its possible release into environment may present a potential risk.

Select this Article		Application of Ozone‐Membrane Filtration Hybrid Process for Drinking Water Treatment and Disinfection Byproducts Formation (Third Place) Bhavana S. Karnik ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)5 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Titania membranes, with a molecular weight cut‐off of 15 kD were used in an ozonation/membrane system that was fed with water from Lake Lansing, which had been pre‐filtered through a 0.45 μm glass fiber filter. The application of ozone gas prior to filtration resulted in significant decreases in membrane fouling. Decreases in the pH resulted in a concomitant increase in the dissolved ozone concentration in the feed water and in an improvement in permeate flux recovery. Increasing the ozone concentration beyond a threshold value had no beneficial effect on permeate flux recovery. Ozone decomposition, resulting in the formation of ⋅OH or other radicals at the membrane surface, is thought to result in the decomposition of organic foulants at the membrane surface and reduce the extent of membrane fouling. A minimum ozone concentration of 0.05 mg/L in the recirculation feed water is required to obtain steady permeate fluxes that are >95% of the initial value. When the effects of combined ozonation and membrane filtration on the degradation of the natural organic matter (NOM) and the formation of disinfection by‐products (DBPs) were investigated, ozonation/filtration resulted in up to a 50% reduction in the dissolved organic carbon (DOC) concentration. Ozonation/filtration resulted in the formation of partially oxidized compounds from NOM that were less reactive with chlorine, decreasing the concentrations of total trihalomethanes (TTHMs) and halo acetic acids (HAAs) by up to 80% and 65%, respectively. A 1kD MWCO membrane with a minimum gaseous ozone concentration of 2.5 g/m³ can result in effective degradation of NOM and meet the regulatory requirements for chlorinated DBPs proposed by Stage 2 D/DBPs Rule.

Select this Article		Groundwater Contamination Source Identification Using Hybrid Optimization Methods (First Place) Matthew Clayton ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)6 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Locating the source of groundwater contamination is an important part of cleaning up groundwater pollution. One way to locate the source is to solve an inverse problem that uses downstream well data to estimate the source. Currently, using a hybrid of global and local search methods we are able to estimate the location of a contaminant source in a simplified two‐dimensional setup, but this is not useful when there are possibly multiple sources in the same area. In this paper, we modify and expand existing single‐source groundwater contamination inverse solvers to tackle the more difficult scenarios of multiple source identification. In order to handle more than one source we modify the groundwater transport model, expand the optimization methods, and create different visualizations of the problem to better understand the solution. We also compare different optimization methods to find which are best for a multi‐source problem, examine the difference between the objective function error versus the actual solution error, and explore the possibilities of a non‐unique solution to the problem. The long term goal of this research is to expand this approach to more realistic three‐dimensional problems in collaboration with the North Carolina Department of Environmental and Natural Resources.

Select this Article		Membrane Filtration Processes for Removing Arsenic from Drinking Water (Second Place) Kristina Oakes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)7 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, arsenic has increasingly become a concern in water quality, especially in drinking water quality. Concerns have risen due to the alarming health effects associated with long term arsenic exposure. This paper reports on the concerns and the methods that are being used to effectively reduce arsenic levels in drinking water. Since arsenic is considered a carcinogen, the EPA has taken action. The Safe Drinking Water Act set the standards for contaminants found in drinking water. Arsenic, one of the contaminants, had a standard of 50 parts per billion (ppb) under the Act. However, in 2001, the EPA established more stringent water quality standards. By 2006, all water supplies must comply with the new 10 ppb standard for arsenic. A very efficient method for removing arsenic from drinking water is a membrane process. Compared to methods used in the past, membrane processes offer a higher and more efficient removal rate. There are four types of membrane processes: reverse osmosis, microfiltration, ultrafiltration, and nanofiltration. Each of these processes offer similar results but have different benefits in their uses. A membrane process is a filtering method driven by a force. That force is usually pressure. Each of the processes is greatly affected by the pore size of the filter. The membrane holds back any contaminant that is bigger than the pore size of the filter. Arsenic is a contaminant that with the correct filter pore size can be stopped at the membrane. Nanofiltration is ideal for arsenic removal. It, along with the other membrane processes, significantly depends on the temperature of the water, the pH, the presence of any other contaminants, the initial concentration of arsenic present in the water, and the operation pressure. Nanofiltration is a high pressure method that produces high removal efficiencies. Furthermore, a study in Bangladesh is highlighted that illustrates the effectiveness of nanofiltration and different methods of applying that process. However, it does require an extensive pretreatment process to initially get the arsenic concentration down to efficient operating levels. With that pretreatment, nanofiltration can then be used to get the arsenic level in the water to measures that meet the more stringent standards set by the EPA. If all water sources and point sources agree to the best available technology, this new level of water pollution control can be achieved.

Select this Article		Effects That Pesticides Have on Public Water Supplies (Third Place) Jared Kohler ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)8 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water is a fundamental part of human life. Unfortunately, no one thinks about the possibility that the water that they are drinking may be contaminated. Within the past decade, however, a variety of pesticide compounds have been discovered in the nation's water supplies, often at concentrations that far exceed regulated limits. Because of this, nearly 14.1 million people in the United States routinely consume water that is contaminated with significant amounts of pesticides. Pesticides are chemicals that are used in agricultural and residential locations to control plant, insect, and animal infestations. Pesticide is a broad name given to categorize a more specific family of chemicals: Herbicides, Insecticides, Nematocides, and Fungicides. Pesticides get into water supplies through a variety of different means which include runoff, rain and snow absorption/melting into the soil, improperly disposed pesticides, improperly applied pesticides, and soil erosion caused by water runoff and/or wind. Pesticides are a heath threat not only because of their toxicity, but also because of their use in almost every facet of human life. Studies that have been conducted on the effects of pesticides on humans focus on two main aspects: acute toxicity of short‐term exposure and chronic toxicity resulting from long term exposure. Acute pesticide poisoning symptoms may include headaches, dizziness, stomach and intestinal upset, numbness of the extremities, spasms, convulsions, and heart attacks. Chronic pesticide poisoning has been is has been known to cause the following adverse health problems: cancer, liver and kidney damage, disorders of the nervous systems, damage to the immune system, thyroid changes, endocrine disruption, and birth defects. Attention has been focused on ways of preventing cases of contamination and on coming to a determination of what levels of pesticides are acceptable in drinking water supplies. Guidelines have been proposed with aims to keep pesticides at levels below those that are considered harmful to human life. These guidelines have been developed from the laboratory data that was discussed earlier and other known pesticide characteristics. Individual landowners are also encouraged to do what they can to prevent water supply contamination. Although steps have been taken since the 1970's to improve the quality of water in the United States, there is still a lot of work that needs to be done if public water supplies are to be cleaned of pesticide contamination. The alternatives to pesticide use seem as if they could be effective if utilized. Unfortunately, it seems that farmers, businesses and industries that use pesticides on a regular basis would not be prepared to risk the loss of crop production to simply protect the environment. The government must intervene and make regulations stricter than they are right now. Until that happens, the general public will continue to take for granted the most important natural resource that they have.

Select this Article		Algorithms of Combinatorial Optimization Applied to Water Distribution Networks Design Juan G. Saldarriaga, Germán Villalba, and Silvia Takahashi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)9 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a new methodology based on algorithms that includes the determination of optimal pressure surface, constraint programming and genetic algorithms to find an approximation to least cost design of water distribution network. REDES and EPANET programs are used for hydraulic simulation and two well known problems are solved finding solutions of less cost satisfying pressure constraints. This methodology is computationally much faster when compared with other algorithms used previously to solve this problem and good solution can be found. Furthermore is possible to optimize known solutions to find better solutions. The Hanoi network problem is tested and better solutions were found than those published previously in the literature.

Select this Article		Analysis of Uncertainty on Water Distribution Hydraulics and Water Quality M. F. K. Pasha and K. Lansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)10 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Since the passage of the Safe drinking Water Act (SDWA) of 1990, researchers have been motivated to work on water quality and system hydraulics issues in water distribution system design and operation. Before 1990 water quality requirements were only imposed at the water source, thus, the primary concern of the water distribution system was systems hydraulics. Today maintaining disinfection levels and pressure are equally important. System modeling can be used as a basis of planning and operation decisions. However, model accuracy and uncertainty will impact the confidence in, thus the conservatism built into, model based decisions. Model prediction uncertainty results from uncertainty in model parameters that are determined through calibration or are based upon modeler judgment. Uncertainty in pressure head has been evaluated from the perspective of system reliability and in design. However, the relative impact of alternative data has not been compared to assess the need for estimating parameters. In addition, water quality within a distribution is strongly affected by the selection of water quality model parameters such as bulk and wall decay coefficients. In addition, since water quality is dominated by advective transport, hydraulic parameters and conditions also impact water quality. This is most clearly seen in the effects of tanks due to flows to and from the storage facility. The hydraulic system representation will also affect the flow distribution and travel times within the system. Many modelers suggest that all pipe models are required to adequately represent the true flow patterns. To date, only anecdotal evidence through analysis of simple networks under deterministic conditions has been presented justifying this conclusion. However, as more pipes are introduced, more uncertain parameters must be defined or calibrated for those components. This paper begins to examine the impact of alternative sources of uncertainty on water quality predictions by examining steady state conditions for a well‐documented mid‐sized system. The objective is to study the effect of alternative uncertain parameters sets on uncertainty levels of hydraulic and water quality variables through Monte Carlo simulation. The input parameters considered are the decay coefficients, pipe roughnesses, pipe diameters, and nodal demands. The output variables evaluated are the nodal pressure heads and concentrations are points throughout the system.

Select this Article		Burst Detection and Location in Water Transmission Pipelines D. Misiunas, M. F. Lambert, A. R. Simpson, M.ASCE, and G. Olsson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)11 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents results from testing of a burst detection and location technique on a water transmission pipeline. The primary targets of the method are medium and large bursts that are the result of a sudden rupture of a pipe wall or other physical element in the pipeline system. The technique is based on the continuous monitoring of the pressure in the pipeline combined with a hydraulic transient modeling. Analysis of a burst‐induced pressure transient wave and its reflections from the pipeline boundaries is used to derive the location and size of the burst. The method has earlier demonstrated promising results on a laboratory pipeline and a dead‐end branch of a real water distribution network. Results presented here show that the approach has a potential to be used for burst detection and location in long transmission pipelines. Bursts of different sizes, locations and opening times were successfully detected and located. Different operational regimes of the pipeline were considered. The technique could help to minimize the response time to the pipe failure and therefore reduce the losses associated with a burst and improve reliability of the pipeline operation.

Select this Article		A Comparison of Navier Stokes and Network Models to Predict Chemical Transport in Municipal Water Distribution Systems B. van Bloemen Waanders, G. Hammond, J. Shadid, S. Collis, and R. Murray ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)12 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract We investigate the accuracy of chemical transport in network models for small geometric configurations. Network model have successfully simulated the general operations of large water distribution systems. However, some of the simplifying assumptions associated with the implementation may cause inaccuracies if chemicals need to be carefully characterized at a high level of detail. In particular, we are interested in precise transport behavior so that inversion and control problems can be applied to water distribution networks. As an initial phase, Navier Stokes combined with a convection‐diffusion formulation was used to characterize the mixing behavior at a pipe intersection in two dimensions. Our numerical models predict only on the order of 12–14 % of the chemical to be mixed with the other inlet pipe. Laboratory results show similar behavior and suggest that even if our numerical model is able to resolve turbulence, it may not improve the mixing behavior. This conclusion may not be appropriate however for other sets of operating conditions, and therefore we have started to develop a 3D implementation. Preliminary results for duct geometry are presented.

Select this Article		Denver Water's System Specific Study for the Stage 2 Disinfectants and Disinfection Byproducts Rule Arnold Strasser, P.E., Bruce Hale, and Edward J. Koval, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)13 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Denver Water (DW) serves over 1.2 million customers and supplies about 500 million gallons per day on a maximum day basis. The DW system includes three treatment plants, 17 major pump stations, over 160 pressure zones with over 400 pressure reducing valves and over 4,300 miles of pipe. DW's primary responsibility is to supply high quality water to its customers at the lowest cost possible. This paper will present the process and results DW used to complete a System Specific Study to meet the Stage 2 DBPR as well as provide guidance to operations for effective energy management relative to water quality. In early 2004, DW completed a three phased approach of developing an all pipes extended period simulation (EPS) model. Phase three was geared at developing an all pipes EPS model that would assist DW in the preparation of an Initial Distribution System Evaluation (IDSE) System Specific Study (SSS) for the Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR). The model was hydraulically calibrated using traditional telemetry data and water age computations were verified through the use of a system wide fluoride tracer test. Ultimately, this process allowed DW to better determine preliminary water quality sampling locations to meet the Stage 2 DBPR than a Standard Monitoring Plan would have allowed. Field sampling was conducted in late 2004 at the preliminary monitoring sites recommended in the initial SSS. Correlation of DBP field data and water age predicted by the model are presented. The findings represent a real world test of the use of a distribution system model and water age to select informative and representative DBP monitoring sites. Field identification of Water Treatment Plant source water and model source trace results are also presented. The model was also used to refine operations relative to energy and water quality requirements.

Select this Article		Development of a JAVA Based Water Distribution Simulation Capability for Infrastructure Interdependency Analyses D. Visarraga, B. Bush, S. P. Linger, and T. N. McPherson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)14 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A linear theory approach is applied to the hydraulic simulation of a water distribution system within the Interdependent Energy Infrastructure Simulation System (IEISS). IEISS is an actor‐based infrastructure modeling, simulation, and analysis tool designed to assist individuals in analyzing and understanding interdependent energy infrastructures. In particular, it has the ability to analyze and simulate the interdependent electric power and natural gas infrastructures. The ultimate goal for IEISS is a multi‐infrastructure modeling framework that can be used to analyze the complex, nonlinear interactions among interdependent infrastructures including electric power, natural gas, petroleum, water, and other network based infrastructures that is scalable to multiple spatial (e.g., urban to regional) and temporal resolutions. The actor‐based infrastructure components were developed in IEISS to realistically simulate the dynamic interactions within each of the infrastructures, as well as, the interconnections between the infrastructures. To enhance its capabilities, a generalized fluid network will be added to the infrastructure framework, which will allow for the analysis of specific fluid infrastructures (e.g., water, petroleum, oil, etc.). In this research, we describe the extension of IEISS to include water infrastructure. The resulting simulation capability (i.e., IEISS Water) will allow the simulation of transmission/distribution‐level water systems in terms of infrastructure specific vulnerabilities and interdependent infrastructure vulnerabilities (e.g., power and water disruptions).

Select this Article		Dynamic Simulation of Tracer in Water Distribution System Fan Jie, Gao Jinliang, Wu Chenguang, and Deng Tao ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)15 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In China water distribution system is highly complex. As a result the management and optimal control of the distribution system face many problems. Water supply trend division is a key parameter of the optimal control for multi‐sourced distribution system. The concepts as quality trend division in distribution system (QTDDS) and energy trend division in distribution system (ETDDS) have been presented according to the different functions. The introduction of a concept that ratio of tracer concentration (RTC), the dynamic model of which has been built, is a significant parameter to control the water quality in water distribution system. And the rationale and method of how to divide the QTDDS with RTC has also been put forward. The principle of how to divide the ETDDS has been presented. With the dynamic simulation of a real distribution network of a metropolis in China, it shows that the RTC model can divide the QTDDS, and both QTDDS and ETDDS play important roles in optimal control of water distribution system.

Select this Article		An Efficient Sampling‐Based Approach for the Robust Rehabilitation of Water Distribution Systems under Correlated Nodal Demands Zoran Kapelan, Dragan A. Savic, and Godfrey A. Walters ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)16 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water distribution system (WDS) rehabilitation problem is defined here as a multiobjective optimisation problem under uncertainty. The two objectives are: (1) minimise total rehabilitation cost and (2) maximise WDS robustness. The WDS robustness is defined as the probability of simultaneously satisfying minimum pressure head constraints at all nodes in the network. Decision variables are the alternative rehabilitation options for each pipe in the network. Uncertain nodal demands are modelled as correlated random variables using the probability density functions (PDFs) assigned in the problem formulation phase. PDFs of the analysed nodal heads are calculated using the Latin Hypercube (LH) sampling technique. Unlike in other sampling‐based WDS design approaches, here, random LH samples are generated to take into account spatial correlation between uncertain nodal demands. The optimal rehabilitation problem is then solved using the newly developed rNSGAII method. In rNSGAII a small number of demand samples are used for each fitness evaluation leading to significant computational savings when compared to the full sampling approach. The new methodology is tested on the New York tunnels case study. The results obtained indicate that new methodology is capable of identifying the robust Pareto optimal solutions under correlated nodal demands.

Select this Article		Estimating Risk Measures for Water Distribution Systems Using Metamodels D. R. Broad, H. R. Maier, G. C. Dandy, and J. B. Nixon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)17 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Recent developments in the field of optimization of Water Distribution Systems (WDS) have focused on incorporating uncertainty into the analysis, recognizing that variables such as demand should be considered as stochastic variables. As a result hydraulic reliability must be considered as a constraint, rather than pressure heads. The most common method of quantifying reliability is to use a Monte Carlo Simulation (MCS). However, this is a very computationally expensive process. In this research, a metamodeling approach was used to reduce this computational intensity. A metamodel is an approximation of an existing model, which takes less time to run, making it much more computationally efficient upon repeated use, such as in a MCS or during optimisation with a Genetic Algorithm. The specific type of metamodel used in this research was an Artificial Neural Network (ANN), as it is capable of approximating any function without specifying the form it will take. Two metamodeling scenarios are used in this research to approximate reliability. First, a metamodel was developed that approximated pressure heads and chlorine residuals for an adaptation of the New York Tunnels problem, from which reliability was calculated. Second, reliability was approximated directly with a metamodel, thus eliminating the need of a MCS completely. The results in this paper have shown that ANN metamodels can be used to accurately approximate common risk measures used to evaluate WDS performance, such as hydraulic and water quality reliability and vulnerability, while offering considerable savings in computational time. It was found that it was more computationally efficient to use ANNs to approximate pressure heads and chlorine residuals than to approximate reliability directly. This was due to the fact that it took a significant amount of time to generate training data for the latter case.

Select this Article		An Evaluation of System Architectures for Contamination Warning Systems Robert Janke, Regan Murray, James Uber, and Steve Allgeier ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)18 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Protecting our nation's water systems from terrorist attacks has become a federal and local priority over the last several years. Recently, water security research efforts have focused on the advancement of methods for mitigating contamination threats to drinking water systems. Research on Contamination Warning Systems (CWS), sometimes called early warning systems, is advancing rapidly, and focuses on detectors and water quality sensors, rapid communication technologies, data analysis methods, and confirmatory sampling and analysis methods. The goal of a CWS is to provide an early indication of both accidental and intentional contamination in drinking water distribution systems in order to reduce the public health impacts, economic effects, and improve a water system's response capability. Under the President's proposed 2006 budget, within the Environmental Protection Agency (EPA), $44 million has been allocated to a pilot monitoring and surveillance program that will provide early warning of intentional contamination events. Drinking water surveillance activities will be piloted in selected cities. This new program is called WaterSentinel. The purpose of WaterSentinel is to not only establish a critical early warning capability in selected cities, but the pilot seeks to Provide “proof of concept” that will encourage other cities across the Nation to adopt monitoring and surveillance activities. The deployment of a contamination monitoring program in selected cities next year, however, relies on technology that is still in the early stages of development, and a full contamination monitoring system has not been validated either in a controlled pilot project or in a real distribution system. This paper uses modeling and simulation to design, optimize, and evaluate contamination monitoring systems.

Select this Article		Field Measurements of Unsteady Friction Effects in a Trunk Transmission Pipeline Mark Stephens, Angus R. Simpson, Martin F. Lambert, and John P. Vítkovský ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)19 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The relative importance of unsteady friction effects in real pipelines remains a matter of debate. This paper presents the results of a set of field transient measurements on a 13.5 km long trunk transmission water pipeline located in regional South Australia. Modelling has been undertaken using efficient rough pipe turbulent weighting function methods to calculate the unsteady friction contribution. The relative importance of unsteady friction, for no‐leak and leak cases, is assessed.

Select this Article		A First‐Order Reliability Method for Contaminant Detection and Isolation T. M. Baranowski and E. J. LeBoeuf ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)20 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The nation has become increasingly concerned with the vulnerability of water distribution systems following the terrorist attacks of September 11^th. Vulnerability assessments may be used to help identify components of water distribution systems (pipes, junctions, and equipment) that require strengthening against possible attacks. Such components can be susceptible to a variety of assaults, including physical destruction and/or chemical contamination. Numerous recent research efforts have focused on the placement of chemical detection sensors within a water distribution network to aid vulnerability assessments associated with contamination events. Reliability of the sensor systems to detect contamination events has received increased emphasis in system vulnerability assessments. Included in these efforts are optimization schemes to provide optimal placement of sensor systems to minimize population exposure, time to detection, or extent of contamination. Another related issue is the probability of isolating a contaminant following sensor detection. In this current effort, we utilize a first‐order reliability method (FORM) to determine the reliability of contaminant detection and isolation. Here, FORM provides a reliability index which can be used to approximate the probability of success or failure in contaminant containment. This aids in consequence management of contamination events by supplying system operators with additional confidence in properly capturing a contaminant plume. The procedure simulates advective transport at varying levels of flow under unsteady‐state conditions

Select this Article		Fuzzy Rules for Hydraulic Reliability‐Based Design and Operation of Water Distribution Systems R. Farmani, D. A. Savic, and G. A. Walters ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)21 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A hydraulic reliability based optimization model has been developed for rehabilitation of water distribution systems. Cost‐effective rehabilitation and replacement schemes will respond to hydraulic requirements, growth and climate change. Such study is a highly complex optimization problem. The improvements may include upgrading the existing components of the network or addition of new pipes, tanks and pumps. Projected future demands will play an important role in conducting these studies by helping to determine the sizing of many replacement and/or additional network components. Due to uncertainty in demand forecasting, pipe roughness and cost estimation, providing adequate service with reliability and a safety factor to allow for uncertainty becomes one of the main objectives in multi‐objective water system design and operation. In this paper an expanded rehabilitation problem is considered where the design variables are the pipe rehabilitation decisions, tank sizing, tank siting and pump operation schedules. To provide flexibility, the network is designed and operated under multiple loading conditions. The cost of the solution includes the capital costs of pipes and tanks as well as the present value of the energy consumed during a specified period. The impact of uncertainty of future demand on system reliability is studied. Fuzzy rules are used to describe the hydraulic reliability of system for solutions under uncertainty. Results are presented for the pay‐off characteristics between total cost and probability value, for 24 hour design and five loading conditions.

Select this Article		A Heuristic Methodology for Locating Monitoring Stations to Detect Contamination in Water Distribution Systems James R. Chastain, Jr., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)22 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The requirements to protect public water systems from external contamination have expanded in the years following September 11, 2001. The areal extent and non‐linear nature of fluid demand and movement in the distribution system makes efficient location of sampling points difficult. This difficulty is compounded by the fact that contamination conceptually can occur at any time and at any point within the distribution system. This paper proposes a methodology to identify strategic locations within the system that can be established as critical detection points for such occurrences. This methodology is different from others in that it uses computer simulations to create a database of water system response to contamination at every node in the system. A process is developed to mine this database systematically after considering concentration thresholds and “time since injection” parameters. Finally, using pivot tables and graphs, a network of monitoring locations is identified to provide efficient coverage of the system under the conditions imposed. Time‐of‐day of injection is also indicated to be a parameter of consequence.

Select this Article		A Hybrid (MT‐LP) Approach to Water Distribution Systems Inverse Modeling Ami Preis and Avi Ostfeld, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)23 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a general new approach for water distribution systems inverse modeling through a hybrid Model Trees (MT)‐Linear Programming (LP) link. The model tree replaces EPANET through learning (i.e., training + cross validation), where the LP then uses the model tree linear rule classification structure to solve an inverse problem. For a given system model trees which mimic the system response for a selected type of application like design, operation, calibration, or water quality analysis, are constructed. This linear tree structure represents forward modeling (i.e., from root to leaves). The implementation of LP on that linear tree structure allows backward (inverse) modeling (i.e., from leaves to root). The approach is demonstrated through two example applications for the design of water distribution systems where selected pipe‐system characteristics (herein link diameters) are treated as the variables to be selected to meet required system pressures.

Select this Article		Hydraulic Simulation of Water Supply Networks under Control J. Deuerlein, R. G. Cembrowicz, and S. Dempe ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)24 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objectives of simulating the hydraulic behavior of a water supply network, being either real or planned, focus upon identifying flow, pressure and velocities, following time variant system's operation or the propagation of water quality in the network, supporting leak detection, verifying the hydraulic impact of different system's elements, guiding gauging and calibration. Existing simulation models represented by available software show different capacities regarding control devices, including pressure control valves, pressure sustaining valves, flow control valves, check valves, speed regulated pumps—operated combined and simultaneously where convergence may not be obtained. Since a rigorous mathematical approach is lacking the system's behavior is presently treated heuristically without guarantee of success. Consequently a new mathematical approach has been derived and is presented here. First, the hydraulic simulation is conceived as optimization of the system's ‘Content’ and ‘Co‐Content’ functions. Second, regarding flow control devices, Convex Analysis is utilized to allow a generalization of the hydraulic equations of system's elements in the form of subdifferential mappings leading to Kuhn‐Tucker conditions, amenable to solution. Third, regarding pressure control devices, the definition of a Nash Equilibrium, according to Game Theory, between the ‘Co‐Content’ and additional minimizing problems, describing the system behavior of the devices, also leads to a solution. Hence, arbitrary flow and pressure controlling devices can now be incorporated in water supply network simulation. Convergence is assured if the system's physics are feasible. The approach has been implemented as part of the water supply network simulation & optimization model KANET.

Select this Article		Identifiability of Contaminant Source Characteristics in Steady‐State and Time‐Varying Network Flows James G. Uber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)25 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Municipal water distribution systems are vulnerable to potential contamination from intentional as well as natural sources. Emergency response actions (e.g., isolation of the contamination via flow controls) must be implemented within hours to limit population exposure and minimize damages. It is important to detect a contamination incident and to identify its characteristics as quickly and reliably as possible, using on‐line sensors, sampling procedures and data processing algorithms. The characteristics of contamination include the contaminant type, the contaminant source locations and quantities, and the current and projected extent of contamination throughout the system. In this paper we discuss the identifiability of the inverse problem to determine the contaminant source characteristics, given time‐series data from online contaminant specific sensors. This source characterization problem is cast in the form of traditional linear least squares estimation. It is shown to be rank deficient and the common methods of QR factorization are proposed to investigate and characterize solution non‐uniqueness.

Select this Article		Identification of Discolouration Risk through Simplified Modelling J. B. Boxall and N. Dewis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)26 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Supply of discoloured water is often the most frequent cause of water quality related customer contacts worldwide. Water suppliers wish to be able to identify pipes within networks that are likely to be the source of discolouration and hence prioritise maintenance activities to efficiently reduce customer contacts. In this paper simple modelling methodologies to facilitate the identification of discolouration risk at pipe level are investigated. Investigations are based on the assumption that discolouration occurs as a result of change in hydraulic conditions with relative risk estimated with reference to velocity or shear stress criterion. The paper culminates in comparison between the pipe level evaluations of relative risk and discolouration contact data to assess the value of the approaches. Results show agreement between groupings of customer contacts and pipes evaluated as posing a high discolouration risk judged against shear stress criteria due to sequential pressure dependent increases in demand.

Select this Article		Importance of Dispersion in Network Water Quality Modeling Zhiwei Li, Steven G. Buchberger, and Velitchko Tzatchkov ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)27 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper applies numerical models to simulate more realistic network conditions and develop preliminary new guidelines on the conditions under which dispersion is important in pipe networks. Instead of adopting the “usual” one‐dimensional Advection‐Dispersion‐Reaction (1D‐ADR) model, a two‐dimensional Advection‐Diffusion‐Reaction (2D‐ADR) model is selected. This eliminates the error caused by estimation of the enigmatic dispersion coefficient, an essential parameter of the 1D‐ADR model. Numerical results from the 2D‐ADR model are compared against numerical results from a 1D‐AR (Advection‐Reaction) model to identify differences caused by dispersion‐related factors, such as time history of source strength, solute reaction rate, pipe diameter and flow pattern. Several source load scenarios are simulated using the 2D‐ADR numerical code in order to confirm a theoretical order‐of‐magnitude analysis of each term in the simplified 1D‐ADR equation. This comparison highlights the relative importance of advection, dispersion and reaction in solute transport during low flow conditions. Results confirm that dispersion is just as important as advection and, therefore, should not be ignored when modeling water quality in laminar flow dominated zones of the water distribution system.

Select this Article		Incorporating Spatial Correlation in a Markov Chain Monte Carlo Approach for Network Model Calibration D. L. Boccelli and J. G. Uber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)28 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract To utilize a drinking water distribution system network model in any decision making process requires a calibrated network model. Typical calibration methods assume known consumer demands and adjust pipe roughness coefficients to fit pressure measurements and storage levels. However, these data contain little explicit information related to hydraulic residence time and travel path, which are necessary to improve water quality representations. Recent field‐scale tracer tests have been shown capable of collecting data related to hydraulic residence time and flow path that can be used to adjust demand pattern multipliers to fit the observed tracer data. Both problem types (estimating pipe roughness coefficients or demand pattern multipliers) can have a spatially distributed component. This research extends an existing Markov chain Monte Carlo calibration algorithm by incorporating spatial correlation into the parameter estimation framework. Results will be generated using synthetic test data to evaluate the ability of the calibration algorithm to regenerate the known roughness coefficients or demand pattern multipliers.

Select this Article		An Integrated Approach to Vulnerability Assessment Vincent C. Tidwell, Consuelo J. Silva, and Sariah Jurado ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)29 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract How might the quality of a city's delivered water be compromised through natural or malevolent causes? What are the consequences of a contamination event? What water utility assets are at greatest risk to compromise? Utility managers have been scrambling to find answers to these questions since the events of 9/11. However, even before this date utility mangers were concerned with the potential for system contamination through natural or accidental causes. Unfortunately, an integrated tool for assessing both the threat of attack/failure and the subsequent consequence is lacking. To help with this problem we combine Markov Latent Effects modeling for performing threat assessment calculations with the widely used pipe hydraulics/transport code, EPANET, for consequences analysis. Together information from these models defines the risk posed to the public due to natural or malevolent contamination of a water utility system. Here, this risk assessment framework is introduced and demonstrated within the context of vulnerability assessment for water distribution systems.

Select this Article		A Mixed Integer Approach for Obtaining Unique Solutions in Source Inversion of Drinking Water Networks Carl D. Laird, Lorenz T. Biegler, and Bart G. van Bloemen Waanders ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)30 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Presidential Decision Directive 63 identified water systems as one of the critical infrastructures to the United States. Following this directive and the passing of The Public Health, Security, and Bioterrorism Preparedness and Response Act there has been increased research effort in both assessing, the vulnerability of drinking water systems and proposing protection measures. Drinking water networks are vulnerable to chemical and biological contamination. While physical security is being used to limit access to some potential contamination locations, due to the distributed nature of drinking water networks, many locations remain unprotected. One proposed method of protection is the installation of an early warning detection system. Sensors installed at various locations throughout the drinking water network could warn utilities companies in the event of a contamination. On its own, an early warning detection system provides only a coarse measure of the time and location of the contamination event. In previous work the authors introduced a large scale nonlinear programming approach that used real‐time concentration information from an installed sensor grid to accurately determine the time and location of the contamination event. This approach introduced unknown, time dependent injection terms at every node in the network and formulated a quadratic program to solve for the time profiles of the injections. The objective function was a least squares minimization of the errors between the calculated and measured node concentrations at the sensor nodes with a regularization term to force a unique solution. The constraints in the optimization problem were the partial differential equations of the water quality model for the network. This problem was then discretized with a fully simultaneous approach, using an origin tracking algorithm to characterize the pipe time delays and remove the need to discretize along the length of the pipes. The resulting large scale nonlinear program was solved using a nonlinear interior point code, IPOPT. This approach was effective at identifying a family of possible injection scenarios. The unregularized formulation of the source inversion problem can have many non‐unique solutions. The regularized formulation, on the other hand, has a unique solution, but this solution is essentially linear combination of possible injection scenarios. With this approach alone, it is difficult to determine if the observed contamination was caused from a single injection location or multiple locations. In this work, we propose a problem reduction technique and formulate a mixed integer quadratic program (MIQP) to identify unique injection scenarios. This formulation includes constraints that further limit the solution space and allows us to distinguish between single and multiple injection locations. Section 2 gives a brief description of the formulation, followed by a discussion of solution non‐uniqueness and how this manifests in the regularized problem. In Section 3 we introduce the mixed integer formulation and show how the problem size can be reduced drastically using active‐set information from the original continuous problem. We show the effectiveness of this approach on a real municipal water network in Section 4. Here we test both single and multiple location injection scenarios. Finally, we present some conclusions and directions for future work.

Select this Article		A Model for Estimating the Acute Health Impacts Resulting from Consumption of Contaminated Drinking Water Regan Murray, James Uber, and Robert Janke ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)31 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract SIR models predict the spread of disease over time through susceptible, infected, and recovered populations, and are often used to design public health intervention strategies. A modified SIR model is linked to flow and transport models for distribution systems in order to predict the health risks associated with contamination events. The proposed framework provides information about the spatial and temporal distribution of health risks in distribution systems, and is useful for understanding the vulnerability of distribution systems to contamination, but also for designing strategies to reduce risks.

Select this Article		Modeling the Distribution of Demands between Tanks in a Water Supply System Deen A. Suleman and Jakobus E. van Zyl ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)32 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of this paper is to model the behavior of water demand in water distribution systems as a separate process. The contribution of a tank to the water demand at a node is defined as the difference in the tank outflow with and without the demand at the node. This does not correspond with the physical contribution of water from the tank to the node, but allows the demand contribution to the tank to be mathematically separated from the hydraulics of the system without demands. It is shown theoretically that for a simple two tank system, the demand contributions of the tanks are proportional to the total demand, and independent of the tank levels. For a two tank system with two demands, the total contribution of a tank to the demand can be determined through susperposition. For more complex systems the independence of the demand distribution with tank level is lost, but superposition can still be used to determine the demand contribution of a tank. Demand distribution has application in network simplification and extended‐period simulation of water distribution using the Explicit Integration method.

Select this Article		Modeling Urban Water Demand within a GIS Using a Population Mobility Model T. N. McPherson and M. Witkowski ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)33 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An important factor in the accuracy of water distribution network simulations is the accuracy of the associated water demand estimates. Water demand has both a spatial and temporal component, and the poor characterization of either can have significant consequences on the results of water distribution network models. Both the temporal and spatial characteristics of water demand are dependent on a wide range of variables describing the demographic, economic, environmental, cultural and legal structure of a community. Each of these variables has a geographic component and geographic information systems, therefore, is a powerful tool that can be used to improve the accuracy of water demand models. In this research, we demonstrate an urban scale water demand modeling approach within a geographic information system that accounts for both the spatial and temporal characteristics of water demand. The spatial component of water demand is improved using high‐resolution datasets on the location of residences, businesses, schools, and other water consumers with unit use coefficients. The temporal component is improved using an activity based population mobility model. The combination of these models and data in a geographic information system produces an urban scale water demand model that can be easily interfaced with water distribution models to provide detailed analyses of system operation. Water demand models are demonstrated for Chicago, IL.

Select this Article		Monte Carlo Simulation of Residential Water Demand: A Stochastic End‐Use Model E. J. M. Blokker, MSc and J. H. G. Vreeburg, MSc ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)34 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water companies are interested in their customers' water demand for network design purposes. To be able to design the network for both everyday demand and the maximum momentary demand, it is necessary to develop a model that gives insight into the networks water extraction on a per second basis. A stochastic computer model to simulate residential water demand was built for this purpose. The end‐use model is survey‐based and applies statistical information per type of water use, i.e. the duration and flow, frequency and the occurrence over a day. Eight main types of end‐use were discerned plus several subtypes that constitute those end‐uses, such as using the kitchen tap for washing hands and for consumption, and showering with a low or high flow. The first simulation results are in good agreement with measured demand patterns.

Select this Article		Multi‐Objective Design of Water Distribution Systems Using Cross Entropy Lina Perelman and Avi Ostfeld, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)35 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The design of water distribution systems involves conflicting objectives: minimizing cost, maximizing reliability, minimizing risks, minimizing deviations from specific targets of quantity, pressure, and quality, etc. The design problem is thus inherently a multi‐objective problem. This paper presents a new multi‐objective scheme for the design of water distribution systems based on Cross Entropy (CE). The Cross Entropy (CE) method is an evolutionary iterative technique based on the concept of rare events, which involves two main stages: (1) generation of a sample of random data (trajectories, vectors, etc.) according to a specified random mechanism, and (2) parameters updating of the random mechanism, on the basis of the generated data, so as to produce a “better” sample at the next iteration. The method derives its name from the cross‐entropy (or Kullback‐Leibler) distance—a well known measure of “information”, which has been successfully employed in diverse fields of engineering and science, and in particular in neural computation. In this paper the CE method is extended to multi‐objective optimization in general, and to multi‐objective water distribution systems design in particular. The CE method is explored through a simple bench‐mark example application.

Select this Article		Multiobjective Optimization for the Least‐Cost Design of Water Distribution Systems under Correlated Uncertain Parameters A. V. Babayan, D. A. Savic, and G. A. Walters ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)36 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The problem of the stochastic (i.e. robust) water distribution system (WDS) design is formulated and solved here as a multiobjective optimization problem under uncertainty. The objectives are to minimize two parameters — a) cost of the network design/rehabilitation; b) probability of network failure due to uncertainty in input parameters. The sources of uncertainty analyzed here are future water consumption and pipe roughnesses. All uncertain model input parameters are assumed to be random variables following some known probability density function (PDF). We also assume that those random variables are not necessarily independent and the matrix giving the correlations between all pairs of uncertain parameters (correlation matrix) is specified. To avoid using a computationally demanding sampling‐based technique for uncertainty quantification, the original stochastic formulation is replaced by a deterministic one. After some simplifications, a fast numerical integration method is used to quantify the uncertainties. The optimization problem is solved by a Genetic Algorithm (GA), which finds the Pareto front by using the non‐dominating sorting GA (NSGAII) for multi‐objective optimisation. The proposed methodology was tested on the New York tunnel problem.

Select this Article		Multistage Stochastic Optimization for Agricultural and Urban Water Management with Imperfect Forecasts Tingju Zhu, Guilherme F. Marques, and Jay R. Lund ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)37 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Long‐term hydrologic forecasts are not widely used in water resource decision‐making practices, partially due to the large forecast uncertainty involved. This paper formulates how long‐term (annual) hydrologic forecasts might improve the management decisions of an integrated regional water resources system, using a three‐stage stochastic optimization model. The three stage model is developed based on a two‐stage model, which the paper also examines analytically. Both models incorporate decisions regarding crop mix, irrigation technology, conjunctive surface and ground water operation, urban water conservation, and water transfers between the agricultural and urban areas. The first stage includes all permanent decisions, such as acreage of perennial crops and urban conservation measures that will exist for multiple years. The second stage consists of temporary decisions, like acreage of annual crops, annual urban conservation measures and annual water transfers, whose impacts are limited within a year, based on imperfect forecast information. The third stage of the three‐stage model comprises recourse decisions that “adjust” the temporary decisions in the second stage based on the “realizations” of hydrology which are conditional on each of the year type forecast employed in the second stage.

Select this Article		Network Modeling to Demonstrate Efficacy of Improved Water Quality Monitoring Santosh Ghimire, Brian Barkdoll, and Paul Bergstrom ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)38 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water quality is a prime concern in the US and the world. In particular, the disinfection and security of water have become important for everyday health and terrorist risk reduction. To mitigate the effects of compromised water quality it is apparent that the quality and frequency of water quality data collection are of primary importance. In order to demonstrate the need for improved water quality data collection, a network solver (EPANET) has been used to model the response of the system to an inappropriate addition of chlorine at the water treatment plant. Simulations have been performed on a real municipal water distribution system (Baraga, MI) of approximately 100 nodes and a population of 9,000 and contaminant plume behavior simulated at select network locations. Concentration levels at selected nodes around the network were examined for time of exposure to unacceptable chlorine levels. It was found that having improved monitoring could reduce response time and human exposure to contamination by approximately 95%.

Select this Article		A Numerical Study of a 2D Multi‐Component Corrosion Model in a Water Distribution System Gh. Naser and B. W. Karney ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)39 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The main purpose of this study is to present a fully transient multi‐component water quality model through a numerical simulation of flow in a pipeline considering both hydraulic and water‐chemistry issues. In other words, the objective is to numerically model the concentration of chemicals in the water distribution systems during the different conditions of flow. The chemicals are released in the system due to the reactions, which take place either in bulk flow or at the pipe‐wall. The later is studied herein. This preliminary study explores on the effects of important parameters such as solution pH and initial concentration of dissolved oxygen on the chemical processes such as corrosion. In this light, considering the dissolved oxygen as main oxidant, the process is chemically modeled as simple anodic‐cathodic reduction‐oxidation reactions (redox reactions). The iron metal oxidized, creating ferrous ion (Fe²⁺) at anode. On the other hand, the reduction reaction produces hydroxide ion (OH⁻) at chatode. Due to concentration gradient, the ions migrate within the system in order to maintain the solution electrically neutral. Then, the ferrous ion reacts with hydroxide ion producing iron hydroxide, which deposits on the pipe‐wall as corroded material. In this study, one‐ and two‐dimensional simulation models are proposed, by which the concentration of each chemical is modeled by the advection‐diffusion‐reaction equation, which is then coupled with continuity and momentum equations for flow. Modeling the turbulence fluctuations by the five region turbulence model, a combination of finite difference and characteristic methods are used to numerically integrate the governing equations for chemical constituents and flow. Results for a case study are compared and show good agreement.

Select this Article		Planning and Operation of Large‐Scale Water Distribution System with Hedging Rules Mario T. L. Barros, M.ASCE, Renato C. Zambon, David M. Delgado, Paulo S. F. Barbosa, and William W.‐G. Yeh, Hon.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)40 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract One of the most critical problems that all megacities (cities with more than 10 million people) face today is the shortage of water supply. Finding a solution to this problem presents a great challenge to hydrologists, urban planners and environmentalists. This paper describes the development of an optimization model for planning and operation of a large‐scale water supply distribution system. An important characteristic of the model is that it considers the hedging rules during a dry period when water supply is insufficient to meet the planned demand and water shortage occurs. The water distribution system is formulated as a network flow model in terms of nodes and links and solved by the GAMS language, which has access to several linear and nonlinear algorithms. A user friendly interface is developed to facilitate the manipulation of a large amount of data and to generate graphs and tables for analysis for decision makers. The developed methodology has been implemented for the São Paulo Metropolitan Area Water Distribution System that supplies water to 18 million people. Some preliminary results obtained show good performance of the model.

Select this Article		Predicting Chlorine Residuals in Unlined Metallic Pipes Robert M. Clark, M.ASCE, Roy C. Haught, and Walter M. Grayman, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)41 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There are numerous factors that can influence the quality of water in distribution systems. These include chemical and biological quality of source water; effectiveness and efficiency of treatment processes, adequacy of treatment facilities, storage facilities and distribution system, the age, type, design, and maintenance of the distribution network, and quality of treated water. Perhaps one of the most serious public health aspects of water quality deterioration in a network is the loss of disinfectant residual which can weaken the barrier against microbial contamination. A factor frequently cited as contributing to the loss of disinfectant residuals is internal corrosion of the pipe wall material. The effect of velocity in contributing to the loss of residual chlorine has been studied in a simulated distribution and has been reported previously. The results of this research has been verified in studies conducted in full scale systems and is reported in this paper.

Select this Article		Red Team‐Blue Team Exercise for Locating Monitors in Distribution Systems Walter M. Grayman, Avi Ostfeld, and Elad Salomons ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)42 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Red team‐blue team exercises are methods of evaluating security by creating a “game” where one team (the red team) attempts to “attack” a target and the other team (the blue team) tries to defend it. This paper describes a computer exercise where the red team simulates the contamination of a water distribution system and the blue team defends the system by installing monitors to detect the presence of the contaminant. This exercise was developed and has been used as part of several demonstrations on the effectiveness of contaminant monitoring systems. For comparison, a mathematical model is applied to the same network to select monitor locations that provide the optimal solution in terms of a set of objectives.

Select this Article		Reducing Online Contaminant Monitoring Uncertainty Using a Bayesian Belief Network W. J. Dawsey, B. S. Minsker, and V. L. VanBlaricum ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)43 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There is a great deal of uncertainty in real time characterization of water distribution system contamination events. Much of this uncertainty is due to the lack of targeted sensors which makes it necessary to use surrogate water quality parameters to indirectly measure the presence of a contaminant. A positive sensor detection can often be validated by pieces of evidence observed in a distribution system. This paper illustrates how Bayesian belief networks can be used to represent distribution system contamination scenarios. A framework was developed that integrated sensor data with other validating evidence of a contamination event. This framework was used to express causality between the events and observed evidence that comprise contamination scenarios.

Select this Article		Selection of Genetic Algorithm Parameters for Water Distribution System Optimization Matthew S. Gibbs, Graeme C. Dandy, Holger R. Maier, and John B. Nixon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)44 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The ability of Genetic Algorithm (GA) methods, to find near optimal solutions to Water Distribution System (WDS) optimization problems has been widely demonstrated. However, one of the main concerns in applying these methods is identifying suitable values for the GA parameters. The values selected for these parameters have a significant impact on the algorithm's behavior, and therefore greatly affect the quality of the final solution found, as well as the time taken to find that solution. A considerable amount of time and effort must be dedicated to the calibration of these parameters for the GA practitioner to have any confidence that the values used are producing the desired results. The impact of each parameter will be dependent on the values of the other parameters, and it is likely that there exists different combinations that will produce the same exploration/exploitation behavior. This offers the potential to reduce the number of parameters requiring calibration, thus making the task of applying these methods much simpler. This paper describes large‐scale sensitivity analyses that have been used to calibrate a real coded GA with a distributed crossover operator, for a WDS optimization problem, the Cherry Hill‐Brushy Plains network, ultimately leading to the identification of a new optimal solution. Through these analyses, groups of parameter values are identified that cause the algorithm to perform very well in terms of algorithm convergence and the quality of the final solutions obtained. These results demonstrate that by understanding the parameters controlling the GA, and the relationships between themthe effort required to calibrate a GA for a given application can be reduced significantly.

Select this Article		A Sensor Location Model to Detect Contaminations in Water Distribution Networks M. Propato, O. Piller, and J. G. Uber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)45 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Real‐time continuous water quality monitoring could provide an increased barrier to protect consumers against contaminations. Among several challenges to be faced to successfully build such a system, there is the sensor location problem that should be designed to satisfy several requirements. A general simulation framework describes the computational tasks necessary to assess consumer exposure from contamination event scenarios. A mixed integer linear program is proposed to identify optimal sensor locations to detect random contaminations occurring in drinking water systems under unsteady hydraulic conditions. Such problem formulation is flexible to accommodate different design objectives whose mathematical differences are only the coefficient values while the number of variables and constraints remains identical. Such feature reduces the computational effort required to determine the tradeoff solutions and it makes more straightforward results analysis and comparison. To optimize problem coefficients calculation, several computational tasks are decoupled. In particular, for large contamination event ensembles, concentration dynamics at consumer nodes can be calculated using a linear input/output model without requiring to execute a water quality model simulation for every contamination scenario.

Select this Article		Solving the Inverse Problem of Deliberate Contaminants Intrusions into Water Distribution Systems Avi Ostfeld, M.ASCE and Elad Salomons ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)46 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A methodology is developed and applied for solving the general inverse problem of a deliberate contaminant intrusion into a water distribution system: given a contaminant detection at one or more online monitoring/sensors stations—identify the injection characteristics: (1) location, (2) starting time, (3) intensity (mass time), and (4) duration. The algorithm is based on the randomized pollution matrix (RPM) concept, developed in previous works by the authors, and taking into account the monitoring stations detection sensitivity, their response delay, and possible different injection probabilities throughout the system. The model outcomes are the system nodes with the highest likelihood to be the injection locations; the approximated injection starting times; intensities; and durations. The model is demonstrated through a base run and sensitivity analysis using a simple example application.

Select this Article		Source Location Inversion and the Effect of Stochastically Varying Demand Sean A. McKenna, Bart Van Bloemen Waanders, Carl D. Laird, Steven G. Buchberger, Zhiwei Li, and Rob Janke ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)47 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, significant advances have been made in the development of gradient‐based optimization algorithms and their application to inverse problems in water distribution systems. We apply a gradient‐based optimization procedure to the problem of identifying the location of a contaminant injected into a distribution system based on data collected at a finite number of sensors. The solution of this problem is complicated by uncertainty in the instantaneous water demands occurring at nodes throughout the distribution system. We characterize the effect of this demand uncertainty on the ability of the inversion algorithm to accurately and precisely identify the correct source location by varying the time step at which the variable demands are aggregated from 30 minutes to 24 hours. These calculations determine the effect of demand aggregation on the inversion results by comparing the results across time step sizes to the results achieved at the smallest time scale (30 minutes). In a distribution system the true water demands at any time step are unknown and represent irreducible uncertainty. We show how large of an effect this irreducible uncertainty has on our ability to locate the source location of contaminants within a distribution system. The calculations are done on a moderately sized distribution system network and the stochastic demands are generated using a recently developed Poisson Rectangular Pulse (PRP) demand generator. The contaminant is simulated with tracer transport using EPANET. Results for the example problem examined herein using 100 sensors show that the inverse approach is capable of identifying the correct source node at all time step aggregations.

Select this Article		Staging of Master Planning of Water Distribution Systems Using Genetic Algorithm Optimization Alana M. Duncker, Angus R. Simpson, and Tomasz Wozniak ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)48 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Master planning of water distribution systems usually involves a long‐time horizon of 25 to 50 years into the future. Estimates of future water demands are made as well as the configuration of the ultimate build‐out of water distribution system. The difficulty with the results of a master planning study is that the near term needs for system expansion may not match the long‐term plans. An approach of using genetic algorithm (GA) optimization for developing two master plans, one for the short term and one for the long term is presented in this paper. In addition, an approach for optimizing the staging of construction to link the short and long term master plans is also presented. This paper highlights a genetic algorithm (GA) master plan study carried out for the Barossa Valley water distribution system in South Australia. First the infrastructure needs (transmission and distribution pipelines) for 2010 were optimized using genetic algorithm optimization for the near term planning of facilities. Pipes in parallel to existing pipes and replacement pipelines were sized. New and expanded pump stations were also considered. Once the 2010 master plan was developed, a staging analysis was carried out to identify a solution to satisfy the current demands (year 2005). A master plan to satisfy year 2025 demand predictions was also developed as part of the study. In the year 2025 master plan, improvements were sized to use components that would have been used to extend the system from year 2010 to 2025.

Select this Article		Stochasticity of Demand and Probabilistic Performance of Water Networks Y. R. Filion, B. W. Karney, and B. J. Adams ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)49 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Accurate prediction and modeling of water demand is crucial to understanding the long‐term performance of systems, as it is to mounting an effective design and operational planning effort. The paper investigates the influence of cross correlation and autocorrelation in demand on the probabilistic, hydraulic performance of water networks, as measured with the mean and variance of nodal pressures. A stochastic demand model that accounts for lag‐1 autocorrelation and lag‐0 cross correlation between demands is applied to generate synthetic series of correlated demands. A Monte Carlo Simulation is coupled with EPANET2 to generate time series of pressures and update the mean and variance of nodal pressures. Preliminary results indicate that enforcing a strong lag‐0 cross correlation in demand decreases the mean of pressures and increases the variance of pressures. This indicates that the frequency of low‐pressure, hydraulic failures is contingent on the level of correlation measured or assumed in a reliability study. Enforcing a strong lag‐1 autocorrelation memory at system nodes produces little or no changes in the mean and variance of nodal pressures, but it is found to govern the period of time a pressure signal can persist below a minimum‐pressure constraints and remain in a hydraulic failure state.

Select this Article		A Systematic Exploration of Uncertainty and Convergence of Inverse Transient Calibration for WDSs B. S. Jung and B. W. Karney ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)50 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Despite over ten years of research into ITC techniques for water distribution systems, many problems remain. One reason for these difficulties is that real water distribution systems invariably have many other uncertainties in addition to the leakage rates and friction factors that are conventionally considered as unknowns. For example, properties such as pipe diameter, wave speed, the possible presence of air, the value of the water demand at the time of the tests, and uncertain measurement accuracy, all add to the complexity and difficulty of obtaining a reliable calibration. The current paper investigates quantitatively how several of these uncertainties deteriorate system calibration, and thus the paper generally considers the necessity of a systematic calibration approach to explicitly include these additional uncertainties during the ITC process. To this end, two evolutionary optimizations, namely Genetic Algorithms and Particle Swarm Optimization, are compared and contrasted during the ITC iterations. The advantage of the evolutionary algorithms is that they help the search to escape from poor local optima in multifaceted and complicate problems and thus to locate a good global (or near‐global) optimum. However, even these approaches can often be expected to converge poorly when the full scale of the field problem is reflected in the search space.

Select this Article		A Theoretical Explanation for Peaking Factors Xiaoyi Zhang, Steven G. Buchberger, and Jakobus E. van Zyl ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)51 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The peaking factor (PF) is the ratio of the maximum flow to the average daily flow in a water system The PF concept has been used in both the drinking water and wastewater industries for nearly 100 years. Since there is some variability in the magnitudes of the maximum and the average daily flow, both can be treated as random variables and the corresponding PF should be interpreted in a probabilistic sense. Conventional methods for estimating the PF are based on empirical deterministic expressions, derived from a combination of field measurements and engineering judgment. For the most part, these existing PF expressions have performed well, but they lack a firm theoretical footing. The objective of this paper is to combine results from the Poisson Rectangular Pulse (PRP) model for residential water use with principles from extreme value analysis to develop a theoretical reliability‐based estimate of the PF. The theoretical predictions are compared against conventional design guides for PF over a range of pipe network sizes. Results show that the theoretical PFs agree quite well with those from conventional empirical methods. The decrease in PF with network size is readily explained. The new PRP based theoretical results are significant because they provide a way to estimate the PF in instances where flow data are scarce or where service area conditions may be changing.

Select this Article		Use of Continuous Recording Water‐Quality Monitoring Equipment for Conducting Water‐Distribution System Tracer Tests: The Good, the Bad, and the Ugly M. L. Maslia, J. B. Sautner, C. Valenzuela, W. M. Grayman, M. M. Aral, and J. W. Green, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)52 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An emerging and innovative technology that is a possible alternative to manual sampling is the use of continuous recording water‐quality monitoring equipment (CR‐WQME) for collecting multiple ion‐specific tracer data. Advantages of using CR‐WQME include the ability to record continuously water‐quality events (including unplanned events) during a tracer test at small time intervals of 15 minutes or less. This recording provides real‐time data when using hand‐held logger equipment to query the CR‐WQME at each sampling location. Also, the labor needed to conduct the test is reduced. Disadvantages could include the cost of multiple ion‐specific sensors and units for large or complex systems, the effort required to calibrate the equipment by setting up a test‐site water‐quality laboratory, and the reliability of the equipment for long‐term monitoring events. In this paper the authors assess the use of CR‐WQME in conducting a tracer test at a military installation in North Carolina. Using results obtained from the tracer test, the authors found that CR‐WQME is an emerging and innovative technology that still requires refinement and the use of some grab samples to provide quality‐assurance and quality‐control procedures during the tracer test. However, CR‐WQME is an excellent option when designing and conducting multiple parameter tracer tests for water‐distribution system model calibration activities.

Select this Article		Using Continuous Monitors for Conducting Tracer Studies in Water Distribution Systems Srinivas Panguluri, Radha Krishnan, Lucille Garner, Craig Patterson, Yeongho Lee, David Hartman, Walter Grayman, Robert Clark, and Haishan Piao ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)53 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The use of online monitors for conducting a distribution system tracer study is proving to be a helpful tool to accurately understand the flow dynamics in a distribution system. In a series of field tests sponsored by the U.S. Environmental Protection Agency (EPA) and the Greater Cincinnati Water Works (GCWW) in 2002‐2003, a food‐grade calcium chloride tracer was introduced into a water system network and the movement of the chemical was traced using strategically placed automated onlineconductivity meters (in conjunction with a limited grab sampling program). The benefits and results of this field testing effort are discussed in this paper.

Select this Article		Using Field Measured Transient Responses in a Water Distribution System to Assess Valve Status and Network Topology Mark Stephens, Martin F. Lambert, Angus R. Simpson, John P. Vítkovský, and John B. Nixon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)54 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Uncertainty about the status of valves in a water distribution system, or the existence of total blockages, is not uncommon. This paper presents an approach for determining topological changes using transient response analysis. Precise information is not available regarding all the physical elements contributing to the transient response of a water distribution system. Thus a parameterised model is developed and calibrated to represent “real” transient responses from a field water distribution system. The robustness of this model, and the methodology for diagnosing topological changes, are confirmed when used to successfully identify closed valves in the field.

Select this Article		Validation and Assessment of Integer Programming Sensor Placement Models Jonathan W. Berry, William E. Hart, Cynthia A. Phillips, James G. Uber, and Jean‐Paul Watson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)55 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract We consider the accuracy of predictions made by integer programming (IP) models of sensor placement for water security applications. We have recently shown that IP models can be used to find optimal sensor placements for a variety of different performance criteria (e.g. minimize health impacts and minimize time to detection). However, these models make a variety of simplifying assumptions that might bias the final solution. We show that our IP modeling assumptions are similar to models developed for other sensor placement methodologies, and thus IP models should give similar predictions. However, this discussion highlights that there are significant differences in how temporal effects are modeled for sensor placement. We describe how these modeling assumptions can impact sensor placements.

Select this Article		Vulnerability Assessment of Water Distribution System to Chemical Intrusions N. Khanal, S. G. Buchberger, S. A. McKenna, R. M. Clark, and W. M. Grayman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)56 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Drinking water distribution systems are vulnerable to a variety of terrorist threats including physical attack, cyber disruption and bio‐chemical contamination. Hypothetical chemical intrusions were made to perform the vulnerability assessment of a water distribution network to find out the vulnerable zone in the network for different chemical intrusion scenarios. Efficacy of the attack logistics: injection location, injection duration, and injection timing were examined in the full model of the Cherry Hills — Brushy Plain water distribution network. The effect of tank mixing on nodal mass loading and population exposure is studied. Simulation results were used to define network in three zones of influence based upon percentage population exposed. The results generated are of statistical significance and are easily understandable by utilities and designers.

Select this Article		Water Distribution System Reliability under a Fire Flow Condition: A Probabilistic Approach Julio Gomes and Bryan W. Karney ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)57 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the technical literature concerned with the design of water distribution systems (WDS), the term ‘fire flow’ is often associated with three distinct challenges: to estimate the actual fire flow needed to fight a fire; to estimate the availability of fire flow in a specific WDS; or, to evaluate the potential impacts of fire flow on WDS reliability. The first two challenges are generally addressed from a deterministic perspective, and, although some probabilistic approaches exist for solving the latter one, they seldom address fire flows explicitly. In general, fire flows are considered as part of a unique nodal flow probability distribution for reliability analysis purposes. Yet one significant question remains consistently unanswered: what is the WDS reliability given that a fire situation occurs? The objective of this study is to present a methodology which can be used to evaluate the WDS reliability under a fire condition. To this end, two different probability distributions are assessed for the nodal flows: one representing the base demands and the other representing the fire flow demands. A Monte Carlo method is used to generate the flows, and steady‐state hydraulic, simulations are performed to derive both nodal and system reliability indexes for a WDS under a fire condition.

Select this Article		The Water Infrastructure Simulation Environment (WISE) Project T. N. McPherson and S. J. Burian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)58 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Los Alamos National Laboratory is compiling and building tools to simulate infrastructure stability following damage events as part of the National Infrastructure Simulation and Analysis Center (NISAC). The Water Infrastructure Simulation Environment (WISE) project is an analytical framework providing simulation capabilities for drinking water distribution, sewage collection and stormwater infrastructures. The purpose of the WISE framework is to develop within the NISAC toolsets with the capability to represent and study water infrastructures in the context of interdependency. The completed toolset will include tools to manage and visualize data in multiple frameworks and formats, simulate water distribution, sewage collection, and stormwater storage and conveyance infrastructures, and to evaluate interdependencies with electric power, natural gas and other infrastructures. WISE will allow quick and accurate management of the large water distribution and sewage system datasets acquired from metropolitan agencies and pre‐process those datasets for use in infrastructure network solvers. Tools developed included ArcWISE, a GIS based graphical user interface that facilitates the acquisition, application and analysis of water infrastructure data in simulation codes, and IEISS Water, a simulation capability for water infrastructure within the Interdependent Energy Infrastructure Simulation System (IEISS) simulation framework. At present, ArcWISE includes tools for estimation of time varying water demand, the improvement of existing water distribution infrastructure and sewage collection GIS data for use in simulation codes, development of input files for those codes, and visualization capabilities. IEISS Water is a water distribution simulation capability for simulating urban scale water infrastructures and their interdependencies.

Select this Article		Water Quality Model Calibration by Means of Fast Messy Genetic Algorithm Zheng Y. Wu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)59 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A water quality model is to predict water quality transport and fate throughout a water distribution system. The model is not only a promising alternative for analyzing disinfectant residuals in a cost‐effective manner, but also a means of providing enormous engineering insights into the characteristics of water quality variation and constituent reactions. However, a water quality model is a reliable tool only if it predicts what a real system behaves. This paper presents a methodology based upon fast messy genetic algorithm that enables a modeler to efficiently calibrate a water quality model such that the field observed water quality values match with the model simulated values. The approach is integrated with a well‐developed hydraulic and water quality modeling system. It provides a generic tool for engineers to construct the sound water quality model in expedient manner. The method is applied to a water system and demonstrated that a water quality model can be effectively calibrated for managing adequate water supply for water utilities.

Select this Article		Water Quality Sensor Placement in Water Networks with Budget Constraints Jonathan W. Berry, William E. Hart, Cynthia A. Phillips, James G. Uber, and Thomas M. Walski ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)60 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, several integer programming models have been proposed to place sensors in municipal water networks in order to detect intentional or accidental contamination. Although these initial models assumed that it is equally costly to place a sensor at any place in the network, there clearly are practical cost constraints that would impact a sensor placement decision. Such constraints include not only labor costs but also the general accessibility of a sensor placement location. In this paper, we extend our integer program to explicitly model the cost of sensor placement. We partition network locations into groups of varying placement cost, and we consider the public health impacts of contamination events under varying budget constraints. Thus our models permit cost/benefit analyses for differing sensor placement designs. As a control for our optimization experiments, we compare the set of sensor locations selected by the optimimzation models to a set of manually‐selected sensor locations.

Select this Article		Water Supply Threat Reduction Using Evolutionary Approaches Zbigniew Skolicki, Moe M. Wadda, Mark H. Houck, F.ASCE, and Tomasz Arciszewski, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)61 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The potential threats to US water supply systems have changed fundamentally in the past four years. Prior to 2001, the major threats were natural causes, accidents, and some malicious behavior by a small group of individuals. Against these threats, water supply agencies have done a truly remarkable job of ensuring a safe, dependable supply. However, threats posed by an organized group of actors may represent a new and different challenge to the security of water supplies. A tool to assist in identifying possible attacks and simultaneously providing remedies to counter these attacks has been developed. The tool uses evolutionary computation as the optimization method, and EPANET as the system simulator. Preliminary examples of its use to identify optimal attacks against a realistic but hypothetical pipe network and corresponding counter measures are presented.

Select this Article		Adaptive Control of Contaminant Releases by Boundary Actuators Rong Wu and Nikolaos D. Katopodes, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)62 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A method is presented for the control of chemical spills. The approach is based on real‐time information provided by solid‐state microsensors installed at appropriate locations and capable of monitoring instantaneous changes in the concentration of several species in solution or suspension. The method also utilizes current flow and transport data provided by a simulation model based on a set of initial conditions of the system. Once a hazardous spill requiring control action is detected by the sensors, the model provides optimal directions to pre‐installed boundary actuators capable of modifying the flow conditions in the system. The technique requires assimilation of data from the sensors to steer the model so the error between its current state and sensor measurements is minimized. The model also performs prediction simulations to determine the optimum set of actuator commands necessary to control the chemical plumes. Results of model control applications are shown to be capable of removing a chemical cloud from a flow through channel.

Select this Article		Adaptive Decision Support System for Real‐Time Operation of the Geum River Basin, Korea John W. Labadie, Darrell G. Fontane, Jin‐Hee Lee, and Ick Hwan Ko ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)63 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A joint international collaboration between the Korea Water Resources Corporation (KOWACO) and Colorado State University has resulted in development of a decision support system (DSS) for daily operations in the Geum River Basin, Korea. The DSS is a customized version of the MODSIM Generalized River Basin Network Flow Model, which has been adapted to the Geum River Basin in particular and Korean conditions in general. Customization of MODSIM into the Korean version KMODSIM is accomplished without the need for any recoding of the model, but rather through use of embedded MS VB.NET scripts. The graphical user interface is translated into the Korean language for ease of use by KOWACO engineers and system operators. The model is not only calibrated to physical and hydrologic characteristics of the basin, but also to the operational and administrative water allocation priorities for multiple water uses including municipal and industrial water supply, irrigation supply, hydropower generation, and low‐flow augmentation for water quality management. Conditional reservoir operational rules adapted to changing river basin conditions are developed using implicit stochastic optimization and incorporated into the daily operational model using embedded VB.NET scripts.

Select this Article		Adaptive Management of the Guadalupe River Watershed, San Jose, CA Alberto M. Gurevich, P.E., M.ASCE, Terrence A. Neudorf, Devin A. Mody, P.E., M.ASCE, and David J. Chesterman, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)64 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract What is adaptive management? At the Santa Clara Valley Water District (SCVWD) in San Jose, California, this term has been typically used to describe activities that will occur once a project is complete. SCVWD is beginning to learn that with adaptive management, a project is never really “complete”. A project is planned, designed, constructed, maintained, and continually improved as part of an overall adaptive management process. Once constructed, the Guadalupe River Flood Protection Project will provide 100‐year flood protection for homes and businesses through downtown San Jose and ultimately, downstream, through the heart of Silicon Valley. A key component of the project is adaptive management. In 2002, SCVWD convened an adaptive management team (AMT) consisting of representatives from SCVWD, U.S. Army Corps of Engineers (Corps), U.S. Fish and Wildlife Service, National Oceanic and Atmospheric Administration Fisheries, California Department of Fish and Game, San Francisco Bay Regional Water Quality Control Board, City of San Jose, and environmental stakeholders. The AMT helps implement the adaptive management process for the project for the next 100 years and is responsible for evaluating progress towards the achievement of the measurable objectives (MOs) outlined in the project's mitigation and monitoring plan (MMP). The AMT also reviews recommendations proposed by SCVWD and the Corps, and provides additional recommendations to assure achievement of the MOs. Going forward, SCVWD envisions integrating the AMT with other forums to expand the adaptive management concept beyond this stretch of Guadalupe River. SCVWD is also a member of the Guadalupe Watershed Integration Working Group, another collaborative that has been established to ensure MMPs for various projects are executed consistently and examined from a programmatic, watershed management perspective. By developing the adaptive management process beyond just one project, we may better be able to answer the question, “what is adaptive management?”

Select this Article		Assessment of Agricultural Production Vulnerability under Global Climate Change—An Overview of the Methodology Romain Laurent and Ximing Cai ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)65 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The impacts of climate change and variability have been an important concern for sustainable agriculture in the U.S. and the world in terms of crop profit (food security in many regions) and environmental preservation. However research on the impacts is still inconclusive and understanding the impacts is not sufficient for appropriate decision making on adaptation options. This situation is partially due to ineffective research approaches. For instance, most of the existing approaches deal with the effect of individual Global Climate Models (GCMs) without a degree of probability attached. Although those approaches may be appropriate for sensitivity analyses and help to define a plausible range of outcomes, none is likely to define the range of plausible adaptive capacities that might emerge in response to climate change scenarios due to the difficulty of handling the uncertainty of climate change. The major uncertainties in projected ranges of regional climate arise from three main sources: (1) Emission scenarios, influenced by economic activity, population growth and technology; (2) Global climate sensitivity, measured by the sensitivity of GCMs to greenhouse gas forcing; and (3) the reliability of the outcomes from various GCMs. Moreover Regional variability occurs between models as different regional responses, and within models through chaotic behaviors and modes of climate variability, especially multi‐decadal variability. Direct output from an individual GCM is subject to the sensitivity and forcing within the individual GCM scenario, which has no further degree of probability attached. If a single scenario is used to model a particular impact, the results may be fairly precise but are conditional on that single scenario, and are unlikely to be representative of other possible futures. At best, a range of projected climate change bounded by its high and low extremes can be used to produce a range of impacts, results that are often too broad to be of practical use in planning for adaptation. Furthermore, the GCM scenarios do not provide information about changes in interannual variability or intermonthly variability. The quantification of climate change uncertainty including the range of the global warming impacts and local climate variability remains a research challenge. In summary, such a methodology is needed that will project ranges preserving local patterns of change while being scaled for different assumptions of climate sensitivity and greenhouse gas emissions and containing a level of probability. This paper describes a methodology to quantify the uncertainty with climate change and the corresponding vulnerability with agricultural production in a particular region. The application of known probability distributions has been used to solve problems in many fields, such as economics, insurance and gambling, where, by applying historical data, statistical methods are used to forecast the probability of a particular set of outcomes. For climate change, projections of climate are derived from physical models (GCMs) used in lieu of a statistically represented history. This technique will be used in this research to calculate projected ranges of regional climate for the key climatic variables that form the input to the agricultural production impact model. Among the previous studies, some used this technique to analyze the impacts of risk regarding climate change on irrigation water demand. This paper presents a more comprehensive analytical framework, including a new approach to determine the GCM model uncertainty.

Select this Article		Conflict Resolution in Water Allocation Considering the Water Quality Issues Mohammad Karamouz, F.ASCE, Ali Moridi, Reza Kerachian, and Masoud Asadzadeh Esfahani ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)66 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Available water resources are often not sufficient or too polluted to satisfy the needs of all water users. Therefore conflict on water, as a result of limitations on quantity and quality of water is a major challenge in water allocation. In this study, a methodology for conflict resolution in water allocation in river — reservoir systems is presented. The proposed model includes an integrated GA‐based optimization and a water quantity/quality simulation model. The objective function of the optimization model is based on the Nash bargaining theory that earned John Nash a noble prize. Nash theory can incorporate the utility functions of the decision makers and the stakeholders as well as their relative authorities on the water allocation process. In the water quality simulation model, the reservoir thermal stratification cycle, the reservoir discharge quality and also the water quality downstream of the reservoir are simulated. The model is applied to the Karkheh River‐Reservoir system in southern part of Iran. The utility functions are based on the reliability of the allocated water to different sectors especially the environmental water demands, quality of the allocated water and in‐stream flow, water storage in the reservoir, and the quantity and quality of the return flows. The results show that this model can be effectively used in optimal water allocation of river‐reservoir systems with conflicting objectives.

Select this Article		Desalination Emerging as a Potential Water Supply in California Fawzi Karajeh, Fethi BenJemaa, Charles Keene, and Brian Smith ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)67 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract California's current population of 35 million is projected to increase by about 12 million by the year 2030. In assuring supply reliability—with water management strategies shifting away from the construction of new dams, reservoirs and conveyance canals—and in addition to water conservation and water recycling, desalination is gaining considerable attention from scientists, resource planners, policy‐makers, and other stakeholders. The main driving force for this renewed interest in water desalination is the remarkable technological advancement in desalination processes which has recently led to a much lower cost of desalinated water than was previously attainable. In 2003, the California Water Desalination Task Force was convened by the California Department of Water Resources pursuant to a new Legislative Law with the aim of looking into potential opportunities and impediments for using oceanwater and brackish water desalination in California, and to examine what role, if any, the State should play in furthering the use of desalination technology. After about six months of deliberations, the Task Force outlined key findings that provide context for evaluating desalination. The findings included some facts and figures about brackish and oceanwater desalination in general and highlights of several environmental issues as well as cost, energy, permitting issues, and growth‐inducement related to desalination. One of the primary findings is that economically and environmentally acceptable desalination should be considered as part of a balanced water portfolio to help meet California's existing and future water supply and environmental needs. The Task Force forecasted that the potential for the increased use of desalination in California is significant and that the opportunities are great for providing water supply from oceanwater and brackish water desalination as well as recovering contaminated groundwater. Existing and envisioned desalination facilities could generate an estimated 860 million m³ (700,000 acre‐feet) per year in the next three decades. The Task Force put forward a set of 29 recommendations classified into four categories covering a broad range of issues including energy, environment, planning, permitting, funding, and equity. A detailed narrative of the Task Force findings and recommendations is presented in this paper.

Select this Article		Determining the “True Cost of Water” in an Automotive Manufacturing Plant Luis Garcilaso, William Gaines, and Brian D. Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)68 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The cost of water consumption has ramifications throughout many areas of our society. This is equally true whether the user be residential, commercial, or industrial. The true cost of water includes many factors beyond simply the purchased water cost. It includes heating, cooling, initial and final treatment(s), and pumping costs. In addition to the direct and indirect costs incurred by the user, there are external costs to society from water quality degradation caused by the use and disposal of water. ‘Eco‐Efficiency Analysis” provides a powerful tool to better quantify the true cost of water by considering both the economic and environmental life cycle impacts of a product or process. This allows the creation of an Eco‐Efficiency Portfolio by utilizing an overall weighting system. The ratio of economic benefit to ecological change can then be more accurately examined. By doing so, a quantitative decision can be made to determine which water use alternative provides the greatest cost‐effective, sustainability. While initial capital costs may be greater under some circumstances, educating consumers of the sustainable manner in which water is being used can result in increased sales and, therefore, profit. The approach for calculating the true cost of water for an automobile plant is described here. Future research will focus on implementing the described approach in an automobile assembly plant.

Select this Article		Development of Water Allocation Policies Considering the Demand Variations: A System Dynamics Approach Mohammad Karamouz, F.ASCE, Ali Moridi, and Nasrin Aghaee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)69 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The water demand and the utility functions of the decision makers and the stakeholders of a river basin are different. Due to changing environmental, social and development conditions, the utility functions of the decision makers/agencies could also vary from time to time. To study the dynamics of water resources system and the relevant policy making issues, the effects of allocated water on the growth rates are not usually considered. A comprehensive water allocation model should consider the conflicting issues facing water users as well as the changing water demands. In this paper, a system dynamics based model is presented for developing the optimal water allocation policies in Karkheh river‐reservoir system in southern part of Iran considering the interactions between the conflicting utility functions, values of water demands and the allocated water. In this model, the water demand is a function of population, land use, crop pattern and the economic conditions of the region which can be affected by the allocated water. The proposed methodology includes a GA‐based optimization model and a system dynamics simulation model. The objective function of the optimization model is based on the Nash compromising theory that can incorporate the utility functions of the decision makers as well as their relative authorities in the conflict resolution process. The system dynamics simulation model is used to simulate the dynamics of different sectors' water demand due to causal loops affected on demand variation during reservoir operation. The results of this study show that the population, the area of agricultural lands, and the industrial water demand have an S‐shaped growth. Furthermore, this model can be used effectively in conflict resolution and optimal water allocation in river‐reservoir systems. According to results of this study, considering the dynamic growth of water demands is more reliable than allocating water based on a constant growth rate for all sectors, because the demand variation due to allocated water to each sector is considered and demands growth due to each sector asymptote. This kind of planning is more useful for developing regions that the regional growth is directly related to the potential and available resources such as water.

Select this Article		Extensions to the Water Rights Analysis Package Modeling System Ralph A. Wurbs ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)70 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Water Rights Analysis Package (WRAP) simulates management of the water resources of a river basin or multiple‐basin region under a priority‐based water allocation system. The model facilitates assessments of hydrologic and institutional water availability and reliability in satisfying requirements for instream flows, water supply diversions, hydroelectric energy generation, and reservoir storage. Basin‐wide impacts of water resources development projects and management practices are modeled. The Texas Commission on Environmental Quality (TCEQ), its partner agencies, and contractors implemented a statewide Water Availability Modeling (WAM) System based on WRAP during 1997–2003 pursuant to comprehensive water management legislation enacted by the Texas Legislature in 1997. Expanded modeling capabilities developed since implementation of the Texas WAM System are designed to support a broader range of decision support needs as well as better address issues identified during implementation of the WAM System. Recent extensions to WRAP involve adding (1) conditional reliability modeling capabilities, (2) daily time step features including flow forecasting and routing, (3) features for simulating flood control operations, and (4) a salinity simulation component.

Select this Article		Free Markets—A Stimulus or Impediment for Integrated Water Resources Management? Stephen E. Draper ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)71 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A significant philosophical controversy erupted in 1992 over the role of economics in integrated water resources management: “Fresh water is a finite and vulnerable resource, essential to sustain life, development and the environment … Water has an economic value in all its competing uses and should be recognized as an economic good.” The debate continues, centering on the basic question. Is the free‐market approach to recognizing water as an economic good compatible with the long‐term goals of IWRM? The basis of IWRM stands on a foundation of four legs: economic efficiency and growth, social equity, environmental protection, and effective governance. The answer to the question, essential when devising successful strategies for integrated water resources management, rests on whether the free‐market approach is compatible with the other three essential supports for IWRM. As a means to deal with the problem, the World Bank has proposed that nations and states introduce tradable property rights to water as a means to “increase the productivity of water use, improve operations and maintenance, stimulate private investment and economic growth, reduce water conflicts, rationalize ongoing and future irrigation development, and free up government resources for activities that have a public good content or positive externalities.” This proposal needs much analysis and debate since the consequences to effective water management are significant. Water markets offer theoretical advantages in being able to transfer water to higher and better uses, at least when these uses are valued according to their financial return. However, even the “perfect” market has disadvantages, not the least of which is the fact that the theory is based on each transaction being based on a rational individual, with perfect knowledge, deliberately maximizing utility. Other disadvantages demonstrate that, while markets are appropriate for many, if not most, situations, they are not appropriate in every instance. The most serious of these disadvantages are the failure of the tradable property rights to water to consider the entirety of integrated water resources management (TRWM).

Select this Article		Integrated Impacts of Climate Change on and Adaptation Strategies for Metropolitan Areas: A Case Study of Metropolitan Boston Paul Kirshen, Matthias Ruth, and Bill Anderson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)72 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Even though urban infrastructure systems are important and are designed according to socioeconomic and environmental conditions that are very sensitive to climate, there have been few major integrated assessments of the impacts of climate change on metropolitan infrastructure systems and services. Since infrastructure systems last considerably longer than decades (some a century or more) and provide the footprint and direction for future development, it is important that decision‐makers understand the short‐ and long‐term consequences of climate change on infrastructure. The CLIMB project was conducted from 1999 to 2004 by a multidisciplinary research team from Tufts University, University of Maryland, and Boston University with assistance from the Metropolitan Area Planning Council (MAPC)and a Stakeholder Advisory Committee made up of sectoral experts. The methodology is summarized in Ruth and Kirshen (2001) and the full methodology and results are available in Kirshen et al. (2004). Metro Boston, which is located in the northeastern United States, is shown in Figure 1 and includes the major cities of Boston and Cambridge and the other 99 municipalities within approximately 20 miles of Boston. The area is bordered on the east by Boston Harbor (the confluence of three major rivers) and on the south, west, and north approximately by the circumferential Route 495, covering an area of 1422 square miles. Metro Boston population is approximately 3.2 million and expected to grow to 3.9 million by 2050. Land use varies from densely populated urban areas in the east, suburbs in the center, and undeveloped farmland and some urban “sprawl” on the fringes. It is the heart of the New England economy and provides its major airport, and seaport facilities. The region is currently experiencing pressure on most of its infrastructure systems and severe development pressure in the municipalities just outside of the core urban areas. It is characterized by a climate with four distinct seasons with annual precipitation of 1000m relatively evenly distributed throughout the year; some as snow in the winter. The average monthly temperature is approximately 10 degree Celsius. One of major findings of the research was that how impacts on and adaptation actions for various infrastructure systems interact could affect adaptation strategies, particularly those related to water resources, the subject of this paper. The paper summarizes the research project and then the importance of these interactions.

Select this Article		Joint Operating Policies Using Sampling SDP for the Geum River Basin in Korea Young‐Oh Kim, Hyung‐Il Eum, and Ick Hwan Ko ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)73 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This study combined two state‐of‐the‐art optimization techniques for reservoir operations: Sampling Stochastic Dynamic Programming (SSDP) and Ensemble Streamflow Prediction (ESP). SSDP using historical inflow scenarios (called SSDP/Hist) derives an off‐line optimal operating policy with its solution procedure moving backward. SSDP/ESP uses ESP forecasted scenarios to re‐optimize the off‐line policy. The proposed SSDP models are applied to derive a monthly joint operating policy during the drawdown period from October to June of the following year for the Geum river multi‐reservoir system in Korea. A cross validation simulation test of 1,900 simulation runs proves that the proposed SSDP/ESP is superior to SSDP/Hist with respect to the optimization of the water supply and the hydropower objectives.

Select this Article		Limiting Factors of Vegetation Expansion on Sandbars Affected by Hydro‐Geomorphologic Changes in Sandy Rivers H. Woo, D. S. Rhee, and H. K. Ahn ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)74 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This study preliminary investigates limiting factors of vegetation expansion on sandbars in the sandy river reaches that are affected by hydro‐geomorphologic changes induced by upstream dams. Attention is paid on two river reaches in the same river basin in Korea; one is the main river reach with a large point bar downstream; the other is a tributary river reach, both of which have been affected by upstream dams. Two limiting factors can be identified for vegetation expansion on the sandbars in the sandy river with hydro‐geomorphologic changes progressed. They would be the difference between sandbar surface elevation and normal water level of the low‐flow channel, in other words, groundwater level, and the bed shear stress during the high flows and their frequencies. Nutrient for plants would not be a governing factor at least for the natural growing of riparian plants such as willows and reeds.

Select this Article		Optimal Water Supply Management Using Dynamic Simulation G. Chung and K. Lansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)75 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Increasing population is stressing already limited water supplies in the arid southwest US and elsewhere. Large‐scale water supply management system is difficult given the complexities of water management policies. The objective of this paper is to develop a set of general water supply planning tool that can assist decision makers with long range planning decisions. The tool consists of simulation and optimization packages. The simulation model is geared to a general audience and developed in a dynamic simulation environment using Powersim Studio. A genetic Algorithm (GA) is linked with the simulation package to determine optimal system expansion and operation policies. Future conditions are assumed to be known with certainty for a sequence of operation periods.

Select this Article		An Optimization Approach for Balancing Human and Ecological Flow Needs E. S. Homa, R. M. Vogel, M. P. Smith, C. D. Apse, A. Huber‐Lee, and J. Sieber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)76 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Balancing human and environmental water resource needs is critical to environmental sustainability. In this paper two concepts are advanced. First, a methodology is introduced to evaluate water management policies and their impacts on the characteristics of both instream flow and water supply reliability. The concept of an “ecodeficit” is introduced to quantify the impact of changes to the natural flow regime resulting from human withdrawals. This metric provides a numerical and graphical representation of the tradeoff between human and ecological needs for available water. Second, we evaluate an approach that involves both simulation and optimization of alternative reservoir release policies. We demonstrate that by refining the quantity and timing of reservoir releases the reliability of a water supply yield can be substantially maintained while improving the satisfaction of ecological flows requirements. These two concepts are early applications of a more comprehensive ecological water supply management approach currently under development.

Select this Article FREE		Optimization of a Water Supply Portfolio in a Stochastic Demand/Supply Environment Brian R. Kirsch, Gregory W. Characklis, and Jocelyn Ramsey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)77 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A model was created that combines both the hydrologic and economic forces at work within the system into a single, integrated programA stochastic reservoir simulation comprises the hydrologic portion of the model, while the economic portion makes decisions in response to the hydrologic conditions. Given the number of permanent rights and options the city owns at the beginning of the year, the initial condition of the reservoir, and the lease/exercise threshold values (α and β), the model determines the expected values of the portfolio cost and reliability. The model also determines the expected number of exercised options and the profile of lease purchases throughout the year. The stochastic nature of the model provides not just the expected values of the results mentioned above, but the ranges and extreme values of those results. Such data allow the variability and risk of the portfolio to be characterized to an extent that could not be matched by linear programming techniques.

Select this Article		Overview of the Environmental and Water Resources Institute's “Guidelines for Integrated Water Resources Management” Project Gerald Sehlke ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)78 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract It has been said that those who fail to learn from the past are doomed to fail in the future. Unfortunately, most people are no longer directly associated with or educated in the management of the water supply that fulfills their basic needs. Therefore, many people believe that water resources management is simply finding a source of flowing or standing water, building a bit of infrastructure to divert, harness or store it and then putting it to use. While this may be true for water users who first develop a given source, successful water management is often a more complicated, robust and iterative process. With the addition of each new user and with each incremental increase in the amount of water being used from a given source, water resources management becomes incrementally more complicated. In the end, successful water resources management programs must incorporate historical and hydrological knowledge, law, socioeconomics, engineering and many other disciplines in order to reduce conflicts and to maximize utilization of the available resource. Integrated Water Resources Management is a systematic approach to optimizing our understanding, control and management of water resources within a basin to meet multiple objects. Recognition of the need for integrating water resources within basins is not unique to the Environmental and Water Resources Institute's Integrated Water Resources Management Task Committee. Many individuals, governments and other organizations have attempted to develop holistic water resources management programs. In some cases, the results have been very effective and in other cases, valiant attempts have fallen far short of their initial goals. The intent of this Task Committee is to provide a set of guidelines that discusses the concepts, methods and tools necessary for integrating and optimizing the management of the physical resources and to optimize and integrate programs, organizations, infrastructure, and socioeconomic institutions into comprehensive water resources management programs.

Select this Article		Overview of Vulnerabilities of Coastally‐Influenced Conveyance and Treatment Infrastructure in Greater Vancouver to Climate Change: Identification of Adaptive Responses B. Burton, L. Gu, and Y. Y. Yin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)79 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Greater Vancouver Regional District (GVRD) and its member municipalities own and operate a variety of infrastructure including: combined, sanitary and storm sewers; creek and ditch drainage systems; and wastewater treatment plants (WWTPs). A significant portion of this infrastructure discharges either directly or indirectly to tidally‐influenced receiving waters. Thus, both this infrastructure and its functionality can be impacted by coastal conditions, especially sea levels. The GVRD has developed a variety of long‐range plans that provide a foundation to manage core infrastructure so as to satisfy various criteria, including protection of the receiving water ecosystem. The Liquid Waste Management Plan (LWMP) outlines a strategy to protect regional sustainability by managing liquid waste and addressing issues such as combined sewer overflows (CSOs), sanitary sewer overflows (SSOs), wastewater treatment upgrading and stormwater management. Climate change, along with sea level rise (SLR), has the potential to impact the functionality of this infrastructure over the time frame of long‐range planning (LRP). The specific vulnerabilities of coastally‐influenced conveyance and treatment infrastructure to the impacts of climate change and SLR have not been widely evaluated in available research. This paper is intended to provide an overview understanding by reviewing some relevant research, identifying and classifying some of the potential vulnerabilities of this infrastructure to climate change and SLR and then discussing possible adaptive strategies for this infrastructure. The field of research into adaptive strategies for infrastructure is expanding, along with a better understanding of these issues. A basic and preliminary methodology to evaluate regional vulnerabilities as part of LRP has been developed for consideration for ultimate refinement and implementation. The magnitude and timing of SLR and climate change is uncertain, but has a large impact on the vulnerability of infrastructure and the scope of appropriate adaptive strategies. Thus, maintenance of maximum system flexibility as reasonable may be an appropriate response for infrastructure planning to respond to a changing climate. Periodic study of developing climate change trends will assist in improving the understanding of both infrastructure vulnerabilities and appropriate adaptive strategies.

Select this Article		Public Water Supply: What Is the Appropriate Federal Role? William E. Cox ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)80 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Responsibility for public water supply is spread across all levels of government under the federal system of governance in effect in the United States. The federal role has undergone significant change over time. The earliest role was primarily one of facilitating state and local activities relating to water supply. More recently, the federal role has shifted from facilitation to regulation. Major regulatory programs such as the Clean Water Act have created a much higher level of federal control over water supply operations. CWA impacts water supply primarily through its section 404 permit program that controls discharge of dredged or fill materials into navigable waters. This program has created a decision framework directly hostile to water supply development due to the priority it gives to protection of natural environmental values. The most recent development in the federal role in water supply has been a new focus on water supply security in the face of increased threats of terrorism. But this interest is limited to protection of water supplies from sabotage and has not addressed the larger issue of water supply dependability. The time is right for reevaluation of the overall federal role in water supply. The current position has some elements of facilitation but is primarily one of opposition to further water supply development to protect natural water environments. While environmental protection is a valid federal objective, it is not the sole objective to be considered. There is need for federal decision processes that provide a neutral forum for determining a balance in water resource use that best meets all of society's needs.

Select this Article		Reliability of Reservoir Firm Yield Determined from the Historical Drought of Record Stacey A. Archfield and Richard M. Vogel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)81 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The firm yield of a reservoir is typically defined as the maximum yield that could have been delivered without failure during the historical drought of record. In the future, reservoirs will experience droughts that are either more or less severe than the historical drought of record. The question addressed here is what the reliability of such systems will be when operated at the firm yield. To address this question, we examine the reliability of 25 hypothetical reservoirs sited across five locations in the central and western United States. These locations provided a continuous 756‐month streamflow record spanning the same time interval. The firm yield of each reservoir was estimated from the historical drought of record at each location. To determine the steady‐state monthly reliability of each firm‐yield estimate, 12,000‐month synthetic records were generated using the moving‐blocks bootstrap method. Bootstrapping was repeated 100 times for each reservoir to obtain an average steady‐state monthly reliability R, the number of months the reservoir did not fail divided by the total months. Values of R were greater than 0.99 for 60 percent of the study reservoirs; the other 40 percent ranged from 0.95 to 0.98. Estimates of R were highly correlated with both the level of development (ratio of firm yield to average streamflow) and average lag‐1 monthly autocorrelation. Together these two predictors explained 92 percent of the variability in R, with the level of development alone explaining 85 percent of the variability.

Select this Article		Review of International and National Efforts Towards Integrated Water Resource Management Matthew D. Davis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)82 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Consensus on what Integrated Water Resource Management means, its scope, how to implement it, and how to measure progress towards it does not exist. A review of international and national definitions and efforts towards IWRM is presented.

Select this Article		On Risk Analysis of Water Resources Systems under Non‐Stationary Conditions Yi Li, M.A.Sc., S.M.ASCE and Barbara Lence, Ph.D., A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)83 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Traditionally, uncertainty‐related analyses of water resources systems, such as flood frequency analyses for mitigation, are performed under stationary conditions, where, statistical properties, such as the means and variances of random variables involved are assumed to be constant with time. In some cases, due to natural and artificial influences, hydrometric data are reportedly experiencing shifts, trends or other changes, even on an annual time scale. In identifying sustainable management solutions for water resources systems it is important to recognize impacts of such changes on risks of system failure. This information may be particularly valuable for long‐term planning of water resources projects. Methods of assessing risks of water resources systems are summarized herein. The work identifies risk analyses for systems with different characteristics, static or dynamic, and non‐repairable or repairable. It is shown that a stochastic point process is an effective tool for risk analyses of systems characterized by non‐stationary conditions. Risk analyses of repairable systems with long‐term non‐stationarities, representative of many cases in the water resources engineering, have not been extensively investigated. A marked inhomogeneous alternating renewal process is shown to be suitable for such cases, and the discussion of this process presented herein provides a foundation for further exploration of its applicability.

Select this Article		Sediment Management of the Oi River Jian Liu, M.ASCE and Peng Lou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)84 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The sediment management of the Oi River in Japan is discussed in this study. A one‐dimensional numerical model is used for predicting the evolution of the river bed and the sediment budget. The model computes one‐dimensional steady flow and non‐equilibrium transport of nonuniform sediment mixtures. In the sediment transport module, bed material load is taken as sediment mixtures for calculating the bed evolution. The nonuniform property of the bed material load is modeled by introduction of a mixing layer, transition layer, and deposition strata. The model was calibrated and verified on the basis of the observations in 1981, 1993, and 1996. The variations of the riverbed elevation and sediment transport for different grain sizes for 30 years are predicted for working out the sediment management measures. The sediment excavation has less influence on the grain sizes of the riverbed. The sediment management measures for different reaches are proposed to reduce sediment disasters to the riverbanks and estuary, and improve the downstream channel environment.

Select this Article		Software for Optimal Integrated Water Resources Management Richard C. Peralta, PhD, P.E., Member ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)85 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract To best integrate management of available water one should coordinate the use of groundwater and surface water in time and space. This requires: data distributed in space and time; the ability to predict system response to stimuli; clearly formulated management goals, constraints, and optimization problem scenarios; the ability to compute optimal management strategies; and ways of implementing the strategies. A strategy is a set of controllable water flows, such as groundwater extraction and injection rates, surface water diversions, and reservoir releases. Simulation/optimization (S/O) models link simulators and optimizers to compute optimal strategies for user‐specified management problems. S/O models are increasingly used for policy development, reconnaissance studies, planning, design, and management. S/O models can help determine the policies, plans, systems, and management that can yield the best consequences. ‘Best’ is defined by the manager/modeler via the formulated optimization problem to be solved. Best is usually defined in terms of water availability, sustainability, crop production, economic, social, or environmental criteria, or combinations. Developing optimal multi‐objective solutions and tradeoff surfaces is simple with a powerful S/O model such as SOMOS. Examples demonstrate S/O model power for integrated water resources management. Capabilities of Simulation Optimization Modeling System (SOMOS) are discussed.

Select this Article		Tufts Watershed Loading Function: Best Management Practice Model for Decision Support J. F. Limbrunner, S. C. Chapra, R. M. Vogel, and P. H. Kirshen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)86 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A watershed model was developed for optimization‐based best management practice (BMP) decision support related to non‐point source nutrient control. The decision support system could be useful in watershed management, such as defining or complying with a Total Maximum Daily Load (TMDL). Tufts Watershed Loading Function (TWLF) was based on the Generalized Watershed Loading Functions (GWLF) and modified to allow for daily simulation of nutrient load generation, BMP behavior and optimization of watershed quality management alternatives. It was applied to the Aberjona River watershed, a small, highly urban basin located northwest of Boston, Massachusetts. BMP simulation models were created with input from local stakeholders to represent a broad range of management options including street sweeping, reduction in fertilizer application, porous pavement, grass swales, and constructed storage. The decision support interface allows users to quickly test scenarios involving BMP options in various land use areas, and could be part of negotiations and public decision making processes. In addition to scenario testing, optimizations were also performed using a genetic algorithm to search for efficient remedial solutions given limited management budgets.

Select this Article		The Use of Continuous Watershed Modeling to Address Issues of Urbanization and Channel Stability in Southern California Anthony S. Donigian, Jr. and Jason T. Love ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)87 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Ventura County Watershed Protection District (VCWPD) in Southern California has developed a Stormwater Quality Urban Impact Mitigation Plan that addresses storm water pollution from new development and redevelopment in the private sector. The plan was developed in fulfillment of an NPDES requirement that “The discharger shall control the post‐development peak storm water runoff discharge rates to maintain or reduce pre‐development downstream erosion, and to protect stream habitat.” To respond to this requirement, VCWPD supported the development of a hydrologic model of the upper Calleguas Creek watershed using the U. S. EPA HSPF (Hydrologic Simulation Program — FORTRAN) model, to evaluate the hydrologic information available from the model for stream erosion assessment and urbanization impacts. The methodology developed for this study combines the continuous hydrologic modeling results with bed shear stress calculations to estimate the ‘% of time for erosive conditions’ for the stream segments. The model was then run with alternative future land use conditions and mitigation alternatives to assess the impacts of urbanization, or mitigation required, to maintain channel stability and ensure stream and habitat protection from scour and degradation.

Select this Article		Use of Indicators in Integrated Water Resources Management Paul H. Kirshen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)88 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Integrated Water Resources Management (IWRM) is “a process which promotes the coordinated development and management of water, land and related resources, in order to maximize the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems” (page 22, Global Water Partnership Technical Advisory Committee 2000). This can be interpreted as the joint consideration of the social, economic, environmental, institutional, engineering issues in water resources management and operation. Sustainability and stakeholder involvement are central concepts. A logical set of steps in the IWRM planning process includes: (1) Statement of Principles for the Process such as the Four Dublin Principles and (2) a Phase 1 or scoping phase for initial determination of major opportunities and problems, identification of major stakeholders and their concerns, and a detailed study plan for Phase 2.

Select this Article		Using Groundwater Artificial Neural Network Models for Adaptive Water Supply Management Nisai Wanakule, M.ASCE and Alaa Aly, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)89 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Groundwater models have been used for various wellfield management optimization applications. However, typical regional groundwater models with coarse spatial discretization are not well suited to provide accurate forecasting of short term changes in groundwater models at specific monitor well locations. The accuracy of such short‐term forecasts is crucial for reasonable application of management optimization models. Artificial neural networks (ANNs) are presented as alternative models that are capable of providing accurate water level forecasts. These ANNs are designed to mimic the governing physical equations with proper initial and boundary conditions. Furthermore, the ANNs take into consideration the short term memory properties for the relevant time series. Results demonstrate that, with readily available data, ANNs can provide highly accurate short‐term forecasts for few days into the future.

Select this Article		Water Quality Modeling Tools to Support Adaptive Management James E. Scholl, F.ASCE, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)90 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper identifies selected planning level tools for developing cost‐effective methods of protecting and enhancing receiving water quality using a watershed approach and adaptive management. The watershed approach includes evaluation of pollutant loads and receiving water impacts and evaluation of pollutant removals and costs. The planning tools include unit pollutant transfer coefficients, continuous simulation, and economic optimization. The use of unit transfer coefficients provides a rationale for estimating the in‐stream water quality concentrations associated with various alternative combinations of point source pollutant loadings for specified hydraulic conditions. Continuous simulation techniques quantify the response of both point and intermittent nonpoint sources of loading on a receiving water body. Economic optimization procedures provide a defensible basis for selecting a least‐cost mix of technologies to achieve specified water quality protection goals. The use of each tool is discussed with respect to guiding decision‐making using adaptive management.

Select this Article		Water Quality Monitoring Network for River Systems: Application of Ordinary Kriging Mohammad Karamouz, F.ASCE, Bahareh Hafez, and Reza Kerachian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)91 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water quality monitoring network design could be a complicated problem, where some questions such as number of required stations, frequencies of sampling, and benefits over cost ratio of monitoring still needs further investigation. These issues are more sensitive in case of river water quality variables, as they are more error‐prone, costly, and time consuming to sample. The basic difficulty underlying the design and evaluation of monitoring systems is the lack of an objective criterion to assess the efficiency and cost effectiveness of the monitoring network. In this paper, a combination of a geostatistical method namely ordinary kriging and the Analytical Hierarchy Process (AHP) is proposed for designing an optimal river water quality monitoring network. The model proposes the location of sampling stations considering the estimation errors of the concentration of water quality variables along the river as well as their relative weights. The efficiency of the model is evaluated using the water quality data of Karoun and Dez Rivers in Iran. The results show the model can be used as an effective tool for optimal design of water quality monitoring networks. This study also shows the capability of geostatistical models for selecting the optimal location of sampling stations as a problem which can not be easily solved by classical optimization models.

Select this Article		Water Resources Planning through Group Model Building in the Okanagan Valley, British Columbia, Canada Stacy Langsdale, Jeff Carmichael, Stewart Cohen, and Barbara J. Lence ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)92 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Research provides evidence that managing water resources in the Okanagan Basin in south‐central British Columbia, Canada, will become increasingly challenging in the future. Climate change will likely alter water supply patterns, and warmer temperatures will result in increased agricultural and residential demand. At the same time, rapid population growth will also result in increased residential demand. The combination of these changes increase future risk of water supply falling short of water demand. In the previous phase of this project, management strategies were evaluated qualitatively. To provide decision support, future scenarios must be combined with a more rigorous evaluation of management options. One way to bridge the gap between technical information and policy implementation is through actively engaging the region's water community in a shared learning process. We are accomplishing this through a group model building process, which facilitates learning through active development of a high‐level scoping model. The objectives of the modeling process include: (1) Creating a basin‐wide water balance and assessing the impacts of climate change relative to other stresses; (2) Identifying and capturing those aspects that are strongly connected to water resources, such as land use; (3) Evaluating adaptation strategies for sustainable water management; and (4) Creating a tool that can be used for public education. The process includes a series of workshops over a period of one year. Participants, who include water managers, planners, political leaders and a diverse range of related interests, will share and negotiate their mental models using system dynamics as a communication tool. A single model will be constructed in STELLA language and supported with existing data. Issues such as flood control, fish habitat, forest management, agricultural and domestic water use, and environmental stewardship may be represented. Adaptation strategies will be included and tested for effectiveness of meeting goals as well as for cost.

Select this Article		Water Tariff Structure and Reform Needs for Socio‐Economic Sustainability in India Mamata R. Singh, V. Upadhyay, Dr., and A. K. Mittal, Dr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)93 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Existing urban water tariff structure in India is too low to cover even operating costs. Poor cost recovery thus leads to lack of funds, poor maintenance, poor service coverage and delivery especially for the poor. Several reform programs have been tried but as an isolated exercise and are unlikely to turn this situation. Comprehensive municipal water sector reform along with tariff structure reform needs to be taken up to improve the delivery of municipal water services. This paper examines the existing tariff models in India, their relevance and problems. It was found that none of the tariff structure could satisfy all the design objectives (cost recovery, economic efficiency, equity, affordability etc.). Also subsidies are not explicit and well targeted for poor population. The paper intends to cover the issues involved in Institutional and tariff reform process. For example, Tariff structure improvement, demand driven approach, privatization and community participation, water policy reform etc. The reform process would thus provide scope for improved financial status of water utilities and need satisfaction of the poor, which eventually would lead to socio‐economic sustainability.

Select this Article		Watershed Management Program in the Pajaro Valley, California, U.S.A.: An Integrative and Sustainable Approach to Stop Salt Water Intrusion and Avoid Depletion of Groundwater Resources Alexander Fortin, Lyndel Melton, and Charlie McNiesh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)94 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Pajaro Valley is a coastal valley located adjacent to Monterey Bay in central California. This location, combined with the naturally occurring soil characteristics, provides a rich agricultural area that is one of the most productive in the world. Agricultural land use is extremely important to the Pajaro Valley's economy and environment. Agriculture provides a source of employment, revenue, and important biological habitats. However, agricultural activities in the Pajaro Valley have and will continue to have a pronounced impact on the area's groundwater resources. The Pajaro Valley historically has relied primarily upon groundwater to meet agricultural, municipal, and industrial water demands. Groundwater pumping has led to overdraft conditions, causing lowered groundwater elevations that have led to seawater intrusion from the Pacific Ocean through the aquifer toward areas of depressed groundwater levels. The overdraft conditions in the Pajaro Valley have resulted in increased pumping costs and long‐term decline in groundwater elevations. Seawater contains chlorides and other salts that can be detrimental to agricultural crops and can exceed drinking water standards. Continued intrusion of seawater into the groundwater aquifer will result in greater portions of the aquifer being unsuitable for municipal or agricultural use. These conditions are not expected to improve unless coastal groundwater pumping is eliminated, overall groundwater pumping is effectively managed, and supplemental water supplies are developed and delivered to the coastal area. The Pajaro Valley Watershed Management Program uses an integrative and sustainable approach to stop salt water intrusion. Six essential water measures have been identified. They include: 1) Management of local runoff to preserve environmental benefits and develop additional supply, 2) Development of 4,000 acre‐feet per year (AFY) of recycled water, 3) Purchase of Central Valley Project (CVP) water contract in partnership with other water resources agencies, 4) In‐lieu groundwater banking, 5) Urban and agricultural water conservation and; 6) Sustainable groundwater extraction management. The Pajaro Valley Watershed Management Program is estimated to cost approximately $165 million and is currently in its implementation phase. This paper evaluates individual components of the program, and outlines the broad benefits of the program which has led to the commitment of local, state, and federal funding.

Select this Article		Actual Storm Events Outperform Synthetic Design Storms: A Review of SCS Curve Number Applicability Jill A. Reilly and Thomas C. Piechota ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)95 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Two historic storm events occurred July 8, 1999, and August 19, 2003, over Las Vegas, Nevada, that met or exceeded 100‐year frequency values with regard to rainfall depths in some areas and peak runoff levels in others. Although devastating in terms of loss of life and property damage, the two storm events provide a rare opportunity to compare synthetic design storms to actual rainfall events in the arid Southwest. Each storm, which occurred over a distinct watershed, is reconstructed using real‐time data from a rain gage system maintained by Clark County Regional Flood Control District. Actual rainfall intensities are then compared to a standard 100‐year, 6‐hour rainfall distribution. The difference in “real” and synthetic storm intensities offers insight into why established 100‐year rainfall depths and flowrates were exceeded during these two events. Actual precipitation depths and intensities are then input into HEC‐1 Flood Hydrograph Package models to evaluate the sensitivity and applicability of SCS (Soil Conservation Service) curve number values for estimating runoff from developed and undeveloped watersheds in an arid environment. By comparing runoff levels recorded at stream gages in each watershed, this paper will show that SCS curve numbers effectively represent runoff from developed watersheds and overestimate undeveloped watershed runoff in an arid environment.

Select this Article		Alternative Circular Wet Well Configurations for Water and Wastewater Pumping Systems David E. Werth, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)96 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Circular pump sumps are ideal for smaller water, wastewater and storm water lift stations due to their compact size, ability to be pre‐fabricated and inherent structural strength in deep water applications. However, existing design standards only encompass stations with up to three pumps with individual pump capacities of 315 1/s (5,000 gpm) or less. Population growth and community development constantly increases the demands placed on water, wastewater, and storm water distribution systems. The increasing demands placed on the water distribution infrastructure often exceed the original design capacity of the existing system. Increasing the capacity of existing pumping infrastructure can reduce the capital investment required to meet the increase in demand by eliminating the need to design and construct new lift stations. However, simply increasing the capacity or installing additional pumps can lead to adverse hydraulic conditions which can accelerate pump wear and decrease performance. Private modeling labs have developed alternative designs in the past; however, this information is often proprietary and not readily accessible for use by other design engineers. The Clemson University Hydraulic Labs have developed alternative circular intake designs which allow for greater capacity and more pumps than encompassed by existing standards. Alternative designs were developed and model tested for both clean water and debris laden flows. Model tests were conducted for a wide variety of possible flow conditions including pump stations with and without debris or solids present. This paper summarizes the results of these studies and increases the number of options that engineers can consider when faced with the need to increase the capacity of existing circular lift stations or in the design of new ones.

Select this Article		Application of Time Series Models to Analyze and Forecast the Influent Components of Wastewater Treatment Plants (WWTPs) JinSheng Huo, William L. Seaver, R. Bruce Robinson, and Chris D. Cox ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)97 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Time series models were developed to describe the statistical characteristics of the influent components of a wastewater treatment plant (WWTP) in Oak Ridge, TN. The data used to generate the models consisted of measurements of flow, temperature, BOD₅, suspended solids, and ammonia nitrogen over nearly a 3‐year period. The data set was characterized by periodically missing values during weekends and holidays. A two directional exponential smoothing method was developed to estimate the values of those missing data points, prior to time series modeling. Several commonly used time series models, including the exponential smoothing model, ARIMA model, and the dynamic regression model, were applied to the time series of the five plant influent variables. The best models for each influent variable were selected based on various statistics and the ability of the models to forecast future values in the time series. The time series models were then used to simulate random time series of the influent variables with the same statistical characteristics as the original data. The original and randomly generated time series were characterized by similar means, standard deviations, cross‐correlations and autocorrelation functions. These randomly generated time series can be used in conjunction with dynamic process models to evaluate the ability of a given design to effectively treat effluent flows under conditions of variability different than those present in the historical data.

Select this Article		Applied Artificial Intelligence to Solve Water Resources and Environmental Problems Sam Gueller, Ph.D., F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)98 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract AI is concerned with concepts and methods of inference and knowledge representation for use in making inferences and is thought as the proper tool for the analysis of complex systems that are difficult to model or represent. A model is a mathematic or logic representation of a prototype, and a prototype is a phenomenon or assessment of a phenomenon in the real world, could be a real or theoretical prototype. The design of a model that can be expressed by numbers is taken as a selectable subset of a generated set. Selection is done by analyzing polynomials within bounded limits, and selecting the subset of polynomials as the model that represent the prototype. Sets are generated as an ordered permutation of data elements of each variable, and inference and deduction is used to find the correspondence of a subset to a known problem, or the problem to a subset. Modeling phenomena of high complexity or difficult analysis are readily solved. In science and engineering, a subset of polynomials can provide solution to problems which otherwise need to be defined by analytic expressions. Raw data from the field or lab can form a subset and subsequently an analytic expression. Uniformity of scientific and engineering reports with a simple and compact common format to substitute equations, formulas, nomographs, tables, curves or specific computer programs, is possible and shown with examples for Peak Flow Discharge, Colebrook‐White Equation (Moody Diagram), Gravity and Pressure Flow, Greenhouse Effect, also of other areas as Vertical Stress due to a Point Load, and Trajectory of an Elementary Particle. This is a computer‐based methodology; software is available and distributed freely.

Select this Article		An Approach to Assessing Potential Compliance with the Proposed Stage 2 Disinfection By‐Products Rule Philip C. Singer and Nora J. Han ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)99 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this study was to assess the degree to which eleven utilities in North Carolina would be able to comply with the impending Stage 2 Disinfection By‐Products Rule. The Stage 2 Rule will require that all utilities meet the 80 μg/L maximum contaminant level (MCL) for trihalomethanes (THMs) and the 60 μg/L MCL for haloacetic acids (HAAs) on a locational running annual average (LRAA) basis. This represents a major departure from past disinfection by‐product (DBP) regulations for which compliance was based on a system‐wide running annual average (RAA). Relevant historical data were obtained from the eleven participating utilities and were transferred into Excel files. The data included quarterly THM and HAA concentrations at each of the current compliance monitoring stations in the utility's distribution system for the past 3 years, mean hydraulic residence times (water ages) associated with each of the stations, and water temperature. For systems using a combined chlorine residual, we assumed that the DBP concentrations would be essentially the same system‐wide. This was verified by observing that the standard deviations of the measured THM and HAA concentrations for systems with a combined chlorine residual were very small relative to the standard deviations for systems using free chlorine. Hence, we assumed that the LRAAs would be the same for all sampling sites, even for new remote sampling stations that might be incorporated into the monitoring program in accordance with Stage 2 requirements. Because chlorine dose and corresponding THM and HAA formation are highly temperature dependent, we developed a record of monthly system‐wide THM and HAA concentrations using the quarterly measured values and monthly average temperature data. We used EPA's Water Treatment Plant (WTP) model to predict changes in THM and HAA levels with changing temperature. The resulting monthly DBP concentrations were then used to calculate LRAAs for THMs and HAAs for the system each month, using the values for the preceding 12 months. For systems using a free chlorine residual, we expected there to be significant spatial as well as temporal variation in DBP levels in the distribution system. For these utilities, we used the measured THM and HAA concentrations from the existing compliance monitoring sites along with the EPA WTP model to predict THM and HAA levels at remote sites with residence times (water ages) of 7–14 days, using knowledge of the water ages associated with each of the DBP monitoring stations. We then used the WTP model to predict monthly THM and HAA levels for these remote sites using monthly average temperature data. The resulting monthly concentrations were then used to calculate maximum LRAAs for THMs and HAAs for the system each month.

Select this Article		Assessment of Groundwater Vulnerability to Nitrate Contamination in Gaza Strip, Palestine Mohammad N. Almasri, Jagath J. Kaluarachchi, Said Ghabayen, Ammar Jarrar, Mac McKee, Anan Jayyousi, and Amjad Aliewi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)100 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Aquifers are vulnerable to contamination from residential, agricultural, and industrial pollutants. Agriculture‐related activities are well‐known to cause nonpoint source pollution of groundwater from nitrate (NO₃). Assessment of groundwater vulnerability to nitrate contamination from nonpoint sources is essential to decision makers, land use planners, environmental regulators, and stakeholders to highlight areas where protection alternative measures should be introduced and where groundwater monitoring and modeling efforts ought to be carried out. Spatial analysis techniques are needed in managing and processing hydrologic and hydrogeologic data. Thus, geographic Information System (GIS) is a sound approach to evaluate the spatial outcomes of the assessment of groundwater vulnerability to nitrate contamination This paper aims at developing a simple yet efficient GIS‐based framework to assess groundwater vulnerability to nitrate contamination through the utilization of the well‐known DRASTIC model. Since DRASTIC provides an assessment of the intrinsic vulnerability independently from the contaminant of concern, this paper proposes an improvement to the DRASTIC model to account for the vulnerability to nitrate contamination. The Gaza Coastal Aquifer (GCA) was taken as a demonstration example to show method development and applicability.

Select this Article		An Assessment on Theoretical Techniques and Engineering Prevention of Debris Flow Disaster in China Xiekang Wang, Shuyou Cao, and Zhixue Guo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)101 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Debris flow composed of several components is a complex natural disaster phenomena, it frequently occurs, seriously affecting the economic development and the safety of human lives and properties in mountainous area. It is become more attention than ever before because of hazardous properties and our protection concept for natural environment in China. This study aims to review debris flow research status including observation, experiments, prediction and control of debris flow for the development of theoretic and engineering applications in the last decade years in China. In the same time, the difficult and deficiency of research techniques for forecast and prevention of debris flow have been put forward in comparison with scientists and experts on debris flow in Japan, New Zealand, USA, etc.

Select this Article		Assessment on Water Safety Degree of China's Regional Development Ruan Benqing, Han Yuping, Jiang Renfei, and Zhang Chunling ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)102 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The regional water safety evaluation system is established from the aspects of the imbalance between water supply and demand, ecological environment, food security, drinking water safety, disaster control, endowing water value and water resources management, etc. In addition, water safety degree is defined in this paper, at the same time, the model of appraising the regional water safety degree is set up by using fuzzy optimum theory of multi‐level and multi‐object. Finally, the comprehensive evaluation on the water safety condition of China's regional development is carried out and the picture of water safety in the whole country is put forward. The results of study indicated that the water safety conditions in quite a few areas in China is not well at present, so the author proposes that every area will fully consider the local water resources condition while confirming the scale of economic development and industry's overall arrangement in the future.

Select this Article		BOD Performance Correlation at Georgia WWTPs J. C. Sheppard, R. O. Mines, Jr., L. W. Lackey, and G. R. Behrend ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)103 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Twenty‐four wastewater treatment facilities in the state of Georgia with a design capacity of 37,850 m³/d (10‐mgd) or greater were evaluated over a twelve‐month period during the 2003 calendar year. The objectives of the study were to determine the effect of influent flow rate on the influent BOD₅ concentration and the effect of influent BOD loading on the effluent BOD₅ concentration. The impact of rainfall volume on influent BOD concentration to each facility was also evaluated.

Select this Article		Characterization of Natural Organic Material in Alaska Drinking Water Sources Using High Performance Size‐Exclusion Chromatography with Ultraviolet Absorbance Detection K. E. Carson and C. R. Woolard, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)104 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract One of the challenges facing many of Alaska's communities is providing drinking water from sources containing high concentrations of natural organic material (NOM). These highly colored waters, locally referred to as “tundra tea”, often result in the formation of disinfection byproducts during treatment. Successful treatment of waters to remove NOM requires a fundamental understanding of the character of NOM beyond what is provided by common measurements such as total organic carbon (TOC). High performance size‐exclusion chromatography using an ultraviolet absorbance detector (UVA) has been used to characterize the molecular weight distribution of NOM. Empirical data from several studies on NOM in Alaska indicate that these low molecular weight compounds play in important role in treatment processes and in distribution system water quality. This paper provides preliminary data from the analysis of Alaska surface waters by high performance size exclusion chromatography with ultraviolet absorbance detection.

Select this Article		Classifying Total and Effective Impervious Surfaces for Urban Hydrologic Modeling WooSuk Han and Steven J. Burian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)105 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes an approach using maximum likelihood classification of high‐resolution (< 4‐m) multi‐spectral data to determine the total impervious areas in a watershed in Houston, Texas, USA. The areas studied included a commercial district, an industrial site, and two residential areas, one with a very small amount of tree canopy coverage and another with significant canopy coverage. An unsupervised approach was tested along with several supervised approaches and the results suggested that the use of the high‐resolution data provided reasonable approximations of total impervious area for the sample areas with negligible canopy coverage, and less accurate results in the area with significant canopy coverage. Currently we are addressing the issue of under the canopy impervious area and developing an approach to estimate effective impervious area by integrating the derived total impervious area surface with topography, drainage network, building morphology, and roadway data in a geographic information system. The techniques to estimate under the canopy impervious area and the effective impervious area are being based on defining flow paths and summing the pixels that drain to a drainage channel, drainage inlet, or some other entry point to the drainage system. The topography data being used is a high‐resolution (1‐m) horizontal dataset derived from airborne LIDAR technology. An automated analysis tool within a geographic information system is being developed and will be described at the conference. Results from the application of the method for a large urban watershed in Houston will be presented at the conference.

Select this Article		Comparison of Lime and Caustic Addition for pH Control and Microbial Communities on Activated Sludge Settleability and Plant Performance—Implications for the Field Yen‐Chih Chen, Matthew Higgins, Sudhir Murthy, Aklile Tesfaye, Walter Bailey, Salil Kharkar, and Steven Puterbaugh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)106 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The performance of bioflocculation and settling of activated sludges is a common problem for many treatment systems. According to divalent cation bridging theory, research has shown that cations are important in floc formation and subsequent settling and dewatering properties. Specifically, divalent cations (such as Ca²⁺ and Mg²⁺) have a positive impact on bioflocculation while monovalent cations (such as Na⁺) can negatively impact bioflocculation. Therefore, the choice of chemicals used for pH control can significantly impact subsequent settling and effluent quality. The objectives of this research were to compare the impact of using either lime, Ca(OH)₂, or caustic soda, NaOH, for pH control, and determine their effect on settling and plant performance of an activated sludge nitrification/denitrification system. The lime would control pH and also add Ca²⁺ which should benefit settling, while caustic addition would add Na⁺ to the solution which could potentially degrade floc properties according to the divalent cation bridging theory. Three laboratory scale reactors were constructed to mimic the five‐stage, full scale Blue Plains wastewater treatment plant in Washington DC. Each reactor was fed effluent from the secondary treatment process and methanol was added as an external carbon source for denitrification. To maintain the pH, one reactor was fed lime (Ca(OH)₂), one reactor fed caustic (NaOH), and one reactor was used as a control with no base addition. The reactors were operated for three solids retention times and monitored for effluent quality and treatment performance as well as floc and settling characteristics. In addition, microbial communities were analyzed using molecular techniques to compare the microbial communities in the lab and full‐scale systems. The reactor fed with Ca(OH)₂ generally had better floc characteristics as well as effluent quality in terms of soluble COD, effluent total nitrogen, and supernatant turbidity, and had greater stability. The microbial communities were compared using polymerase chain reaction − denaturing gradient gel electrophoresis (PCR‐DGGE) targeting on both universal bacteria and ammonia oxidizing bacteria (AOB). The results showed that the lime addition reactor had the most diverse bacterial community followed by caustic addition and the control. The control reactor also had a much less diverse population of AOBs which can contribute to stability problems. Interestingly, results from the full‐scale system showed that greater AOB community diversity was generally associated with better plant performance and stability. The results from this research support the divalent cation bridging theory, in that Ca²⁺ addition generally provided improved treatment performance compared to the control with no cation addition, and the Na⁺ addition reactor. Therefore, the use of Ca(OH)₂ for pH control would be the recommended choice for achieving better settleability, treatment performanceand plant stability compared to NaOH addition. The results have significant implications for full‐scale treatment plants that are considering potential chemicals to add to their treatment processes, in that divalent cation based alternatives are a better choice when they are available.

Select this Article		A Conceptual Framework for Managing Nitrate Contamination of the Gaza Coastal Aquifer, Palestine Mohammad N. Almasri, Said Ghabayen, Jagath J. Kaluarachchi, Ammar Jarrar, Anan Jayyousi, and Mac McKee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)107 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Public concerns over the groundwater quality of the Gaza Coastal Aquifer has grown significantly in recent years and has focused increasingly on anthropogenic sources for the problem. The Gaza Coastal Aquifer is an important source of water to over 1.3 million residents and is utilized extensively to satisfy agricultural, domestic, and industrial water demands. Evidence indicates that the nitrate (NO₃) levels routinely exceeded the maximum contaminant level (MCL) of 10 mg/L NO₃‐N in 90 percent of the water supply wells. Degradation of groundwater quality in the Gaza Coastal Aquifer due to nitrate pollution and the continuously increasing demand for potable water have motivated the restoration of the aquifer. Restoration efforts have intensified the dire need for developing protection alternatives and management options (MOs) such that the ultimate nitrate concentrations at the critical receptors are below the MCL. This paper presents a generic conceptual framework for the management of groundwater contamination from nitrate for the Gaza Coastal Aquifer. The framework incorporates an assessment of existing data and future monitoring needs, conceptual models of groundwater flow and nitrate fate and transport, and decision‐making tools to study the impact of different MOs considering both environmental and economic aspects.

Select this Article		Debris Flow Triggered by Ice‐Lake Break in Tibet Cheng Zunlan, Hu Pinghua, and Geng Xueyong ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)108 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Debris flow triggered by break of ice‐lake is one of special occurrences in frigid alpine areas. In 1981, there was such a debris flow occurring in the Zizangbu Gully on the south slope of the Himalayas, of return period more than 100 years. Through analysis of this very occurrence, the present paper discusses in details its forming condition, initiation mechanism, developing trend, and hazards.

Select this Article		Debris‐Flow Hazards and Prevention Measures in Beijing Lijun Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)109 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Beijing is located in the north end of north china plain, its coordinates is 115°25′ 117°30′ E and 39°28′ 41°05′N, its total area is 16800km², in which the mountain area is 10400 km², covers 62% of the total area. The highest mountain is Donglingshan mountain in Mentougou region, its elevation is 2303m. The slope area of hill below 200m covers 23.1% of the total mountain area. The slope are above 25°covers 46.4% of the total mountain area. The area of the plain is 6400 km², coves 38% of the total area. The lowest elevation is small than 10m. In history, the Debris‐flow in Beijing mountain area happened frequently. Latest years, with the implementation of the control measures, the hazards were prevented effectively.

Select this Article		Design Considerations for Autothermal Thermophilic Aerobic Digestion Harlan G. Kelly, Wayne Urban, and Roger Warren ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)110 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract ATAD design recommendations are developed from University research, demonstration pilot studies, and several years of plant operation and assessment. These investigations have provided a design approach for those who may be considering the ATAD process for biosolids treatment. Pilot work and operating systems have provided information for recommendation on design. Limited full‐scale investigations were initiated at the Golden Heart WWTP in 2002. From this, we have determined that selection and design for the ATAD should consider the following: (1) Process selection and appropriateness; e.g., what are the design criteria for the ATAD process and what are the special considerations for equipment selection. (2) Physical plant design; e.g. what are the process constraints, complexity and minimum systems and how do they compare with alternative systems. (3) Process design; e.g. can one use conventional design criteria from anaerobic or aerobic digesters and what are the paramount considerations that must be included in any design. Selection and design are discussed under the above three headings. Important reminders in design of ATAD are that penalties will be paid for over‐design and that criteria used for aerobic or anaerobic digester design are not necessarily appropriate for ATAD.

Select this Article		Development of a Graphical Assessment Method for Interpreting Stream Conductivity Data Arthur D. Kney, David Brandes, Maura Allaire, Joe Goodwill, and Jason Boyd ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)111 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A newly developed graphical assessment method addressing conductivity data evaluation normalized by concurrent alkalinity data is introduced in this paper. This simple method provides insight into the complexity of a conductivity measurement. It enables users such as volunteer stream monitors and professionals to differentiate geological influences from anthropogenic influences. Conductivity is a measurement done by most water quality novices and specialists throughout the United States and around the world. Although conductivity is easy to measure the resulting data is often difficult to interpret due to geologic and anthropogenic influences, both of which contribute significant impact making the specific source difficult to trace. Within Bushkill Creek watershed (Northampton County, Pennsylvania) the bedrock geology is predominantly carbonate and shale, which naturally weather calcium, magnesium and carbonate ions into solution thereby providing a source of naturally high conductivity. However, the watershed is also influenced by anthropogenic activity. Volunteer stream monitors commonly document measurements of conductivity up to 1000 μmho/cm and at times higher, in the lower Bushkill watershed. Due to these elevated values, volunteers often raise as the question: “Is the high conductivity due to the natural geologic setting and/or the influence of anthropogenic sources?” This question illustrates the difficulty of conductivity evaluation.

Select this Article		Development of Design Criteria for Regional Stormwater Management Facilities to Maintain Geomorphic Stability in Cedar Creek C. A. Rohrer, N. A. Postel, P. A. O'Neill, and L. A. Roesner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)112 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Cedar Creek Watershed located in Lenexa, Kansas is presently undeveloped, but plans for residential communities and an urban business park are currently being designed for this rapidly growing Kansas City metropolitan suburb. The City of Lenexa, while wishing to accommodate responsible development, is committed to maintaining the natural setting and geomorphology of the stream corridors that will receive the drainage from these new urban developments. They propose to do this through a combination of on‐site BMPs and regional detention basins. This paper discusses the procedures that were used to determine the design criteria for the regional detention basins so that the current geomorphic condition in the natural stream system would be preserved to the maximum extent practicable. Fifty‐three years of historical precipitation data were applied to the USEPA SWMM model to conduct continuous hydrologic and hydraulic simulations, generating continuous stream flow hydrographs in the receiving stream channels. On‐site BMP and regional detention criteria were selected to allow post‐development replication of pre‐development flow frequency curves and the critical portions of the shear stress duration curves. The critical portion of the shear stress curve is described as the duration of shear stress magnitudes above which stream bed and bank erosion are expected to take place. Critical shear stress values were identified during field surveys. Critical flow thresholds were extrapolated from critical shear stress values. These critical flow thresholds were used to identify return frequencies above which the duration of stormwater must be controlled to pre‐development levels. Instream continuous stage data generated by the SWMM model were used to examine erosion potential through the use of an erosion potential index. This index calculated increases in excess shear between pre‐development and various post‐development management control scenarios, allowing identification of the stormwater management scenarios that allowed erosion potential to remain constant under future development conditions to the maximum extent practicable.

Select this Article		Distribution of Thickness of Debris Flow Deposition Li Yong, Hu Ping‐Hua, and Hu Kai‐Heng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)113 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Deposition is often the only relic left by a debris flow and therefore the only source for estimation of hazards. Fortunately, real debris flows consisting of surge series have been observed every year in Jiangjia Gully, Yunnan, China, providing a complete scenario of debris‐flow deposition. Observations of surges suggest a relationship between the initiation and deposition in sense that the stopped surge is in the semblance of flowing surge, which allows one to infer the deposition from the motion. Deposition thickness is assumed to take distribution similar to the flow depth, both in form of power law. And through the Weibull distribution of flow velocity, a lower limit can be settled for the power exponent of the thickness distribution, which turns out to be further related to the hydrograph of debris flow. Findings in this paper provide a quantitative way for evaluating debris flow.

Select this Article		Effect of Plant‐Barriers on Debris Flow Guifen Li, Lianxing Wang, and Cifen Bi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)114 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The North‐west part of China is suffered form serious water shortage and poor vegetation. Debris flows with heavy sand soil are often observed when rain‐storm happens. One of the important measures for soil‐and‐water conservation is to apply plant barriers (bush dam). Specially selected trees and bushes are to be planted in the courses of rivulets and channels to form flexible plant‐barrier. The experimental study in laboratory and the process of building plant‐barriers are described in this paper. And the effect of the plant‐barriers for blocking debris flow also was discussed.

Select this Article		Effect of Turbulence on Organic Material Biodegradation Lin Luo, Meijing Wang, and Xiangju Cheng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)115 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract By studying the effect of turbulence on biodegradation of organic material, the universal formula between the biodegradation rate and the turbulent kinetic energy is derived on the basis of the biodegradation rate in different turbulent intensities. Having analyzed the formula from the mathematic point of view, the effect can be considered as the “first order reaction” related with the turbulent kinetic energy, and the empirical formulas obtained by other researchers can be resulted from the universal formula in the paper. The relationship between the turbulence and the biodegradation rate obtained here can be used to better explain the effect of turbulence on biodegradation of organic material theoretically. The formula could be used to provide the real biodegradation rate in rivers from laboratory experimental data. The biodegradation of organic material in rivers could be classified as sensible to turbulence impact and non‐sensible ones.

Select this Article		Efficient Generation of Annual Exceedance Probability Maps Masako Amai Gardner, Christopher M. Smemoe, E. James Nelson, and Rob M. Wallace ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)116 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The United States Federal Emergency Management Agency (FEMA) flood insurance rate maps (FIRMs) define a single line delineating the floodplain boundary at the 100‐year recurrence interval. The U.S. Army Corps of Engineers (USACE), at the suggestion of the National Research Council, now promotes the concept of Annual Exceedance Probability (AEP) as the method used to determine the probability of flooding caused by the failure of a levee or other flood control structure at a particular study point. By using the HEC‐1 (HMS) and HEC‐RAS models for hydrologic and hydraulic calculations in conjunction with the Watershed Modeling System (WMS) for floodplain delineation, an AEP map can be created to determine and visualize the spatial distribution of the probability of flooding. An AEP map represents a continuous solution of the probability of flooding, rather than a single boundary line between areas considered at risk to a 100‐year event and those not at risk. A single line definition often leads to unreasonable litigation over extents because, within limits of probability, engineers can use modeling input parameters to develop separate, yet reasonable results according to a client's self interests. An AEP map is generated using Monte Carlo techniques to run hundreds or thousands of hydrologic/hydraulic/floodplain mapping simulations in order to capture the natural variability and model uncertainty inherent in the flood modeling/mapping process. The result is a spatial distribution of flood probability that, together with a map of infrastructure, can be integrated to determine actual flood damage (or flood protection) in terms of dollars. This paper/presentation will focus on the work of multiple AEP map case studies with the intent of better understanding the process of creating an AEP map in addition to learning more about the number of simulations required for convergence to a consistent AEP solution.

Select this Article		Estimating Seasonal and Diurnal Variations in Influent Characteristics for Optimization of Aeration Operations: A Case Study for Applicability of Respirometric Techniques at Fairbanks, Alaska A. J. Pinto, D. L. Barnes, and D. M. White ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)117 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Wastewater characterization experiments were carried out at the wastewater treatment facility at Fairbanks, Alaska. These experiments were carried out to trace the diurnal and seasonal variations in the influent flowrate and organic loading. The considerable difference in the wastewater flow and loadings was influenced between summer, fall and winter. The seasonal variations could be attributed to change in population numbers and seasonal activities. Based on the observed variations, oxygen production and supply was analyzed as a possible avenue for costs savings in a high purity oxygen activated system. The ability of respirometry to make suitable predictions makes it applicable for such a purpose. Different benefits of respirometry have been discussed and several site‐specific recommendations have been made for the application of respirometric techniques at the Fairbanks wastewater treatment facility. The results indicate that the possible savings by optimizing oxygen production and supply based purely on variations in influent loadings may not be an attractive option. However, if these cost savings were to be combined and seen in the light of post‐treatment cost benefits, the application of respirometry of aeration optimization may serve to an attractive operation given the high operation and maintenance costs for this medium size facility.

Select this Article FREE		Evaluating Microbial Partitioning Differences under Storm and Dry‐Weather Conditions Gregory W. Characklis, Mackenzie J. Dilts, Otto D. Simmons, Leigh‐Anne H. Krometis, Christina Likirdopulos, and Mark D. Sobsey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)118 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The degree to which microbes in the water column associate with particles has important implications for microbial transport in receiving waters, as well as for microbial removal via sedimentation (e.g., detention basins). In this work, microbial partitioning between the particulate and suspended (i.e. unbound) phases is explored under storm and dry weather conditions. While previous stormwater studies have documented evidence suggestive of microbial‐particle attachment, these relationships have not made a distinction between the types of particles to which the microbes are attached (i.e. organic vs. inorganic) and are therefore insufficient for evaluating the impacts of partitioning on microbial fate and transport. Unattached organisms in suspension, or those attached to less dense organic particles (density <1.2 g/cm³), will exhibit very different transport properties than those attached to denser clay or silicate particles (density 2–3 g/cm³). Given that most water quality models currently assume that all microbes exist as unattached organisms, quantitative estimates of microbial partitioning to denser particles would be particularly useful in regulatory efforts to model the location and severity of water quality impairment (e.g. TMDL).

Select this Article		Experimental Design of a Long‐term Study on Landscape Irrigation Using Household Graywater M. C. Criswell, L. A. Roesner, Y. L. Qian, M. E. Stromberger, S. M. Klein, and C. Marjoram ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)119 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract As communities throughout the United States are becoming interested in innovated approaches to water resource sustainability, household graywater reuse for irrigation is gaining in popularity. Some states, including California, Arizona, and New Mexico, and several other counties have legalized the practice. However there are some concerns with household graywater irrigation that need further scientific study. One concern is the possibility of household graywater irrigation adversely impacting the soil environment and/or irrigated horticultural plants over the long term. Another concern is the possibility of irrigated graywater being a pathway for the spread of human diseases. This study developed recommendations for scientific experiments to alleviate information gaps regarding household graywater irrigation impacts. Developed experimental protocols will be implemented in a future Water Environment Research Foundation (WERF) study (Phase II). This study protocols addresses: (1) Household graywater: water quality, collection, treatment, and storage; (2) soil chemistry changes due to graywater application; (3) graywater effects on soil microbiology; (4) indicator organisms presence for human health considerations; and (5) impacts on various classes of residential landscape plants. This paper presents study findings including the recommendations made for greenhouse and prototype experiments.

Select this Article		Faecal Sludge Management, St. Elizabeth, Jamaica Ana Martha Fernandes, Paul Kirshen, and Richard Vogel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)120 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the developing nation of Jamaica 70% of the population depends on on‐site sanitation (OSS) which can provide an effective and low‐cost option for rural wastewater treatment. However, there are serious environmental and human health effects associated with their mismanagement and deterioration. We describe a methodology to determine suitable areas for faecal sludge (FS) treatment systems and to select an optimum combination of FS treatment options for the region. A regional decision model of FS treatment was developed which incorporated treatment alternatives to hauling or pumping to existing centralized systems. The problem is formulated as a linear programming model which selects the optimal combination of treatment options and locations for the region based on a variety of social, economic, and environmental constraints.

Select this Article		Flood Control Decision Support System in Dongtiaoxi Basin Hu Changwei, Yuan Ximin, Liu Shu, and Zhang Hongpin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)121 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The flood control decision support system discussed in this paper is developed to protect the glorious Hangzhou City from inundation. The calculation area of this system is not large, but the condition is rather complicated: there are reservoirs upstream and several flood detention areas in the middle reach. In order to simulate the flood, the flood detention areas must also be taken into consideration besides the river, so a new method for multi‐model cooperative calculation is developed to achieve this objective. The latest computer technologies are also applied in the system, such as: GIS, Distributed database, Browser/Server architecture, Client/Server architecture and three‐dimensional visualization, making the system practicable and easy to use.

Select this Article		Flow Pattern of Fish Habitats in Engineered Stream Jen‐Yang Lin, Yen‐Chang Chen, and Han‐Chung Yang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)122 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper is intended to establish a mechanism by using Froude number to associate the relationship between flow conditions and fish habitats. In open channel hydraulics, Froude number, which contains two variables: water depth and water velocity, is extensively applied to describing flow type. Utilizing single hydraulic variable such as Froude number to define flow type simplifies two variables, water depth and water velocity, in describing the differences of flow types. The study site is in the Dago Stream, Taipei City, Taiwan, with aim to find the confident intervals of fish habitat occurrence proportion and Froude number distribution during regular flow. After fieldwork in The Dago stream, there are nine aboriginal fishes, however the Scaphesthes barbatulus and Gambusia affinis are excluded from this statistic due to the little amount. This information can be applied to torrent control, depending on changes of channel morphology to create an Environment of habitat heterogeneity and biodiversity.

Select this Article		Formation and Decay of Trihalomethanes and Haloacetic Acids in Full‐Scale Drinking Water Distribution Systems: A Case Study Philip C. Singer, Savita A. Schlesinger, Cora Nichols, Helene Baribeau, and Lina Boulos ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)123 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this study was to determine and evaluate some of the factors that affect the formation and decay of disinfection by‐products (DBPs), specifically trihalomethanes (THMs) and haloacetic acids (HAAs), in full‐scale drinking water distribution systems. Five utilities throughout the United States were sampled 6–8 times over a period of 15 months. Utilities were chosen based on source water characteristics, seasonal temperature variations, geographic location, type of secondary disinfectant utilized, and several characteristics specific to each distribution system. In addition, each utility had a hydraulic model of their distribution system that was used to determine residence times at sampling locations in their system. This paper describes the results for one of the five utilities chosen to participate in the study. The selected utility employed combined chlorine as their secondary disinfectant and operated the distribution system using several different hydraulic scenarios. Sampling locations were chosen on the basis of residence time, pipe material and pipe diameter, and other factors specific to the distribution system. Twelve to sixteen sampling locations were chosen to represent a range of conditions. Samples collected were analyzed for pH, temperature, secondary disinfectant residual, assimilable organic carbon (AOC), total organic carbon (TOC), ultraviolet (UV) absorbance, heterotrophic plate counts (HPCs), THMs, HAAs, bromide, and ammonia, nitrite and nitrate. Results obtained for the subject utility demonstrated that, for some hydraulic scenarios, the total chlorine residual remained constant throughout the distribution system, while for other scenarios, a significant decrease in residual chlorine was observed at several of the sampling locations. THM and HAA concentrations were uniform throughout the system when the disinfectant residual remained constant, while a decrease in HAA concentrations was seen at those sampling locations that exhibited a decrease in total chlorine residual to values less than 0.6 mg/L. Elevated HPCs and evidence of nitrification were also observed at these same locations.

Select this Article		Fouling of Quartz Surfaces in a Low‐Pressure High‐Output (LPHO) Ultraviolet Disinfection Reactor Treating a Groundwater Source: Foulant Characterization, Distribution, and Phosphate Effects Isaac W. Wait and Ernest R. Blatchley, III ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)124 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The application of ultraviolet (UV) irradiation as an effective method of drinking water disinfection continues to grow, stimulated by regulations mandating reductions in disinfection by‐products and improved inactivation of Cryptosporidium. Fouling of the quartz lamp sleeves used in UV reactors is a process that can limit the efficacy of UV disinfection systems. Sleeve fouling, including suspended particle impaction, precipitation of dissolved minerals, and off‐gassing caused by lamp material volatilization and breakdown, interferes with the disinfection process by absorbing radiation that would otherwise pass through the quartz lamp sleeve and into the water being treated. A commercially produced, enclosed, low‐pressure high‐output (LPHO) reactor was used in a once‐through (non‐recirculating) configuration with a groundwater high in dissolved mineral concentrations, including calcium and iron. Metals present in the foulant were identified and quantified by acid digestion of accumulated materials. Spatial distribution of foulant was characterized using acid digestion and scans of lamp UV transmittance at multiple points. UV lamp‐containing sleeves were compared to control sleeves to identify the contribution of thermal effects on the fouling process. Phosphate addition — a treatment step used to inhibit corrosion and sequester iron and manganese — was investigated by conducting experiments where phosphate was added. Decreases in radiation intensity were observed for both the phosphate treated and untreated case, and decreases were more significant for the treated case. Lamp sleeve UV transmittance (UVT) illustrated the potential effect of sleeve fouling on reactor performance, and also highlighted the difference between a heated sleeve and unheated control. Results highlight the importance of calcium, iron, and manganese to sleeve fouling, and illustrate the changes in fouling that can be induced by common treatment steps.

Select this Article		Frequency Characteristics of Long‐Duration Rainfall Events Eric D. Loucks, Kimberly A. Oriel, and Mitchell C. Heineman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)125 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The generalized extreme value (GEV) distribution has been used successfully to define quantiles of extreme rainfall in the Southeastern Wisconsin Region. However, attempts to apply it to storms with durations of 120 to 600 hours produced poorer fits than expected. An investigation was conducted to determine how the frequency of long duration storms differed from that of shorter storms. The frequency estimate of long storms is important in the Milwaukee area because long storms can cause combined sewer overflows by exhausting available storage facilities. When fitted to the GEV, long duration storm events produced increasingly larger positive values of the shape parameter, κ. This yields a distribution that is bounded from above, which is not useful for modeling extreme rainfall. Additional fits to the data were obtained by forcing κ = 0, yielding the Gumbel distribution. Using the partial duration series did not improve the model but did shed light on the underlying characteristics of long duration storms. One issue is that there are two types of long duration events appearing in the data: 1) events dominated by a single extreme storm of fairly short duration, and 2) events consisting of a series of smaller storms. The partial duration series also showed that the events tended to occur in “bunches” surrounded by gaps of several years. This caused the annual series and partial duration series to differ significantly and raised the possibility that the partial duration series included non‐independent events. This paper presents results comparing various frequency models for the 120‐, 240‐, 360‐, 480‐, and 600‐hour rainfall events in Milwaukee. Even with positive values of κ, it was found that the best fits occurred when the annual series was fit to the GEV distribution.

Select this Article		Impact of Booster Chlorination on THM Production: A Simulated Analysis Brian T. Carrico and Philip C. Singer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)126 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Chlorine is commonly used in drinking water treatment as both a primary disinfectant and as a secondary disinfectant to carry a residual in the distribution system. The continuing formation of disinfection by‐products (DBPs), including trihalomethanes (THMs), due to reactions between residual chlorine and natural organic matter (NOM) has led utilities and researchers to seek innovative ways of managing disinfectant residuals. One such management strategy that has been proposed is the use of booster chlorination (re‐chlorination), but relatively little research has been done on this topic. Previous research has indicated that the rates of chlorine consumption and THM formation remain the same under re‐chlorination conditions. For this study, a model water comprised of NOM extracted from Lake Drummond, Virginia was chlorinated under two scenarios: one representing conventional chlorination, and one representing booster chlorination. Chlorine consumption and THM formation were monitored over a 72‐hour time period, and the results show that both THM formation and chlorine consumption were the same under both scenarios. The results of this study also confirm the findings of previous research that THM formation and chlorine consumption are linearly correlated, even under re‐chlorination conditions. Additional work is ongoing as part of this study to explore the effect of booster chlorination on chlorine consumption and THM formation in distribution systems using hydraulic models.

Select this Article		Impact of Sewage Line Spills on Pathogen Levels in Recreational Waters Parmeshwar L. Shrestha, Douglas Hamilton, Neil Jordan, Macan Doroudian, Sandra Hong, and Deborah Proctor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)127 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this study was to quantify the effect of City of Los Angeles sewage spills that reach the storm drain system on bacteria concentrations in Santa Monica Bay (SMB). The combined effect of dilution, transport, and die‐off decreases bacteria concentrations with increasing distance downstream of the spill source. To assess the association between sewage spill events and bacteria levels in SMB, five specific spills were selected for detailed evaluation. Four of these spills occurred during dry weather and one during wet weather conditions. Each spill was characterized by spill date, volume, duration of release, transport path, distance to outfall, and measured concentrations of total coliform, E. coli/fecal coliform, and enterococcus at the source. Spill volumes ranged from 522 gallons to 560,000 gallons. Four of these spills entered SMB via Ballona Creek, and one was transported to the ocean via the Los Angeles River. The City of Los Angeles monitors bacteria levels daily at 18 different stations, located near major storm drains, along the SMB shoreline. By examining trends in the monitoring data at stations closest to the discharge point prior to and following the date of the spill and examining weather conditions as well as the occurrence of more than one spill that could affect the same area in the same time frame, it was possible to assess the impact of these spills on receiving waters. This approach was adopted for three of the five spills. For the remaining two spills, no monitoring data were available; for these spills, bacteria concentrations at the outfall were estimated using a simplified dilution and die‐off model. The results indicate that there is little, if any, association between Los Angeles sewage line spills and the levels of pathogens measured in SMB. Even on days following the largest spills, bacteria levels in SMB in the vicinity of the discharge point did not increase significantly.

Select this Article		Impact of Wastewater Reuse in Burlington County, New Jersey on Adjacent Wetlands Crystal L. Mattson, Kauser Jahan, Ph.D., and Gina Berg ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)128 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Burlington County has been engaged in land use planning through a number of programs. The County is taking bold measures for environmental protection through open space acquisition and preservation, farmland preservation, watershed management initiatives, and smart growth planning. The County is also involved in water supply management via a proposed Credit Bank. This credit allows a limited supply from the Potomac‐Raritan‐Magothy (PRM) aquifer to the various users in the County. Saltwater intrusion problems in the PRM aquifer have led the New Jersey Department of Environmental Protection (NJDEP) to mandate this area as a Critical Water Area and limit water withdrawals. The County thus needs to address future water demands and investigate alternate sources of water. One such potential source is the beneficial reuse of reclaimed wastewater. The importance of reclaimed water for beneficial reuse (RWBR) became significant during the drought of 1999 in New Jersey. During the drought period many wastewater treatment plants received authorization to reuse their treated effluent for various beneficial reuse applications. Several facilities have now built in effluent reuse as part of their NJPDES permit. Reclaimed wastewater is being considered now as a valuable resource by municipalities, industries, County parks, and recreational and residential developments. Currently, the feasibility of wastewater reuse in Burlington County is being investigated with special focus on the impact to adjacent wetlands. Samples have been collected from golf course impoundments that are currently receiving reclaimed wastewater for turf grass irrigation. Samples were analyzed for nitrogen, phosphorus, and fecal and total coliform bacteria. Results to date indicate that significant amounts of nitrogen, phosphorus, and fecal coliforms are not being introduced to the impoundments by the treated effluent discharged into the golf course retention ponds. Nitrate, total phosphorus, and fecal coliform concentrations detected above those introduced by the treated effluent indicate that there are other sources of contribution at the monitored sites.

Select this Article		The Influence of Climate, Land Use and Tidal Mixing on Water Quality in Newport Bay, Southern California Abhishek M. Pednekar, Stanley B. Grant, Youngsul Jeong, Ying Poon, and Carmen Oancea ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)129 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. There is growing concern about a possible link between global climate change and the spread of infectious diseases. Previous reports suggest that coastal water quality—and by implication human health risk—are influenced by global climate variability. However, relatively little is known, either qualitatively or quantitatively, about how coastal water quality is impacted by the combined influence of local‐scale changes (e.g., land‐use changes) and global climate variability. To fill this knowledge gap, we compiled and analyzed a 32 yearlong time series of water quality measurements (n∼68,304) in Newport Bay, a regionally important embayment in southern California. To identify dominant spatial and temporal trends in the time series, we utilized a mathematical technique widely employed in the atmospheric and ocean sciences—called Empirical Orthogonal Function (EOF) analysis. The results show that 69% of the temporal water quality variability is associated with rainfall, implying that a very large fraction of the water quality signal can be attributed to storm water runoff. Moreover, trend analysis on the time series demonstrate that water quality, particularly during winter storms, is influenced by long‐period processes that generate more local rainfall, including El Nino Southern Oscillations (ENSO) events. Indeed, we demonstrate that the water quality signal measured in Newport Bay can be reproduced by a simple box model that takes, as input, daily estimates for the load of fecal pollution flowing into the Bay from the watershed, solar radiation, and tidal mixing residence times. Analytical and modeling tools developed for this study should be readily generalizable to other field sites. The results presented here should be useful for both policy makers interested in developing Fecal Coliform TMDLs for the Bay, and scientists interested in understanding how climate changes influence the spread of infectious diseases.

Select this Article		The Influence of Mining Draining Water on Water Environment in Zibo Coal Mine, Shandong Province, China Zhang Jianli and Su Dongsheng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)130 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A mass of mining drainage is discharged during coal mining in Zibo, Shandong Province, China. Mining drainage is characteristic with high SO₄²⁻, hardness, and total dissolved solids (TDS), some is acid, contains heavy metal. It flows downslope or along channel and finally discharge into the Xiaofu River. Mining drainage lowered the pH value, raised the hardness and the contents of SO₄²⁻, Fe, Al, and trace‐elements. Mixing process of mining drainage and the river water, the neutralization of river water and surrounding rocks, and the precipitation of Fe and Al, all the mechanisms play important roles. Polluted Xiaofu River is used to irrigate farmland downstream of Xiaofu River such as in Mashang. SO₄²⁻, hardness, TDS and Ni, Rb of groundwater is higher in irrigation area with polluted river. The irrigation water affects the quality of shallow groundwater.

Select this Article		Innovative UV Technology for Water Treatment Systems Lily Sanchez, Victor Tarashenko, Steve Oster, Francis Wang, and Gary Johnson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)131 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Environmental applications for UV light include UV disinfection, UV oxidation, and ozone generation. UV disinfection includes applications for drinking water, treated wastewater, irradiation of food, and point disinfection. UV oxidation, with hydrogen peroxide, ozone, or UV alone, is commonly used to oxidize toxic organics in aqueous solutions for environmental remediation, and organic oxidation in Various chemical processes. What all of these applications have in common is that the most common UV source used today is the Argon‐Mercury arc lamp. Though UV applications are widespread, lack of better UV source has caused the state of the art to mature. Much work was done in the 1990s and arc lamps were developed to their full potential. Fill gas pressures were increased, various halogens have been added, and more energy was input to the lamp, resulting in high‐output lamps. But as fill pressure increases, the output wavelength shifts to longer wavelengths that are less effective. So while more output power is available, overall efficiency decreases. This paper discusses promising, preliminary research by Russian and U.S. scientists and engineers into finding a source of high power, high‐efficiency, short wavelength UV.

Select this Article		Intra‐Storm Variability in Stormwater Quality and Its Impacts on Microbial Partitioning Leigh‐Anne H. Krometis, Gregory W. Characklis, Otto D. Simmons, III, Mackenzie J. Dilts, Mark Sobsey, and Christina Likirdopulos ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)132 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Recent studies indicate that a substantial fraction of microbes in stormwaters are attached to particles, which can significantlyimpact their fate and transport. Attachment to particles may increase settling rates and decrease die‐off, resulting in microbial accumulation in bottom sediments and disappearance from the water column. Quantification of partitioning behavior is essential for improving water quality modeling, a critical component of regulatory efforts related to water quality management (e.g. TMDLs) or contaminant mitigation (e.g. detention basins). The objective of this study was to investigate the attachment behavior of five microbial indicators (fecal coliforms, E. coli, enterococci, C. perfringens spores, and total coliphage) throughout storm hydrographs to identify any patterns or changes in this behavior; to assess the total loadings of attached and free‐phase organisms throughout storms; and to evaluate the percentage of attached organisms residing in specific size fractions. This study deviates from past research in that it focuses on those microbes attached to settlable particles, examines changes in attachment throughout storm hydrographs and evaluates partitioning behavior within specific particle size ranges.

Select this Article		Investigation of Cryptosporidium and Giardia Concentrations in Combined Sewer Overflow and Stormwater Runoff Russell D. Arnone, Michael Borst, and Joyce Perdek Walling ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)133 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Since the first identified Cryptosporidium outbreaks occurred in the 1980s and the massive 1993 Milwaukee, WI outbreak affected more than 400,000 people, the concern over the public health risks related to protozoan pathogens Cryptosporidium and Giardia has grown. Both organisms are recognized causative agents of gastrointestinal illnesses linked to the consumption of contaminated surface or groundwater. This study, part of a planned series to estimate the urban contribution to the total Cryptosporidium and Giardia load to surface waters, focused on combined sewer overflow (CSO) and stormwater. Limited data had been available for assessing the loads of these two pathogens in CSOs. CSO samples were collected from six outfalls in five municipalities in the U.S. and analyzed using a modified U.S. EPA Method 1623 that addressed the high solids content of CSO. Results showed that CSO from urban areas was not a significant contributor of Cryptosporidium to surface waters; it was found to be a Giardia source Stormwater samples were collected from three stormwater outfalls. Each outfall was sampled during two separate rain events. Sample locations were chosen based on United States Geological Society (USGS) land use/land cover classifications. Cryptosporidium was found in small quantities at 50% of the locations, and Giardia was significantly found at 75% of the locations.

Select this Article		Legal Liability of Faculty on Applied Research Projects J. J. Orlins and D. E. Werth ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)134 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract University faculty on virtually all campuses must engage in teaching, scholarly activity, and service. The distribution of effort between these three pillars of academe varies from institution to institution, with larger universities generally emphasizing research (one type of scholarly activity), and smaller colleges often focusing on undergraduate education. No matter what the size or nature of the institution, all faculty must do some sort of work to remain current and contribute to the body of knowledge in their field. Basic research, funded by government grants, is likely the most common form of scholarly work among engineering faculty. Applied research, funded by external sources (either government or private) is somewhat less common but growing rapidly and contributes a great deal to scholarly activity on college campuses. The benefits of applied research are three‐fold: a technical solution is developed for a “client” (the external funding source), faculty members and student researchers apply their expertise to real‐world problems, and the university provides a service to the broader community. Unlike basic research, where fundamental concepts are investigated and technical journal articles produced, applied research focuses on specific problems, and results in study reports, recommendations, and (sometimes) engineering designs. With a decrease in government funding for fundamental research, faculty members are increasingly turning to applied research projects to fill the funding gaps. The issue of legal liability resulting from applied research projects is not often addressed on college campuses. Who is responsible if an engineering disaster results from recommendations made in an applied research report prepared by a faculty member — or even a student? Is it the student? The faculty member? The university? This paper explores the ways legal liability for applied research is handled at two different types of institutions: a large research‐oriented state university, and a smaller undergraduate education‐focused state college.

Select this Article		Minimum Flow Estimated by the Froude Number Yen‐Chang Chen, Jen‐Yang Lin, Eric Hsienshao Tsao, and Jung‐Chen Huang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)135 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Following the development and management of water resources to satisfy the human demand, the quantity and quality of flow in streams change in both space and time. With increasing recognition of streams being fundamental to human existence, concerns for the effect on the stream ecosystem have been raised by government, biologists and private citizen groups interesting in preserving the natural integrity. It is necessary to maintain instream minimum flows to provide for preservation of wildlife and other environmental values. This study proposed a method for estimating the minimum discharge needed to maintain good biological quality. It is based on the Instream Flow Incremental Method (IFIM) that is a habitat based tool used to evaluate the environmental consequences of various water and land use practices. However the habitat suitability curves are obtained by the Froude number calculated by a two‐dimensional computational fluid dynamic model. Then the habitat suitability curves are used to determine the weighted usable area. The minimum flow will be 80 percent of the maximum weighted usable area. The available data of the Fungane Creek is used to illustrate the proposed. The results show that the minimum flow of stream can be easily and efficiently determined by the Froude number.

Select this Article		A Model of Flood and Waterlogging Disaster Loss Assessment Based on the Remote Sensing and GIS Spatial Information Grid Ding Zhixiong, Hu Yalin, Li Jiren, and Huang Shifeng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)136 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Flood and waterlogging disaster is very serious in China. An applicable, reliable and useful model of flood disaster loss assessment is imperative in the task of flood prevention, wrecking and disaster relief. Flood disaster loss assessment is processed by establishing GIS spatial information grid model. Social‐economic and flood character parameters obtained from GIS spatial information grid are introduced, and a calculation formula of flood disaster loss rate is given in this paper. Flood disaster loss assessment and analysis of storing flood water effect is processed in Menwa Storing Floodwater Area on basis of flood remote sensing monitoring in 2003's Huaihe river flood. The result indicate that the model of flood disaster loss assessment based on spatial information grid is feasible and applicable, and Menwa Storing Floodwater Area has brought into an important play in the task of 2003's Huaihe river flood prevention.

Select this Article		Modeling and Evaluating Temperature Dynamics in Wastewater Treatment Plants Scott A. Wells, Dmitriy Bashkatov, and Jacek Makinia ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)137 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract With new government regulations governing the discharge of heated effluents into receiving waters, there is much interest in providing a model of temperature dynamics in wastewater treatment plants (WWTP). This type of model would allow operators to evaluate alternatives for reducing effluent temperatures, such as covering secondary clarifiers. This type of tool would also be of use to demonstrate the difficulty in some installations of affecting effluent temperatures. A model of temperature in a WWTP was developed and tested at a facility in Vancouver, Washington during both summer and winter conditions. Temperatures were taken at 6 control points throughout the treatment plant and used as a basis for model calibration and evaluation. Meteorological data such as air temperature, dew point temperature, wind speed and direction and solar radiation were obtained from nearby weather station. The impacts of the discharge on the Columbia River were also discussed. Also, the basic model was tested in an aeration model using detailed temperature data from a Washington County, Oregon, USA wastewater treatment facility.

Select this Article		Operational System of Flood Monitoring and Assessment Using Space Technology in China Li Jiren ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)138 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract China is often suffered from various kinds of natural disasters, while flood and waterlogging is one of the disasters, which affect seriously the sustainable development of society and economy in China. The general situation of flood and waterlogging disaster in China is first introduced briefly in the paper. Chinese government pays a lot of attention to flood disaster management, including flood monitoring and assessment by space technology. With regard to the application of space technology in this field, the user requirements are analyzed. For flood disaster management, an operational and professional system is important and necessary. This paper mainly introduces the operational and professional system of flood monitoring and disaster assessment by space technology in China. Due to the significant difference between operation and scientific research, the parameters for operational and professional system by space technology in this field are concluded. The operational and professional system by space technology for flood monitoring and disaster assessment in China is introduced in detail, especially the information needed before, during and after flood disaster as well as their acquisition and communication. The construction of background database, including baseline of water body, land use classification social and economic data as well as its update are very important for disaster assessment before, during and after the occurrence of flood. The preparedness before flood and its contribution to decision making for the purpose of disaster mitigation is emphasized. The real‐time transmission system of airborne SAR and its improvement are introduced. The results on flood disaster monitoring and assessment in previous years are shown in the paper to illustrate the importance of application of space technology in this field. The organizations, operational mechanism, information and communication requirements are concerned. The gap on application of space technology to flood disaster management is analyzed, including gaps on technology, finance, real‐time data acquisition, education, operation, policy and so on. Some suggestions for establishment of integrated regional or global and real‐time system to support flood disaster management are also proposed in the paper, including the mechanism for operational system, data policy, technology exchange and training, combination of space‐derived data with conventional data and so on.

Select this Article		Optimal Risk‐Based Expansion Strategy of Sewer Infrastructure System in a Fast Growing Urban Region under Uncertainty Ni‐Bin Chang, E. Annette Hernandez, and Eric Davila ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)139 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Lower Rio Grande Valley (LRGV) in South Texas has emerged as a warehouse and transportation center between Central America and the U.S. due to the impact from The North American Free Trade Agreement (NAFTA). According to the Lower Rio Grande Valley Development Council's (LRGVDC) investigation, the area's population has increased by 39.8% in the last 10 years. It is estimate that the population will continue to grow at a rate of approximately 4% per year. The City of Pharr is one of the fast‐growing cities in the Valley, which demands larger wastewater treatment capacity in the near future. Risks and uncertainties arise in various aspects of decision analysis with respect to several available expansion options. Finding of the optimal risk‐based decision of sewer network expansion with time‐varying constraints must be accounted for in long‐term planning. In this study, background information has been garnered regarding population projections as well as land use based on the City of Pharr zoning policy. The planning model ran for three five‐year periods beginning in 2005 and ending in 2020. Historical population data is used to forecast the population for each time period. The waste stream generated is divided into three distinct sewer sheds: 1) South region, 2) Central region, and 3) North region. The City of Pharr anticipated that most of its growth would be concentrated in the North Region; therefore, Pharr considered building a new wastewater treatment plant in that Region. The other options available to the City of Pharr also include routing of their wastewater to the McAllen wastewater plant on the southern side of McAllen, and expanding the Pharr wastewater plant on the southern side of Pharr. Parameters used in optimization analysis in the second stage would be generally defined as interval numbers in a grey integer‐programming model. To identify the optimal risk‐based decision, a cost analysis model in conjunction with optimization scheme is prepared for determining the most cost‐effective expansion strategy under uncertainty. The outputs would reflect the systematic concerns about integrative uncertainty within this analysis leading to enable decision makers and stakeholders to make risk‐informed decisions.

Select this Article		Planning for Stream Sustainability in Lenexa, Kansas P. A. O'Neill, R. Prager, T. Jacobs, and L. A. Roesner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)140 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Cedar Creek Watershed located in Lenexa, Kansas will soon be transformed from an undeveloped area into an urban community of residential areas and a business park as development pressures continue in this rapidly growing Kansas City metropolitan suburb. The City, while welcoming responsible development, is determined to not sacrifice the watershed's natural water resources as development progresses. This study was undertaken by the City to develop a plan for siting and sizing a system of multi‐use stormwater facilities designed to protect the natural resources within the watershed, while providing flood control benefits and recreational amenities. The stormwater facilities were designed so that the hydrologic characteristics of their discharge, after the watershed was developed, would preserve the geomorphic characteristics of the stream to the maximum extent practicable. The ultimate goal was to minimize future flooding potential, preserve water quality and stream habitat, and maintain long‐term ecologic sustainability in the receiving stream system. A key component of the plan development was a hydro‐geomorphic evaluation of the relationship between the changes in hydrology due to development, and the long‐term geomorphic stability of the natural stream system. The final product was a watershed management plan that identified locations along the stream corridor for siting the multi‐use stormwater facilities and design criteria sizing and outlet design so that they provided flood control, water quality, and geomorphic stability by properly controlling the stream forming rain events. In addition, future roadway alignments were recommended to minimize adverse effects to the stream corridor. Lastly, a park and trail system was integrated into the plan to provide recreational opportunities adjacent to the business park.

Select this Article		Predicting and Managing Spillover Water for Reservoirs in Semi Arid Islands: The Case of the Kouris Reservoir in Cyprus K. Aristeidou and J. W. Eheart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)141 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract More than 97% of precipitation on the Mediterranean island of Cyprus falls between October and April. During the rest of the year, the streams on the island dry out, and the inflow to the reservoirs is negligible. On the other hand, the highest water demand is in the summer months, due to irrigation and tourist industry needs. During rainy years, some of these reservoirs may spill over at the end of the rainy season. Most of this spill over water ends up to the sea, and is considered wasted. If the volume of spillover water could be predicted a few months in advance, this water could be used for a “low value” purpose, like groundwater recharging. A model that can be used for estimating, on a real time basis, the exceedance probabilities of future spilling volumes, is proposed. The model is based on historical reservoir inflow and evaporation data and the predictions are on a monthly basis. The model predictions are updated at the end of each month, based on inputs of the inflow of the previous month and the current storage of the reservoir, enabling the operator to revise the reservoir release policy, taking into account the new information. Two water release optimization strategies that utilize the model predictions are proposed. The first method is based on a target reliability analysis, while the second one is based on a benefit cost analysis.

Select this Article		Probabilistic Approach to Residence‐Time Distribution in Water Treatment Units V. G. Tzatchkov, S. G. Buchberger, and A. Martin‐Dominguez ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)142 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Imperfect hydraulic behavior of water treatment units, expressed by stagnation zones and bypassing, may substantially reduce the treatment efficiency. Flow tracing residence‐time distribution based techniques are commonly used to identify if such undesirable effects take place inside the unit and what is their extent. A probabilistic approach to obtain the theoretical residence‐time distribution function for a series of continuously stirred tank reactors with possible stagnation zones and bypassing is presented in. this paper. It is shown that binomial probability distribution can be used to describe the passage of a particle through the series of N reactors with possible bypassing at each individual reactor. The well known residence‐time distribution functions for one or several continuously stirred tank reactors with no stagnation zones and no bypassing, are also shown to be obtained in terms of probability. Applying these principles, the residence‐time distribution function is derived providing some physical insight. The result is identical to that obtained earlier by Laplace transform technique. An optimization procedure, implemented in MSExcel, is then used to obtain the number of tanks, and the fraction of stagnation zones and bypassing minimizing the difference between tracer test data and unit's residence‐time distribution function. Results were compared with experimental data obtained from actual drinking‐water treatment plants in Mexico.

Select this Article		Probabilistic Approach to the Estimation of Urban Stormwater Pollution Loads on Receiving Waters S. A. Kuzin and B. J. Adams, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)143 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, the issue of receiving water protection from pollution by urban stormwater discharges has gained in importance. This paper examines the basic processes and functions behind urban stormwater pollutant delivery into surface waters and develops a set of tools that allow the estimation of pollutant load dynamics on receiving waters and the generation of statistics of pollutant concentration in stormwater runoff and in the receiving water mixing zone. In particular, the group of expressions developed in this paper allows the calculation of runoff parameters (volume, discharge rate and pollutant load) on an event average basis for an unregulated catchment. Using Monte Carlo simulation techniques, the runoff pollutant concentration probability distribution (as event averages) are obtained. Merging these runoff statistics with the stream parameters allows the receiving water pollutant concentration characteristics to be obtained as well as the probability of exceeding threshold pollutant concentrations in the mixing zone of a stream. The simulation can be performed with different levels of complexity with respect to catchment hydrologic representations and pollutant load functions. As a result, the magnitude of influence of urban runoff on a surface water body can be determined, pollutants of concern can be identified, and certain remedial measures recommended. The probabilistic approach allows for more rational and refined assessments of surface water quality. As opposed to the calculation of pollutant concentration in the mixing zone based on average values and extreme flow statistics, probability‐based calculations yield complete probability distributions of pollutant concentrations in the stream and the probability (frequency) of exceeding the limiting pollutant concentration. This work concentrates on approaches to chemical criteria violation control in smaller scale receiving waters; e.g., low‐discharge rivers and creeks as this type of receiving waters is the most common and the most vulnerable to pollution from stormwater discharges.

Select this Article		Quantitative Assessment for the Effects of Non‐Point Source Pollution Loads on Water Environment of Plain Area Ruan Xiaohong, Gao Jing, and Ao Jing ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)144 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The non‐point source (NPS) is the main cause of surface water pollution in Taihu Lake basin in southeast China, therefore the quantitative analysis for the effects of NPS on water environment is the vital basis for water pollution control in the area. Surface water quality models, with the emphasis on the spatial and temporal changes of pollutants, are the most important tools for watershed environment management planning, which provide scientific basis for assessment and control of NPS pollution of watershed environment. However, because of the characteristics of the generation of agricultural NPS pollution loads, its spatial and temporal distribution was averaged in water quality simulating for a long time, which reduced the precision of prediction and the feasibility of real‐time forecasting. In water quality simulation, the spatial and temporal distribution of agricultural NPS pollution loads can be determined based on the concept of catchment area of unit river length. When the time scale of calculation is relatively long (e.g. yearly), pollutant load of non‐point source can also be averaged annually and put into segments; and when it is relatively short, pollutant load can be distributed based on storm duration. This paper presented the methods of agricultural NPS pollution loads estimation and its spatial and temporal distribution for the plain area watershed. The estimation of NPS pollution load involves the characteristics of runoff pollution loads from different land uses, such as dry land, paddy‐field, urban areas etc. In this paper, Suzhou is taken as a case study, for there are so many rivers and streams, which form a complex stream‐net. The result of the case study showed that the represented empirical formula for estimation of NPS is feasible. The method of spatial and temporal distribution of NPS pollution loads based on the concept of catchment area of unit river length can improve the prediction precision of water quality models, as well as make it possible for real‐time water quality simulation in the plain area.

Select this Article		Reservoir Watershed Management in Taiwan Jan‐Tai Kuo, Chou‐Ping Yang, and Cheng‐Daw Hsieh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)145 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Powerful typhoon Aere hit northern Taiwan on August 25, 2004 which brought huge amount of sediments and debris into Shihmen Reservoir. It caused high concentration of suspended sediment in the reservoir and water treatment plants were shut down. Taoyuan area of 2 million people and industries were without water supply for two weeks. Since then, watershed protection has become a very important issue. Now Taiwan government has proposed the National Land Protection Act to ban the dvelopment for mountains area of above 1500 m. This paper reports and discusses the watershed development and management in Taiwan. Both technical and administrative aspects are included in the paper. Some sound strategies are proposed.

Select this Article		Sensitivity of Detention Basin Volume to Rainfall Input Bradford A. Bohler, Eric M. Hahn, En‐Ching Hsu, and A. Ramachandra Rao ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)146 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the Midwestern United States, four major rainfall depth estimation methods are used to determine runoff depths and volumes. The purpose of this study is to analyze the difference in detention basin volumes computed by using these rainfall depths. The four rainfall depths used in this study are calculated from Chen's Method, the National Weather Service, the depths published by the Indiana Division of Natural Resources in Technical Paper Number 40 and the depths published in the “Rainfall Frequency Atlas of the Midwest.” One of these four depths is used to determine the detention volumes required for residential developments in Indiana. However, there are no guidelines as to which rainfall depth must be used. The rainfall depth analysis was performed for three locations in Marion County, Indiana. The rainfall depths determined by Chen's Method were calculated based on the location in Indiana to find the corresponding coefficients. The depths from the National Weather Service, Indiana Division of Natural Resources and “Rainfall Frequency Atlas of the Midwest” were read from the figures provided in these publications. The Marion County ordinance required that a detention basin be large enough to hold runoff from the post‐developed 100‐year storm and discharge this runoff at a rate no larger than the runoff from the pre‐developed conditions for a 10‐year storm. From these ordinance requirements, detention volumes were calculated. TR‐20 and HEC‐HMS models were used for the analysis. The changes in detention volumes obtained by using different rainfall depths are discussed. The data from the “Rainfall Frequency Atlas of the Midwest” usually gave the largest detention storage volume and that from TP‐40 the smallest.

Select this Article		Side‐By‐Side Evaluation of Stormwater Proprietary BMPs Fidelia N. (Ola) Nnadi, Ashraf Z. Al‐Hamdan, and S. Marie Romah ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)147 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a side‐by side study to determine the relative pollutant removal effectiveness of three proprietary end‐of‐pipe BMPs, namely, Baysaver, CDS, and Stormceptor. In this study, a controlled laboratory conditions were used in order to provide documentation of the performance of the BMPs. For that purpose, a lab facility was constructed at the University of Central Florida (UCF). The setup of the facility has the ability to pump flows required to replicate runoff events. Using this type of setup enables the relatively rapid testing of BMPs to evaluate their performance, under repeatable and consistent conditions for multiple flow rates, different constituents, particle sizes, and sediment concentrations. In this study, five tests were conducted with five different flow rates: 1.6, 1.28, 0.96, 0.64, and 0.32 cfs. The studied pollutants were sediments (TSS, TDS, and Bed load), nutrients (nitrogen and phosphorous), Metals (Fe, Cu, Zn, Cr, Ni, Cd), and litters such as organic leaves, soda cans, plastic bottles, and cigarette butts and boxes. The results showed that some of the pollutants decreased in concentration while others increased between the influent and the effluent of the units. The results also showed that the performances of the studied BMPs for the pollutants varied. Baysaver had the lowest TSS removal efficiency. Even though TSS removal efficiencies of CDS and Stomceptor were higher than Baysaver, they were still relatively low. All the units had good performance in removing the large sediment particles and litter. The results also suggested that nitrogen was produced in the Stormceptor unit during the testing program. Other than removal efficiencies, the paper also presents some factors that should be considered in BMP evaluation. The review engineer will need to decide which factors to include in an evaluation and their respective importance to the user.

Select this Article		Storm Water Runoff from an Urban Watershed in Southern California: Top‐Down Approach for Characterizing and Modeling Pollutant Loading Rates Cristiane Q. Surbeck, Stanley B. Grant, and Jong Ho Ahn ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)148 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. In southern California, storm water runoff from urban watersheds impacts coastal water quality. At the present time, coastal water quality impairments are usually managed through the development and implementation of a total maximum daily load (TMDL) plan, for which waste load allocations (WLA) and load allocations (LA) are developed, respectively, for the primary point and non‐point sources of pollution in the watershed. The WLA and LA values are developed after weighing different pollutant source management scenarios, typically with the help of a distributed model of the watershed — for example, the geographical information system (GIS) model called BASINS. Because of challenges associated with this approach, we explore an alternative paradigm for modeling pollutant flow out of large watersheds that we term top‐down, as opposed to the bottom‐up approach employed by distributed models described above. In this alternative approach, the emphasis is on developing scaling relationships for pollutant loading rates that apply at the scale of large sub‐drainages and the watershed as a whole. These scaling relationships could, in principle, be used for engineering calculations (e.g., for the design phase of storm water treatment facilities), to assess the contribution of individual watersheds to coastal pollution, and as a benchmark against which distributed models can be compared and tested. To this end, a series of studies were carried out at three sites in the Santa Ana River watershed, a large urban watershed encompassing in southern California. From the data, fecal indicator bacteria loading rates appear to scale as a power law with volumetric flow in a manner that varies by site, but is robust within, and between, storms at a single site. The physical basis for these scaling relationships, as well as the relationship between contaminants and particles eroded during storm events, are explored and developed.

Select this Article		Stormwater Hydrology in a Developing Coastal Plain Watershed C. Williams, G. Huynh‐Ba, C. McGee, and J. Orlins ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)149 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Southern New Jersey is part of the Atlantic Coastal Plain, with generally flat topography and sandy soils. Hydrologic estimation techniques employed by state regulatory agencies typically rely on NRCS methods such as TR‐55 and TR‐20 with pre‐defined runoff hydrographs. While these techniques work reasonably well in the steeper Piedmont regions of northern New Jersey, they typically over‐predict runoff quantities in southern New Jersey by an order of magnitude. Several alternative unit hydrographs have been proposed for coastal plain regions, including the DelMarVa unit hydrograph, developed for the Delaware‐Maryland‐Virginia peninsula, and the Upper Maurice River unit hydrograph in southern New Jersey. To verify the applicability of these types of alternative approaches, a study has been conducted in support of developing Regional Stormwater Management Plans for several watersheds in the region.

Select this Article		Structural Storm Water (Sedimenter‐Filters) Treatment BMPs Emilio Rodríguez and Claus Pardo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)150 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Petroleum refining requires relatively large volumes of water and consequently produces four types of wastewater: cooling water, process water (Oil with Water or Water with Oil), sanitary sewage water and Stormwater. Surface runoff water is intermittent and contains spills on the surface from equipment leaks and materials that may have been collected in drains. Runoff surface water also includes water coming from the crude process units and products in storage tank or tanks farms. Stormwater is the portion of rainfall that originates as runoff water, which does not evaporate or percolate into the ground. Stormwater volumes are a function of rainfall and runoff area. Both factors are highly variable or site‐specific. Wastewaters are treated in onsite wastewater treatment facilities and then discharged to POTWs or to surface waters under NPDES permits. Stormwater is the major source of wastewater, but it is the stream that requires less treatment. The Best Management Practices (BMPs) includes a variety of treatment processes; however acceptable solutions are highly dependent upon the properties of the wastewaters and the volume. A common practice is the segregation of the relatively clean rainwater runoff from the process streams to reduce the quantity of oily sludges generated. For the purposes of water handling, Stormwater is divided into three categories: uncontaminated, potentially contaminated and contaminated. This categorization is based on the type of area from which the Stormwater is generated. The best way to control the volume of contaminated Stormwater is to reduce and isolate contaminated areas. The BMPs includes methods for preventing the contamination of Stormwater; API Publication 4602 presents additional details. In general, the tank farms are big areas in a typical Oil refining facility. For this reason, these are surfaces with high potential of generating significant wastewater quantities from rainfall water. Typically, this area generates wastewater compounds of rainwater and oily water coming from the crude and product storage tank. In tanks farm, it is a common practice to drain the rainwater from contained areas, with a piping drainage system and valves placed through the dikes or walls. These control valves are usually closed and have the capacity to segregate the wastewater if it is contaminated. The Hamaca Crude Upgrader project in Venezuela with an investment of $ 1.5 Billion has the novel experience with the introduction of sedimenter‐filter in the tank farm's control drainage system. These sedimenter‐filters have the capacity of improve the quality of the Stormwater in the early phase. A refinery wastewater stream may contain oil in three forms: oil globules, emulsified oil and dissolved oil, and additional sediments and suspended‐solids. The oil globules, sediments and the suspended‐solids can be removed by the sedimenter‐filter. These filters are small concrete structures with a sedimentation chamber and filters with grating and geotextile layers. Primary wastewater treatment consists of installing an API separator or impounding located downstream of the wastewater drainage systems. The accumulation of sediments reduces the efficiency of the API separator and requires a longer cleaning period (plant shut down). If the API separator is also used for Stormwater, the sediment will typically contain larger amounts of sand, dirt or solids that may also contain hydrocarbons and small amounts of heavy metals. Purpose of this paper is to show that the sedimenter‐filter upstream of wastewater drainage systems reduces significantly maintenance requirements of the drains net and API separator or impounding, improves the quality of the Stormwater in the early phase (reducing TSS and sediments) fulfilling environment laws and prevents contaminants downstream in the drainage system. Additionally, this paper proposes the sedimenter‐filter like a new action inside the BMP for tanks farm. The Best management practice (BMPs) has a window of opportunities, to innovate and to implement new actions. The scope of this proposal is for refinery and/or Petroleum terminals.

Select this Article		Study on Warning and Emergency Stages of Tan‐Shui River K. C. Yeh, M. J. Chen, and E. T. Lin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)151 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of this paper is to examine the existing warning stages of the target stations in the Tan‐shui River basin and to propose suitable warning and emergency stages. First, historical damages during the flood periods and the hydrographs of water surface elevation of the target stations are analyzed. Necessary actions that the government and people should take are also discussed. Referring to the strategy adopted by other countries, such as Japan, America, and Mainland China, the definitions of the warning and emergency stages for Tan‐shui River are proposed. Seventeen representative sets of historical typhoon floods are selected. On the basis of the inundation area and depth data, we analyze the rising speed of the floods, and the critical inundation elevations of the river banks or levees. Second, some circumstances should be considered including: (1) limited sample size of the historical typhoon floods, and (2) the uncertainties of the hydrological conditions, including the rainfall in the watershed and the sea level during typhoon period. Thus besides 17 sets of historical flood events, 187 synthetic sets of flood events are generated. Third, the rising speeds of the stages for the total 204 sets of food events at target stations are computed by using 1‐D numerical channel‐network hydraulic model. According to above approaches, the warning and emergency stages of the target stations in Tan‐shui River can be determined more practically and precisely because the hydrological uncertainties of the watershed are considered.

Select this Article		SWMM and SMADA Model Predictions vs. Field Data Travis Heier, E.I.T., A.M.ASCE and Steven K. Starrett, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)152 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objectives of this study were: (1) conduct sediment and nutrient runoff research during golf course operation on a watershed of 416 ha, (2) determine how the values of SWMM and SMADA‐PLOAD compared to 8 years of measured data for modeled total suspended solids, SS, total nitrogen (organic and inorganic nitrogen), total N, and total phosphorus (othrophosphates, condensed phosphates, and organically bound phosphates), total P, for the native prairie and during golf course construction and operation, and (3) make recommendations as to how to use SWMM and SMADA‐PLOAD to model golf course dominated watersheds. At the watershed outlet during early golf course operation, field measurements showed average annual loadings of 475, 0.46, and 1.14 kg/ha/yr for SS, total P, and total N respectively. SMADA‐PLOAD predicted 309 (−35%), 0.45 (−2%), and 6.49 (+468%) kg/ha/yr for SS, total P, and total N respectively. SWMM predicted 582 (+23%), 0.63 (+36%), and 1.53 (+34%) kg/ha/yr for SS, total P, and total N respectively. SMADA‐PLOAD was recommended if a very general estimation was necessary. If field measurements were available, SWMM would be model of choice because of calibration capabilities.

Select this Article		Understanding Factors Affecting Odor Production from Anaerobically Digested Biosolids: Digester SRT, Dewatering and Polymer Type Matt Higgins, Yen‐Chih Chen, E. J. Barben, Michele Mittman, Matthew Dawson, Sudhir Murthy, William E. Toffey, Chris Peot, and Michelle Mittman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)153 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Over the last few years, significant research has been undertaken to understand the production of odors from biosolids cake, and also to understand the factors which impact odors and finally to develop methods to reduce odors. The research reviewed in this paper shows that most odor is related to volatile organic sulfur compounds (VSCs), especially methyl mercaptan and dimethyl sulfide. These compounds are produced by the microbial degradation of protein in the cake. Greater amounts of protein have been shown to increase odorant production. Therefore, factors which will increase the bioavailable cake protein content will also increase the production of VSCs. Factors that were studied which impact bioavailable protein and increase odors include shear associated with high solids centrifuges and higher polymer dosages. Greater SRTs during digestion reduced protein content and odorant production. In developing strategies to control VSC production, the focus should be on reducing bioavailable protein.

Select this Article		15 Years Experiences of Sustainable Urban Storm Drainage in the City of Malmo, Sweden P. Stahre ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)154 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the City of Malmo in Sweden the concept of sustainable urban drainage has been applied more systematically since the late 1980's. The characteristic feature of sustainable urban drainage is that aesthetics, multiple use and public acceptance of the drainage facilities play a very important role in the planning. For a successful result a close co‐operation between the different technical departments in the city and an active involvement of the public is of greatest importance. The planning of sustainable drainage systems is much more complex and time‐consuming than the planning of traditional underground drainage systems. During 15 years experiences of sustainable urban drainage in Malmo a new approach for the planning has evolved. This new approach is described briefly. Today most new developments in the city of Malmo are planned according to the sustainable drainage concept. The ambition is that the urban drainage facilities shall be regarded as a positive asset in the city environment. In the paper some examples are given of how the new types of drainage facilities have been implemented in Malmo.

Select this Article		Analysis of Fecal Coliform Bacteria in Spring Creek above Sheridan Lake in the Black Hills of South Dakota Patrick Schwickerath, Thomas Fontaine, and Scott Kenner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)155 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Spring Creek is a perennial stream that originates above Hill City in the Black Hills of South Dakota. Spring Creek, from the origin to the inlet of Sheridan Lake, has been listed on the 1998 303(d) list of impaired waterbodies for South Dakota for exceeding fecal coliform bacteria water quality criteria. The listed portion of the Spring Creek Watershed is approximately 126 square miles (327 square kilometers). The average annual precipitation in the Watershed ranges from 20 to 24 inches (51 to 61 centimeters) per year. Over 97 percent of the Watershed is ponderosa pine forest. A water quality monitoring program was completed from May 2002 through July 2003. Water quality data collected for this reach of Spring Creek indicate that the stream does not meet the water quality criterion for the beneficial use of immersion recreation. Immersion recreation has the most stringent water quality criteria for fecal coliform bacteria in this reach. For this section of Spring Creek from May 1 to September 30 of each year, the criterion requires that the geometric mean of five samples taken over 30 days is not to exceed 200 colony‐forming units (cfu)/100 ml and that the daily maximum is not to exceed 400 cfu/100 ml. Water quality data have been collected since 1976 for this section of the creek. The Total Maximum Daily Load for the impaired reach was developed using a watershed approach with the BASINS and HSPF models. Several Best Management Practices (BMPs) were modeled to determine a combination that would bring fecal coliform concentrations down to acceptable levels. The BMPs included reducing the human pathogen sources, a litter control program, buffer zones and filter strips, and better animal waste management. Two possible combinations of BMPs were found that reduced the concentrations in the creek to acceptable levels. Monitoring of fecal coliform concentrations in the impaired reach of Spring Creek should be continued after BMPs are implemented.

Select this Article		Analyzing Potential Benefits of Low Impact Development in Reducing Combined Sewers Overflows Avinash S. Patwardhan, Ph.D., P.H., J. Timothy Hare, Thomas Jobes, and Daniel Medina ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)156 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Inadequately managed stormwater runoff and combined sewer overflows (CSOs) continue to threaten the biological health and diversity of our streams. The threat comes from both increased volume and rate of stormwater runoff and the pollutants transported by stormwater from various land‐use practices. Research conducted provides extensive evidence that land‐use decisions play a pivotal role in water quality and ecosystem health. Research also suggests that conventional stormwater management practices cannot adequately protect aquatic resources. As a result, there is significant interest among the planning and engineering communities in innovative Low Impact Development practices that protect natural hydrologic processes. Considered as a new approach to stormwater management for years, LID firmly established itself over the past few years as a powerful component in the stormwater management toolkit. LID seeks to minimize the impact of stormwater in new development and redevelopment, restore and protect ecosystems, and reduce the financial burden of construction and maintenance of stormwater management infrastructure. This paper presents an overview of LIFE model developed from basic principles of LID, i.e. controlling the runoff at the source and its application to a CSO sewershed for evaluating the potential benefits of LID in reducing CSO overflows. LIFE is a continuous‐simulation, model based largely on physical processes that occur within bio‐retention facilities, vegetated swales, green roofs, and infiltration devices, as well as effects of site fingerprinting and soil compaction. The study sewershed is an approximately 28 acre. Approximately 65% of the watershed's 28 acres are covered with impervious surfaces. The sewershed is predominantly residential, but there are some community/institutional land uses that occupy significant land areas in the sewershed. The goal of LIFE model application is to evaluate LID strategies into the existing cityscape to evaluate the possibility of reducing the number of overflows to the receiving creek while providing ancillary benefits to the community.

Select this Article		Application of Polyacrylamide to Enhance Silt Fence Performance J. Arjunan, S. Yeri, E. Stevens, B. J. Barfield, and K. A. M. Gasem ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)157 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Conventional barrier methods of erosion control, in particular silt fence, have demonstrated poor performance at trapping clays and fine silts due to inadequate detention time for settling. Trapping efficiency can be improved by flocculation of clays into larger particles with higher settling velocities. Studies have shown that clay flocculation can be induced by anionic polyacrylamides (PAM) in conjunction with divalent cations. Although anionic PAM is available commercially with different charge densities and molecular weights, the flocculation characteristics of a given anionic PAM are not the same for all soils. The purpose of this study is to investigate the flocculation characteristics of three anionic PAMs on four different soil types. Jar test experiments were conducted to treat the sediment with PAM and divalent cations. Flocculation efficiency, suspended solid concentration (SSC), particle size distribution, and floc size of the treated samples were determined with the experimental protocol developed. Specifically, a factorial design is implemented to determine the best (a) PAM type and concentration, and (b) calcium ion concentration that will produce larger flocs with higher settling velocities, for each type of soil considered in this study. Sediment concentrations ranging from 25,000 to 200,000 ppm will be considered. Field testing will be conducted to identify the most effective means of incorporating the PAM with the silt fence installation.

Select this Article		Application of Real Time Control for CSO and SSO Abatement: Lessons Learned from 6 Years of Operation in Quebec City H. Colas, L. Robitaille, A. Charron, C. Marcoux, M. Laverdière, and D. Lessard ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)158 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In 1999, the City of Quebec commissioned a global optimal real‐time control system (GO RTC) with rainfall and flow predictive capabilities for its westerly district wastewater system. This GO RTC system served mainly to reduce separate and combined sewer overflows in the St. Lawrence River and in the St. Charles river. The project involved the implementation of five flow regulation sites in order to take full advantage of excess conveyance, treatment, and in‐line storage capacity whenever available. This first phase of the project was a world premiere for this level of real‐time control. Now, other communities have taken Quebec City's lead and have implemented such real‐time control systems, such as Montreal and Louisville, KY. The design and operation of real‐time control in Quebec City drew upon six years of operational experience in order to, among others: 1) Meet and exceed the expected performance defined in the RTC studies; 2) Evaluate the behavior and performance of real‐time control under various weather and system degradations; 3) Analyze and assess critical elements in the integrated chain of control from the field to the central station; 4) Refine the design of real‐time control systems to ensure safety, reliability, adaptability and flexibility; 5) Enhance the central decision support system, the Csoft software; 6) Better integrate operational needs through RTC system implementations; and Modify RTC measurement and control techniques for better results in various hydraulic conditions.

Select this Article		Application of SWMM5 for BMP/LID Quality Evaluation Wayne C. Huber, William J. Wells, and Ian K. Besaw ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)159 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The new (fall 2004) USEPA SWMM5 model has been used on projects related to management of stormwater in the general urban and specific highway environments for evaluation of hydrologic and water quality impacts of wet‐weather controls (WWCs) commonly known in the United States as so‐called best management practices (BMPs) and low impact development (LID). The functionality of SWMM5 for simulation of water quality impacts of WWCs is compared both to the predecessor SWMM4 versions and to the needs of practitioners and researchers. This paper shows the results possible for common WWCs, such as storage devices, infiltration systems, and any device for which a removal function and/or minimum effluent concentration may be formulated.

Select this Article		Benefits of Sewerage System Real‐Time Control Mary K. Stinson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)160 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Real‐time control (RTC) is a custom‐designed computer‐assisted management system for a specific urban sewerage network that is activated during a wet‐weather flow event. Though uses of RTC systems had started in the mid 60s, recent developments in computers, telecommunication, instrumentation, and automation made RTC an advanced technology of the 21^st century. There have been huge improvements in the sophistication and dependability of these systems. Currently, RTC systems can be designed to address any aspect of sewerage management by controlling: combined sewer overflows, surcharges, sanitary sewer overflows, flooding, in‐line and off line storage, load increases to treatment plants, and locations of unavoidable discharges to receiving waters. An important feature of the RTC management is its cost effectiveness. RTC operations maximize storage, a source of substantial savings. The U. S. Environmental Protection Agency (U.S. EPA) Urban Watershed Management Branch's predecessor storm and combined sewer overflow management research program has been compiling information on RTC systems since 1967. Management of eight RTC projects have been completed and two are in progress. The findings from the U.S. EPA studies will support and illustrate multiple uses and benefits of RTC.

Select this Article		Best Management Practices and Water Quality Standards—How to Bridge the Gap Scott Taylor, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)161 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Phase I NPDES stormwater program is entering its fourth round of permits, and permit requirements continue to ‘ratchet down’ with the goal of achieving receiving water standards for surface waters. Although each state is officially operating under the US EPA's 1996 ‘Interim Permitting Approach for Water Quality‐Based Effluent Limitations’, NPDES permit language in California often does not allow discharges to ‘cause or contribute to the exceedance of a receiving water standard’. Further, with the implementation of Total Maximum Daily Loads (TMDLs), many NPDES permits now include load allocations for specific constituents in stormwater runoff. Some programs such as the Wisconsin DNR have begun placing numeric limits on selected stormwater constituents. Unfortunately, the sophistication of BMPs is failing to keep pace with the increased demands of regulation. Several studies have been completed for typical municipal discharges showing that water quality standards cannot be achieved through the implementation of a comprehensive (source and treatment control) BMP program. This paper examines the steps that could be taken to achieve water quality standards for some of the primary potential impairments to receiving waters of most interest to the public: toxicity, bioaccumulation, dissolved oxygen depletion, eutrophication, sanitary quality, sedimentation and litter/oil and grease. Passive and active treatment technologies, combined a more aggressive form of source control can achieve water quality standards in receiving waters for some cases. However for other impairments, wet weather standards must be created to recognize the extremely difficult technical issues associated with source control and treatment. It is imperative that planning of more advanced stormwater programs begins now to avoid the extremely costly mistakes that will come with a piecemeal and reactionary approach to meeting NPDES requirements.

Select this Article		BMP Design Based on Real‐Time Quality Monitoring A. C. Rowney, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)162 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There are a wide range of practices applied to the analysis and design of BMPs. Some are very simple in nature, some quite complex, and the suitability of a device or approach in a particular context depends on a range of factors including stormwater quality and quantity, receiving system tolerance, regulatory requirements and preferences of the engineers, owners and other stakeholders involved in BMP selection and implementation. As a result, the factors that constitute best practices in design vary substantially from circumstance to circumstance, and general statements about BMPs must be qualified by the recognition that individual cases need to be treated according to the circumstances governing each case. With that recognition in mind, this paper discusses the notion that BMP design might be substantially altered, and performance improved, if real time water quality monitoring data were available to enable real time operating decisions.

Select this Article		BMP Performance Comparisons: Examples from the International Stormwater BMP Database Michael E. Barrett, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)163 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper explores the relative pollutant removal performance of several BMPs using data contained in the International Stormwater BMP Database. These BMPs include retention ponds, extended detention basins, vegetated swales, and sand filters. While the Database contains numerous studies with varying amounts of detail, this comparison is based on the performance of only those sites with reported basic design characteristics and water quality data (event mean concentrations) so that constituent concentrations can be accurately determined and related to the design of the individual BMP. The use of selected BMPs has a number of advantages. Some of the variability in performance observed for facilities of a specific type can be explained by differences in design and/or watershed characteristics; consequently, the expected performance for a given set of conditions can be predicted more accurately. In addition, the differences in performance among BMP types for a given set of conditions can also be established with a higher degree of certainty. Finally, the screening process allows the identification of a number of prominent data gaps that should be targeted in future monitoring activities. The principle measure of performance for each of the selected BMPs is their discharge quality. This was found to be largely a function of the influent concentrations for many constituents. A comparison of the discharge quality as a function of the concentration in untreated runoff demonstrates substantial differences in performance among these BMPs for many constituents. This analysis has been conducted independently of the team which developed and maintains the Stormwater BMP Database and this interpretation should not be construed as approved or endorsed by the Database team.

Select this Article		Canada's CSO Technologies Manual — A Comprehensive Design and Resource Manual G. Zukovs and J. Marsalek ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)164 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Municipal wastewater authorities are increasingly exploring new and innovative treatment technologies, which are specifically designed for combined sewer overflows (CSOs). When applied as part of an overall wastewater management strategy, these technologies can produce efficient and cost‐effective solutions for CSOs. However, like all technologies they require systematic design and proper operation. In many cases, the basic information needed by municipal decision makers and their engineers to evaluate, select and design CSO treatment technologies has been difficult to assemble. In recognition of this need, the Government of Canada through the Great Lakes Sustainability Fund has recently developed a CSO Treatment Technologies Manual, which should serve to provide advice and guidance on the application of physical and physical‐chemical technologies for the treatment of CSOs.

Select this Article		Capacity Assurance Program Planning: Cincinnati Case History Joseph Koran, P.E., Marty Umberg, P.E., and Nancy Schultz, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)165 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Like most municipalities, the Greater Cincinnati area has been experiencing growth in infiltration and inflow, resulting in basement backups and sanitary sewer overflows. US EPA and Ohio EPA initiated enforcement actions to require the Metropolitan Sewer District of Greater Cincinnati (MSDGC) to achieve compliance with the federal Clean Water Act prohibition of untreated discharges from the sanitary sewer system. In 2002, the parties entered into a consent decree requiring numerous specific actions to relieve the overflows. The MSDGC is also under consent decree to update the combined sewer overflow long‐term control plan. This paper briefly summarizes the negotiated consent decrees and presents detailed discussion of the mandated capacity assurance program. The first step of the MSDGC capacity assurance effort, the assessment of existing sewer system capacity and restrictions, was completed in early 2004 using system wide monitoring and modeling. In 2004 and early 2005, the models were used to identify capacity restrictions and size alternatives to relieve those restrictions under four design storm conditions. Life cycle costs to implement the alternatives are being tabulated for each problem area and each design storm. This paper summarizes the steps taken to assure timely identification of the four distinct capacity assurance plans. The paper also discusses approaches to balance these four design storm plans against the community's limited ability to pay for both sanitary sewer overflow and combined sewer overflow control.

Select this Article		Case Studies Using RTC as a NMC and as a Stormwater BMP Philip Cheung, P.E., Nancy Schultz, P.E., and Bruce Prince, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)166 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Real time controls (RTCs) are valued as a means to achieve the maximum capture of pollutants in combined sewer systems for meeting the EPA guideline of Nine Minimum Controls (NMC). Several communities also utilize RTCs to realize reductions in pollutant discharges from stormwater systems. This paper summarizes several of the examples where RTCs are being used as a cost effective combined sewer overflow control and/or stormwater pollutant reduction measure, i.e., as a stormwater best management practice (BMP). In combined sewer systems, real time controls are used to store peak flows in the sewers until treatment plant capacity becomes available, or to divert flows to less stressed portions of the sewer system, or to divert flows to storage facilities. In all cases, the net result is a reduction in the frequency and volume of combined sewer overflow, and hence an increase in the percentage of the stormwater runoff from the combined sewer service area that is captured and treated. The paper discusses several examples, concentrating on the case of Cornwall, Ontario where real time controls were retrofit, at minimal cost, to capture greater portions of the combined flow when stormwater increases the flow rates. Real time controls are less common in separated storm sewer systems, but they do exist. One example is in Edmonton, Canada where sensors are installed to monitor potentially toxic flows in an online oil removal facility. The contaminated stormwater is diverted to temporary storage if an accidental spill occurs on the roadway and disposed of appropriately when it is safe to do so. In another example, Milwaukee, WI is using an RTC system originally built for sanitary and combined sewer overflow control to effect capture of 40 percent of the total suspended solids in stormwater runoff from a proposed highway expansion. Other examples exist at airports to divert runoff contaminated with deicing chemicals to treatment while higher, less concentrated flows go to the storm sewer discharges. For each example, the paper presents the configuration of the RTC system, the costs allocated for stormwater pollution BMP portion, and the expected performance. To the extent possible, the studies and reasoning that led to selection of RTCs as a tool to improve capture and treatment of polluted stormwater are also summarized.

Select this Article		City of Toronto's Wet Weather Flow Management Master Plan M. D'Andrea, W. J. Snodgrass, and P. D. Chessie ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)167 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Urban development within the City of Toronto and surrounding regions has adversely impacted the aquatic environment. Changes to the hydrologic cycle and land use practices have increased flows and contaminant contributions to area surface waters, during wet weather, from storm sewer and combined sewer overflow discharges. The City of Toronto has developed a Wet Weather Flow Management Master Plan to address the impacts of wet weather flows. The study area extended across the City of Toronto, encompassing six major watersheds and the waterfront. A new philosophy in wet weather flow management was adopted which recognized rainwater as a resource; wet weather flows were to be managed on a watershed basis; and a hierarchical approach to wet weather flow management was to be used, starting with at source, followed by conveyance and finally end‐of‐pipe control measures. A series of 13 objectives were identified, grouped into four major categories: water quality, water quantity, natural areas and wildlife, and sewer system. An innovative approach integrating hydrologic, hydraulic and water quality predictions from land based, watershed and lake models, respectively, was used to assess the effectiveness of various strategies. The receiving water response indicated that source controls and conveyance controls were insufficient to achieve the receiving water objectives of the Plan. The Plan's objectives can be met only through the implementation of a comprehensive set of measures consisting of: source controls, conveyance controls, end‐of‐pipe controls, basement flooding protection works, stream restoration works, shoreline management, enhanced municipal operations and an enhanced public education and community outreach program.

Select this Article		Conversion of an Urban Pond to a Water Quality Treatment Pond J. T. Smith, P.E., CPSWQ, M.ASCE, W. F. Hunt, PhD, P.E., M.ASCE, and S. Jadlocki ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)168 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An aging urban pond in Charlotte, North Carolina was monitored for a period of one year prior to a water quality enhancement project for the pond and nearby drainage network. The 11 ha (27 ac) watershed for the .24 (ha (0.6 ac) pond consisted of mixed residential and commercial uses. Inflow and outflow composite samples were collected from August 2003 thru July 2004. Samples from 17 storms were analyzed for a suite of pollutants and event mean concentrations (EMC's) were determined for each storm. The pond was enhanced by the addition of a forebay, a detention component and a littoral shelf around its edge. In addition, a number of drainage improvements were made within the watershed to remove failing conveyances. The detention component of the pond was designed to store and hold the runoff associated with a rainfall of 2.54 cm (1 in) for a period of up to 24 hours. Water Quality results for the post construction period were not available at the time of this writing. During the pre‐construction monitoring period, mean Total Kjeldahl Nitrogen (TKN) and Ammonium‐Nitrogen (NH₄‐N) EMCs at the outlet were 32% and 19% higher than the inlet concentrations respectively. Mean Nitrate Nitrogen (NO₃‐N) and Total Nitrogen (TN) concentrations were shown to be 77% and 20% lower at the outlet. 16% and 63% reductions in Total Phosphorous (TP) and Total Suspended Sediments (TSS) concentrations respectively were observed from the inlet to the outlet. Copper, Lead and Zinc concentrations were reduced by 71, 39 and 49 % respectively. Statistically significant differences between the observed inlet and outlet mean concentrations was observed for all pollutants excepting TP and NH₄‐N.

Select this Article		CSO Regulation in Great Lakes Region of Canada and the United States — A Comparative Evaluation G. Zukovs ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)169 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Great Lakes Region includes municipalities in both Canada and the United States that are presently engaged in CSO management. Regulation of CSOs is a shared responsibility between the federal and the state or provincial governments in both countries. In practice, CSO regulation in Canada is largely a provincial responsibility and hence in the Great Lakes falls under the auspices of the Province Ontario. In contrast, in the US, the federal government through the US EPA has defined national CSO control program requirements. Although the states bordering the Great Lakes have their own policies, the core of the state programs is derived largely from the federal program. The paper outlines the major aspects of the two key CSO policies in the Great Lakes Region — Ontario's Procedure F‐5‐5 and the US CSO Control Policy. In the discussion of the policies the main differences and similarities are examined.

Select this Article		Decentralized and Low Impact Development (LID) Controls for Combined Sewer Overflow Management Neil Weinstein, Wayne Huber, Eric Strecker, James Heaney, Marcus Quigley, Charles Glass, Kim Stephens, and Philip Jones ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)170 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This paper presents the findings of several critical studies that the project team is conducting to evaluate the feasibility and long‐term viability of using decentralized controls for CSO management. The project team has developed a substantial set of analysis tools for use in the development of modeling and monitoring programs, including proposed classification schemes for decentralized controls and descriptions of unit processes. The study also provides guidance on determining the feasibility and effectiveness of controls, including an analysis of optimization, cost, and techniques to manage runoff volume, peak discharge rate, and water quality. Regional case studies on strategies, costs, and maintenance practices are presented.

Select this Article		A Design Aid for Conventional Silt Fence Technology E. Stevens, S. Yeri, B. Barfield, J. Arjunan, and A. Selvakumar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)171 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Using studies conducted of the effectiveness of conventional silt fence installed on and off the contour at the Silt Fence Test Facilty (SFTF) at the USDA Hydraulics Laboratory located in Stillwater, OK, a model was developed of sediment trapping by silt fence when not installed on the contour. Based on these studies and other results from the literature, the model predicts the performance of silt fence when installed in a “bowl” type arrangement with an impoundment area at the downslope end formed by an upslope extension. The model not only predicts flow through the fence, but the presence of undercutting or overtopping. Results presented include evaluation of the accuracy of the model as well as suggestions for its use as a management tool.

Select this Article		Design and Pollutant Reduction of Vegetated Strips and Swales Anna Lantin, P.E., CPESC, CPSWQ, M.ASCE and Michael Barrett, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)172 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Vegetated strips and swales are relatively low‐cost Best Management Practices (BMPs) designed to treat stormwater runoff by using biological and chemical processes in soils, infiltration, and vegetation to filter and reduce pollutants. Vegetated strips and swales can be incorporated with roadway projects in a highway environment as well as along roads common in city, residential, commercial, and parking lots in an urban environment. Pollutant reduction of vegetated strips and swales has been evaluated as part of comprehensive research studies. The studies were conducted on behalf of transportation agencies to determine the pollutant removal efficiency of vegetated strips and swales for treatment of stormwater runoff. A Roadside Vegetated Treatment Sites Study was a 2‐year comprehensive monitoring study to determine the pollutant removal of existing vegetative areas adjacent to highways. The strip test sites consist of vegetated areas not intended for treatment of stormwater runoff. Performance evaluation included: (1) determining the average differences in water quality between runoff at the edge of pavement and after passing through the vegetated strips of various widths; (2) effect of site characteristics on pollutant reduction, (3) effect of differences types of vegetation and coverage on pollutant removal effectiveness, and (4) climate. Results indicate that substantial reduction in concentration occurs for solids and metals. It was found that these constituents effectively achieved irreducible minimum (steady state) concentrations within a few meters from the edge of pavement. Findings from these sites were compared to results from another study of vegetated strips designed for stormwater treatment.

Select this Article		Determining BMP Inspection and Maintenance Costs for Structural BMPs in North Carolina W. F. Hunt, Ph.D., P.E., W. G. Lord, and J. T. Smith, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)173 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract As stormwater structural treatment practices are becoming an increasingly larger part of the urban landscape, so, too, does the need to keep them in good working order. Eighteen agencies/firms which conduct stormwater practice maintenance were interviewed to determine costs for specific maintenance tasks of several stormwater practices. Data have been collected for bioretention areas, dry detention, green roofs, permeable pavement, sand filters, underground detention, wet ponds, and stormwater wetlands. As of early February 2005, data had been analyzed for three of the practices (dry detention, sand filters, and wet ponds). Initial analyses show that (1) maintenance costs were substantially higher than inspection costs, (2) economies of scale existed for maintenance costs within a practice, (3) sand filters were substantially more expensive to maintain an a per watershed acre (hectare) treated basis than wet ponds or dry detention, and (4) communities which plan to assume the responsibility of maintaining stormwater practices within its jurisdiction, will need to procure a considerable amount of money. Upon the study's completion in mid‐March, five more practices will have been evaluated.

Select this Article		Developing an Effective Urban Runoff Management Approach William C. Lucas ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)174 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract It is well recognized that the best approach to mitigate watershed impacts of urbanization is to develop RMPs (Runoff Management Practices) that focus on retaining rainfall where it lands. This is a fundamental benefit of Low Impact Design (LID). Recent monitoring studies have shown that the reductions in runoff volumes and peak flows using LID can be substantial. However, there are still serious deficiencies in realistic LID design approaches, let alone the monitoring and verification of such approaches. It is remarkable just how much effort in setting standards and criteria for RMP design is based upon incomplete, and sometimes faulty, science. Even the more advanced statewide BMP (“Best” Management Practice) manuals allocate specific reduction efficiencies to RMPs, and/or allocate a supposedly precise “point system” to certain RMP designs, methods that only attempt to characterize just how well these designs would really work. The thinking is, at least this approach gets the design community to think outside of the heretofore typical flood control design “cookbook”. As a result, on one hand, RMP designs that are effective may not meet the criteria of the “new cookbook”, while on the other hand, less effective RMP designs that do fit the new cookbook are given more credit than they deserve. This presentation explores the status of current modeling approaches, the potential for their acceptance by the regulatory community, recommendations for modeling improvements, and the current need for verification of modeling approaches.

Select this Article		Development of Adjustment and Scaling Factors for Measured Suspended Solids Removal Performance of Stormwater Hydrodynamic Treatment Devices Qizhong Guo, M.ASCE, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)175 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Suspended solids removal performance of a manufactured stormwater treatment device varies greatly with operating conditions and laboratory or field evaluation techniques. Laboratory testing and field monitoring protocols have been established to evaluate the performance (removal efficiency or effluent concentration) of manufactured stormwater treatment devices and other structural BMPs. However, deviations from the recommended evaluation conditions and techniques are expected and may lead to a significant difference in the measured performances. Range of the parameters/variables specified within the protocol itself may also have a significant effect on the measured performances. Potential effects of six variables are discussed in this paper: TSS vs. SSC methods, operating flow rate, size of the treatment unit, size and density of solid particles in the influent, solids concentration/loading in the influent, and initial volume of solids at bottom of the treatment unit. It is recommended that appropriate adjustment and scaling factors be developed to support certification of performance claims and to appropriately design the stormwater treatment system.

Select this Article		Development of an SSO Mitigation Plan: Lessons Learned from the Field David Sample, PhD, P.E., Rob Bocarro, PhD, P.E., and Monique Latalladi, EIT ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)176 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Wastewater collection and conveyance systems have long been a neglected component of many municipal wastewater systems, due to a lack of funding and management focus. Increased population growth has resulted in increased wastewater flows. Aging systems may not have the hydraulic capacity to receive the increased flows due to a large volume of Infiltration and Inflow (I/I) and lack of periodic maintenance. This may result in a Sanitary Sewer Overflow (SSO) to receiving waters. With the implementation of the Total Maximum Daily Load (TMDL) program and watershed protection programs, SSO events have received increased attention from regulatory agencies. Utilities are required to record the events and estimate the volume of the spills as they occur. The purpose of the evolving Capacity, Management, Operations, and Maintenance (CMOM) program is to minimize SSO events by requiring that each wastewater utility develop a comprehensive program. A response plan is still needed, however, to address the negative impacts of SSO events to receiving waters. Fulton County, Georgia (the county in which the bulk of the City of Atlanta is located), operates a 45 million gallons per day (MGD) wastewater system consisting of 16 sewersheds, 5 treatment plants, 45 pump stations, over 300 miles of pipelines, and over 42,000 manholes. The system primarily serves residents in the unincorporated portions of the County in areas to the north and south, effectively bisected by the city limits of Atlanta, which operates a separate system. The County is currently developing several action plans in response to CMOM requirements. Noted action plans include development of a comprehensive sewer collection system model and master plan, implementation of a comprehensive maintenance program, replacement or rehabilitation of key conduits, and upgrades at pump stations. It is the goal of the County to become more proactive, instead of reactive, in terms of its activities; however, again a response plan was needed, and in fact required for SSOs. MACTEC assisted Fulton County in developing a procedure for responding to SSO events in isolated waterbodies such as lakes and wetlands. This methodology uses a simple series of charts to simplify the calculation of carbonaceous and nitrogenous Biochemical Oxygen Demand (BOD). The process takes as an input the volume of the waterbody and the volume of the spill and estimates the size and schedule of run times for aeration equipment deployed in response to the SSO event. Several iterations of this procedure were developed to simplify the methodology applied in the field. MACTEC developed and conducted a series of training classes with Fulton County's sewer collection system personnel. Despite technological difficulties and a disparity between educational backgrounds, the sewer collection system personnel provided valuable feedback on the state of the system and the methodology applied. As the CMOM program evolves, it will be important to consider some of the lessons learned from operational personnel to ensure effective implementation.

Select this Article		Development of the Lake Tahoe Watershed Model: Lessons Learned through Modeling in a Subalpine Environment John Riverson, Clary Barreto, Leslie Shoemaker, John Reuter, and Dave Roberts ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)177 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A comprehensive watershed model has been developed for the Lake Tahoe basin as part of the 2007 Lake Tahoe technical Total Maximum Daily Load (TMDL) initiative. Integral to this effort was the adaptation of the model to include research results from various parallel ongoing studies, as well as unique subalpine environment considerations. The primary reasons for developing a watershed model were (1) to determine basin‐wide estimates for watershed loading of sediment and nutrients to Lake Tahoe based on land use type, (2) to provide input to the Lake Clarity TMDL Model, (3) to create a platform for load allocation and (4) to project load reductions from BMPs and other management scenarios. No such model had been previously developed for the Lake Tahoe basin. This paper focuses on insights gained through modeling analysis of site‐specific watershed and meteorologic features and approach development, and presents a selection of innovative solutions that emerged from the process. The high level of detail involved in compiling, analyzing, and organizing the required data for modeling not only benefits the current TMDL objectives, but also, forms a lasting database of information to support other future scientific and water quality planning studies. Three selected watershed insights gained through the process include: (1) increased understanding of the impact of watershed physical setting, topography, and land use, (2) the effect of watershed features on meteorological spatial variability, evapotranspiration, and temperature lapse rate in a subalpine environment, and (3) the domineering impact of snowfall/snowmelt sequences on hydrology, water quality, and selected management practice alternatives. The lessons learned will help guide TMDL decision makers to more realistic conclusions when employing models in complex mountainous environments.

Select this Article		Development of the San Diego Creek Natural Treatment System Master Plan E. W. Strecker, M.ASCE, P. M. Mangarella, N. Brandt, E. T. Hesse, K. M. Rathfelder, and M. Leisenring ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)178 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A Natural Treatment System (NTS) Master Plan that includes a watershed‐wide network of constructed wetlands was evaluated for treatment effectiveness of dry weather base flows and runoff from smaller more frequent storms in a 120 square mile (311 km2) urban watershed. The goal of the ‘regional retrofit’ wetland network is to serve as an integral component in watershed‐wide Best management Practices (BMPs) for compliance with pollutant loading limits (TMDLs) requiring discharge limits of sediments, nutrients, pathogen indicators, pesticides, toxic organics, heavy metals, and selenium. The NTS Plan was assessed with ‘planning‐level’ water quality models that account for the integrated effects of the planned 31 NTS facilities. The NTS Plan is estimated to achieve total nitrogen (TN) TMDL for base flows and reduce in‐stream TN concentrations below current standards at most locations. Total phosphorous TMDL targets would be met in all but the wettest years. The fecal coliform TMDL would be met during the dry season, but not all wet season base flow conditions, and not under storm conditions. The NTS Plan is not designed to meet the sediment TMDL, but would capture, on average, about 800tons/yr (726,000 kg/yr) of sediment from urban areas. The wetlands are estimated to remove 13 percent of the total copper and lead, and 12 percent of the total zinc in storm runoff. The NTS Plan provides a cost‐effective alternative to routing dry‐weather flows to the sanitary treatment system.

Select this Article		EcoRoofs (Greenroofs)—Stormwater Research Results in America Tom Liptan and Eric Strecker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)179 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. All cities have two primary impervious elements; rooftops and pavement, with a typical average of about 50% of the surface area of a city at full build out. The results of this imperviousness levels have been well documented and include increased destabilization of streams and increased runoff pollutant loadings and concentrations. This paper will present an overview of the research that is taking place in the United State on the effects of EcoRoofs (green roof) to reduce runoff and improve water quality. The paper includes a summary of published research as well as information obtained from a survey of known researchers. Results to date have shown that EcoRoofs can significantly reduce runoff volumes as well as reduce peak flows. Water quality results have been somewhat mixed with some pollutant concentrations being reduced while others increase. The factors that affect this include soil types, roof maintenance and roofing materials. The reduction in runoff volumes however helps to reduce pollutant loadings even in some cases where concentrations increase. Studies from a wide geographic distribution will be evaluated, including North Carolina, Pennsylvania, Florida, Chicago, New York City, Vancouver, and Portland, Oregon. The paper will also present a more detailed evaluation of monitoring data from Portland EcoRoofs and how such data can be used to validate design and modeling approaches for stormwater management. This will include how the effects can be factored into management efforts for controlling combined sewer overflows as well as separated systems and be considered together with other low impact development approaches.

Select this Article		Effect of Canopy Cover on the Volume of Rain Throughfall Jeff Cochran, M.S.C.E., Shirley E. Clark, Ph.D., P.E., M.ASCE, and Melinda M. Lalor, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)180 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Stormwater runoff has become increasingly difficult for municipalities to manage as areas experience development. This increase in residential and commercial development has led to a substantial reduction in the natural canopy cover, and post‐development plantings have not begun to replace the loss. This study was carried out to establish the extent to which post‐development rain throughfall, and resulting runoff, could be reduced by leaving canopy cover in place. The study compared the volume and intensity of rain that reached the ground in an open area (no canopy cover) versus two areas with intact canopy covers. Rain gauges were placed in a parking lot, and in wooded areas in an environmentally‐friendly development in Shelby County, Alabama. Rain was measured for a period of twelve consecutive months and rain throughfall was compared between the sites by season (Spring/Summer vs. Fall/Winter) and by rainfall depth. The sites were sufficiently close to each other to assume that the rainfall characteristics were the same between the sites in terms of the intensity and the variation of intensity and volume during the storm. Investigation of the relationship between the amount of throughfall on an area without canopy cover and with canopy showed that, for these sites, even in an area with high rainfall intensities, canopy cover could be expected to reduce the total throughfall by approximately 13.5% during spring and summer months. No significant results were seen for intensity but this evaluation was limited by the study techniques. The results of this project indicated that in areas where reducing stormwater runoff is desirable, there is a significant, measurable advantage to preserving the natural canopy on a site wherever possible. The reduction of the rainfall amount reaching the ground reduces the amount of runoff that has to be managed by the developer and the property owner. It also could be expected to reduce the amount of erosion being generated from a site.

Select this Article		Effect of Detention Basin and BMP Shape and Outlet Type on Outlet Hydrology Rajesh Rajan and Larry A. Roesner, PhD, P.E., F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)181 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract It is a proven fact that an increase in watershed imperviousness alters the hydrology and hydraulics. The increased imperviousness leads to increase in flows (both peak flow and volume) from the watershed. The current practice is to reduce peak outflows in the post development scenario case to that of the predevelopment rates. What is undeveloped, is still a point of contention and is a grey area. This study is an extension on the study done on the effects of the current design practice for flood control and Best Management Practices on the flow frequency curves. This study would take the analysis further by examining the effects of different outlet combinations built into various shape detention basins on the flow frequency curves.

Select this Article		Experience with High‐Rate Treatment of Stormwater in a Pilot Installation in Toronto, Ontario, Canada J. Wood, J. Marsalek, M. Yang, Q. Rochfort, C. He, P. Seto, and P. Chessie ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)182 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Treatment of urban stormwater by clarification, with and without flocculant addition, was investigated in Toronto, Ontario, Canada using a pilot‐scale clarifier with removable lamellar plates. Almost 90 stormwater runoff events were characterized at the study site and found significantly polluted, in comparison to the U.S. NURP median site data. Earlier research results indicated good treatability of this stormwater by lamellar clarification with flocculant addition (total suspended solids, TSS, removal of 83%, at a total vessel surface‐loading rate of 15–35 m/h), but there were concerns about laborious plate cleaning after storm events. With the aid of numerical modeling, hydraulic improvements to the clarifier inlet zone were retrofitted in 2004, which permitted the removal of the lamellar pack without a significant loss in treatment efficiency. In the modified clarifier without lamellas, addition of a cationic polymeric flocculant at 4 mg/L provided a TSS removal of 77%, at surface‐loading rates up to 43 m/h. The use of the polymer did not increase the acute toxicity of the process effluent. The stormwater sediment and clarifier sludge at this site were severely polluted by several heavy metals (Cu, Mn, Zn), according to the Ontario aquatic sediment quality guidelines, and the clarifier sludge would require special disposal considerations. The treatment process tested appears to be applicable in projects requiring intensive stormwater treatment at compact sites.

Select this Article		Factors Affecting Long‐Term Performance of Wet Retention/Detention Basins by a Continuous Simulation Model Ashok Pandit and Chi Hyueon Youn ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)183 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A macro spreadsheet model, WEANES (Wet Pond Annual Efficiency Simulation Model), developed to predict the long‐term (multi‐year) or average annual removal efficiencies of wet retention/detention basins, is used to show how the model can serve as a design, planning, and permitting tool for consulting engineers, planners and government regulators. WEANES determines the long‐term efficiencies by modeling the following three processes: 1) Conversion of daily rainfall hyetographs to a hydrograph using the Santa Barbara Urban Hydrograph (SBUH) method, 2) Conversion of the inflow hydrograph through the wet‐pond to yield outflow hydrographs from the outlet structure by routing using the Level Pool Method, and 3) Calculation of inflow and outflow pollutant loads and pond efficiency by estimating daily inflow and outflow loads. Average annual wet pond efficiencies are calculated based on annual mass loads in and out of the pond. The model uses historical, site‐specific, multi‐year, rainfall data, usually available from a nearby National Oceanic and Atmospheric Administration (NOAA) climatological station to estimate basin efficiencies. This paper provides examples of model applications and also shows results of sensitivity analyses to identify key model parameters for increasing long‐term pond efficiency.

Select this Article		FAEST, a New Silt Fence Technology for Construction Sites S. Yeri, B. Barfield, E. Stevens, K. Gasem, J. Arjunan, M. Matlock, and J. Hayes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)184 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Sediment has recently become an emphasis in the EPA NPDES storm water rules due to its impact on habitat in stream channels. Currently silt fence is commonly used as a best management practice (BMP). Field inspection by (Barfield and Hayes, 1992, 1997) found that silt fence, when installed according to standards, was still not effective in controlling sediment. Also, shallow overland flow was concentrated by the silt fence and sought the weakest spot on the fence where it could undercut or overtop the fence. Modification to current silt fence technology is required that is effective in trapping sediment and is also economically feasible. To accomplish this, a geotextile apron, an integral part of fence, is used in front of the fence to control the lateral flow and resulting undercutting. The lateral flow is further restricted by incorporating lateral flow barriers at equal intervals and oriented at an angle to the fence. Our initial field test results indicate that with new design silt fence is effective in reducing the sediment concentration flowing through the fence by 2/3^rd of the incoming sediment load, resulting in a higher trapping of sediment compared to conventional silt fence technology.

Select this Article		Framework Design for BMP Placement in Urban Watersheds Fu‐hsiung Lai, Leslie Shoemaker, and John Riverson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)185 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A number of stormwater control strategies, commonly known as best management practices (BMPs), are used to mitigate runoff volumes and associated nonpoint source pollution due to wet‐weather flows (WWFs). BMP types include ponds, bioretention facilities, infiltration trenches, grass swales, filter strips, dry wells, and cisterns. Another control option is “low impact development” (LID)—or hydrologic source control—which strives to retain a site's pre‐development hydrologic regime by combining impervious area controls with small scale BMPs, reducing WWFs and the associated nonpoint source pollution and treatment needs. To assist stormwater management professionals in planning for BMP/LID implementation, the U.S. Environmental Protection Agency (EPA) initiated a research project in 2003 to develop a decision support system for selection and placement of BMP/LID at strategic locations in urban watersheds. The BMP/LID assessment tools based on sound science and engineering will help develop, evaluate, select, and place BMP options based on cost and effectiveness. The system is called the Integrated Stormwater Management Decision Support Framework (ISMDSF). The ISMDSF will provide a means for objective analysis of management alternatives among multiple interacting and competing factors. The desired outcome from the system application is a thorough, practical, and informative assessment considering the significant factors in urban watersheds. The ISMDSF will be applied to several diverse urban watersheds to evaluate and demonstrate its capability. The initial phase of this research is expected to be completed in 2005 and will include a comprehensive design and a functional system with all pieces in place but not all functionalities. The subsequent phase will include enhanced geographical information system (GIS) capabilities for visualization of placement options, more powerful post‐processors, expanded cost estimating functions, improved BMP simulation processes, and more importantly, a multiple objective optimization component. The development of GIS‐based tools and preparation of their documentation are expected to be completed by 2008.

Select this Article		Gully Study Revisited Robert R. Wells, Carlos V. Alonso, and Andrew Simon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)186 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Gully erosion is a highly visible form of soil erosion that affects soil productivity, restricts land use, and threatens roads, fences and buildings. Gullies are relatively steep‐sided channels, recently formed within a valley where no well‐defined channel previously existed, which experience ephemeral flows during heavy or extended rainfall. This paper serves as an introductory literature review of gully types and processes and takes a probing look at two ephemeral gully studies conducted in Mississippi. This research is part of a USDA‐ARS initiative to provide new information on gully‐erosion processes (sediment production and migration) and gully‐stabilization efforts (BMP's) in the Lower Mississippi River Basin.

Select this Article		Holistic Stormwater Management in Military Installations: LID Retrofits, Stream Restoration, and Pollution Prevention at MCAS New River, North Carolina Daniel E. Medina, Ph.D., P.E., Kirk R. Kropinack, Michael Clar, P.E., J. Timothy Hare, P.E., and Thomas E. Higgins, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)187 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the innovative stormwater management approach that the Marine Corps Air Station New River is implementing towards stormwater management. The installation is using a combination of Low Impact Development retrofits, stream restoration, and pollution prevention, to address stormwater peak flow mitigation, water quality improvement, and reduction of inflows into the wastewater system. The improvements include bioretention facilities to retrofit parking lot, stormwater planters to treat roof runoff, naturalization of concrete channels, stormwater diversions, changes in operating procedures, and signage and education to minimize contaminants entering the waterways. The improvements installed are being used as educational opportunities for base personnel as well as for the surrounding community.

Select this Article		Hydraulic Properties of Cementitious Porous Pavement as a Filtration Interface for Rainfall‐Runoff Treatment X. Kuang and J. Sansalone ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)188 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Porous pavement is a structural low impact development (LID) material for rainfall‐runoff control. In this study, pore characteristics of cementitious porous pavement (CPP) material, including total porosity (ϕ_t), effective porosity (ϕ_e), pore size distribution (PSD)_pore, and tortuosity (τ) are examined using x‐ray tomography (XRT) and conventional gravimetric‐geometric methods. The methodology and results provide tools when modeling CPP material as an infiltration interface, a conveyance/storage medium for liquid and gas, a filtration material for particle removal from runoff. Hydraulic conductivity and particle removal efficiency of CPP material are presented based on experimental measurements. Results indicate that high particle removal efficiencies and high hydraulic conductivities can be achieved with CPP.

Select this Article		Identifying Regional BMP Retrofit Opportunities Tom Bonigut, P.E., CPESC and Scott Taylor, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)189 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract NPDES municipal stormwater permits are based on an iterative BMP approach to reduce the discharge of pollutants from storm drainage systems to the Maximum Extent Practicable (MEP) and to protect beneficial uses of receiving waters. Municipal permits and the regulated agencies' stormwater management programs have typically focused on implementation of site‐specific or activity‐specific BMPs to meet the MEP standard for surface runoff pollution prevention or reduction (e.g. structural BMPs required to be incorporated into new development projects or source control BMPs required to be implemented by municipal maintenance staff). However, as municipal permits and programs move toward watershed‐based BMP implementation, there must be greater consideration for regional watershed BMPs in addition to the site‐by‐site BMPs that are typically considered. In particular, the regional watershed approach should include a process for identifying and evaluating the feasibility of implementing regional treatment BMPs for existing developed areas of a watershed. This paper discusses studies conducted to identify and prioritize potential structural retrofitting opportunities within the existing drainage infrastructure in developed areas of several Southern California watersheds. A Geographical Information System (GIS) model was used to initially identify possible retrofit locations that satisfied desired search criteria. Field reconnaissance of preliminary sites identified by the GIS model was then conducted to refine site information and focus on technical feasibility by considering site‐specific factors that might preclude a successful retrofit project. A list of potential retrofit BMPs was developed based on technical feasibility, life cycle cost and constituents of concern in the receiving waters. Conceptual BMP designs and cost estimates were prepared for the top ranked sites. A framework was developed to define an optimal range of watershed area for retrofit based on previous studies and considering construction economies of scale and expected benefits.

Select this Article		Initial Operation of the Udall Natural Area Regional Stormwater Quality Best Management Practice Jeremiah W. Knuth, Kevin P. McBride, and Larry A. Roesner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)190 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The field of urban stormwater management has lead to an interest in urban stormwater runoff quality and practices to control stormwater runoff concentrations. Best Management Practices (BMPs) have been developed to improve the quality of stormwater runoff before it enters natural water bodies. Investigation of the stormwater quality enhancement characteristics of the newly constructed Udall Natural Area extended detention‐constructed wetland BMP in Fort Collins, Colorado was conducted in an effort to understand start‐up operation of BMPs. Overall, the Udall Natural Area appears to be significantly reducing constituent concentrations of total suspended solids, total nitrogen, total phosphorous, total copper, and total cadmium within urban storm runoff. Escherichia coli was also monitored with no significant change in concentration observed within urban storm runoff. This study also showed no statistical reduction in constituent concentrations during base‐flow but rather suggested the possible increase of TSS and TP concentrations.

Select this Article		Instream Steroid Hormone Levels in a CAFO‐Impacted Watershed and Biological Removal Strategies John H. Easton, Ph.D., M.ASCE, Adrian R. Dongell, and Eva Oberdörster, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)191 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Endocrine disrupting compounds (EDCs) are chemicals that interfere with normal hormone function, either via synthetic chemicals that act or block normal hormonal activity or through exposure to high doses of natural hormones, such as in this study. EDCs are important because of increasing evidence linking exposure to reproductive and other health effects in humans and wildlife. Two potential sources of EDCs in the aquatic environment are confined animal feeding operations (CAFOs) and wastewater treatment plant (WWTP) discharges. The North Bosque Watershed in North‐Central Texas was studied to characterize steroid hormone levels and their relationship to land‐use. The North Bosque River watershed is impacted by CAFOs, specifically dairies, and urban contributions of WWTP discharges and stormwater runoff. Water was sampled monthly for steroid hormones including 17β‐estradiol (E2), Progesterone (P), and Testosterone (T). The linear regression correlation coefficients (R²) for dairy land use verses geometric mean hormone levels generally ranged from 0.55 to 0.77. Incorporation of additional land‐use variables increased the R² values up to 0.97. In addition, this study examined the biological treatability of these compounds using bench‐scale conventional suspended growth methodologies. Decreasing the Food‐to‐microbe ratio (F/M), ranging from 0.5 to 0.05 in this study, did improve hormone removal from 60–70% to 80–90% or better depending upon the target hormone.

Select this Article		The Integrated Unit Process Design Approach for Urban Water Quality Design M. M. Quigley, E. W. Strecker, M. Leisenring, W. C. Huber, J. Heaney, N. Weinstein, J. Sansalone, and D. Bodine ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)192 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Research being conducted by the authors under the National Cooperative Highway Research Program project “Evaluation of Best Management Practices for Highway Runoff Control” and the Water Environment Research Foundation project “Critical Assessment of Stormwater Treatment and Control Selection Issues” seeks to advance the state‐of‐the‐practice of stormwater design through the application of basic scientifically and technically sound engineering principals using a fundamental unit process design methodology. The research findings are being incorporated into guidance manuals aimed at both the design of highway runoff controls (including low impact designs) and, in the case’of the WERF guidance documents, stormwater treatment approaches. The intent of these manuals is to provide a means for better applying research on the relationship between design and performance specifically emphasizing the importance of matching water quality goals to fundamental unit processes that address those goals. To that end, the research discussed in this paper has integrated findings from a number of sources including work by the authors conducted as part of the International Stormwater Best Management Practices Database project as well as the above referenced projects. Significant effort has been made in the research to provide a framework where various sources of theoretical unit process performance information, laboratory and controlled studies, pilot studies, and full scale field monitoring efforts can be effectively used together in the design process. The paper pays particular attention to discussing the current state of the practice of these different sources of performance information and identifies research gaps. This paper introduces the overall philosophy of the integrated unit process design approach and challenges readers to fundamentally change the way they approach the design of urban stormwater control systems.

Select this Article		Integrating CSO Control into Regional Watershed Management Kirk Westphal, Barbara Blumeris, and Gary Mercer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)193 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Merrimack River is one of New England's major waterways, with five major urban centers located along a river whose watershed is densely forested. The headwaters originate in the White Mountains of New Hampshire, and the river discharges to the Atlantic Ocean in Massachusetts, north of Boston. The river and its tributaries supportnumerous beneficial uses, including water supply, recreation, aquatic habitat, and hydropower production. Pollutants such as bacteria, nutrients, and metals have impaired the water quality in portions of the watershed and hence the attainment of these beneficial uses is often restricted. Much of the abatement emphasis has focused on reducing the magnitude and frequency of combined sewer overflows (CSOs) from the five communities who have jointly sponsored this study in association with the U.S. Army Corps of Engineers: Manchester and Nashua in New Hampshire, and Lowell, Haverhill and the Greater Lawrence Sanitary District in Massachusetts. Until now, however, CSO abatement has been enforced at the local level without the benefits of a comprehensive regional policy for watershed management. Further, little scientific information has been available to quantitatively estimate and compare expected improvements in use attainability resulting from community CSO abatement projects and from other abatement and river restoration measures. This study is aimed at identifying relative contributions of point‐source and diffuse pollution, and linking improvements in use attainability with incremental abatement measures in each type of pollution source. Results from a comprehensive field monitoring program covering 80 miles of the river during dry and wet weather were used to calibrate simulation models of the river and its watershed. The models were then used to evaluate and compare the likely changes in use attainability associated with CSO abatement measures, wastewater treatment plant effluent reductions, stormwater runoff controls (urban and rural), and alternative dam operations. With an increased understanding of the sensitivity of the river to various types and levels of restorative measures, a regional watershed management program is being developed to provide scientific guidance for regulatory policy and the prioritization of municipal expenditures. This will help ensure that federally directed CSO expenditures in local pollution abatement will have measurable and commensurate riverine benefits at the regional level. It will also provide needed guidance concerning CSO expenditures that may yield comparatively little value with respect to use attainability.

Select this Article		Integrating On‐Site Water Management Practices: A Field Study in Prince George's County, Maryland Tham Saravanapavan, Leslie Shoemaker, Jenny Zhen, Allen Davis, Mike Clar, Sharon Meigs, and Mow‐Song Cheng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)194 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Decentralized and integrated stormwater management is becoming an efficient alternative to more conventional “centralized” structural Best Management Practices (BMPs). Decentralized management techniques, targeted to provide infiltration and minimize runoff closer to the sources, not only meet the stormwater control targets but also maintain the natural ecosystem integrity. On the other hand, conservation and reuse of rainwater and grey water are also emerging as environmentally sensitive “green” architectural techniques. Although both stormwater management and green architecture techniques have similarities, the disciplines have had limited interaction in practice. This study takes a holistic approach to site‐level water management by examining both in‐home and on‐site water management concurrently. An integrated assessment of site‐scale water balance provides a quantitative assessment of the benefits of a comprehensive approach that results in virtually no off‐site runoff. The analysis was performed on a demonstration site location in Bowie, Maryland, that is representative of single family home. A comprehensive site characterization and evaluation of water uses were performed. The site characterization includes a review of site information (e.g., soils, land use, topography, percolation test, and septic system history) and a field exploration including soil borings, infiltrometers, and chemical sampling of rooftop runoff. Water use profiles for the site potable water, grey water, wastewater, rooftop runoff, and stormwater were evaluated to understand the opportunities and alternatives for integrated stormwater management. A number of alternative scenarios were screened through technical, economical, and social feasibilities and potential alternatives were recommended. The study also evaluated and recommended innovative alternatives for designing the site landscaping for cleansing runoff and conserving water through stormwater recycling, and on‐site wastewater treatment (septic) system that integrates opportunities to efficiently utilize water at a site scale.

Select this Article		The Integration of Low Impact Development and Conservation Design: The New Castle County, Delaware, Experience Michael Clar, P.E. and John Gaad ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)195 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The Land Use Department of New Castle County, Delaware, under an ordinance referred to as Environment First has become one of the first local government agencies to promote the integrated use of Low Impact Development (LID) technology and the Conservation Design approach. This paper provides an overview of how these two methods can work together to result in ecologically sensitive land development scenarios.

Select this Article		International Perspective on BMPs/SUDS: UK—Sustainable Stormwater Management in The UK P. B. Spillett, MSc, PhD, FIFM, S. G. Evans, MSc, MIBiol, CBiol, MIFM, and K. Colquhoun, PhD, MIBiol, CBiol ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)196 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The philosophy behind sustainable drainage systems (SUDS) and the different techniques employed in the UK are briefly described. The role of a variety of organizations involved in the management of stormwater is explored along with the complex framework of administrative, legal and statutory issues which represent a barrier to further implementation of SUDS. A national initiative to find the way forward is outlined. The privatized status of the water industry in England and Wales and the role of the economic regulator have lead to an important research project resulting in the development of a whole life costing model for SUDS/BMPs.

Select this Article		Japanese Project Spirit 21: Development and Testing of CSO Treatment Technologies and Instrumentation Systems N. Horie, M. Kabata, and H. Sano ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)197 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The early sewer systems were built in Japan as combined sewer systems(CSS), which played an important role in urban development. In recent years, significant pollution of receiving waters by combined sewer overflows (CSOs) conveying large oil balls was reported and the Ministry of Land, Infrastructure and Transport (MLIT) addressed this issue by establishing a CSS Advisory Committee with a mandate to report on CSO control. This study was followed by publications of Guidelines and Explanation of CSO control by the Japan Sewage Works. To develop appropriate technologies, MLIT initiated a project called Sewage Project, Integrated and Revolutionary Technology for the 21^st Century, or SPIRIT 21. The project conducts research in the following areas of CSO treatment and instrumentation: (a) debris removal (screen), (b) high rate filtration, (c) coagulation and separation, (d) disinfection, and (e) measurement and control instrumentation. 24 technologies were proposed in all by the private industry and proceeded to field test in 13 cities. Up to Mar.2005 all technologies have been tested successfully and proposed for use in practical applications. For examples, two types of high rate filtration, ballasted clarification with microsand, and bromine disinfection. In two filtration plants, upflow filters employing special filter media and operated with or without coagulant addition, achieved suspended solids removals up to 70%, at surface load rates up to 1000 m/day. Ballasted clarification was another process successfully tested and approved for practical applications. Bromine disinfection was found feasible for use in CSO disinfection, with the main advantage of short reaction times. The project is operated in partnership of five groups: (a) MLIT — defined and promoted the project theme, (b) Academic institutions — provide technical advice for evaluation of R&D plans and results, and conduct basic research, (c) Municipalities — provide demonstration sites, (d) Private sector — propose/supply technologies, and fund and operate projects, and (e) JIWET coordinates and manages the project. MLIT started “Urgent Subsidy for CSS improvement” in 2002, that requires municipalities to submit “CSO urgent improvement plan” to MLIT by Mar.2005 Amended Ordinance of Sewerage Law stipulated structure of outlet facilities and effluent quality standard to be fulfilled within 10 years, with exception of some large cities within 20 years. The SPIRIT21 result indicate that this project succeeds in providing CSO treatment technologies to Japanese municipalities addressing CSO problems.

Select this Article		Laboratory Comparison of Oil Removal by Four Drain Inlet Inserts B. K. Currier, M.ASCE, J. R. Johnston, M.ASCE, and M. S. Werlinich ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)198 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Vehicular motor oil from leaking vehicles, illegal disposal, and accidental spills is often carried to receiving waters via stormwater flows. Storm drain inlet inserts have been developed to remove oil from stormwater. Unfortunately, knowledge of their effectiveness in removing oil and grease under common field conditions is lacking. In this study, oil capture and retention performance was examined for four drain inlet inserts — the DrainPac™, FloGard+Plus™, Hydro‐Cartridge™, and Ultra‐Urban™ inserts. To approximate the illegaldisposal or accidental spill scenario, a spike dose of 4 liters of used motor oil was applied to each insert. The inserts were subsequently flushed with oil‐free water to determine retention during runoff events. The percent of oil retained by the inserts after flushing ranged from 5 to 55 percent. To approximate the stormwater runoff scenario, used motor oil was continuously dosed at around 15 mg/L. Each insert received a cumulative volume of nearly 454,000 liters (120,000 gallons), which simulated an annual loading. The loading was broken up into 20 applications to simulate individual storms. Flow rates for individual events were either 57, 95, or 132 L/min (15, 25, and 35 gpm) to simulate different rainfall intensities. Paired composite samples of influent and effluent were collected for each insert test. While removal was consistent throughout the test for individual inserts, removal efficiencies among the inserts varied considerably, ranging from negligible to about 60 percent. When sediment was added to the synthetic runoff, inserts that provided settling showed better oil removal than those without settling. Even so, the best removal efficiency observed when sediment was present was only about 40%, though this result is based on only two experimental runs.

Select this Article		LID Solutions for an Industrial Site Avinash S. Patwardhan, Ph.D., P.H., Joel Haden, Thomas Jobes, and Patrick Graham ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)199 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Industrial site development can result in substantial impacts to water quality and quantity. While permitting requirements may reduce impacts, they are limited in addressing long‐term cumulative and operational impacts from the changes in land uses and cover. Many of these developments occur within watersheds containing impaired waters across the Southeast. Approximately 25,000 acres of industrial sites are developed or expanded each year in the 201‐county Tennessee Valley Authority (TVA) power service region. TVA's mission is to promote sustainable economic development, energy production, and environmental stewardship. This paper describes methodologies used to perform stormwater evaluations at a TVA facility, including hydrologic and water quality modeling. The hydrologic and water quality modeling was accomplished with the use of the LIFE™ model, developed by CH2M HILL to simulate Low Impact Development (LID). The LIFE™ model is a continuous‐simulation, physically based model that accounts for processes that occur in bioretention facilities, bioswales, green roofs, and infiltration devices, as well as the effects of site fingerprinting and soil compaction. Tennessee Valley Authority is in the process of installing several demonstration projects using LID designs.

Select this Article		Long‐Term Modeling of Structural BMPs Using STORM within a Spreadsheet Mitchell C. Heineman, P.E. DEE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)200 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Storage‐Treatment‐Overflow‐Runoff Model, STORM, was developed for the US Army Corps of Engineers in the 1970s. The model applies the rational method at an hourly timestep to compute stormwater runoff to a storage‐treatment control structure. A fixed treatment rate is used to compute outflow, utilization of storage, and overflow. The model provides a simple but useful paradigm for diverse applications. One of its original uses was estimating combined sewer overflow for entire cities. Today one of its most important uses is for sizing stormwater detention basins (a.k.a. structural BMPs). The use of STORM for this purpose is described in the California Stormwater Best Management Practice Handbooks. STORM's core algorithms are incorporated into the NetSTORM program, which also includes functionality for linking multiple control structures within a STORM framework, and processing and statistical analysis of precipitation data. The STORM component of NetSTORM is now incorporated into a dynamic‐link library file (DLL) which can be referenced as a function in a spreadsheet program. This allows direct calling of STORM from a single cell in a spreadsheet. The present project differs from work previously described where the STORM algorithms were coded in Visual Basic for Applications (VBA) and interpreted by the spreadsheet program. Because the STORM DLL references compiled Fortran code, it can analyze a 50‐year precipitation record in less than one‐quarter second on a typical PC, making it practical for a variety of applications. The STORM DLL can be flexibly deployed within a spreadsheet for applications such as multi‐objective optimization and development of user‐customized tables of capture efficiency, overflow volume, and overflow frequency with minimal constraint on the length of the precipitation record that can be reasonably analyzed. The STORM DLL has been used in several studies. An example spreadsheet has been developed demonstrating its use for optimizing cost of a stormwater treatment facility based on unit costs for treatment rate and storage tank size and constraints on overflow frequency. A second example demonstrates its use for sizing a dry detention pond where specified annual capture efficiency and overflow frequency is sought with constraints on drawdown time and basin volume. The STORM DLL is available free of charge to the public.

Select this Article		Long‐Term Performance Modeling of Vegetative/Infiltration BMPs for Highways Chelisa A. Pack, James P. Heaney, and Joong Gwang Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)201 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Nonpoint source pollution from highway stormwater runoff is a growing water quality concern and highway drainage systems are being re‐evaluated for how well they can passively treat stormwater runoff. Vegetated buffer strips along fill slopes in the highway cross section can mitigate pollutants in stormwater runoff by infiltration and sedimentation. The existing models for vegetated buffer strips range from simple percent removal estimates to models with very complex routing and sediment transport algorithms for a single design storm. Instead of a design storm approach, the model proposed in this paper uses long‐term precipitation data and a simple modeling framework to estimate concentration reduction and volume reduction through a vegetated buffer strip on an average annual basis. Data from field studies are used to support the spreadsheet‐based model framework. In order to function effectively for passive stormwater treatment, buffer strips need an adequate vegetative cover. The model results clearly show the benefits of open drainage (vegetated swales) over closed drainage (curb and gutter systems).

Select this Article		Low Impact Development (LID) Retrofit Strategies for CSO Controls Neil Weinstein, P.E., R.L.A., AICP and Philip Jones, EIT ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)202 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This project is a grant from the National Fish and Wildlife Foundation to demonstrate the potential for community‐based planning for the development of CSO controls in conjunction with large‐scale community redevelopment projects. One of the challenges concerning the use of LID in urban areas is that citizens' groups and property owners are often more concerned with the appearance of the neighborhood and economic development than with spending resources on water quality retrofits. Water quality planners must therefore balance the community's goals with the expectations of developers, land use planners, and stakeholders concerning the integration of BMPs into the infrastructure. The Anacostia section of Washington, D.C. is the focus of a large‐scale redevelopment effort. The project focuses on how LID controls can be integrated into the master plan for Anacostia, and how customized strategies and techniques can be developed to address the master plan vision of the project. The effectiveness of different approaches was modeled to determine the optimal combination(s) of LID landscape and building practices that can be incorporated into the plans in order to meet regulatory and water quality objectives. Different scenarios were explored, including water conservation and harvesting, green roofs, and other structural and non‐structural controls. The Prince George's County BMP Evaluation Module was used to demonstrate the effectiveness of the systems. Another focus of the project is on how to construct and maintain these systems to insure their long‐term success. This includes private and public partnerships, overlay zones, financial incentives, and business improvement districts to maintain the long‐term viability of the facilities.

Select this Article		A Low‐Impact Development Approach for a Coastal Resort in Southern California Eric W. Strecker, P.E. and E. Todd Hesse ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)203 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. A new 115‐acre resort has been proposed at the location of the Pelican Hills Golf Club, in Newport Beach, CA. The proposed resort project drains to the Pacific Ocean through Crystal Cove State park, a California State designated Area of Special Biological Significance (ASBS). One of the environmental goal for the project were to have no effect on the downstream water bodies, including stream channels as well as the ASBS. To meet this goal, objectives included no increase in runoff, infiltration, or pollution from the project so that the downstream water bodies will not be impacted. To analyze the effects of the proposed system, a long‐term simulation mode using over 40 years of local hourly rainfall data was developed. The EPA's Stormwater Management Model (SWMM) was used to develop and size the system components in order to meet the project goals. Pre‐development runoff, infiltration, and pollutant loads were evaluated with the use of the model to then allow for evaluation of potential project alternatives. “Traditional” low‐impact development approaches were first investigated. It was determined that to meet the strict goals of no change in runoff conditions, that about 35 percent of the project area would need to be employed in biorention areas, bioswales, etc. This was not an acceptable project design. An innovative water quality and quantity management system thatincludes the use of cisterns to capture and “recycle” runoff from up to 1.2 inches of rainfall was then developed. The SWMM model was used to size the system. The captured runoff will be used to irrigate the two adjacent golf courses (greens), resulting in water conservation in addition to stream and ocean waters protection. The overall system also includes bioswales, catch basin filters, water quality basins, and numerous source and site planning controls. The analyses demonstrate the value of employing long‐term simulations to more accurately assess the effectiveness and designs of low impact development approaches (hydrological source controls). The analysis determined that in cases where a large portion of a project area is not available, that more intense LID approaches such as Cisterns may need to be employed. The key that made cisterns a viable approach was the fact that golf course greens require irrigation in a relatively short time after the end of rainfall. The overall project points out that in the arid southwest, where storms arrive typically back‐to‐back, more intense approaches may be needed if the runoff and infiltration must be maintained at pre‐development levels.

Select this Article		Measuring the Success of a CSO Control Program Elizabeth F. Locke, Eric D. Loucks, and Steven R. Heinz ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)204 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Milwaukee Metropolitan Sewerage District (MMSD) is implementing a comprehensive program to further reduce the frequency and volume of collection system overflows during wet weather conditions. Under this program, MMSD strategies have included construction of additional flow storage and conveyance facilities, increased wet weather treatment capacity and upgraded the real‐time control (RTC) in the operation of gates and diversions in the collection system. The most effective way to measure the impact of all of these improvements in the system is to use simulation models. The MMSD has formed a comprehensive modeling team charged with the responsibility of building and maintaining hydrologic and hydraulic models of the collection system.

Select this Article		Methodology for Design and Optimization of Highway Detention Basins Derek N. Rapp, James P. Heaney, and Joong G. Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)205 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Detention basins store increased runoff resulting from impervious highway surfaces, treat the runoff through sedimentation and then slowly release it. Many methods exist for designing detention basins including simple design storm approaches and more complex simulation models. This paper describes a continuous simulation/optimization model that provides accurate design results but remains relatively simple to operate. The model is spreadsheet‐based so virtually all engineers can understand it, and it is directly linked with Excel's Solver (and Premium Solver add‐in) to determine an optimal, least cost, design. A first order reaction equation including a background concentration is used to represent the settling rate of suspended solids in the model. Conventional design methods are compared with optimized least cost designs and the results indicate that the model is relatively accurate at determining high performance, low cost designs. The comparisons showed that significant cost savings could be achieved by selecting the appropriate storage volume and release rate. The derived cost‐performance relationship showed that any increased performance above 85% results in relatively high marginal costs. The significance of this study is the development of a relatively simple model that caters to a wide range of users and provides a direct link to optimization algorithms. The model has advantages over conventional design methods by including multiple storm events, antecedent conditions and cost‐effective designs. Yet, the model remains much simpler to operate than more complex simulation models.

Select this Article		A Micro & Macro‐Model Approach to Evaluating Greenroofs as a CSO Control in New York City Gary M. Ostroff, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)206 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In principle, the efficacy of greenroofs as a Best Management Practice (BMP) is very clear, but their usefulness in a large city such as New York is much harder to demonstrate. HydroQual, working in conjunction with Earth Pledge and the Gaia Institute, is developing a modeling analysis approach that treats greenroofs as fully developed elements of a mechanistic model of the city sewer system so that a genuine assessment of their impact, in the near and the long‐term, can be made.

Select this Article		Modeling a Bioinfiltration Basin William C. Heasom, P.E., MSCE, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)207 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An existing traffic island at Villanova University was retrofitted to become a bio‐infiltration BMP serving a drainage area of 1.3 acres, one‐half of which is impervious parking and roadway area. It is part of the Villanova Urban Stormwater Partnership Best Management Demonstration Park. Designed to infiltrate 70 to 80% of the yearly rainfall, the facility mitigates the delivery of nonpoint source pollution and streambank‐eroding surges to Darby Creek downstream. Construction was completed in early 2002 and instruments were installed to record rainfall and pool level at 5 minute intervals. A v‐notch weir was added to measure outflow volumes and a model for the system was developed in HEC‐HMS. The model uses Green‐Ampt and kinematic wave methods to predict runoff and infiltration volumes and outflow hydrograph shapes. With three years of data collection, observation, and model calibration, a clearer picture is emerging of the physical processes at work within the basin and its watershed. This understanding will be useful in the design of similar systems in the urban landscape.

Select this Article		Nutrient‐Based Ecological Considerations for Stormwater Management Basins: Ponds and Wetlands Chris Nietch, Mike Borst, and Scott Struck ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)208 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The effects of stormwater pond and wetland best management practice (BMP) designs on phosphorus and nitrogen concentrations in effluent was considered using extant data and experimental observations from pond and wetland mesocosms. Relative difference between BMP types were evaluated with respect to several nutrient forms and in relation to untreated stormwater runoff. The mesocosms allowed for direct measurement of time integrated nutrient influent and effluent mass loading. Based on an extended effluent monitoring protocol, these BMP treatments tended to have little effect on total nutrient mass differences between influent and effluent loads. However, significant nitrate removal from BMP influent was observed and appeared to be controlled by influent concentration. The observed nutrient concentrations in BMP effluent could be explained by the reservoir of exchangeable nutrient in basin pore water and the nature of primary production within a BMP type; phytoplankton vs. macrophyte dominance. For example, wetlands tended toward lower effluent phosphorus loading than ponds, which coincided with lower pore water soluble phosphorus pools that were driven by sequestration in macrophyte tissues. Ponds showed a greater potential for effluent nutrient loading than wetlands, which was partly a function of the lower runoff volume to permanent pool volume ratios (Vr:Vb) in pond design. Overall the data suggest little potential for sustained total nutrient removal in these basins at influent loads typical of urban stormwater runoff. Due to the nature of nutrient cycling in mature pond and wetland systems, we suggest a refocusing toward temporally‐extended BMP effluent monitoring for better estimation of their effects on nutrient load quantity and quality for TMDLs.

Select this Article		Occurrence and Relative Abundance of Mosquitoes in Stormwater Retention Facilities in North Carolina Charles S. Apperson, William F. Hunt, III, Shawn Kennedy, Bruce A. Harrison, and William G. Lord ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)209 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Throughout the 2004 mosquito season, 52 stormwater retention facilities were sampled to characterize the seasonal occurrence and relative abundance of mosquito species in relation to the structural complexity and biological diversity of the facilities. The three different types of facilities included standard wet ponds (n = 20), innovative ponds (n = 14), and wetland ponds (n = 18). All retention structures were sampled at the beginning, middle and end of the mosquito season so that seasonal changes in mosquito production could be characterized. Overall samplings, mosquitoes were collected from 34% of the retention structures. Fourteen species representing 7 genera were collected, but only 5 species (Culex erraticus, Cx. territans, Anopheles quadrimaculatus, An. punctipennis and Uranotaenia sapphirina) were commonly collected in all three types of stormwater management facilities. In general, the seasonal prevalence and relative abundance of mosquito species did not vary among three types of retention structures. A significant association (P < 0.01) between the presence of mosquito larvae or pupae and the absence of mosquitofish was found for innovative and wetland stormwater retention facilities but not for standard retention facilities (P > 0.05).

Select this Article		Optimal Sanitary Sewer Overflow Management Strategies Considering Reliability, Scheduling, and Permitting Restrictions Len Wright, Ph.D., P.E., Shawn Dent, P.E., and Rolf Ohlemuetz, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)210 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The long‐term management of wet‐weather SSOs may involve some combination of increased capacity of conveyance, storage, and treatment systems along with flow reduction through collection system rehabilitation. The amount of flow reduction attained by rehabilitation has been difficult to predict during project planning phases because many unknown variables affect rehabilitation performance. Post‐auditing of rehabilitation efforts has shown widely varying results. Rehabilitation as an SSO control does show promise as part of a long‐term management plan, especially when the long‐term rehabilitation strategies may be revised based on interim, mid‐project performance data. However this form of adaptive management plan may not be amenable to short‐term performance goals that must be met to avoid permit violations and subsequent enforcement actions. The trade‐offs between short‐term permit enforcement, reliability of the management plan and long‐term level‐of‐service performance goals must be balanced in a cost‐effective manner. Centralized, downstream storage and treatment controls tend to be more reliable solutions for meeting SSO goals and permit requirements in the short term because they are more controlled and the effect of these controls on the wet‐weather response hydrograph is well understood. Rehabilitation is a decentralized solution and it is difficult to predict performance for SSO management through RDII reduction. However, when the problem is approached from a long‐term perspective, that of an infrastructure maintenance problem, rehabilitation becomes more attractive. It is likely that persistent maintenance efforts that are fine‐tuned by adaptive management strategies based on measured performance data will pay off in a cost effective manner over the life cycle of the infrastructure. This is because pipes that are deteriorated and leak RDII into the system will eventually fail structurally and will require repair or replacement to maintain service. This expense will occur regardless of the downstream SSO controls that are installed. The time frame for meeting performance goals becomes a critical factor in SSO management decision‐making. In the long‐term, it may be approached as an asset management problem, minimizing the life‐cycle costs while meeting a level of service that prevents SSOs to some defined frequency. In the short term the variability.

Select this Article		Performance Monitoring of a Stormwater Wetland Best Management Practice Matthew Rea and Robert G. Traver ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)211 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This paper presents the results from monitoring water quality inflows and outflows from a stormwater wetland best management practice. Multiple samples were taken during each storm event and were coupled with flow monitoring to develop pollutographs. During storm events, the wetland showed a removal efficiency of nearly 70 percent for total suspended solids, while dissolved components such as reactive phosphorus and chlorides showed little or no overall removal. A significant “first flush” can be seen during storm events, with large peak inflow concentrations. These high concentrations are reduced greatly by flow through the wetland. A parallel base flow study prelimarily shows approximately 60 percent removal of reactive and total phosphorus, and nearly 80 percent removal of total nitrogen. Chloride passed directly through the system for both storm events and baseflow. Overall, the levels of all nutrients and pollutants in both influent and effluent are well below recommended water quality standards.

Select this Article		Performance of a Stormwater Wet Pond with Side Bank Filters Betty Rushton, Ph.D and Kara Teague ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)212 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The stormwater pond is located at the Florida Aquarium in Tampa and is designed to treat 4.2 hectares (10.4 acres) of street and urban runoff. It is an effluent filtration system that incorporates artificial side bank filters packed in aggregate to slowly release storm runoff after rain events. The pond was monitored throughout a two year period. Year 1 includes data from November 2000 through August 2001. During this drought year 16 rain events were monitored. Monitoring was discontinued for eight months during the construction of a cruise ship terminal. Year 2 includes data from June 2002 through October 2003. The longer time period and above average rainfall resulted in water quality samples for 38 rain events. The under drains were also sampled for both flow and water quality. Load efficiency calculations were made on a monthly basis, since the rain, inflow and bypass outflow occurred only during rain events, but the under drains flowed continuously. The results indicate that the stormwater system is not effective for removing dissolved nutrients and may be dewatering the ground water. Ten percent more water left the site compared to storm event flows into the pond. Efficiency calculations on a yearly basis showed that dissolved nutrient loads increased considerably. For example, an increase of 84 percent was measured for ammonia and 64 percent for orthophosphorous when the entire system was evaluated. Other nutrient species were only moderately reduced (14 to 17 percent). In contrast, total suspended solids and most metal loads were reduced by a significant amount (79 to 89 percent). Only a few samples at the bypass outflow did not meet the State of Florida Class III water quality standards in Year one (12% for lead), while a much greater number failed to meet standards in year two (27% for copper, 23% for lead and 4% for zinc). Although higher concentrations were measured in year two, the greater number of non‐compliant samples was also caused by the greater amount of rain, which made the pond water much softer and the standard more stringent. A more complete report is available from the author by request.

Select this Article		The Performance of Conventional Silt Fence Technology When Not Placed on the Contour E. Stevens, S. Yeri, B. Barfield, A. Jeyarathan, J. Hayes, and A. Selvakumar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)213 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Studies were conducted of the effectiveness of silt fence installed on and off the contour at the Silt Fence Test Facilty (SFTF) at the USDA Hydraulics Laboratory laboratory in Stillwater, OK. Sediment laden flow from a source area was generated by a rainfall simulator using three different soil textures. This flow was directed to conventional silt fence erected on three different cross contour angles. Through use of special sampling apparatus, flow from the source area was sampled for flow rate, sediment concentration, and eroded size distribution. The same measurements were also made of flow along the toe of the fence and flow through the fence. Using these results, a model was developed of erosion of the toe trench to determine the point of failure by undercutting. The accuracy of the method was evaluated using the data collected.

Select this Article		Phosphorus Trade Credits for Non‐Point Source Projects T. Andrew Earles, Ph.D., P.E., Wayne F. Lorenz, P.E., and Wilbur L. Koger ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)214 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Cherry Creek Reservoir in the Denver Metropolitan area is subject to the Cherry Creek Reservoir Control Regulation (Control Regulation), which establishes a total maximum annual load (TMAL) for the reservoir of 14,270 pounds of phosphorus. The load is distributed among phosphorus sources including background, non‐point and regulated stormwater, municipal and industrial wastewater facilities, individual sewage disposal systems and industrial sources. As a part of the control regulation, the Cherry Creek Basin Water Quality Authority (CCBWQA) is authorized to implement and maintain a Trading Program that allows phosphorus trading and the sale of phosphorus pounds in the Cherry Creek Watershed. The Trading Program allows dischargers seeking new or increased phosphorus waste load allocations to obtain additional pounds of phosphorus by constructing non‐point source projects to remove phosphorus. These non‐point source projects must go beyond minimum CCBWQA phosphorus removal requirements for best management practices (BMPs). The amount of phosphorus removed by a non‐point source project that can be traded to a point source discharge is subject to a Trade Ratio, which is determined from factors including: 1) Dissolved/particulate phosphorus characteristics of phosphorus removed by the non‐point source project versus point source discharge characteristics. 2) Phosphorus fate and transport including relative locations of point source discharge and non‐point source project relative to the reservoir, travel time, contact time and potential for transformation, and other factors 3) Providing a net benefit to the reservoir in terms of the TMAL. The Trade Ratio is designed so that phosphorus trades result in a net decrease in the annual load to the reservoir by limiting increases in point source discharges from trades to a fraction of the load reduction provided by the non‐point source projects. Actual Trade Credits awarded are based on monitoring data collected at non‐point source project sites. This paper provides an overview of the CCBWQA Trading Program Guidelines and describes the Arapahoe County Water and Wastewater Authority (ACWWA) Lonetree Creek Pond L‐3 Trade Credit Project. This project involves the retrofit of an existing BMP to create a Phosphorus Reduction Facility (PRF) eligible for Trade Credits. The Pond L‐3 project is the first project for which Trade Credits have been approved under the CCBWQA guidelines and serves as an example for future projects. This paper provides an overview of the project as well as the process required to obtain approval and determine Trade Credits.

Select this Article		Pitfalls of “Over‐Calibrating” a Model of Infiltration and Inflow Ademir Paceli Barbassa, Ph.D. and Len Wright, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)215 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Measurements of rainfall and sanitary sewer flow were made for 2 wet seasons in Vallejo CA., for 1998–1999 and 2000–2001. The Rainfall Derived Inflow and Infiltration (RDII) response to wet weather was estimated from these data. Two Unit Hydrograph (UH) models of the hydrologic response of the sanitary sewer to rainfall were developed from the measured RDII response. One model was based on parameters estimated with Ordinary Least Squares (OLS) multiple regression and the other by a constrained Linear Program (LP). OLS is an unconstrained estimation method, therefore the UH ordinates may take on negative values. However, negative UH ordinates do not make physical sense for most sanitary sewer systems inundated by high RDII rates. UH ordinates estimated by the Linear Program were constrained to non‐negative real numbers. Negative RDII response (sewer ex‐filtration) is atypical for most RDII‐dominated areas and is therefore not considered. RDII response is typified by a long, slow, positive response to rainfall. The UH models for this study were based on 500 hourly time steps, and therefore 500 dependent variables, to capture the response to rainfall. This response necessitates a long UH lag period to capture the response time. For the calibration phase, data from one wet season were used, and verification of the calibrated model was done with data from the second wet season. Results indicated that the UH estimated by OLS multiple linear‐regression provided lower calibration error than the UH developed by the constrained LP. However, upon completion of the verification phase, the LP demonstrated a lower error rate than the OLS UH. It is believed the unconstrained OLS model “over‐calibrated”, or fit too close, to the calibration data by allowing negative UH ordinates. The LP, which was constrained to only non‐negative ordinates, provided a more realistic representation of the calibration data. It is possible that a highly calibrated hydrologic model produces more error in general than a less‐calibrated model (i.e. one with higher calibration error). Engineers who may use the simple UH linear response model to simulate lengthy RDII responses should be aware that while OLS multiple linear regression is easily performed in a spreadsheet or a common statistical program, limitations of the method may increase the error in estimates of response during un‐calibrated periods. The LP may also be easily set‐up in a spreadsheet or a statistical software package and the analysis may be constrained by any number of realistic bounds, such as non‐negative ordinates, peak rate capacity limitations of the physical system, or any other site‐specific limitation.

Select this Article		Pollutant Associations with Particulates in Stormwater R. Morquecho, R. Pitt, and S. E. Clark ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)216 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Many studies have identified metals in urban runoff as a major contributor to the degradation of urban streams and rivers. Metals of most concern are copper, cadmium, chromium, lead, mercury, and zinc. Metals in urban runoff can occur as dissolved, colloidal and particulate‐bound species. Therefore, it is important to measure all forms of heavy metals, especially the particulate and filterable fractions, when determining their fate and effects. The objectives of these tests were to determine the associations of heavy metals (along with some major constituents and nutrients) with different‐sized particulates using cascade sieves and filters. Sequential extraction experiments were also conducted to examine the treatability and other characteristics of the filterable (<0.45μm) portion of the heavy metals using Chelex‐100 resin, UV‐light exposure, and Anodic Stripping Voltammetry (ASV). Preliminary results show that total phosphorus and chemical oxygen demand are associated with the particulates and in general decrease with a decrease in particle size. Obviously, concentrations should all decrease with filtration. However, there were periodic jumps in concentrations for some conditions, reflecting variability in the analytical method and the sample handling. Results using ASV show the metals of concern (Zn, Cd, Pb and Cu) all present in the dissolved (<0.45μm) fraction of the stormwater samples with Zn normally present in the highest concentration. Exposure of the samples to UV light increases the concentration of most of the metals, indicating a dissociation of metals from organic complexes or colloids. Sampling and analyses is continuing through April 2005. Sample fractions will be analyzed for Zn, Cd, Pb and Cu using ICP‐MS, and the sequential extraction procedures and toxicity tests will be completed.

Select this Article		Pollutant Removal Capacity of Stormwater Catchbasin Inserts R. Remley, R. A. Morgan, F. G. Edwards, K. R. Brye, and Steven J. Burian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)217 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Transportation facilities such as parking lots or maintenance yards often do not have provisions to treat stormwater prior to discharge. Catchbasin inserts can provide a retrofit alternative as a method to meet the new National Pollution Discharge Elimination System Phase II stormwater pollution prevention regulations. Six inserts manufactured by five manufacturers were evaluated for removal of suspended solids, petroleum hydrocarbons, and zinc using a pilot scale catchbasin and a simulated stormwater. At a flowrate of 0.011 to 0.013 m³/s (180 to 200 gpm) and pollutant concentrations of 225 to 260 mg/L suspended solids and 30 to 42 mg/L total petroleum hydrocarbon, the inserts were capable of removing 11 to 42 percent of suspended solids and 0 to 40 percent of total petroleum hydrocarbons.

Select this Article		Real Time Control of Sewers: Overview and State of the Art Z. C. Vitasovic and L. Yde ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)218 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Real time control (RTC) is increasingly gaining acceptance in the mainstream practice of managing wastewater conveyance networks. However, although the concepts, and even some applications, have been around for a number of years, RTC is still not common in wastewater conveyance networks.

Select this Article		Residential Manmade Lake System Design for Storm Water Treatment Bruce M. Phillips ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)219 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Aquascape facilities have traditionally been considered ornamental and landscape features primarily serving aesthetic purposes in golf courses, parks and residential developments. However, aquascapes can be applied with innovative design elements to function as primary infrastructure facilities in urban developments, replacing typical stormwater facilities and adding value to the community. These specialized types of aquascape systems integrate a living ecosystem into an urban environment, which maintains water quality through natural biological processes. Planned aquascape features, particularly in semi‐arid areas, offer a combination of many unique advantages for storm water management as well as other benefits that are not available in conventional engineered systems, including: (1) continuous year‐round natural treatment process, (2) storm water conveyance and storage, (3) exceptional water quality, (4) flood protection, (5) combined landuse elements, (6) significantly reduced infrastructure costs, (7) dry weather flow treatment, (8) landscape and aesthetic treatment with natural water system, (9) increased surrounding land values, (10) natural ecosystem benefits, (11) recreational design feature, and (11) urban design element for communities. The necessity for storm water pollution control has received increased public attention, especially with the escalating environmental regulations focusing on non‐point source pollution and protection of receiving waters. As of March 2003, the Phase 2 portion of the NPDES (National Pollutant Discharge Elimination System) storm water regulations require developers and municipalities alike to more seriously address storm water quality through the implementation standard structural control measures or Best Management Practices (BMPs). These methods generally have limited pollutant removal effectiveness, perform single functions, require considerable land, maintenance issues, construction costs, difficult integrating with the land plan, and are typically unsightly having limited aesthetic appeal to the community. Integrating large scale specialty aquascape systems through constructed lakes, ponds, small creeks, or other water features can replace traditional underground drainage infrastructure and provide highly effective storm water treatment resulting in water quality not available through other conventional methods.

Select this Article		The Role of Stormwater Research in BMP Design — Pathogens and Regulatory Demands Scott D. Struck, Michael Borst, and Ariamalar Selvakumar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)220 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Environmental Protection Agency strives to protect human health, ensure the safety of drinking and recreational waters, support economic and recreational activities, and provide healthy habitat for fish, plants, and wildlife. To accomplish these objectives, the Agency emphasizes restoring and maintaining our oceans, watersheds, and their aquatic ecosystems. Urbanization results in more impervious areas that cause larger quantities of stormwater runoff. This runoff can contribute significant amounts of pollutants (e.g., litter, oils, microorganisms, sediments, nutrients, organic matter, and heavy metals) to receiving waters. To improve water quality in urban and suburban areas, watershed managers often incorporate structural best management practices (BMPs) to remove or reduce pollutants contained in stormwater runoff. In this project, constructed wetlands and retention ponds were evaluated for reducing microbial concentrations from urban stormwater runoff. Several studies have looked at the capabilities of these BMPs to reduce pollutant concentrations and loadings. Few studies, however, have focused on the internal mechanisms occurring in these BMPs and fewer yet on using these BMPs for treating microbial pollutants. Preliminary results indicate both types of BMPs can lower microbial concentrations from urban stormwater runoff. Retention ponds had greater removal rates for enterococci and E. coli in June and September sampling events. However, further reduction may be limited by irreducible concentrations contained in the urban stormwater runoff and/or the sediments entering into or existing within the BMPs. The disparity in results may be due to light, temperature, and predation differences between the two treatments.

Select this Article		Soil Structure Effects Associated with Urbanization and the Benefits of Soil Amendments R. E. Pitt, S. Chen, S. Clark, and J. Lantrip ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)221 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The effects of urbanization on soil structure can be extensive. Infiltration of rain water through soils can be greatly reduced, plus the benefits of infiltration and biofiltration devices can be jeopardized. This paper is a compilation of results from several recent and on‐going research projects that have examined some of these problems, plus possible solutions. Basic infiltration measurements in disturbed urban soils were conducted during EPA‐sponsored research. That project also examined hydraulic and water quality benefits of amending these soils with organic composts. Prior EPA‐funded research examined the potential of groundwater contamination by infiltrating stormwater. In addition to the information obtained during these research projects, numerous student projects have also been conduced to examine other aspects of urban soils, especially more detailed tests examining soil density and infiltration during lab‐scale tests, and methods and techniques to recover infiltration capacity of urban soils. This paper is a summary of this information and it is hoped that it will prove useful to both stormwater practice designers and to modelers.

Select this Article		Still Herding Cats: An Institutional Framework for Stormwater Management Michael A. Ports, P.E., D. WRE, F.ASCE and Tom Jacobs ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)222 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Now more than 1,800,000 people live in the Greater Kansas City Metropolitan Area. The area straddles the border between the states of Kansas and Missouri. Moreover, the area consumes part or all of eight counties and all or part of one hundred sixteen incorporated municipalities. By far the largest municipality is Kansas City, Missouri (KCMO) with a population exceeding 450,000. Spread out over 320 square miles, KCMO now includes parts of four counties and continues to grow in both population and area as new territory is annexed. Roughly half of KCMO lies north of the Missouri River and half south. The area south of the river generally is older and much of it is served by combined sewers. KCMO extends from the old downtown and industrial areas along the river southward some 18 miles characterized by newer and newer developments. The Northland generally is much younger in character and continues to undergo rapid urbanization. Despite the many hurdles, the community as a whole has made substantial progress. Numerous independent, yet related, initiatives have yielded positive results. Foremost among different initiatives is the development of regional design standards for stormwater management and erosion and sediment control. Also significant is the Jackson County Stormwater Committee, which provides a forum for the municipalities within the county to discuss issues of mutual interest. While successful within the county, the committee suffers from the same cross boundary problems. Within KCMO three significant efforts are underway. First, the Stormwater Coordinating Committee has been formed with formal representatives from all KCMO agencies involved in stormwater. It provides a needed and effective forum for coordination and communication. Second, the KC‐One project has been launched with much fanfare. Its mission is the development of a comprehensive city‐wide stormwater management program. And third, the KCMO Water Services Department invited senior representatives from Johnson County Wastewater and the Wyandotte County Department of Public Works to discuss issues of mutual concern. The group agreed that the forum provided was valuable and, therefore, should continue to meet. Interestingly, it further was decided to expand the scope of the forum to include all aspects of drinking water, wastewater, and stormwater as well as invite more stakeholders throughout the region.

Select this Article		Storm Water Evaluation for TMDLs and Implementation in Urban Northeastern Watersheds Tham Saravanapavan, Mark Voorhees, and Andrew Parker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)223 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Habitat/aquatic impairments in an urban environment are often associated with multiple stressors, including known and unknown pollutants, storm water runoff, hydrologic modifications, riparian corridor encroachment, and channel alteration. These stressors may be acting either individually or cumulatively. In the absence of comprehensive physical, chemical, and biological data it is often difficult to determine each stressor's role and significance in contributing to the impairment. As a result, developing TMDLs and implementing improvements to address these impairments presents unique and complex challenges. This paper presents an approach to TMDL development and implementation planning for data‐limited urban watersheds using a manageable watershed model and a flow analysis. Evaluation of data in many New England watersheds has shown that habitat/aquatic impairments are frequently related to excessive urban development and the accompanying increased storm water runoff. Not only does the storm water runoff regime (including changes in the peak and base flows) alone lead to problems, but increased runoff also generally leads to increased pollutant transport capacity and loading. Therefore, using storm water as an “umbrella” surrogate to address a suite of stressors contributing to aquatic life impairments is a plausible option in urban areas (where discrete local problems have not been identified). The use of surrogate indicators expressed as quantitative targets is an important tool for developing TMDLs. This paper demonstrates application of simple watershed models to support flow duration analysis and hydrologic target identification for TMDL development in Maine, Vermont, and Massachusetts. It also exemplifies how the approach can be extended to support storm water implementation planning.

Select this Article		Stormwater BMP Evaluation and Feasibility Study—An Assessment of the Ability of BMPs to Be Able to Meet Potential TMDLs for Lake Tahoe Eric Strecker, Jim Howell, Andi Thayumanavan, Marc Leisenring, Marcus Quigley, and John Reuter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)224 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Over the past several decades, there has been a noticeable decline in the clarity of Lake Tahoe. The subject has been one of much debate and study and the scientific community agrees that this decline is largely due to increased human activities within the watershed tributary to the lake as well as potential atmospheric deposition from regionally adjacent areas. Although BMPs have been implemented to target pollutants in surface runoff, water quality of the Lake has still not improved to desired levels. Therefore, enforceable restrictions on nutrients and sediment being carried to the lake via surface water, Total Maximum Daily Loads (TMDLs), are being established for the Lake's watershed. The purpose of this Stormwater BMP Evaluation and Feasibility Study was to evaluate the cost‐effectiveness and other attributes of alternative project level and basin‐wide enhanced BMP implementation for reducing urban runoff pollution to Lake Tahoe. As part of this study, the effectiveness and costs of a variety of currently implemented BMPs, viable improvements to these BMPs, and potentially effective new and enhanced technologies were evaluated. This paper describes the approach for gathering and developing this information. The results of this work are intended to ultimately be incorporated into a watershed model to estimate the potential reductions in loading of pollutants to the lake through BMP implementation on a basin‐wide scale. The current and potential future performance of BMPs (and their costs) will be considered within the context of TMDL development as well as in future Tahoe Basin plan development efforts. The paper provides a summary of the potential for BMPs and enhanced BMPs to meet potential loading reductions for fine particulates and nutrients. The approach including long‐term simulation modeling to ascertain the hydrologic and hydraulic performance of potential BMP sizing and designs, assessment of BMP performance through a combination of statistical assessments of the International BMP Database and unit processes, and local Lake Tahoe BMP performance information. The effort determined that significant reductions in fine particulates and phosphorus are achievable if appropriate BMP types (wet ponds, wetlands, and extended detention ponds with a small pool) are employed.

Select this Article		Stormwater BMP Monitoring for Performance: The Charlotte Experience J. T. Smith, P.E., CPSWQ, M.ASCE, W. F. Hunt, PhD, P.E., M.ASCE, S. Jadlocki, and P. R. Eubanks ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)225 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Structural Stormwater Best Management Practices (BMPs) have been embraced by many communities across the United States as a method of improving stormwater runoff quality. Performance standards for such BMPs however, are often poorly researched. Performance monitoring of structural BMPs can be challenging as poorly designed, constructed and maintained BMPs are often not suitable for monitoring. A stormwater BMP monitoring program was developed for the purpose of determining pollutant removal effectiveness of specific BMPs. 12 individual BMPs were chosen from a pool of potential sites for monitoring. The goal of the monitoring program was to determine pollutant removal efficiency and hydrological performance for each site. Specific BMP types chose included: wetlands, bioretention, wetponds and wet ponds with littoral shelves. Individual BMP's were chosen to represent typical structural BMPs being implemented within the region. A monitoring protocol document was developed for each BMP to ensure that requirements were met for inclusion in the National Stormwater BMP database. BMPs were selected and fitted with monitoring equipment for the determination of pollutant removal performance. Flow paced water quality samples were collected from inflow and outflow locations. Samples were collected during 24 runoff producing events over a 2 year period and analyzed for pollutants commonly found in stormwater runoff. The monitoring program was designed so that data could be included in the in the National Stormwater BMP database.

Select this Article		Stormwater Pond and Wetland Maintenance Concerns and Solutions Sally Hoyt and Ted Brown ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)226 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract With the preponderance of stormwater ponds and wetlands across community landscapes, the specific need for detailed and representative pond and wetland maintenance guidance that spans the design, construction, and post‐construction phases has arisen as a priority for many communities. The current federal stormwater regulations (e.g., Phase I and Phase II NPDES rules) make it incumbent upon permitting authorities and permittees to address stormwater treatment practice operation and maintenance as a major programmatic component. This paper highlights recent guidance developed by the Center for Watershed Protection and Tetra Tech (through support from EPA) that has been developed to assist communities in meeting the stormwater pond and wetland maintenance challenges that face them. The guidance identifies eight common maintenance problem areas associated with stormwater ponds and wetlands and details important considerations during the design, construction, and post‐construction phases aimed at minimizing the burden of long‐term maintenance. This paper limits its focus to key planning and design phase considerations.

Select this Article		Stormwater Treatment Using Upflow Filters M. Pratap, U. Khambhammettu, S. E. Clark, and R. Pitt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)227 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this research, an upflow filtration system was developed, and its effectiveness was demonstrated. Five filtration media (lightweight sand, pool‐filter sand, fine‐grade sand, peat moss and compost were examined for solids removal ability in bench‐scale tests. The objectives were to determine (1) the optimum flow rate (no separation of the media from the gravel or within the media, and where suspended solids removal was “best”); (2) the suspended solids loading that reduced the flow rate to certain end points; (3) the breakthrough point (i.e., where the effluent concentration equaled the influent concentration) for each media. The evaluation parameters were flow rate, and effluent turbidity, total solids and particle size distribution. Statistical comparisons of the filters demonstrated that the compost‐sand and peat‐sand performed better (had greater removals) for turbidity and total solids during the early to the intermediate part of the filter run when compared to sands. Late in the filter run, the peat‐sand filter still produced significantly better effluent than the pool sand and the fine sand; however, solids washout from the compost‐sand filter occurred and the compost‐sand filter performed worse than the two sand filters. For the particle size distribution data, all media were statistically indistinguishable from each other.

Select this Article		Strategies/Guidance for Managing Stormwater: Infiltration vs. Surface Water Discharge Shirley E. Clark, Katherine H. Baker, Melinda M. Lalor, J. Bradley Mikula, and Catherine S. Burkhardt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)228 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Past studies have identified urban runoff as a major contributor to the degradation of many urban streams and rivers. The management of municipal stormwater runoff necessitates decisions as to whether the “disposal” of runoff should be through infiltration, surface discharge or a combination of the two. Typically, this management is addressed through the use of “best management practices” (BMPs) at the site in question or at a location in the conveyance system prior to discharge to a receiving water body either above or below ground. These BMPs may be selected based on site‐specific conditions and discharge requirements, but often they are selected based on past history of what has worked in the municipality, the experience of the planners with specific BMPs, and regulatory requirements on the federal, state and local level. The primary objective of this project is to develop a preliminary guidance document for municipal planners and engineers to use when they are evaluating their various stormwater management options, especially as they balance master planning requirements for their specific localities/regions and regulatory requirements. The preliminary guidance manual will propose a simple decision tree analysis structure to guide planners through the steps needed to determine the requirements for infiltration as well as the water‐quality standards and quality of stormwater that may inhibit the use of infiltration.

Select this Article		Sun Valley Park Storm Water Infiltration Basin Demonstration Project Kathleen Higgins, P.E. and Curt Roth, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)229 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Sun Valley Park pilot demonstration project proposes to manage storm water runoff and associated surface street flooding via installation of new storm drains upstream of Sun Valley Park, provide for the beneficial use of storm water via infiltration to the regional groundwater system, and ensure protection and/or improvement of regional groundwater resources. The Project was initiated by the County of Los Angeles Department of Public Works (LACDPW) Watershed Management Division to address chronic flooding conditions in the Project area, and to promote urban watershed management. LACDPW retained the CH2M HILL Team to provide the engineering services necessary to prepare the concept and final design for the Project. LACDPW partners for the project include the City of Los Angeles Department of Recreation and Parks, the City of Los Angeles Department of Public Works, the Upper Los Angeles River Area Watermaster, and TreePeople. All partners and other stakeholders have participated in the Watershed Stakeholders Group that designated this Project as the first demonstration project for the Sun Valley Watershed.

Select this Article		Update on EPA Guidance for the NPDES Municipal Storm Water Program J. H. Collins ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)230 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Center for Watershed Protection (CWP) and Tetra Tech, Inc., are collaborating to support EPA prepare a series of guidance documents targeted at helping small municipal separate storm sewer systems (MS4s) implement their programs.

Select this Article		Use Attainability Analysis: Process and Examples Sri Rangarajan, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)231 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Use Attainability Analysis (UAA) is a regulatory framework that allows state regulatory agencies to review the physical, chemical, biological, economic, and socio‐economic issues and determine the appropriate beneficial uses for specific water bodies. This framework can be used when the swimmable and fishable goals of the Clean Water Act are not attainable. This paper presents an overview of the UAA process, reviews regulatory guidance developed by some states, and provides a case study to discuss why UAA was undertaken and the specific challenges faced and solutions developed.

Select this Article		Using GIS to Prevent Sanitary Sewer Overflows and Comply with CMOM Requirements Nathan J. Schaedler ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)232 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Environmental Protection Agency (EPA) recently estimated that between 23,000 and 75,000 sanitary sewer overflows (SSOs) occur each year in the United States, resulting in releases of between three to ten billion gallons of untreated wastewater. Most SSO events are caused by sewer blockages, while most SSO volume appears to be related to events caused by wet weather and excessive inflow and infiltration. SSOs have a variety of causes, including blockages, line breaks, sewer defects that allow inflow and infiltration (I/I), lapses in sewer system operation and maintenance, inadequate sewer design and construction, power failures, and vandalism. The microbial pathogens and other pollutants present in SSOs can cause or contribute to water quality impairments and other environmental and human health problems. With limited budgets to rehabilitate and/or replace existing collection system deficiencies, it is important that municipalities and agencies prioritize segments of the collection system from most critical to least critical and develop short and long‐term capital improvement plans based on this prioritization. Through a case study of an SSO evaluation conducted at a military facility in Southern California, the use of off‐the‐shelf GIS software was used as a tool to conduct a comprehensive risk‐based SSO evaluation of a collection system. This risk based evaluation provides a cost‐effective method to help municipalities and agencies identify areas within their collection system that are at greatest risk for sanitary sewer overflows, prioritize deficiencies, and then plan for short and long‐term rehabilitation and/or replacement options. Conducting this evaluation will also help municipalities and agencies comply with their NPDES permits and applicable Capacity, Management, Operation, and Maintenance (CMOM) requirements and/or guidelines.

Select this Article		Utility Data Archiving for Risk Management Trent G. Schade, Jeff C. Frechtling, and Chris Brausch ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)233 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract EPA let a contract for a consultant to collect information about historical changes in operations and maintenance, design and construction, and planning and siting for water and wastewater infrastructure. The goal of this research study is to determine risk management alternatives for owners of these utilities with the addition of uncertainty from climate changes. CDM, as awardee for this contract, proposed a reasonable and well‐conceived plan to EPA to collect this information from a host of utilities. As CDM mobilized the data collection effort, they quickly realized several difficulties in collecting that data. EPA responded to this dearth of information by altering the question under review to—can we quantify benefits of archiving data about various phases of infrastructure development and operations? This paper provides case‐study evidence of the value maintaining long‐term detailed data about utility design, operations and planning. By understanding past practices and the associated costs at a local level, utility owners and operators will be better able to respond to unknown or unforeseeable future events.

Select this Article		The Value of Infiltration‐ and Storage‐Based BMPs for Stormwater Management Drew B. Shelton and Richard M. Vogel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)234 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Many storage and infiltration‐based BMPs can match or improve upon the performance of traditional stormwater‐management practices. However, engineers need decision tools in order to choose between different types of BMPs. We introduce a methodology for comparing the cost‐effectiveness of detention‐based flow reduction with that of infiltration‐based technologies using a simple generalized model and standard planning equations. Since the approach is general, we are able to evaluate the general conditions under which infiltration‐based BMPs improve upon storage‐based BMPs in terms of both cost and effectiveness. We document the relative cost effectiveness of storage‐ and infiltration‐based BMPs as a function of the climatic, soil, and land‐use conditions that yield the desired flood objectives. Initial results indicate that the capital cost of detention is usually lower than that of infiltration based alternatives regardless of the scale of the project, although the cost‐effectiveness of infiltration increases in more urbanized environments. Regardless of the capital costs, infiltration has many benefits that detention does not. Many of these, including water quality and groundwater recharge, are difficult to quantify. Depending on the values assigned to these measures, infiltration may provide a greater overall benefit than detention.

Select this Article		Water Management in British Columbia: Issues and Influences J. S. Mattison and M.‐L. Moore ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)235 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract British Columbia is Canada's western most province, bordering Alaska to the northwest, Yukon to the north, Alberta to the east, and Montana, Idaho, and Washington states to the south. British Columbia is richly endowed with water resources, which are an important part of the province's history, culture, and economic development. This paper begins with a brief description of the hydrology of the province, the historical development of the water resources, and the current legislative and management framework. With this background, four key issues or influences that will affect future water resource development in British Columbia will be discussed. One of the first considerations that the Province is addressing is the aboriginal assertion of rights and titles. Treaties with First Nations peoples have only been established in a small part of the Province. Dealing honourably with First Nations' claims will result in the largest allocations of water made this century. Secondly, operational reviews of the 400 major dams in British Columbia are required to ensure that a wide range of social and environmental benefits are achieved in addition to the water supply and power generation, for which the dams were built. Thirdly, we are beginning to realize the effects that climate change is bringing. Processes and resources that enable the people of British Columbia to adapt to climate change through behaviour changes are needed. Finally, as a result of these influences, a revision of our legislative and regulatory framework will be necessary to ensure that we have the right tools to effectively manage our water resources.

Select this Article		Water Quality Assessment and TMDLs for the Flathead River Headwaters Planning Area, Montana Ron Steg, Jason Gildea, and Kevin Kratt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)236 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Flathead River Headwaters Total Maximum Daily Load (TMDL) Planning Area (TPA) drains approximately 4,369 square miles in northwestern Montana and Canada. Twelve stream segments and one reservoir in the Flathead River Headwaters TPA appeared on Montana's 1996 Clean Water Act section 303(d) list. The listed causes of impairment included flow alteration, other habitat alterations, nutrients, suspended solids, and siltation. Cold‐water fish and aquatic life were the beneficial uses listed as impaired or threatened. Available data and information were reviewed and compiled and used to assess current use impairment status. A suite of targets and supplemental indicators were developed to address the lack of numeric water quality standards, to evaluate “natural” conditions, and to assess the complex interrelationship between water chemistry, physical habitat, and biology. Restoration and follow‐up monitoring plans were developed for all waters determined to be impaired.

Select this Article		Wet Basins: Analysis of Nutrient and Metals Removals Laura Larsen, P.E., CPSWQ, M.ASCE and Michael Barrett, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)237 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Over the past five years, the California Department of Transportation (Caltrans) has operated a vegetated wet basin in Southern California. The wet basin included design features to provide stormwater treatment and to protect the public. In general, the wet basin was designed with a permanent pool of water with varying depths and a vegetated bench around the perimeter of the basin. Wet basins rely on physical, biological, and chemical processes to remove pollutants from stormwater runoff. It is thought that the sedimentation removes particulates, organic matter, and metals. Biological uptake removes dissolved metals and nutrients. The chemical processes include precipitation, and chemical adsorption. Analysis of pollutant removal efficiencies of this design has shown only a small percentage of nutrient and metal removal occurred through the biological uptake by the vegetation. A larger percentage of the nutrient removal was attributed to the other processes occurring in the wet basin. The need for vegetation in a wet basin may not be as critical as once thought. Reducing the amount of vegetation in a wet basin also may reduce the available breeding area for mosquitoes. Investigation of other wet basin designs throughout the country has shown varying levels of public concern with basins holding water. It has been thought in California that side slopes of 4:1 are necessary for public safety. As an added precaution fences have been used to prevent access. In other areas within the United States, wet basins have been perceived as a welcomed water feature and the safety measures are not as stringent.

Select this Article		Wet Weather Flow Management in the Great Lakes Areas of Concern Sandra Kok and John Shaw ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)238 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Under the Government of Canada's Great Lakes Program, the Great Lakes Sustainability Fund and its predecessor programs (the Great Lakes Cleanup Fund and the Great Lakes 2000 Cleanup Fund) were established to implement cleanup actions and strategies that would contribute to the restoration of impaired beneficial uses in environmentally degraded areas (known as Areas of Concern) in the Great Lakes. The Great Lakes Sustainability Fund is administered by Environment Canada on behalf of eight Government of Canada departments. Contributing to impaired beneficial uses are municipal wastewaters generated from the urban centres in the Great Lakes Areas of Concern. These municipal wastewaters include sewage and wet weather related discharges (combined sewer overflows and stormwater runoff). This paper provides an overview of the Municipal Wastewater Program of the Great Lakes Sustainability Fund and highlights the progress made to date under the program towards wet weather flow management and the program's role in developing and demonstrating sustainable approaches and technologies in the Great Lakes Areas of Concern.

Select this Article		Wet‐Weather Pollution from Commonly‐Used Building Materials Shirley E. Clark, Melinda Lalor, Mukesh Pratap, Richard Field, and Robert Pitt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)239 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Development in sensitive watersheds continues to pose environmental problems for receiving waters. One contributor to the long‐term pollution of sensitive waterways is building and construction materials. However, the long‐term effect of many building materials on the environment has not been quantified. Prior testing of these materials in the laboratory has indicated that the potential for release (primarily nutrients, lighter hydrocarbons, pesticides, and metals) is significant. Additional testing for metals' release from aged roofing panels also has shown that the potential for pollutant release still exists after 60 years of exposure to the environment. The data that is missing from a complete evaluation of specific building materials is behavior over the lifespan of the material, including the critical period of initial exposure. This paper provides an overview of the limited literature available on the subject, results from laboratory testing of common building materials and aged roofing panels, and an overview of the next phase of needed research.

Select this Article		Anchor Ice Flooding in Jackson, WY Steven F. Daly ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)240 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Jackson, Wyoming, located in the Teton Mountains in northwest corner of Wyoming along Flat Creek, has experienced wintertime flooding caused by the production of frazil ice and anchor ice in Flat Creek. Anchor ice formation is common in shallow, turbulent streams but flooding caused by anchor ice in urban areas is rare in North America. Anchor ice is formed when frazil ice crystals are deposited on the channel bottom during cold periods when the flow of the creek becomes supercooled. The anchor ice builds up on the bottom of the channel and causes the water levels to rise upstream. Jackson has installed three “thaw wells” that pump ground water into Flat Creek. The ground water, at a reported temperature of 7.8°C, warms the flow of Flat Creek slightly and prevents supercooling for some distance downstream of each thaw well. The existing thaw wells, however, did not provide complete protection for Jackson during the winter of 2000–01, the first winter they were in operation. This report is a study of the ice‐related flooding problems in Jackson. It describes the Flat Creek watershed, the winter climate of Jackson, the existing thaw wells and their performance during the winter of 2000–01. The length of Flat Creek that can be kept above 0°C and protected from anchor ice production determines the performance of the thaw wells. The performance was estimated based on a simple heat transfer model that assumed well mixed flow, a linear heat transfer relation between the water surface and the atmosphere based on temperature difference, and one‐dimensional steady flow in the creek. It was found that the distance protected depends on the air temperature and, to a lesser extent, the flow rate of Flat Creek. The analysis roughly agrees with the performance of the wells during the winter of 2000–01.

Select this Article		Assessing Long Term Domestic Water Needs in the Arctic E. Strang and D. White ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)241 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The overall objective of this research was to understand how humans rely on freshwater at local and regional scales in selected parts of the Arctic, how these dependencies have changed in the recent past, and how they are likely to change in the future. This study is taking place on the Seward Peninsula in northwestern Alaska, where climate induced changes in the hydrologic cycle are currently being observed. This paper documents results to date on past industrial and domestic water demand on the Seward Peninsula. Preliminary results suggest that water use was high in the Nome Mining District and then decreased proportionally with the decline of placer mining operations. Water was used in placer gold mining operations on the Seward Peninsula to run hydraulic giants and sluice boxes. Because water was one of the limiting factors in mining operations, a series of ditches diverted nearly all available surface water in the Nome mining district between 1905 and 1914 for industrial use. The domestic water demand, that is, water used for drinking, cooking and cleaning, increased over the past 40 years as piped water and sewer systems were installed in many villages. Domestic demand can increase by 900% when a community installs piped water. The increase in demand corresponding to this change of delivery system can be seen in the difference between water consumption in a village with a central watering point, such as Wales, and a village such as Brevig Mission, where every house is connected to a piped water and sewer system. Historical pressures on the freshwater resource are being used to better understand the vulnerability of the resource now and in the future.

Select this Article		Distribution and Transport of Fecal Bacteria in a Rural Alaskan Community M. K. Chambers, M. R. Ford, D. M. White, S. Schiewer, and D. L. Barnes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)242 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Without piped water and sewer, some Alaska Native communities are at increased risk for diseases caused by waterborne pathogens. Whether treated water from the washeteria or untreated water from traditional water sources is used, care must be taken in transport and storage. Use of untreated water from traditional sources requires more attention to risk as source areas and catchments can become contaminated by pathogens from honeybucket disposal sites, dogs, and local wildlife. This study is being conducted to determine the major pathways of contamination outside the home in a rural Alaskan community. Pathways under consideration include vehicles, shoes, and surface flow. In early summer many puddles in and around town tested positive for total coliform and E. coli, indicators of fecal pollution. While the concentrations of coliform bacteria were low in many cases, members of the total coliform group were widely present and several areas around town had high concentrations of E. coli. E. coli was also detected on at least of half the tested shoes, dog paws and tires of ATVs returning from the dump, indicating that these may serve as vectors transporting pathogens to the home.

Select this Article		Freeze Up Processes Steven F. Daly, P.E., PhD, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)243 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. River ice freeze up processes will be reviewed. The presentation will include energy budget, frazil and anchor ice, freeze up ice run types, and ice cover formation processes.

Select this Article		Freezeup Ice Jam Control on the Deschutes River at Bend, OR: Ice Boom Design Criteria Re‐Examined A. M. Tuthill ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)244 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This study investigated the effectiveness of an ice boom installed on the Deschutes River in Bend, Oregon in 1987. The boom was built following a severe freezeup ice jam in December 1983 that flooded 110 homes with total damages of $900,000. Since 1987, the Deschutes River at Bend has seen many changes, placing the ice boom's effectiveness in doubt. This study determined if, under current conditions, the ice boom retained sufficient frazil ice to prevent downstream ice jam flooding. The study also examined other ice control options, such as raising the water level at a dam downstream of the boom and dredging to reduce water velocity and improve frazil ice capture at the boom. Moving the boom to a more favorable location and reconfiguring the boom were also investigated. Study results suggest that the conventional ice boom performance criteria of surface water velocity ≤ 0.7 m/s and Froude number ≤ 0.08 may be un‐conservative for predicting frazil ice capture. The study also found that, when using calculated average channel velocity to evaluate the ice retention capacity of a boom, variations in the vertical and horizontal water velocity profiles can be very important.

Select this Article		Geochemistry of Surface‐Waters in Mineralized and Non‐Mineralized Areas of the Yukon‐Tanana Uplands B. Wang, R. B. Wanty, and J. Vohden ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)245 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Geological Survey (USGS) and Alaska Department of Natural Resources (ADNR) are continuing investigations on element mobility in mineralized and non‐mineralized areas of the Yukon‐Tanana Upland in east‐central Alaska. The chemistry of stream water is evaluated in the context of regional bedrock geology and geologic structure. Sampling sites were located in the Big Delta B2 quadrangle, which includes the mineralized areas of the Pogo claim block. The area is typified by steep, subarctic‐alpine, boreal forest catchment basins. Samples were collected from catchments that either cross structural features and lithologic contacts, or are underlain by a single lithology. Waters are generally dilute (< 213 mg/L TDS), and are classified as Ca²⁺ and Mg²⁺ − HCO3− to Ca²⁺ and Mg²⁺ − SO42− waters. Gneissic lithologies are more SO42− dominated than the intrusive units. The major‐ion chemistry of the waters reflects a rock‐dominated aqueous system. Trace‐element concentrations in water are generally low; however, As and Sb are detected near mineralized areas but in most cases rapidly attenuated downstream and processes other than simple dilution are controlling the concentrations of these trace elements. There is a tendency toward increasing SO42− concentrations downstream in waters both proximal and distal to mineralized areas. More work is necessary to determine what proportion of the increase in SO42− could be derived from the oxidation of sulfide minerals as opposed to water influenced by the underlying gneissic units.

Select this Article		Hubbard Glacier Advances Despite Global Warming George A. Kalli ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)246 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The shrinking of glaciers throughout the world is often referenced as an indicator of global warming. There are exceptions to this trend, however. Hubbard Glacier, North America's largest tidewater glacier, located near Yakutat, Alaska, is one such exception. It is currently in a state of advancement that threatens resources important to the Alaska community of Yakutat. This paper will review the recent movement of Hubbard Glacier and its possible future implications upon the community of Yakutat. Potential flood damage reduction measures currently being evaluated by the Alaska District of the United States Army Corps of Engineers (Corps) and other agencies will also be discussed.

Select this Article		Hydrologic and Hydraulic Factors for Railroad Crossing of Three Glacial Streams near Fairbanks, Alaska C. S. Maniaci, J. Theurich, and R. F. Carlson, P.E., Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)247 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Alaska Railroad Corporation is planning to extend its northern line from near Fairbanks to the Delta Junction area, a distance of about 120 km. The proposed route extension will cross three glacial streams: Delta Creek, Little Delta River, and Delta River. All are classic glacier fed stream channels with steep slopes, and wide braided channels carrying large sediment load. In support of a feasibility study for the railroad extension route, hydrologic and hydraulic engineering information has been developed to aid in the preliminary design of stream crossing structures for these three streams. Specifically, magnitude, duration, and frequency of flood flows, the water surface elevation/flow relationship, and the extent and depth of flooding in the main channel belt and the riparian zones are the focus of this study.

Select this Article FREE		Hydrological Model Simulations and Physical Impacts of a Tundra Watershed Affected by Wildfire, Seward Peninsula, Alaska A. K. Liljedahl and L. D. Hinzman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)248 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract To be able to quantify the impacts of a climate change in an arctic region, we need knowledge about the properties of the area. Water is of decisive importance in shaping the ecosystem. Due to dynamic changes in the hydrology, promoted by indirect or direct disturbance, a site can evolve to a drastically altered state. The climate is shown to strongly influence the frequency of wildfires (Burn, 1998), which is both caused by and creates an altered hydrological system. The aim of the study is to investigate how the hydrological dynamics and the physical impacts of a tundra watershed are affected by a wildfire that occurred August 2002 at the central part of Seward Peninsula, Alaska. Yoshikawa et al. (2003) has shown that a fire can, in the long term (more than a decade), cause an increased thickness of the active layer in permafrost regions. Between mid June and mid September 2004, field measurements have shown a 60‐meter increase of an eroded streambed in Niagara Creek, a phenomenon first observed after the fire. A hydrologic computer model, TopoFlow, will be used to investigate the wildfire's impact in this sub‐arctic hydrological system where the increased thaw depth and changed evapotranspiration are important parameters. Air and soil temperatures, precipitation, net radiation, wind speed, snow and thaw depth field measurements are available during the years 1999 – 2004. TopoFlow will be calibrated with pre‐fire field data of discharge. The result of the modeling will be discussed together with observed physical impacts and earlier spatial and temporal hydrological modeling in the area. An investigation of the effects of a fire on a tundra environment can result in a better understanding of the impact a warming climate and its secondary effects on the arctic ecosystem and its morphology.

Select this Article		Ice Control Structure Design Jon E. Zufelt, P.E., PhD, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)249 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Ice jams can result in quite sudden increases in water level with the resultant flooding causing large monetary damages, even along smaller waterways. The blocked flow area attributed to the ice jam and the increased shear on the water flow due to an extra stationary boundary at the water's surface result in water elevations much higher than open water flows at the same discharge. Spring snowmelt events coupled with a strong winter ice cover can result in the highest stages of the year, and significant flooding. Many options exist for ice jam flooding control, including structural measures and non‐structural techniques. Structural measures might entail levees, small dams, or an ice control structure (ICS). Non‐structural methods include application of heat through natural or man‐made sources, flow or discharge control, and moving flood‐prone structures out of the floodplain. The idea behind an ICS is to stop ice that is moving down a river at a location where jamming would not cause damages. The ICS is usually placed upstream of the historical damage area, thereby trapping the ice that would normally jam in the damage location and thus keeping water elevations in the protected area below damage levels. This paper points out some of the design steps for an ICS at a perennial ice jam site in central New York State.

Select this Article		Investigating Survivability of Coliform in Extreme Environmental Conditions Hrishikesh Adhikari, David L. Barnes, Silke Schiewer, Daniel M. White, and Malcolm R. Ford ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)250 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Pathogens are viable in the environment for long periods of time (months to years) even in extremely cold regions such as Alaska. This research is concentrated on investigating the presence of pathogens in different conditions of temperature and moisture content in soils using coliform as an indicator for fecal contamination. The results obtained using most probable number gas fermentation technique suggest that the change in the coliform count was insignificant with varying temperature (−28 °C to 20 °C) for studied period Furthermore, studies with different soil moisture content also suggest that coliform survive the seasonal variations. The viability of these pathogens as indicated by coliform can be related to the diseases such as diarrhea, which are major concern in rural Alaska. Therefore, the results of this research highlight the need of revising the waste management practices employed in rural Alaska.

Select this Article		Mathematical Modeling of River Ice Transport and Ice Jam Formation Hung Tao Shen, P.E., PhD, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)251 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Dynamic and thermal processes on river ice transport, including ice jam formation, will be discussed. Mathematical modeling of river ice processes as well as examples of river ice models will be presented.

Select this Article		Mineralization, Watershed Geochemistry, and Metals in Fish from a Subarctic River, Alaska L. P. Gough, B. Wang, J. G. Crock, R. R. Seal, and P. Weber‐Scannell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)252 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract We report on the levels of trace metals and metalloids in Arctic grayling (Thymallus arcticus), an important freshwater sport and subsistence fish in the Fortymile River, east‐central Alaska. Functional biogeochemical baseline values and (or) ranges are presented for 38 major‐ and trace‐elements in the muscle (fillet) and liver of 34 fish collected from 11 sampling sites in the watershed. In addition, we present N‐, C‐, and S‐isotopic data for muscle samples. These data are the first to be reported for Arctic grayling in this region of Alaska. Geometric means for total Hg in muscle and liver tissue are 0.069 and 0.062 ppm, respectively. These levels are more than an order of magnitude below the FDA permissible value for methylmercury in fish fillets. In general, we noted little variation in the elemental concentrations in muscle tissue among samples at each of the 11 fish‐sampling sites. No definitive link could be attributed between biogeochemical patterns and regional lithology. Stomach‐content chemistry varied widely (relative muscle tissue or liver) and generally reflected sediment chemistry—a component of the ingested material. Stomach‐content material was examined for the occurrence and frequency of macroinvertebrates and their chemical composition in three fish. Results showed considerable diversity, with 9 to 15 invertebrate taxa of which both aquatic and terrestrial individuals were found. The N‐isotopic compositions of muscle fillet samples are homogeneous (δ¹⁵N = 7.6 − 9.7 permil), reflecting a restricted, low trophic (primary predator) position for the grayling. C and S isotopic compositions (δ¹³C and δ³⁴S) of fillet samples range from −33.1 to −25.8 permil and −8.4 to 8.2 permil, respectively, suggesting heterogeneity of food sources (both aquatic and terrestrial).

Select this Article		A Multi‐Scale Assessment of As(V)‐Aluminum Oxyhydroxide Interactions Kunaljeet Tanwar, Paras Trivedi, and Silke Schiewer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)253 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Hydrated aluminum oxides (HAO) have been identified as major sinks for contaminants, such as arsenic, in aquatic and soil ecosystems. This research focused on the assessment of As(V)‐HAO interactions by combining macroscopic studies with x‐ray absorption spectroscopy (XAS). Sorption of As(V) onto HAO was studied as a function of reaction time, sorbate loading, and the presence of phosphate. The short‐term isotherm studies indicated that HAO has a high sorption capacity for As(V) (approximately 1.9×10⁻³ mol As(V) g⁻¹ HAO) and the uptake of As(V) was not significantly affected by equimolar amounts of phosphate at pH 4.5. The results of long‐term kinetic studies, where a continuous influx of As(V) was maintained, revealed rapid initial sorption to the external surface of HAO within less than four hours, followed by slow uptake over several weeks, which could be attributed to intraparticle diffusion. Complementary XAS analyses suggested that As(V)‐HAO interactions can be described by one average reaction mechanism, resulting in bidentate inner‐sphere complexes. This mechanism was independent of time, sorbate loading, and the presence of phosphate under the reaction conditions employed in this study. Overall, the results of this research emphasized that microporous oxyhydroxides of aluminum are much larger sinks for oxyanions, such as As(V), than presently understood.

Select this Article		Numerical Simulation of Surface and Suspended Freeze‐Up Ice Discharges F. Chen, H. T. Shen, D. Andres, and M. Jasek ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)254 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a numerical model based on a two‐layer ice transport formulation for surface and suspended ice runs for thermal‐ice variation along the river during freeze‐up is presented and validated with an analytical solution and field data from Peace River.

Select this Article FREE		Permafrost Controls on Hydrological Processes in a Changing Climate L. D. Hinzman, K. Yoshikawa, and D. L. Kane ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)255 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The primary control on local hydrological processes in northern regions is dictated by the presence or absence of permafrost, but is also influenced by the thickness of the active layer and the total thickness of the underlying permafrost. As permafrost becomes thinner or decreases in areal extent, the interaction of surface and subpermafrost ground water processes becomes more important (Figure 1). The inability of soil moisture to infiltrate to deeper groundwater zones due to ice rich permafrost maintains very wet soils in arctic regions. However, in the slightly warmer regions of the subarctic, the permafrost is thinner or discontinuous. In permafrost‐free areas, surface soils can be quite dry as infiltration is not restricted, impacting ecosystem dynamics, fire frequency and latent and sensible heat fluxes. Other hydrologic processes impacted by degrading permafrost include increased winter stream flows, decreased summer peak flows, changes in stream water chemistry, and other fluvial geomorphological processes. Hydrologic changes witnessed include drying of thermokarst ponds, increasing importance of groundwater in the local water balance and differences in the surface energy balance.

Select this Article		Reconnaissance Study of Effects of Knik Arm Crossing Causeway Nathanael Vaughan and Robert F. Carlson, P.E., Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)256 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An economical alternative for the proposed Knik Arm crossing is likely to include a bridge structure and causeway combination. The causeway portion of the crossing has the potential for reflecting part of the twice‐daily tide (or a long period wave) energy downstream on the flood tide and upstream on the ebb tide. The backwater effect of a structure during a flood wave on a river channel is an analogous situation. The energy reflection has the potential to change the water current and tidal height pattern away from the structure, which will be of particular concern in the vicinity of the Port of Anchorage. We conducted a preliminary computer model study of potential effect of the proposed crossing on the nearby hydraulic parameters of water surface elevation and velocity. We compared two situations‐with and without the causeway. The fixed‐bed model shows increased velocity (0.5 m/s) in the causeway opening and decreased velocity (−1.5 m/s) in the downstream lee areas of the causeway arms. The water surface elevation decreased somewhat (−0.5 m) in the downstream lee areas. A “no change” condition appears to exist in the vicinity of the Port of Anchorage.

Select this Article		River Ice Controls and Physical Modeling Andrew M. Tuthill, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)257 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. River ice control, mitigation, and management will be discussed, including both structural and non‐structural techniques. The principle of scaling criteria, and techniques of physical modeling, which is particularly useful in the design of ice control structures will also be discussed.

Select this Article		River Ice Ecology Terry Prowse, PhD and Hung Tao Shen, P.E., PhD, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)258 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. River ice is known to produce many hydrological extremes. It can significantly modify a number of other physical and chemical processes that have important biological implications. It determines the nature, quality and abundance of various in‐stream, deltaic and riparian habitats. An overview of the current of state of knowledge about the ecological aspects of river ice will be presented.

Select this Article		Seasonal Variations in Fecal Coliform Bacteria in a Cold Region Stream T. L. Wilson, G. Stahnke, W. Schnabel, and K. Duddleston ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)259 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This manuscript represents the initial results from an ongoing study designed to characterize fecal coliform (FC) populations in a cold region, urbanized stream. Thus far, the stream has not been shown to exhibit significant variability over short durations (1 hour) under low‐flow conditions. Coefficients of variation (C_v) obtained under these conditions were similar to the C_v of the FC enumeration method itself. Over longer durations (months), FC values varied considerably, and log‐transformation of the values was necessary to justify an assumption of normality. An assessment of the FC values from three sampling locations over a period of seven months indicated that the FC values obtained from urban locations were significantly higher than those obtained at an upstream woodland location. The values originating at the two urban locations, however, were not significantly different from one another. An assessment of the seasonal variability in FC concentrations provided mixed results. There were a higher number of distinct spikes identified during the warmer months, and these spikes were attributed to rainfall events, high flow events, and/or increased animal activity. There appeared to be an underlying baseline that indicated year‐round inputs as well. Indeed, this year‐round baseline was sufficient enough such that there was no significant seasonal difference as measured by the Tukey's pairwise comparison at the 95% confidence level. Likely year‐round contributors could include leaking sewer lines or resident waterfowl. Alternatively, the year‐round baseline could be the result of long‐term survival of bacteria in creek sediments. These initial findings are under further investigation, and updated results will follow.

Select this Article		Seasonal Water Quality in Ship Creek, Alaska Jon E. Zufelt, P.E., PhD, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)260 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Ship Creek, while relatively small in drainage area at only 300 km², is one of the most important watersheds in Alaska. As it drops over 1000 meters in just over 30 km on its voyage from the mountains to the Cook Inlet, it passes through open tundra, spruce and cottonwood forests and tidal flats. The uppermost reaches of Ship Creek are within the Chugach State Park where water quality might be considered pristine. Wildlife influences include the activities of moose, black and brown bears, Dall sheep, coyote, wolf, and beaver. The creek then enters the Fort Richardson Army Base and flows through steep mountain canyons and glacial moraines. The land drained by the watershed includes military training areas (Stryker vehicles), firing ranges from small arms to 81 mm mortars, two 18‐hole golf courses, Alaska's busiest highway, and a State Fish Hatchery. Ship Creek then enters Elmendorf Air Force Base where it drains family housing areas, an active airfield, an old landfill, an 18‐hole golf course and another State Fish Hatchery. Upon leaving the relative green of Elmendorf, it enters the industrial heart of the city of Anchorage, passing many warehouses, truck and rail terminals, and an abandoned power plant at the head of tide. Its last kilometer to the Cook Inlet is through muddy tidal flats. Figure 1 shows a schematic of Ship Creek and its location relative to the bases and the city of Anchorage.

Select this Article		Teaching Climate Change Impact on Cold Regions to Multidisciplinary Undergraduate Students Hayley H. Shen and Hung Tao Shen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)261 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Climate change concerns all walks of life. Its impact is everywhere but most acutely felt in the cold regions. A few degrees of change in air temperature could mean drastic change of plant growth season, river navigation, permafrost stability.. among numerous other examples. The frequency of climate change issues appearing on the news demands more education on these topics. By their natures, climate change impacts on cold regions are multi‐disciplinary. The trans‐Alaska pipeline is a typical case where many socio‐economical, science and technology pros and cons intersect. In fall of 2004, we are offering a science seminar course to the junior class of Clarkson University's honors students. The character of our honors program is to “focus on the current and emerging problems in science, technology, and society” and “learn by solving real‐world problems in multi‐disciplinary teams”. Each semester students from this program must take a course together no matter what major they are in. In the junior year, this course is called “The Science Seminar”. In this paper we will describe the process from proposing this course to assessing the outcome at the end. The course consists of four activities: instructors' lectures, students' preparatory home works, students' group projects, and weekly and final presentations. In this paper we will describe how students were prepared to conduct a team project of their choice, under the general theme of climate change impact in cold regions. We will give detailed examples of how they progress in teams towards their project goal and how they shared the knowledge with the rest of the class. We will also summarize their scientific findings. This course is designed so that depth of knowledge is obtained from individuals and within individual teams, and breadth of understanding is obtained through periodic short presentations and feedbacks from other classmates with diverse background. Our hypothesis is that this kind of courses can offer a powerful way to educate undergraduate students on many ongoing research topics and their interdependency in climate change in cold regions.

Select this Article		Thermokarst Evolution in Sub‐Arctic Alaska: A Study Case Prathap Kodial, Horacio Toniolo, Larry Hinzman, and Kenji Yoshikawa ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)262 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Several landscape modifications are indicative of a warming climate in Arctic arid Sub‐arctic regions. Preliminary results of detailed analyses on the development of a thermokarst are presented here. Thermokarst occur when massive ice buried in permafrost thaws allowing the surface to rapidly subside. Although thermokarst is a natural process that often happens when ice‐rich permafrost is disturbed, the cause of the recent acceleration in the initiation of new thermokarsts is believed to be the changing climate, which has warmed markedly in Interior Alaska in recent decades. The study site is located in the Caribou‐Poker Creeks Research Watershed (CPCRW). The watershed is situated in Central Alaska, 50 km northeast of Fairbanks, Alaska. The permafrost distribution is discontinuous in the area and the ice‐rich nature of these frozen soils makes them particularly susceptible to thermokarsting and erosion. The research involves both field and laboratory analyses. Direct measurements of water flowing into the thermokarst and suspended sediment sampling were conducted from spring to fall, 2004. Two topographical surveys were performed in the same period. Suspended sediment concentrations and grain size distributions were obtained in laboratories at the University of Alaska Fairbanks. Initial results indicate: a) high flow rate and low sediment concentration during breakup, and b) a reduction in the water discharge and high sediment concentration values during the summer, in spite of the unusually dry conditions that occurred during this period. Substantial morphologic changes were observed along the summer months. For example, the upstream end of the thermokarst migrated approximately 2.5 meters by successive collapsing events. A new pond was created and partially filled with sediments from the soil matrix. In a pre‐existent depression the bed sediment deposit thickness was, on the average, in the order of 60 cm. Thus, the local topography was intensely altered. As a consequence of these modifications, the flow patterns were also changed in the area. It is expected that a new small stream will develop in the site.

Select this Article		Trace Metal Concentrations in Snow from the Yukon River Basin, Alaska and Canada Bronwen Wang, Larry Gough, Todd Hinkley, John Garbarino, and Paul Lamothe ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)263 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. We report here on metal concentrations in snow collected from the Yukon River basin. Atmospheric transport of metals and subsequent deposition is a known mechanism for introducing metals into the northern environment. Potential sources of airborne elements are locally generated terrestrial sources, locally derived anthropogenic sources, and long range atmospheric transport. Sites were distributed along the Yukon River corridor and within the southeastern, central, and western basin areas. Snow samples were taken in the spring of 2001 and 2002 when the snow pack was at its maximum. Total‐depth composite samples were taken from pits using clean techniques. Mercury was analyzed using cold vapor atomic fluorescence spectrometry. All other elements were analyzed by inductively coupled plasma‐mass spectrometry. In samples from remote sites, the concentration for selected metals ranged from: 0.015 – 0.34 ug/L for V, 0.01 – 0.22 ug/L for Ni, < 0.05 – 0.52 ug/L for Cu, 0.14 – 2.8 ug/L for Zn, 0.002 – 0.046 ug/L for Cd, 0.03 – 0.13 ug/L for Pb, 0.00041 – 0.0023 ug/L for filtered‐Hg. Because the entire snow pack was sampled and there was no evidence of mid‐season thaw, these concentrations represent the seasonal deposition. There was no significant difference in the seasonal deposition of V, Ni, Cu, Zn, Cd, and Pb at these sites between 2001 and 2002, and no north‐south or east‐west trend in concentrations. Samples taken from within communities, however, had significantly higher concentrations of V, Ni, Cu, Zn, and Cd in 2001, and Ni, Cu, and Pb in 2002 relative to the remote sites. Our data indicate that the atmospheric deposition of metals in the Yukon River basin is relatively uniform both spatially and temporally. However, communities have a measurable but variable effect on metal concentrations.

Select this Article		Addressing Surface Water Treatment Challenges in the North with Two‐Stage Pressure Filtration Dan V. Boccia, P.E., John A. Warren, P.E., and Michael Soltis, EIT ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)264 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Many communities in rural Alaska must utilize river water due to the absence of other safe, adequate water sources. River water in the north is characterized by large seasonal quality differences including high turbidity during the spring, high organics during the late summer and fall, and high iron and manganese during winter. By pilot testing raw water from the Eek River, it was determined that a two‐stage pressure filtration system consisting of contact clarification/flocculation followed by dual media sand filtration would meet treated water quality objectives. Results of system testing for a new facility constructed in Eek, Alaska indicate that the system is extraordinarily effective, with particle count reductions in the Cryptosporidium and Giardia size ranges exceeding 2.5 logs.

Select this Article		Advances in Biologically‐Based Sensors for Endocrine Disrupting Compounds in Water Chris G. Campbell, Ph.D., Sharon E. Borglin, Ph.D., William T. Stringfellow, Ph.D., F. Bailey Green, Ph.D., and Allen Grayson, M.S. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)265 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Endocrine disrupting compounds (EDCs) are contaminants that can mimic hormones and that are biologically active at low concentrations (less than parts per billion). Common EDCs include surfactants like nonylphenol, pharmaceuticals such as 17β‐estradiol, or industrial chemicals including dioxins. Given that there are numerous EDCs that can negatively affect humans and wildlife, general screening techniques like bioassays and biosensors may provide an essential rapid analysis capacity. Commonly applied bioassays include the ELISA and YES assays, but promising technologies also include ER‐CALUX™, ELRA, Endotect™, RIANA, and IR‐bioamplification. Two biosensors, Endotect™ and RIANA, are field portable using non‐cellular biological detection strategies. Environmental management of EDCs in water requires integration of biosensors and bioassays for monitoring and assessment. Many available biologically‐based technologies are ready for testing in remote field applications.

Select this Article		Application of Temporal Neural Networks in Long‐Lead Rainfall Forecasting Mohammad Karamouz, F.ASCE, Saman Razavi, and Shahab Araghinejad ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)266 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, an investigation on applying dynamic Neural Networks in long‐lead rainfall forecasting is presented. Among different components in building ANNs, time delay operators, recurrent connections and the hybrid method are used to design the temporal neural networks. Using these components, three types of temporal network architectures are investigated. Recurrent neural network, time delay neural network, and time delay recurrent neural network are used to forecast monthly precipitation time series from one to six months lead time. These models are applied to forecast the rainfall of Karoon drainage basin in south‐western part of Iran based on 31 years of monthly data. 21 years of data are used for models' calibration and 10 remained years are used for models' validation. Besides, a conventional multilayer perceptron network and an autoregressive integrated moving average model are investigated in order to compare the temporal networks performance. The validation results show that all temporal neural networks especially time delay recurrent neural network perform significantly better than standard MLP and ARIMA models in long‐lead rainfall forecasting.

Select this Article		Collaborations with the International Science and Technology Center and the Science and Technology Center in Ukraine Lily Sanchez and Kris Surano ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)267 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The International Science and Technology Center and the Science and Technology Center in Ukraine (STCU) are non‐governmental organizations whose mandates are to foster the goals of international nonproliferation by distributing donor funds from the United States, Canada, and the European Union to former Soviet Union (FSU) scientists to work on non‐defense related research projects. To that end, the ISTC and STCU provides support to scientists working on conversion projects, many of which relate to research and development to improve public health and the environment, especially in the recipient countries. For example, the STCU organizes workshops to give scientists from Ukraine, Uzbekistan, and Georgia, the three FSU countries supported through the STCU, the opportunity to meet with international environmental colleagues. This paper discusses opportunities by the ISTC and STCU to encourage the exchange of information. This paper also describes the opportunities for former Soviet weapons scientists to become better integrated in the global environmental science community and to help find Western engineers and scientists with whom to collaborate in future ISTC and STCU proposals and projects.

Select this Article		Computational Platforms in Environmental Modeling M. M. Aral and J. Guan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)268 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In environmental modeling field, as environmental engineers, we no longer only address modeling issues in association with fate and transport processes, evaluation of large scale optimal remediation design alternatives or reactive modeling of complex chemical mixtures, but we are also asked or expected to provide these models or simulation tools in computationally user friendly environments. This is directly linked to the significant advances made in information technology field recently. In this new and challenging environment, the computational platforms developed should, by design, provide the user the best transparent environment for access to these complex models. The computational platforms that are at our disposal for this purpose are several and includes platforms such as desktop computer based visual computational tools or GIS based computational tools which also now gives us access to visual computational tool platforms. Multimedia Environmental Simulations Laboratory at Georgia Tech is in the process of developing such computational tools to assist engineers and health scientists to conduct environmental and/or health risk modeling in field applications. As an introduction, some of these software tools which are available for general use in public domain will be Reviewed in this paper. These tools are identified as the “Analytical Contaminant Transport analysis System” (ACTS), Spatial Analysis Interface System (SAINTS), Exposure Risk Analysis System (RISK and Watershed Modeling for Disaster Response (WMD‐R). In this paper, we describe the general features of ACTS and WMD‐R since RISK platform is similar to ACTS and SAINTS platform is similar to WMD‐R. Further demonstration of the capabilities of these software platforms with site‐specific applications can be found in other publications of the authors as they are referenced in this paper.

Select this Article		Development of Inductive Receiving Water Model for Application in TMDLs Mohammad Tufail and Lindell Ormsbee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)269 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Various receiving water models, such as HSPF, WASP5, and CE‐QUAL are frequently used in the development of TMDLs, especially in the context of nutrient loadings and DO impacts. In most cases, such models can be extremely data intensive and difficult to use. This paper will discuss the development of two inductive models for DO response to nutrient loadings and its application in the development of a nutrient TMDL for the DO impaired Beargrass Creek in Louisville Kentucky. The associated models were developed using two separate AI modeling techniques: artificial neural networks and genetic programming/genetic algorithms. Data for use in constructing the two models was obtained from continuous water quality monitors that were strategically placed in the downstream reaches of the watershed as well as other discrete sampling for water quality constituents. Modeling of the system response was complicated by backwater effects from the Ohio River. The paper discusses the utility and advantages of use of inductive approach when adequate data sets are readily available.

Select this Article		Evaluation of Capacitive Desalination Technology for Drinking Water Treatment in Rural Alaska Helen Traylor, Ph.D., P.E. and Craig Woolard, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)270 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract One emerging technology with potential for application in rural Alaska and other small communities is capacitive desalinization. This technology utilizes electrodes made from activated carbon fabric coated with a conductive material. When these electrodes are layered into a capacitive cell and a DC power supply is applied, the individual electrodes are charged. Dissolved ions in the water are attracted to the electrode of opposite polarity, thus removing the dissolved ions from solution. These dissolved ions accumulate in the electrode pore structure and are discharged as a concentrated waste stream by shorting the electrodes to ground. Capacitive desalination systems are solid state devices with few moving parts and no requirement for chemical addition. These characteristics suggest that this technology may have the potential for application in rural Alaska. This paper summarizes the preliminary results from a study conducted with an Electronic Water Purifier (EWP) capacitive desalination system manufactured by Sabrex, Inc., on water from Goose Lake (Anchorage, Alaska) and Oscarville, Alaska. Experiments were performed to evaluate the ability of the EWP system to remove the high concentrations of natural organic material (NOM), dissolved inorganics, and organics present in the source waters.

Select this Article		Functionalized Nanoelectrode Arrays for In‐Situ Identification and Quantification of Regulated Chemicals in Water W. Graham Yelton, Michael P. Siegal, and Kent B. Pfeifer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)271 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The nanoelectrode arrays for in‐situ identification and quantification of chemicals in water progressed in four major directions. 1) We developed and engineered three nanoelectrode array designs which operate in a portable field mode or as a distributed sensor network for water systems. 2) To replace the fragile glass electrochemical cells used in the lab, we designed and engineered field‐ready sampling heads combining the arrays with a high‐speed potentiostat. 3) To utilize these arrays in a portable system we designed and engineered a light‐weight high‐speed potentiostat with pulse widths from 2 μsec to 100 msec or greater. 4) Finally, we developed the parameters for an analytical method in low‐conductivity solutions for Pb(II) detection, with initial studies for the analysis of As(III) and As(V) analysis in natural water sources.

Select this Article		Impact of Climate Change on Water Resources in Yongdam Dam Basin, Korea Kim Byung Sik, Kim Hung Soo, Seoh Byung Ha, and Kim Nam Won ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)272 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The main purpose of this study is to investigate and evaluate the impact of climate change on the runoff and water resources of Yongdam basin. First, we construct global climate change scenarios using the YONU GCM control run and transient experiments, then transform the YONU GCM grid‐box predictions with coarse resolution of climate change into the site‐specific values by statistical downscaling techniques. The values are used to modify the parameters of the stochastic weather generator model for the simulation of the site‐specific daily weather time series. The weather series fed into a semi‐distributed hydrological model called SLURP to simulate the streamflows associated with other water resources for the condition of 2CO₂. This approach is applied to the Yongdam dam basin in southern part of Korea. The results show that under the condition of 2CO₂, about 7.6% of annual mean streamflow is reduced when it is compared with the observed one. And while Seasonal streamflows in the winter and autumn are increased, a streamflow in the summer is decreased. However, the seasonality of the simulated series is similar to the observed pattern.

Select this Article		Integrated Chemiresistor Sensors with Preconcentrators for Monitoring Volatile Organic Compounds in Water Clifford K. Ho and Jerome L. Wright ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)273 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Chemiresistor microsensors have been developed to provide continuous in‐situ detection of volatile organic compounds (VOCs). The chemiresistor sensor is packaged in a rugged, waterproof housing that allows the device to detect VOCs in air, soil, and water. Preconcentrators are also being developed to enhance the sensitivity of the chemiresistor sensor. The “micro‐hotplate” preconcentrator is placed face‐to‐face against the array of chemiresistors inside the package. At prescribed intervals, the preconcentrator is heated to desorb VOCs that have accumulated on the sorbent material on the one‐micron‐thick silicon‐nitride membrane. The pulse of higher‐than‐ambient concentration of VOC vapor is then detected by the adjacent chemiresistors. The plume is allowed to diffuse out of the package through slots adjacent to the preconcentrator. The integrated chemiresistor/preconcentrator sensor has been tested in the laboratory to evaluate the impacts of sorbent materials, fabrication methods, and repeated heating cycles on the longevity and performance of the sensor. Calibration methods have also been developed, and field tests have been initiated.

Select this Article		Integrated Hydrologic Modeling Using Distributed Decision Support Robert M. Wallace, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)274 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This presentation describes a dedicated decision support system integrating remote sensors, Internet available data and computational modeling to provide soil moisture information for fire suppression and mobility purposes at the Fort Hood Military Reservation. Results are delivered through GIS enabled backend servers using secure HTTP resources. Multiple levels of Data and modeling results are made available for authenticated users.

Select this Article		Managing Water Resources Systems for Sustainable Development in Underdeveloped Regions Emmanuel U. Nzewi, PhD, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)275 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. West African river basins are characterized by numerous perennial streams such as the Niger, Benue, Volta and Senegal rivers, and agricultural watersheds that are potentially ideal for large‐scale farming as well as for the development of hydropower and the support of major industries. These river systems can provide adequate municipal, industrial and domestic water supply. In addition, there are significant groundwater systems that complement surface water supplies. A sustainable balance must be maintained between water resource needs for industry (particularly the manufacturing and agricultural sectors), and the public and private water supplies. In addition, hydropower production, water quality concerns, local navigation and other miscellaneous uses must be coordinated. Sustainable water resources development in underdeveloped regions involves the implementation of a set of management strategies that will ensure a holistic approach to water allocating water for the major uses. Sustainability, with respect to water resources, can be defined as developing and managing operations (that involve water use) today in a manner that will not prevent or preclude the ability to continue the same operational activities 30 or so years from now. The long‐ and short‐term operating practices must be such that water resource systems are not negatively impacted in these communities so they continue to be healthy places to live and work. Practices for sustainable development, in the context of underdeveloped regions, must be implemented in a meaningful way that considers the areas' circumstances when compared to developed regions. The differences between sustainable development strategies for developed and underdeveloped regions will be highlighted.

Select this Article FREE		Observations of Contamination Warning Systems for Water: What They Should Provide Decision Makers? Kevin M. Morley and J. Alan Roberson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)276 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The tragic events of September 11, 2001 have compelled various sectors responsible for the nations critical infrastructure and key resources (CI/KR) to assess their vulnerabilities and take actions to reduce their exposure to the risk of a terrorist attack. The water sector is no exception and has responded in a variety of ways to address these concerns and needs. One issue of increasing importance to both the water sector and the government is the development of effective contamination warning systems to monitor and detect the contamination of a drinking water supply or distribution system.

Select this Article		An Overview of U.S. EPA Research on Remote Monitoring and Control Technologies for Small Drinking Water Treatment Systems Craig L. Patterson, Roy C. Haught, James A. Goodrich, Christopher A. Impellitteri, and Hector E. Moreno ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)277 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There are approximately 160,000 small community and non‐community drinking water treatment systems in the United States. According to recent estimates, small systems contribute to 94% of the Safe Drinking Water Act violations annually. A majority of these are for microbiological MCL violations. Small drinking water system research is being conducted at the U.S. EPA's Test & Evaluation (T&E) Facility in Cincinnati, Ohio with an emphasis on “package plants” for biological, physical, and chemical treatment of drinking water sources. Research studies are designed to provide guidance to operators of small Public Water Systems to ensure compliance with current regulations including the Surface Water Treatment Rule and the Groundwater Rule. Several U.S. EPA studies have focused on packaged filtration and disinfection systems equipped with remote telemetry units and Supervisory Control and Data Acquisition (SCADA) systems. SCADA systems are commonly used by large (not small) water utilities to control and monitor their operations. However, the constant monitoring requirements for small system operators in remote locations can incur substantial costs in time and travel. Remote monitoring and control systems offer a cost‐effective way to reduce manpower requirements by providing real‐time monitoring of water quality, continuous control of operating conditions, and the reporting of information electronically from a “centralized” location.

Select this Article		Parallelization of a 3‐D Coast Circulation Model for Continental Shelf Circulation—QUODDY Zhiyu S. Shao, Scott A. Yost, and Chunfang Chen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)278 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Numerical simulation of large scale problems has a sharply growing computation demand. One of the solutions of this problem is to apply parallel computing technology. In this paper, the dominant parallel strategy used in engineering application, Domain Decomposition, is discussed and implemented in three parallelization applications. The main focus of this study is a 3‐D finite element model, QUODDY, which solves the linearized shallow water equations forced by tidal or other barotropic boundary conditions, wind and/or density gradients. A 2.5 degree turbulent closure model by Mellor Yamada is utilized in the simulation. The sequential QUODDY code is studied first. Then Domain Decomposition approach implemented in the sequential code. By dividing the task into several smaller portions, the computation time was reduced dramatically. Message Passing Interface (MPI) protocols are used for the communications in all processors. Implementation of MPI improves the portability of the paralleled code. The performance of the parallel code is studied and shows good performance.

Select this Article		Parallelization of the WASH123D Code—Phase II: Coupled Two‐Dimensional Overland and Three‐Dimensional Subsurface Flows Jing‐Ru C. Cheng, Robert M. Hunter, Hwai‐Ping Cheng, Hsin‐Chi Lin, and David R. Richards ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)279 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The parallel WASH123D is designed to simulate watershed systems using a coupled system of one‐dimensional (1‐D) channels, 2‐D overland areas, and 3‐D subsurface media on parallel scalable computers. The U.S. Department of Defense High Performance Computing Modernization Program funds the parallelization of the watershed model through the Common High Performance Computing Software Initiative in order to solve one aspect of the battlespace environment, which includes space, weather, ocean, and soil, to develop a complete coupled battlespace environment. Tasks in this project include parallel algorithm development, software toolkit development, and performance studies. Currently, the parallel version, which includes coupled 2‐D overland and 3‐D subsurface flows, is completed and packaged for application projects, such as calibration and validation of the coupled 2‐D/3‐D Biscayne Bay Coastal Wetland inland flow model presented in this paper, on various computer architectures.

Select this Article		Real‐Time Remote Monitoring of Drinking Water Quality Srinivas Panguluri, Roy C. Haught, Craig L. Patterson, E. Radha Krishnan, and John Hall ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)280 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Over the past eight years, the U.S. Environmental Protection Agency's (EPA) Office of Research and Development (ORD) has funded the testing and evaluation of various online “real‐time” technologies for monitoring drinking water quality. The events of 9/11 and subsequent threats to the nation's infrastructure have expanded the focus of this research. Currently, EPA's National Homeland Security Research Center (NHSRC) is funding additional research to evaluate a variety of remote water quality monitoring (RWQM) technologies. The evaluations focus on the ability of the commercially available technologies to be used as a tool to detect deliberate or accidental contamination of water supply and water distribution systems. This paper highlights some of the lessons learned from the past and ongoing research related to RWQM conducted by EPA at the EPA's Test and Evaluation (T&E) Facility in Cincinnati, Ohio, and other field locations.

Select this Article		Scalability of Integer Programming Computations for Sensor Placement in Water Networks Jonathan W. Berry, William E. Hart, Cynthia A. Phillips, and Jean‐Paul Watson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)281 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Integer programming (IP) is a general optimization technology capable of expressing most resource allocation decisions. More specifically, IP is the optimization of a linear objective function subject to linear contraints and additional nonlinear integrality constraints. For sensor placement problems, discrete decision variables usually represent decisions to place or not place a sensor at a particular network location. Discrete and rational derived variables compute the effect of various attacks. For the past two years, we have investigated a number of IP models for sensor placement with varying public‐health‐related objectives and varying assumptions about input data, water transport, and response. In those studies, we used IP as a tool to explore tradeoffs between number of sensors and population vulnerability. In this study, we focus on IP technology itself, as applied to sensor placement problems. In this paper, we empirically investigate the difficulty of solving some sensor‐placement IPs on various computing platforms. We consider serial solution using commercial codes and parallel platforms using the PICO (Parallel Integer and Combinatorial Optimizer) parallel IP solver. We discuss algorithmic advances that might push the frontiers of tractability.

Select this Article		Scalable High‐Performance Heuristics for Sensor Placement in Water Distribution Networks Jean‐Paul Watson, William E. Hart, and Jonathan W. Berry ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)282 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A number of algorithms have been developed to solve the problem of where to place a limited number of sensors in a water distribution network such that public health protection from accidental or intentional contaminant injections is maximized. However, the ability of these algorithms to solve real‐world, large‐scale sensor placement problems has yet to be demonstrated. Existing research exhibits at least one of three fundamental flaws. First, most algorithms are tested exclusively on small‐scale networks, leaving open the question of scalability. Second, many algorithms are heuristic in nature and no effort has been made to establish empirical or theoretical performance bounds. Third, the modeling assumptions underlying some algorithms are physically unrealistic, raising questions regarding the utility of the resulting solutions in operational settings. We describe a modeling methodology that precisely captures the impact of contaminant injection on a distribution network. Using exact methods, we generate provably optimal sensor placements for networks containing up to roughly 3,000 junctions using high‐performance computing platforms; the magnitude of the model currently prevents solution for larger networks. Next, we use a simple heuristic based on GRASP, local search, and path relinking to quickly generate solutions to even larger networks containing up to 12,000 junctions. Where solvable via exact methods, we demonstrate that the heuristic yields solutions that are globally optimal. These results conclusively demonstrate the practical application of this heuristic to solve very large sensor placement problems under realistic modeling assumptions, and uniquely provides an empirical performance bound for the algorithm.

Select this Article FREE		Use of Continuous Recording Water‐Quality Monitoring Equipment for Conducting Water‐Distribution System Tracer Tests: The Good, the Bad, and the Ugly M. L. Maslia, J. B. Sautner, C. Valenzuela, W. M. Grayman, M. M. Aral, and J. W. Green, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)283 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The use of water‐distribution system models for analyses and assessments of contamination events—including historical, current, and future events—requires a calibrated water‐quality model. Conducting tracer tests by injecting a conservative compound into the distribution system (e.g., calcium chloride) or shutting off an additive compound (e.g., sodium fluoride) and collecting concentration data at selected sampling locations can provide the information required to calibrate a water‐quality model. Spatially large water distribution‐system networks can be complex and may have unknown or variable operational characteristics. Collecting water samples (“grab samples”) to capture unique water‐quality event, such as the passing of a tracer's peak concentration at a sampling location, can be manpower intensive and costly. Also, the tracer front and peak can be missed during the test if a sudden or unplanned change in operational characteristics occurs.

Select this Article		Using Multi‐Node Computers for Assessing Flow and Transport at the Waste Isolation Pilot Plant, Carlsbad, NM T. S. Lowry and R. L. Beauheim ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)284 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Waste Isolation Pilot Plant (WIPP) in southeast New Mexico has been developed for underground disposal of transuranic waste in halite beds of the Permian Salado Formation. Managed by the Department of Energy, the WIPP has been operational since March 1999. The most important water‐bearing unit above the Salado Formation is the Culebra Dolomite Member of the Rustler Formation (Culebra), which lies about 200 m below ground surface and 400 m above the repository. Here, two investigations are conducted using parallel processing that address separate issues in the Culebra that may have an effect on the groundwater flow field in the area surrounding the WIPP site. The first investigation looks at current and future potash mining in the upper Salado Formation, within and outside the WIPP boundary. Potash mining causes subsidence of the Culebra, resulting in higher transmissivities that may change regional groundwater flow patterns. A Monte Carlo approach is used to characterize model uncertainty. The second investigation assesses possible causes for an observed water‐level rise in 17 monitoring wells in the Culebra over the last 10 to 15 years. Two possible scenarios for the rise in heads are: (1) leakage into the Culebra of refining‐process water discharged onto potash tailings piles, probably through subsidence‐induced fractures and/or leaky boreholes; and (2) leakage into the Culebra of water from units above or below the Culebra through poorly plugged and abandoned boreholes. Leakage rates for each scenario are inversely modeled and calibrated to linearized drawdowns of 12 monitoring well hydrographs.

Select this Article		Alaska Highway Construction Billy G. Connor, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)285 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The construction of the Alaska Highway has been hailed as a major engineering project of the 20^th Century, a century of massive infrastructure development in the United States. The construction was completed in two phases: a pioneer road followed by the construction of an all weather road. While numerous text and film documentaries focus on the soldiers and construction workers and the hardships faced, the project hinged on the efforts of the surveyors and professional engineers who selected routes and designed the roadway without the benefit of detailed reconnaissance, soils data, and hydraulic information. Surveyors and engineers performed their tasks admirably in a hostile environment with the sound of bulldozers at their backs.

Select this Article		The Bureau of Reclamation—Its History John Robert Moody ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)286 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. On June 17, 1902, Theodore “Teddy” Roosevelt signed into Law the Reclamation Act to develop the resources of the western states and territories for agriculture. The United States Reclamation Service began the tasks of surveying land, building roads, installing telegraph and telephone lines, and setting up the general infrastructure that would be used to construct the public works required for collecting, storing and conveying water for irrigation. Engineers were sought from colleges and universities to build a cadre of men who could plan, design, construct and operate the dams, power plants, canals, and appurtenant works that still serve irrigation projects and the public today. The first hydroelectric generation was in 1904 at the site of Roosevelt Dam, a key feature of the Salt River Project in Arizona. Early engineers on projects in Montana included Frank Crow who was later the construction engineer for Hoover Dam. The Safety of Dams Act thrust Reclamation into investigations and designs for modifications to make dams safer. Through over a century of water for the west, the men and women of the Bureau of Reclamation planned, designed constructed and maintained the thousands of facilities that made available the water resource conveyed to the land resource for agriculture. Other important benefits included flood control, recreation, fish and wildlife, and municipal and industrial uses. Today, the mission of the Bureau of Reclamation is to manage, develop and protect water and related resources in an environmentally and economically sound manner in the interest of the American Public.

Select this Article FREE		The Columbia Basin Project — Its History and Future John Robert Moody ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)287 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Columbia Basin Project is one of the two projects constructed by the Bureau of Reclamation that were each selected as one of the Top Ten Public Works Projects of the 20^th Century by the American Public Power Association. The Columbia Basin Project includes the Grand Coulee Dam and the 1.1 million agricultural acres designated to be served by water diverted from the Columbia River at Grand Coulee Dam. In the late 1800's, it was recognized that the Columbia Basin with its soils and long summer days of sunshine had the potential for being highly productive if water could be diverted and conveyed into the region. Conceptual plans included an extensive canal system that diverted from the Pend Orielle River at the Idaho‐Washington border conveying water over 130 miles south and west to serve the million plus acres. For an irrigation project of this magnitude, many questions had to be answered, and financial support had to be garnered. Established in 1902, the U.S. Reclamation Service (subsequently renamed the Bureau of Reclamation) undertook general investigations in 1904. Ultimately, a decision was made to divert by pumping from the Columbia River at the north end of the Grand Coulee the annual water supply required to irrigate the 1,100,000 proposed acres lying over 50 miles to the south.

Select this Article		The Early History of Wastewater Treatment and Disinfection Jeanette A. Brown, P.E., DEE, F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)288 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Sanitation practices began as early as 10,000 BC. Environmental engineering methods were used by the Romans and by the Minoan Culture helping to prevent disease in those cultures. The Greeks even imposed a user charge to cover the cost of waste disposal. Later on, events in Europe and England led to environmental regulations and the inventions of various treatment processes to satisfy them. In the 1800's the need for disinfection followed from an understanding of pathogens. Some of the early methods and the various chemicals and equipment needed to feed chemicals into a waste stream are illustrated. Finally the future of wastewater treatment technology and disinfection is discussed.

Select this Article		The Eklutna Water Project Lynda L. Barber‐Wiltse, Ms P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)289 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only. Glacial water is pristine; it has been held in a frozen reservoir for thousands of years, protected from modern day pollution. Across the U.S. and overseas, it is sold and served as a unique product. In Alaska, glacial water is available to many residents simply by turning on the faucet. The Eklutna Water Project delivers water from an alpine glacial lake to people in the Municipality of Anchorage. It is the largest water supply project in Alaska and one of the largest projects of any type in the history of Anchorage. The Eklutna Water Project is a source of pride for Anchorage. It can efficiently and economically treat enough glacial water to meet the needs of the Municipality well into the 21st century. It stands as a prototype for other large scale glacial water treatment projects in cold regions around the world. It also left a legacy of new design standards and construction methods that can be applied across a broad range of civil and structural engineering projects.

Select this Article		The History of the Clean Water Act Ken Kirk Dee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)290 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. America's Clean Water Future … The Need for a Federal Re‐Commitment As a direct result of the Clean Water Act's Construction Grants Program, the United States now enjoys perhaps the most advanced system of regional or “area‐wide” wastewater treatment entities in the world. Secondary treatment is now the norm and many treatment plants have progressed beyond secondary treatment to advanced treatment technologies. Waterways that once were declared dead have been revitalized. Simply stated, the Grants Program was the most successful environmental public works program in the nation's history. It is no wonder that those of us who experienced this period of history not only understand but believe in the great accomplishments that can be achieved through a strong federal‐state‐local partnership. At the same time, we are now concerned about yet another looming water quality crisis directly attributable to the weakening of this historic partnership before the job is complete. Despite the tremendous progress made during the years of the Grants Program (1973–1991), it is clear that we are again losing ground in the battle to protect water quality. We are still far from the “zero discharge” and swimmable/fishable goals of the CWA, with over 40% of the nation's waters remaining impaired. Furthermore, the U.S. Environmental Protection Agency (EPA), the Congressional Budget Office, and the Government Accountability Office all performed their own independent studies of the nation's water infrastructure funding needs. Their estimates show a startling consensus of an estimated gap of $350 billion to $600 billion dollars over the next 20 years to repair and replace aging pipes and treatment works. The presentation will explore how to overcome this funding gap, including the concepts of increased rates, asset management and dedicated federal funding via a trust fund. The presentation will also focus on what the future will look like absent a meaningful federal/state/local funding partnership.

Select this Article		Railroad Building in the Great Land Thomas Brooks, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)291 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This presentation will explore the need, construction and operation of the three major railroads in Alaska, the White Pass and Yukon, the Copper River and Northwestern, and the Alaska Railroad. All three railroads presented engineers and constructors of the day with the unique challenges of Alaska's remoteness, harsh climate, and political machinations. Of the three, two remain in operation today as vibrant, working railroads.

Select this Article		Trans‐Alaska Pipeline System Howard Thomas, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)292 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Alaska has had two OCEA award‐winning projects over the years. The first of these was the Trans‐Alaska Oil Pipeline extending from Prudhoe Bay to Valdez. Mammoth in its scope and undertaking, the 48‐inch‐diameter, 800‐mile‐long pipeline was built to unprecedented environmental standards. It was completed in 38 months by 28,000 workers in June 1977. The system has provided nearly 25 percent of the nation's domestically‐produced crude oil (14 billion barrels) over the past 30 years. The presentation will made by an ASCE member who was a key member of the project design and construction team and is very familiar with issues related to the permafrost terrain it traverses.

Select this Article		What Was the First University to Grant Environmental Engineering Degrees? C. Joseph Touhill, Ph.D., P.E., DEE, F.AIChE, F.ASCE, Nicholas L. Clesceri, Ph.D., P.E., F.ASCE, and Herbert M. Clark, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)293 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The answer to this question is: Rensselaer Polytechnic Institute (RPI). This paper chronicles the foresight of Professor Edward J. Kilcawley and the efforts of his Committee on Environmental Engineering in establishing the nation's first curriculum in the new discipline, environmental engineering. The paper describes the odyssey that began with Professor Kilcawley's August 18, 1954, letter to the RPI Dean of the Faculty on the concept for the new discipline; an odyssey that eventually led to granting of the nation's first accredited environmental engineering degrees in 1961. It also focuses upon important decisions made at RPI that define and influence the practice of the profession even today. Many people, whose names are familiar to engineers who helped to guide and grow the profession, contributed to the founding of the new curriculum and their input will be recognized in the paper. The paper relies upon the extensive library archives at RPI and the memory of one of the original committee members, co‐author Dr. Herbert M. Clark, for proof of RPI's claim to primacy.

Select this Article		Antibiotic Resistance Analysis of Enterococci in Chester Creek Graham R. Stahnke, William Schnabel, Khrys Duddleston, and Tammie Wilson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)294 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Antibiotic Resistance Analysis (ARA) is a technique that can be employed to identify the source of fecal indicator bacteria in rural and urban watersheds. In this ongoing study, ARA is being utilized to investigate the sources of Enterococcus bacteria in Chester Creek, Anchorage, AK. Possible sources of fecal bacteria in the Chester Creek Watershed include waterfowl, moose, bear, beaver, domestic animals, and sewer/septic inputs. Thus far, 170 isolates have been collected and used for ARA. Results to date indicate that the antibiotic resistance of unknown isolates increases with downstream distance. Isolates originating from moose have shown to be resistant to only five of the eleven antibiotics tested, and indicate that antibiotic resistance in moose may depend on the age of the animal. Canine isolates have shown to be primarily resistant to four of the eleven antibiotics tested including CEP, GEN, KAN, and STR. Further isolate testing using ARA is ongoing and more complete results will be presented at the conference.

Select this Article		Application of the AC/TC Bacterial Ratio for Watershed Quality Management of Stormwater Introduced Pathogens Gail M. Brion ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)295 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A new bacterial ratio has been developed and proven by multiple case studies to provide information on both potential source and fecal age. This ratio utilizes the conventional total coliform test, comparing the relative concentrations of different colonies that form on a membrane filter fed by m‐Endo media. These bacterial colonies can be classified into 3 types; typical (TC), atypical (AC), and background. The ratio obtained by dividing the AC by the TC concentrations (AC/TC) defines shifts in populations between indigenous and introduced bacteria, with the indigenous bacteria providing a baseline against which the concentrations of the introduced, fecally‐associated bacteria are evaluated. Different values of the AC/TC ratio can be ascribed different relative pathogen risk levels. When the AC/TC ratio is low (<5), fresh fecal material is being added to surface water and pathogen risk can be expected to be higher. As time passes, the AC/TC ratio increases (>20) and can be related to healthier water quality conditions with respects to pathogens that die‐off in the environment. Different types of fecally impacted runoff are reported to have statistically different AC/TC values with human sewage at the lowest end of the spectrum with a value of 1.5 under normal conditions. Applications of the ratio for detecting hot‐spots of human sewage in a watershed and as a control standard for watershed quality are presented, along with a modeling approach that can reliably predict human enteric virus in stormwater impacted surface water using the AC/TC ratio.

Select this Article		Arsenic (V) Sorption on Crab Shell Based Chitosan Hong Zhang and Silke Schiewer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)296 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This research focuses on studying the sorption of As(V) on crab shell based chitosan. Chitosan contains amino groups, which appear to be responsible for the uptake of As(V). Additionally, the degree of deacetylation (DDA) of the sorbent, which determines both the amount of functional group and the crystallinity of the sorbent, is a very important factor in the sorption process. The DDA was determined by Fourier transform infrared spectroscopy (FTIR). The sorption studies suggest that maximum uptake occurs over the pH range 3–6. Adsorption isotherms indicate that the sorption capacity of the sorbent increased significantly with increasing degree of deacetylation (DDA) from 10% to 80%, but decreases as DDA approaches approximately 90%. These results suggest that chitosan can be used for treating As(V) contaminated waste‐water.

Select this Article		Awwa Research Foundation Overview: Desalination, Salinity and Concentrate Management, and Future Research Plans Jason Allen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)297 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Developing new sources of drinking water presents many challenges, leading water utilities to focus on the optimal use of existing supplies. Salinity is emerging as a serious concern in municipal water supplies. At elevated concentrations salinity, normally measured as total dissolved solids (TDS), can damage crops and landscape plants, impart an unpleasant taste to drinking water, and corrode pipes, cooling towers, and other structures. Currently 17% of the streams in the United States that have “high withdrawal]” for municipal water use have TDS > 500 mg/L (Smith et al., 1994). Desalination technology offers promising strategies for reducing or removing TDS thereby achieving optimal use of existing water sources, however there are numerous hurdles to overcome. Desalination technology is currently very energy‐intensive and results in large volumes of waste streams.

Select this Article		Biosorption of Pb(II) onto Citrus Pectin: Effect of Process Parameters on Metal Binding Equilibrium and Kinetics Ankit Balaria, Silke Schiewer, and Thomas Trainor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)298 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Heavy metals such as lead are persistent in the environment and can accumulate in the food chain, exhibiting toxic effects. Biosorption is considered a reliable, efficient, and low‐cost technique for metal removal from waste water. Citrus peels show particular promise as biosorbents because they are available cheaply as waste products from the fruit juice industry and have been shown to be effective sorbents of aqueous metals. The main biopolymer thought to be responsible for metal binding by citrus peels is pectin. Our current work is focused on developing a better understanding of the interactions between citrus pectin and heavy metals. We utilize macroscopic sorption studies to provide a picture of interactions between Pb(II) and two types of citrus pectins having different methoxy content. The effects of pH and ionic strength on surface charge and metal uptake are studied. Effects of pectin and Pb(II) concentrations, and presence of competing ions on total Pb(II) uptake were also studied. The results obtained suggest highly efficient metal binding with high rate and capacity.

Select this Article		Bubble Entrainment and Distribution in a Model Spillway with Application to TDG Minimization Shae S. Hoschek, Pablo M. Carrica, and Larry J. Weber, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)299 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An experimental study of the two‐phase flow downstream of a model fish bypass is presented. Experiments were carried out on a 1/24 scale model of a fish bypass under study for construction at Wanapum Dam, on the Columbia River in Washington State. The model was operated at the design condition of skimming flow regime, and at the possible off‐design plunging and surface jump regimes. Gas volume fraction data was collected using a specifically built optical phase detection probe on a three‐dimensional grid, and the phase indicator function was recorded at selected locations. It was found that on model scale the skimming flow regime effectively prevents bubbles from reaching deep into the talrace, resulting in considerable lower gas volume fraction than plunging and surface jump regimes. For this geometry, the surface jump regime entrains air deeper than plunging regime. Total dissolved gas (TDG) estimations were made assuming that the bubbles are instantaneously absorbed by the water. The instantaneous source of TDG was computed. Time distributions of the indicator function are also reported.

Select this Article		Bureau of Reclamation Activities and Research in Concentrate Management Scott R. Irvine and M. Kevin Price ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)300 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Bureau of Reclamation (Reclamation) has been investigating and addressing salinity issues related to municipal, agricultural, and industrial water use in the West for more than a century. Likewise, the U.S. Department of Interior (Interior), through the Office of Saline Water (OSW) and the Office of Water Research and Technology (OWRT), has been at the forefront of desalination and concentrate management since the 1950s. Reclamation has funded national research specific to concentrate issues since the mid‐1990s. More recently, Reclamation has collaborated with various other research organizations, utilities, and stakeholders to assess future needs in concentrate management and prepare a roadmap on how to address those needs. A review of Reclamation's activities at various project locations illustrates the challenges in managing concentrate. A summary of research funded by Reclamation helps to identify the areas most promising for finding solutions and setting priorities for the future. Among the identified priorities is the need to better integrate the science of concentrate management into its regulation. The development of concentrate management guidelines directly addresses this need by the involvement of the water users and the scientific and regulatory communities.

Select this Article		Characterization of Lead Dust Emissions at a Recreational Firing Ranges Jack Duggan, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)301 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A soil sampling and analysis study was performed to characterize the distribution and speciation of lead shot and lead species at a recreational skeet and trap range in Eastern Massachusetts. Samples were collected both within and outside of the maximum shot fall zone of the range. Samples were subsequently split into 0–2″, 2–4″ and 4–6″ depth sections. Results reveal that the majority of lead is present at 0–2″ as both lead shot and lead shot fragments retained on #8 and #16 sieves. For each section, a particle size distribution was determined. Samples from each sieved fraction were then analyzed for lead content. Concentrations of lead in respirable soil particles were determined to characterize airborne lead levels generated during remedial recovery operations. In all cases, bulk soil sample concentrations underestimated lead concentrations present in respirable particles. Based on these results, exposures to both on‐site and off‐site receptors were considered. Results indicate that the exposure assessment of dust inhalation from recreational firing ranges should not be performed based on soil concentrations that solely characterize bulk soil levels of lead.

Select this Article		Clay Permeability Changes—Flexible Wall Permeameter & Environmental Scanning Electron Microscope Arunkumar Selvam and Brian Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)302 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Clays and their composites have been widely used in the past for secondary containment walls for underground storage tanks and landfills. These materials, also called liners, are an inexpensive method of preventing seepage of chemicals into the groundwater from underground storage tanks and landfills. In this study the behavior of clay liners is examined on a microscopic level. The clay fabric changes observed in the images from an Environmental Scanning Electron Microscope will be compared to the permeability changes in clay under similar conditions. The permeability changes will be recorded using a Flexible Wall Permeameter. The presented observations will have important ramifications for clay modification to reduce seepage of chemicals through the clay liner. The experiments are being planned currently and results will be presented at the conference.

Select this Article		Climate Change and Human Health: Infrastructure Impacts to Small Remote Communities in the North John A. Warren, P.E., James E. Berner, MD, and Tine Curtis, PhD ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)303 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In northern regions, climate change can include changes in precipitation magnitude and frequency, reductions in sea ice extent and thickness, and climate warming and cooling. These changes can increase the frequency and severity of storms, flooding, or erosion; other changes may include drought or degradation of permafrost. Climate change can result in damage to sanitation infrastructure resulting in the spread of disease or threatening a community's ability to maintain its economy, geographic location, or cultural‐tradition leading to mental stress.

Select this Article		Concentrate Management: Status of the Joint Water Reuse & Desalination Task Force Research Program J. J. Mosher and J. M. Casteline ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)304 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Membrane processes of seawater, brackish water, and reclaimed water represent one of the fastest growing segments of the water and wastewater treatment market. As of 2002, approximately 461 water and wastewater treatment plants in the United States larger than 25,000 gallons per day (gpd) use membrane technologies. However, environmentally responsible management and disposal of the resulting concentrates at an affordable cost is a significant challenge to water and wastewater utilities and industry. The management and disposal of concentrate is a significant issue for both inland (i.e., landlocked) cities and coastal regions. Inland communities, which are without access to large saline water bodies, must find environmentally acceptable methods to dispose of concentrate. Inland communities in California, Arizona, Nevada, New Mexico, Texas, Florida, and other states do not have access to a large saline water body to dispose of concentrate and other disposal options may be limited.

Select this Article		Delay between Sensing and Response in Water Contamination Events Elizabeth Bristow, S.M.ASCE and Kelly Brumbelow, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)305 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Determining the consequences of a water contamination event is an important concern in the field of water systems security. Morbidity and mortality resulting from such a contamination are influenced in part by the amount of contaminated water consumed and the time between consumption and medical treatment. Water quality sensors in the water distribution network may shorten this time and help the users avoid the contaminant's adverse effects by alerting authorities to unusual water quality parameters; otherwise, the authorities may first suspect contamination when the victims begin seeking treatment. Once the irregular water quality parameters have been detected, some time may still elapse before all users stop consuming the contaminated water. Modeling this additional delay is the focus of this paper. This delay has been divided into five independent, sequential processes. The first phase is the amount of time required to transmit the sensed or measured contaminant concentrations to the local authorities. The second process includes the authorities' efforts to verify that there is a genuine contamination event. The third stage includes any measures that the authorities take in preparation to alerting the public to the threat including agency coordination, drafting announcements, contacting media, and printing flyers. The fourth phase of the delay is the time required to transmit the news of the contamination to the public. The final period encompasses the time elapsed while the system users, after being informed of the contamination, decide whether or not to comply with instructions on how to avoid the adverse effects. Probability distributions are constructed for the duration of each phase of the delay based on data collected from historical water contamination events and other disasters and characteristics of typical sensor networks. The entire response process is modeled using a Monte Carlo approach to determine probability distributions of response delay.

Select this Article		Detection and Control of Combined Sewer Overflow Events Using Embedded Sensor Network Technology Timothy P. Ruggaber, M.ASCE and Jeffrey W. Talley, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)306 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The American Society of Civil Engineers considers combined sewer overflow (CSO) control the greatest water/wastewater infrastructure need in the United States and estimates that it may cost up to $45 billion to solve. CSOs fill their receiving waters with pathogens, nutrients, and organic matter, which can lead to human illness and the eutrophication of these water systems. A wireless embedded sensor network may be a cost effective method of monitoring and controlling the flow of the sewage in the combined sewage lines resulting in a reduction in the number and severity of CSO occurrences. This in‐situ system is able to turn an existing “dumb” control system into one that is able to adjust and act on its own in response to changing flow conditions with minimal alterations to the current system. Prototypes are currently being evaluated to support a field deployment in sections of the South Bend, Indiana storm water/wastewater distribution network in the summer of 2005. Wireless sensor networks have already been successfully tested in the two lakes on the University of Notre Dame campus as a part of design evalution for full‐scale network.

Select this Article		Enhancing Oxygen Transfer in Subsurface‐Flow Constructed Wetlands T. P. Chan, N. R. Shah, T. J. Cooper, J. E. Alleman, and R. S. Govindaraju ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)307 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Conventional subsurface‐flow constructed wetlands (SFCW) for wastewater treatment are typically designed as horizontal plug‐flow vegetated beds. Limited oxygen, provided mostly by slow transfer through air‐water interface, turns these systems anaerobic, thus requiring a long hydraulic retention time (HRT) to achieve desired effluent quality. A SFCW treatment system with biofield effluent disposal has been designed and constructed for the highway I‐70 rest area station near Greenfield, Indiana. A number of features were incorporated into the design of this system in an effort to enhance oxygen transfer. They include 1) a pair of parallel wetlands that can be operated in a cyclic “draw‐and‐fill” scheme — allowing filling of one wetland while draining the other, and 2) a vertical filter with coarse gravel at the front section of each wetland cell. It is expected these modifications can significantly improve biological oxygen demand (BOD) and nitrogen removal, therefore reducing the HRT of the system. This paper presents details of the modified design, flow and treatment data from the first year of operation, and early experience gained during this period.

Select this Article		The Environmental Impact of Cruise Ships Juliette Commoy, MSE, Catherine A. Polytika, MSE, Rebecca Nadel, and Jonathan W. Bulkley, Ph.D, F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)308 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The impact of cruise ships on the environment is an important issue that needs to be addressed in order to mitigate damage to the surrounding ecosystem. Cruise ships generate significant quantities of wastes that the industry disposes of with surprisingly little regulation. For example, the cruise ship industry is not subject to the same environmental standards as land‐based industries. Furthermore, where there is regulation, there is often marginal enforcement. Due to the concentration of cruise ships in a small number of environmentally sensitive areas, the potential environmental impacts of the industry are intensified. As the size of the cruise ship industry increases, the need to regulate the environmental effects of cruise ships is becoming more urgent. The cruise ship industry is very large and is rapidly expanding. In 1998, more than 223 cruise ships worldwide carried an estimated 9.5 million passengers. Many of these cruise ships are the size of small cities. Between 2002 and 2005, cruise ship companies plan to add 51 more ships to the fleet, many of which are larger than any existing cruise ships. As the size of the cruise ship industry increases, so does the industry's potential for causing adverse environmental impacts. The first section of this paper provides an introduction to the cruise industry and a description of the different waste streams generated daily by a typical cruise ship. It also describes the consequences of pollution on the environment. The next section discusses current regulations and their efficiency in regulating waste streams. The next section addresses the actions being taken to mitigate the environmental impact of cruise ships and provides an assessment of the effectiveness of these actions. Finally, the last section provides recommendations on future actions needed to reduce adverse environmental burdens and impacts arising from cruise ship operations.

Select this Article		Estimating Urban Landscape Evapotranspiration Simon Eching and Richard L. Snyder ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)309 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Irrigation controllers can greatly assist in automating landscape irrigation scheduling and if properly used and routinely adjusted, controllers can improve water use efficiency. They are now widely used to manage landscape irrigation. A new generation of controllers, the so called ET controllers, have recently entered the market. ET controllers scheduled irrigation based on evapotranspiration data, which are either entered manually or automatically downloaded to the device. Although this is an improvement over the older controllers, site specific information such as microclimate, plant type, plant density, and stress conditions may be required. However, scientifically‐based information on these parameters is limited. In California, as in most of the west, the landscape industry is huge and growing and there is increased competition among water users. Consequently, managing irrigations to optimize efficient water use is critically important to stretch existing water supplies. The MS Excel ® program LIMP.XLS was written to help landscape professionals and homeowners to calculate ET_o rates, determine landscape coefficient (K_L) values, estimate landscape evapotranspiration (ET_L) and determine irrigation schedules.

Select this Article		Evaluation of Point‐Of‐Use and Centralized Treatment Systems for Arsenic Removal in Small Drinking Water Systems in Alaska D. A. Persinger and C. R. Woolard, P.E., Ph. D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)310 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In 2006 the EPA's new regulation for arsenic in drinking water will go into effect. Approximately 75 of the regulated public water systems in Alaska will be out of compliance with this new regulation. This paper summarizes two years of research on arsenic removal technologies at the University of Alaska Anchorage, School of Engineering. Two reverse osmosis Point‐of‐Use (POU) systems, a Kinetico and a Culligan Good Water system, were evaluated for six months on private wells in West Anchorage. The Kinetico reduced arsenic concentrations by 49% and the Culligan system by 53%. A Multi‐Pure absorptive media POU system was monitored for one year at a private well in West Anchorage. This system reduced arsenic concentrations by 99.3%. An Adedge Point‐of‐Entry absorptive media system was monitored at a 15‐housing unit condominium at Big Lake. This system performed well reducing arsenic levels by 95.3%.

Select this Article		EWRI Task Committee Efforts on Establishing Concentrate Management Guidelines for Desalination and Water Reuse Michael Hightower and Patrick Brady ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)311 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract At present, there are no industry‐wide concentrate management performance standards for the types of desalination and water reuse technologies identified in the recently completed “Desalination and Water Purification Technology Roadmap”. Additionally, brackish and sea‐water desalination and concentrate management regulations vary significantly from state‐to‐state, region‐to‐region, and internationally. For example, the best management practices recommended for concentrate disposal in one state may not be allowed in an adjoining state. In other cases, receiving water quality criteria either do not exist, or may require a concentrate stream's quality to be significantly better than the quality of the receiving water. As desalination and water reuse become an increasingly larger part of our water supply and water use portfolio, improved guidance and standards on environmentally, ecologically, and economically sound management practices for desalination and water reuse concentrate are needed. Several organizations including the American Water Works Association, Ground Water Protection Council, Water Reuse Foundation, and the Environmental Protection Agency are working cooperatively through an American Society of Civil Engineers‐Environmental and Water Resources Institute task committee to develop a consensus ‐based assessment and provide recommendations and guidance on sound concentrate management practices for new and existing desalination and water reuse facilities of all sizes. The task committee was established in early 2004, and this paper provides an overview of the goals, objectives, and progress of the committee.

Select this Article		Field Comparison of Optical and Clark Cell Dissolved‐Oxygen Sensors Janice M. Fulford, William J. Davies, and Lisa Garcia ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)312 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Three multi‐parameter water‐quality monitors equipped with either Clark cell type or optical type dissolved‐oxygen sensors were deployed for 30 days in a brackish (salinity <10 parts per thousand) environment to determine the sensitivity of the sensors to biofouling. The dissolved‐oxygen sensors compared periodically to a hand‐held dissolved oxygen sensor, but were not serviced or cleaned during the deployment. One of the Clark cell sensors and the optical sensor performed similarly during the deployment. The remaining Clark cell sensor was not aged correctly prior to deployment and did not perform as well as the other sensors. All sensors experienced substantial biofouling that gradually degraded the accuracy of the dissolved‐oxygen measurement during the last half of the deployment period.

Select this Article		Getting to Zero Waste—Wisconsin's Efforts to Minimize Global Climate Change Steven D. Brachman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)313 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The State of Wisconsin has been a leader in recycling and waste reduction for a number of years. With the passage of 1990 Recycling and Waste Reduction Act 335, the State banned over 15 items from landfill disposal and created a series of financial mechanisms to further waste reduction efforts. Since the Act's passage, the State has provided over $300 million in grants and loans to municipalities and businesses and achieved a 40% reduction from landfill disposal. However, despite this significant effort, many materials are still being landfilled. Based upon these results, more recent attempts have been made to address problem materials. The UW‐Extension, in cooperation with staff and students from the Milwaukee School of Engineering, has targeted several key materials for waste reduction efforts. These include: (1) Electronic equipment, especially TVs and computers; (2) wood wastes and (3) mercury containing materials. These studies have indicated that further reduction of these materials will lead to significant reductions of green house gas emissions, decrease the toxicity of waste disposal, and lead to less reliance on landfill disposal. This paper will highlight these research findings as well as the strategies being proposed and implemented to achieve further reductions in Wisconsin's municipal solid waste.

Select this Article		Greenhouse Gas (GHG) Emissions from Publicly Owned Treatment Works (POTWs) and Innovative Abatement Technologies—A Review S. Rao Chitikela, Ph.D., P.E., DEE and S. Chandran, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)314 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Several wastewater and solids treatment and fuel combustion operations within POTWs produce air contaminant emissions including greenhouse gases (GHGs). Specifically, the processes that would cause the CO₂, CH₄, and N₂O GHG emissions were identified and their global warming potentials were reviewed. The stoichiometric relationships of bioprocesses of wastewater treatment that cause GHG emissions were reviewed and reported in this paper. Additionally, the CO₂, CH₄, and N₂O emission factors of fuel combustion operations were included. Recommendations and processes, such as fuel cell operation using anaerobic digester gas and microbial fuel cells (MFCs) for continuous electricity production using municipal and industrial anaerobic processes, were included for future review and direction of POTW operations.

Select this Article		Greenhouse Gases and Animal Agriculture: Extent of Problem and Controls William F. Ritter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)315 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The livestock industry is a major contributor of greenhouse gases (GHG) in the U.S. Enteric fermentation accounted for methane emissions of 114.9 Tg CO₂ equivalent from livestock in 2001. Livestock manure methane emissions were 39.0 Tg CO₂ equivalent and nitrous oxide emissions were 58.0 Tg CO₂ equivalent. The largest source of GHG emissions from manure was beef, followed by dairy and swine. Anaerobic lagoons contributed the most to GHG emissions from dairy cattle manure. The largest source of GHG emissions from swine manure was from deep pits followed by anaerobic lagoons. Covering of anaerobic lagoons and utilizing the gas is one technology that can be used to reduce methane emissions. Reducing the nitrogen excreted in the manure through diet manipulation will reduce nitrous oxide emissions.

Select this Article		Host Specific Differences in Fatty Acid Methyl Ester Profiles of Indicator Organisms as a New Tool for Microbial Source Tracking Metin Duran and Berat Z. Haznedaroglu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)316 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this study is to test the hypothesis that indicator organisms isolated from different host categories, i.e., from human and animal, would have distinctly different whole‐cell fatty acid profiles that can be used to track sources of microbial pollution. The FAME profiles fecal coliforms (FC) isolated from feces of poultry, bovine, swine, waterfowl, deer and sewage samples were investigated. Stool samples from several individuals within each host category were collected and cultured on selective and differential media. A known source library was constructed with 314 FC isolates cultured from five possible sources of fecal pollution; 99 isolates from sewage; 29 from bovine; 29 from poultry; 50 from swine; 46 from waterfowl; and 61 from deer. Whole‐cell fatty acids were extracted from isolated FC and quantified by a gas chromatograph with flame ionization detector (GC/FID). A linear discriminant function differentiated FC isolates of human origin from those of livestock and wildlife origin at 99% accuracy. The same discriminant function was used to predict sources of 37 FC isolates cultured from water samples taken from a well‐protected natural pond where the only significant source of fecal matter was known to be waterfowl. As expected, 81% of the pond isolates were classified as wildlife while the remaining 19% were identified as livestock. These results provide evidence that the FAME profiles of indicator organisms show statistically significant host specificity and have the potential to be used as a phenotypic Microbial Source Tracking (MST) tool.

Select this Article		A Hybrid Meshing Scheme for Environmental Studies Based on Surface Feature Detection Sebastian Rath, Erik Pasche, Kai Kaapke, and Volker Berkhahn ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)317 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Measurements, experiments and numerical simulations together provide the essential information for forecasts and decisions in environmental engineering. Predominantly, the use of numerical simulations relies on the methods of finite elements, finite differences, finite volumes or Lattice Boltzmann. Numerical simulations in hydrodynamics commonly describe the topography in terms of meshes, which are supposed to give an appropriate approximation of the terrain as achieved by field measurements. Nowadays, the approximation of the terrain via meshes makes use of high resolution topographic survey data, such as LiDAR, InSAR or echo sounding bathymetry. This paper focuses on triangular mesh generation for remote sensing data, applicable for numerical simulations based on the finite element method. Triangle meshes in an irregular adjustment are called triangular irregular networks (TIN). Accuracy and efficiency of the suggested approach are verified for an application in flood hazard assessment and for a typical discharge event.

Select this Article		Implementation of a Pilot Scale Evapotranspiration Landfill Cover for Use in Cold Regions William. J. Lee and William E. Schnabel, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)318 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This manuscript describes an ongoing study designed to test the viability of an evapotranspiration (ET) landfill cover as an alternative to a compacted clay cap (CCL) in South Central Alaska. A key component of the study involves the development of real time in situ soil moisture profiles via electrical resistivity tomography (ERT). Two adjacent pilot‐scale caps were constructed in Anchorage, Alaska and will be monitored over a period of five years. The first cap, a CCL cap, was constructed to meet or exceed the specifications provided in Alaska Administrative Code 18 AAC 60.395(a) at the time of project planning. This cap contains a 15 cm (6 inch) erosion layer planted with grass underlain by an “impermeable” (K_sat < = 1 × 10⁻⁵ cm/sec) compacted clay layer ] 46 cm (18 in.) thick. The alternative cap, an ET cover, consists of a 60 cm (2 ft.) layer of high water holding capacity soil planted with a locally‐obtained mixture of approximately 80% balsam poplar (Populus balsamifera)/black cottonwood (Populus trichocarpa) or hybrids thereof, 10% quaking aspen (Populus tremuloides), and 10% little leaf/golden willow (Salix alba Vitel, S. arbusculodies). The two competing caps (10m × 20m each) were constructed within basin lysimeters in order to allow for the measurement of moisture running off or percolating through the bottom of the caps. A water balance is being performed for both caps. Water inputs and outputs as well as other relevant climactic and soils data are being measured in near real time. Evapotranspiration, the only variable in the water balance not directly measured, is being estimated via the Penman‐Monteith equation (1), on‐site sap flow instrumentation, and as a function of the water balance. The soil frost depth is being computed with the Richardson equation as given by Emerson. Each cap has an ERT array installed. These arrays measure the soil resistivity in Ohm‐meters. The resistivity values will be used to compute volumetric soil moisture as well as provide a cross‐sectional indication of frost penetration.

Select this Article		Implementing New Air Quality Standards for Incinerators F. Jason Martin, P.E., M.ASCE and Don Rensner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)319 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract On December 1, 2000 the U.S. Environmental Protection Agency (EPA) issued 40 CFR 60 Subpart CCCC, New Source Performance Standards (NSPS) for Commercial and Industrial Solid Waste Incineration (CISWI) sources constructed after November 30, 1999 or modified after June 1, 2001. These standards protect public health by reducing exposure to air pollution, including dioxins, particulate matter, and metals. Facilities must comply with emission limitations and operating limits; submit a siting analysis and a waste management plan; meet operator training and qualification requirements; and perform operational monitoring activities under this NSPS. On August 4, 2004 the first incinerator in the United States to be regulated by this standard was put into operation by CNH America LLC (CNH) in Wichita, Kansas. This paper describes the basics of the CISWI NSPS and discusses the NSPS interpretation and implementation issues encountered during the permitting and start‐up process for this incinerator. Important lessons include defining regulatory authority for the CISWI NSPS, a successful petition to EPA for non‐standard operational limits, and surviving a typographical error in the printed regulation that was identified after the unit began operating.

Select this Article		A Laboratory Study of Sediment Phosphorus Flux in the Latian Dam Reservoir S. Isazadeh, M. Tajrishy, A. Nazari, and A. Abrishamchy ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)320 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Latian dam is located on the Jajrood River in the northeast of Tehran the capital of Iran. It is one of the most important water supply reservoirs in this city and supplies 30 percent of the total water demand of 11 million people in this city. This research measures phosphorus release from sediments of Latian Dam and the role of the tubifex in phosphorus release. Because of sediment composition variation, sediment sample were taken from two points in the Latian dam. The sediments were analyzed for total phosphorus, the form of phosphorus and release rate under different conditions of water column and the absence or present of tubifex. The results show that the amount of phosphorus are equal in the two points of the dam but the sediments that have clay in their texture have a greater phosphorus release rate than the sediments that have sand in their texture in anoxic periods. Furthermore in the Latian Reservoir the tubifex has been shown to contribute significantly to the phosphorus release.

Select this Article		Managing Mosquitoes in Stormwater Treatment Devices Marco E. Metzger ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)320.2 Full Text: \| Download PDF
	+ -	Show Abstract The federal Clean Water Act, as amended in 1987, requires states to develop and implement nonpoint source pollution management programs (see Copeland 1999, 2003). These mandated programs require that certain measures be taken to abate pollutants carried by rainwater and urban (i.e., dry weather) runoff, herein collectively referred to as stormwater runoff. A principal component of stormwater programs is the implementation of Best Management Practices (BMPs), a term first adopted in the 1970s to represent actions and practices used to reduce the flow rates and the constituent concentrations in runoff (WEF and ASCE 1998).

Select this Article		Managing Surface Water for Flood Damage Reduction Suresh Hettiarachchi, Bob Beduhn, Jeff Christopherson, and Matt Moore ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)321 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The South Washington Watershed District (SWWD) initiated a study of the Wilmes Lake Subwatershed (Figure 1) to quantify the flood risk and identify potential solutions to minimize flood damage potential. The study was initiated following completion of the 2002 minor plan amendment for the SWWD Plan. The technical work associated with preparing the minor plan amendment identified flooding potential in the Wilmes Lake Subwatershed. The purpose of this report is to provide information for use in the SWWD's major plan amendment currently being prepared by the SWWD. The base model used for the Wilmes Lake Subwatershed was taken from previous work done by the SWWD for the 2002 Minor Plan Amendment. The base model utilizes year 2000 aerial photographs and topography collected by Washington County and supplemented with site specific elevation and location surveys conducted by the SWWD to acquire additional information in key areas. A complete GIS database was generated to track the source data and create a metadata file. The SWWD chose to utilize the hydrologic and hydraulic model XP‐SWMM version number 75, dated February 27, 2003, to develop the hydrologic and hydraulic information necessary for the Minor Plan Amendment. The non‐linear reservoir method in XP‐SWMM was used to estimate the runoff hydrographs from the land surface. These resultant hydrographs were then routed through the drainage system's network of ponds, pipes and channels using the EXTRAN block of XP‐SWMM.

Select this Article		Modeling the Effect of Ozonation on Acid Yellow 17 Dye in a Semi‐Batch Bubble Column Laura W. Lackey and Richard O. Mines, Jr ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)322 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A pilot‐scale ozonation process employing a semi‐batch column was used to study the removal of acid yellow dye 17 from synthetic wastewater in a semi‐batch bubble column. The effect of initial dye concentration on system performance was evaluated. This study utilized an 11.12‐L, clear, PVC column that was filled with 8‐L of tap water tainted with the acid yellow 17 dye for each experimental run conducted. Ozone was supplied to the system by sparging the gas through three porous stainless steel filters fixed in the reactor 0.15‐m from the bottom of the column. The ozone supply rate was held constant at 3.78 L/min. Acid yellow 17 dye concentration (measured‐as‐A₄₀₀), chemical oxygen demand (COD), five‐day biochemical oxygen demand (BOD₅) and the quantity of ozone utilized was measured as a function of ozonation time during each experimental run. Results indicate that ozonation is very effective at removing acid yellow 17 dye from synthetic textile wastewater. The biodegradability of the dye in the synthetic wastewater was evaluated by monitoring changes in BOD₅ with respect to COD. The initial BOD₅:COD ratio was 0.0083 and over time increased by an order of magnitude to a maximum ratio of 0.126 at 30 minutes. These results indicate that the biodegradability of the wastewater increased with an increase in ozonation time. Two‐film theory was used to kinetically model the gas‐liquid reactions occurring in the reactor. Modeling results indicated that during the first 10 to 15 min of ozonation, the system could be characterized by a fast, pseudo‐first order regime. By combining a differential mole balance on the gas phase ozone concentration within the reactor with film theory, this initial period of the ozonation reaction was successfully modeled. With continued ozonation, system kinetics transitioned through a moderate then to a slow regime. Successful modeling of this period required use of a kinetic equation corresponding to a more inclusive condition. Model results are presented.

Select this Article		Mosquito Production from Storm Water Catchment Systems in Michigan Michael G. Kaufman, Alicia K. Bray, Danielle Makowski, and Edward D. Walker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)323 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Culex mosquito production from storm water catchment systems in urban and suburban areas affects the potential for transmission of West Nile virus and other mosquito‐borne viruses in urban areas. We quantified mosquito associations with wet and dry retention ponds, mitigated wetlands, and street catch basins in urban sites in Michigan in longitudinal, sampling studies in 2003 and 2004. Larvae and pupae of Culex pipiens, the primary vector of West Nile virus in eastern North America, were most commonly associated with dry retention ponds and were rare in wet retention ponds and mitigated wetlands. By contrast, larvae of Culex territans (whose adult females bite frogs) and of Anopheles species were associated with wet retention ponds and mitigated wetlands. Catch basins were commonly colonized by Culex pipiens and produced them heavily, but unevenly depending upon physical location of the catch basin (curbside gutter, or lawn) and by nature of the water input (street wash or combination of street wash and house sump system). These studies suggest management strategies to limit Culex production based upon engineering principles and biological associations.

Select this Article		Multidimensional Simulation of the Two‐Phase Flow Downstream of Spillways for Total Dissolved Gas Prediction M. Politano, P. Carrica, C. Turan, and L. Weber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)324 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Elevated supersaturation of the total dissolved gas (TDG) concentration in water may cause gas bubble disease (GBD) in fish. Spillway discharges at hydropower dams are the main source for TDG supersaturation in the Columbia and Snake basins in the Northwest. Since the most important source for TDG is the mass transfer from the bubbles, a proper model for TDG prediction must account for the two‐phase flow found in the stilling basin. Some numerical studies had been conducted in the past to predict TDG, most of them relying on experimental models for the gas phase distribution. A better approach is possible through the use of mechanistic models that rely less on empirical information. We use a mixture two‐phase flow model to predict the gas distribution, TDG concentration, and bubble number density on the stilling basin. The method used in this work assumes one variable bubble size, which may change due to mass transfer and local pressure. The equations of the proposed model were implemented into the commercial code FLUENT through UDS's and UDF's. The multidimensional fields of TDG, gas volume fraction, bubble sizes and velocities of the bubbles are presented and discussed. The TDG concentration downstream of spillways was calculated and compared against available field data. Effects on the overall flow caused by the aeration introduced by the spillways are discussed.

Select this Article		A Neural Network Based Classification Scheme for Sorting Sources and Ages of Fecal Contamination in Water Gail M. Brion, Srinivasa Lingireddy, and T. R. Neelakantan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)325 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Artificial neural network (ANN) modeling that used a set of simple bacterial measurements and informational inputs was successfully applied to data observations from a small watershed for the purposes of distinguishng between human sewage and animal‐impacted runoff, fresh runoff from aged, and agricultural land use associated fresh runoff from that of suburban land‐use associated fresh runoff. The ANN approach was able to classify sewage from heavily contaminated runoff with greater than 99% accuracy. Turbidity was found to be relatively unimportant as an input variable for sorting sewage from runoff, while gross measurements of gram‐negative and gram‐positive bacteria were required. ANN classification of aged suburban runoff from fresh, and agricultural runoff from suburban was accomplished with greater than 90% accuracy.

Select this Article		A Numerical Simulation of Evapotranspiration Landfill Cover Performance at Three Cold‐Region Locations William Schnabel, William Lee, and David L. Barnes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)326 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The use of evapotranspiration (ET) covers for final closure of landfills has seen increased use over the last several years. This increase is in part due to economics and public acceptance. The ideal climatic regions for the use of ET covers are arid and semi‐arid regions. To date the use of ET covers has not been thoroughly investigated in cold regions. The purpose of this paper is to investigate the use of ET covers in Alaska. Water and energy balances were calculated for hypothetical ET covers using daily weather data during the period 1986 to 1999 for the three population centers in Alaska ‐ Juneau, Anchorage, and Fairbanks. The SHAW (Simultaneous Heat and Water) model was used to make these calculations. Results from these simulations show that an ET cover would most likely be effective if used in regions with climatic conditions similar to Fairbanks and possibly Anchorage depending upon the type of soil selected. According to this analysis, these results are due to relatively cold and dry winters in these regions as well as the period of maximum evapotranspiration roughly corresponding with the period of maximum precipitation.

Select this Article		A Py GC/MS Investigation of Dissolved Organic Matter and DBPs Sarah Seelen, Daniel White, Ph.D., P.E., Craig Woolard, Ph.D., P.E., Vincent Autier, and Kenji Yoshikawa, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)327 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Dissolved organic matter (DOM) is present in nearly all surface waters and many groundwaters used for domestic water supplies. The standard analyses for organic matter in water, DOM and color, provide very little information about the character of the organic matter, or its potential to serve as a disinfection by‐product (DBP) precursor, biological substrate, or membrane foulant. Pyrolysis‐gas chromatography/mass spectrometry (py‐GS/MS) is an analytical tool commonly used to create a molecular ‘fingerprint’ of DOM. Py‐GC/MS was used to analyze DOM in drinking water well, artesian spring, and stream water samples collected over the past four years from two discontinuous permafrost watersheds near Fairbanks, AK. DOM was characterized on a molecular level to better understand its role in water source development and drinking treatment. This paper will summarize findings that relate DOM chemistry to source identification, membrane treatment, and DBP formation.

Select this Article		Sizing UV Disinfection Systems for Water Reuse Douglas E. Jones, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)328 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In 2003, the City of Auburndale's Raymond Allred Wastewater Treatment Plant (WWTP) became the first facility in Florida constructed to meet the Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse, published in December 2000 by the National Water Research Institute / American Water Works Association Research Foundation (NWRI/AWWARF). These guidelines, and the 2003 revisions, serve as the design basis for high‐level UV disinfection systems at wastewater treatment facilities in Florida. The NWRI/AWWARF guidelines establish minimum design requirements for UV disinfection of filtered reclaimed water. An integral part of the guidelines is performance‐based testing in which the dose delivery capability of the UV reactor is experimentally validated. The Auburndale WWTP will serve as a “case study” of how to utilize the performance‐based testing results to properly size UV disinfection systems for reuse applications. This will include establishing an acceptable minimum dose, reactor layout, and redundancy requirements. In addition, actual operating data from the Auburndale UV system will be reviewed and compared to permit requirements.

Select this Article		Soil‐Lead Contamination Screening Tool Maria S. Marin, Lance Franklin, and Carol J. Miller, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)329 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of this study is to review existing data of soil lead contamination in the Detroit metropolitan area and evaluate the sources and the impacts of this contamination in human health and the environment. Contamination in surficial soils, surface water, and river sediments are considered in this review. An efficient field testing method for soil lead determination has been developed to further investigate the frequency, significance and sources of urban soil lead contamination.

Select this Article		Sources of Greenhouse Gases at Mineral Quarries and Review of Innovative Operational Methods Kristian Witt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)330 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Quarries are generally considered sources of particulate matter (PM); however, they may be considered a large source of certain greenhouse gas. These sources include, but are not limited to, cement kilns, lime kilns, asphalt plants, non‐road diesel engines, and mobile sources. This paper includes the review of potential sources of greenhouse gas at mineral quarries, and their significance compared with other major industries. Additionally, the potential control strategies using some innovative operational methods were reviewed.

Select this Article		Storm Event Monitoring in the Great Smoky Mountains National Park R. B. Robinson, C. Roby, J. Buchanan, T. Barnett, and S. E. Moore ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)331 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Baseline stream water pH in the Great Smoky Mountains National Park is generally good, however, over 95% of the streams have alkalinity less than 10 mg/L as CaCO₃ making them susceptible to large pH drops during acidic storm events. Recent stream monitoring has given a better understanding of how stream water quality responds to storm events. Four multi‐parameter water quality loggers or sondes and three co‐located auto‐samplers were installed along a stream reach in the Great Smoky Mountains National Park. The sondes recorded pH, conductivity, turbidity (three sondes), temperature, and stage every 15 minutes. The data have showed pH drops to as low as 4.0 which is consistent with the precipitation pH in the region. This poor water quality in storm events is suspected to be partly to blame for extirpation of native brook trout. Water samples representative of various portions of a storm hydrograph were analyzed for alkalinity, pH, major ions, and a suite of trace metals including aluminum, copper, and zinc. Metals analyses of storm event samples showed increases in some trace toxic metals (Al, Cu, and Zn) during storm events and exceedences of water quality criteria. Concentration‐duration‐frequency curves of pH and turbidity sonde were constructed to show how frequently the pH is below a given level and for how long.

Select this Article		Sustainable and Climate Sensitive Hydrologic Design and Management of Hydrosystems Ramesh S. V. Teegavarapu and Lindell Ormsbee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)332 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Understanding the impacts of climate change on hydrologic design and management of hydrosystems is one of the important challenges faced by practicing hydrologists and water resources management professionals. Insufficient hydrologic record lengths become hindrance to explain the natural variability and effect of future climatic changes on the hydrologic design. However, many hydrologic design methods that rely on the peak discharges need to take into consideration the impact of climate change on major inputs influencing the behavior of hydrologic systems. Revisions are required for design procedures and modeling tools that help in management of hydrosystems. Examples of such revisions include use of renewed Intensity‐Duration‐Frequency (IDF) curves in hydrologic designs and inclusion of soft‐computing approaches such as fuzzy theory in mathematical programming tools. The paper discusses issues related to impacts of climate change on hydrologic design and application of soft‐computing approaches for sustainable and climate sensitive management of hydrosystems. Real‐life case studies are presented for assessing the applicability of soft‐computing approaches wherever possible.

Select this Article		On‐Line Submission: U S Postal Service Southeast Area Water Program Initiatives Carroll Burgess, Asif Ansari, and Southeast Area Environmental Team ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)333 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Southeast Area (SEA) of the United States Postal Service (USPS) encompasses five states: Florida, Georgia, Alabama, Mississippi and Tennessee. SEA maintains over 3,500 postal facilities including approximately 100 large processing plants and vehicle maintenance facilities. The SEA has a workforce of over 90,000 employees and operates a fleet of approximately 24,000 delivery and administrative vehicles. The SEA generates annual revenue of approximately $7 billion. Nine postal districts—or geographic delivery regions covering specific zip codes—comprise the SEA. One of the ongoing initiatives of the SEA is the development and improvement of existing environmental programs, such as the SEA's Water Program. The USPS's internal Environmental Compliance Review (ECR) trend analysis indicates approximately 22% of non‐compliance findings at USPS SEA facilities have been related to the federal Clean Water Act (CWA). Based on this analysis, the SEA used an environmental management systems (EMS) approach to water compliance and management to demonstrate that it is fulfilling its obligations to customers, employees, and the environment. Using EMS principles, compliance “gaps” were identified by reviewing results from the “most common findings” of the ECR Program. The SEA developed the Water Program (SEA Water Program) based on the “gaps” analysis. The SEA's Strategic Plan focuses on enhancing the SEA's overall environmental performance while simultaneously achieving the commitments of the USPS Transformation Plan, including fostering growth, improving operational efficiency and enhancing performance based culture. One of the ongoing initiatives of the SEA is the development and improvement of existing programs, such as the SEA' Water Program. This submission focuses on the FY02–FY04 achievements of the SEA's Water Program and demonstrates how the Program represents the SEA's commitment to use an EMS approach to enhance existing environmental programs.

Select this Article		Using Stable Carbon and Nitrogen Isotope Analysis to Construct Food Web Models along the Truckee River Christa Fay and Laurel Saito ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)334 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The Truckee River is an important resource for the state of Nevada. It is a water supply and hydropower source for the cities of Reno and Sparks and supplies water to agricultural lands in the Lahontan Valley. According to an assessment completed by the United States Geological Survey in 1998, it appears that influences on water quality and associated biological activity are detrimentally affecting the food web in the river. The construction of food web models using stable carbon and nitrogen isotopes will enhance the understanding of anthropogenic impacts on aquatic communities. These models incorporate stable carbon and nitrogen isotope data from samples collected in August 2002 and March and August 2003 and 2004. Excel's Solver module will be used to construct the models by minimizing deviations between predicted and observed stable isotope signatures while simultaneously solving for diet proportions of all food web species, and estimating carbon and nitrogen signature trophic enrichment factors. The food web models are linked to base signatures provided by periphyton samples. Results of the food web sampling and modeling are presented. Models such as these have the potential to aid in bioassessment by helping to determine how the food web within the river will change as species are introduced or eliminated and as carbon and nitrogen sources change due to anthropogenic impacts.

Select this Article		Voluntary Emission Reductions at a 300 MGD Municipal Wastewater Treatment Plant Thomas A. Henning, P.E., M.ASCE, Jeffrey Schilling, and F. Jason Martin, P.E., CHMM, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)335 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Concern of the effects of global warming has increased interest in emissions of greenhouse gases. The US Department of Energy and some states, including Wisconsin, have developed voluntary greenhouse gas reduction reporting programs to promote activities that reduce greenhouse gas emissions or sequester carbon. The Milwaukee Metropolitan Sewerage District (MMSD) has elected to participate in the Wisconsin program using emission reductions that occur from activities at the South Shore Wastewater Treatment Plant. This paper provides an overview of the MMSD voluntary emission reduction program and presents the amount of emission reductions achieved at the South Shore plant. Digester gas is used to power blower engines that supply air to the secondary aeration system. Digester gas is also used in boilers and an on‐site generator that supplies electricity to the plant. We present activities at the plant that are eligible to be included in the program and methodologies for estimating greenhouse gas emission reductions.

Select this Article FREE		Water Resources/Environmental Engineering Ethics Steven K. Starrett, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)336 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The NSPE Code of Ethics states that engineers shall: hold paramount the safety, health and welfare of the public, work only in areas of competence, issue public statements only in an objective and truthful manner, act as a faithful agent, avoid deceptive acts, and conduct yourself honorably and responsibly to enhance the honor, reputation, and usefulness of the profession. The ASCE Code of Ethics follows these same ideas and also requires engineers to provide learning opportunities for those engineers that are under their supervision.

Select this Article		The Application of Fuzzy System with Recursive Least Squares Method to Mid and Long‐Term Runoff Forecast Fang Liu, Jian‐Zhong Zhou, Jun‐Jie Yang, and Fang‐Peng Qiu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)337 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Focused on the characteristics of runoff forecast, this paper applies a fuzzy system with recursive least squares method to mid and long‐term runoff forecast. The fuzzy system has advantage of combining natural language and data information. With Single Value Fuzzifier, Product Inference Engine, Center Average Defuzzifier and Gaussian Membership Function, this system works as a universal approximating in the application. In the case study, the runoff records of Big huofang reservoir are analyzed. The final forecast results show that the proposed fuzzy system provides explicit insights into historic system behavior and is valid in mid and long‐term runoff forecast.

Select this Article		A Dynamic Programming for Searching Rule Curves C. Chaleeraktrakoon and A. Kangrang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)338 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Rule curves are basic guides for operating a reservoir system. This paper thus formulates a dynamic programming (DP) for searching the optimal rule curves. The programming technique is appropriate for the searching due to its staged characteristic. The formulated DP can be applied to a single or multiple reservoir systems. The DP has been applied to find the optimal rule curves of the Bhumibol and Sirikit Reservoirs (the Chao Phraya River Basin, Thailand). Results have been used for assessing the rule curves of accepted simulation practice. It can be concluded that the simulation approach does not ensure to always yield the optimal rule curves of the considered systems.

Select this Article		Evaluation of Advanced Genetic Algorithms Applied to Groundwater Remediation Design Marcia S. Hayes and Barbara S. Minsker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)339 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Optimal design of a groundwater pump and treat system is a difficult task, especially given the computationally intensive nature of field‐scale remediation design. Genetic algorithms (GAs) have been used extensively for remediation design because of their flexibility and global search capabilities, but computational intensity is a particularly difficult issue with GAs. This paper discusses a new competent GA, the hierarchical Bayesian Optimization Algorithm (hBOA), which is designed to reduce the computational effort. GAs operate by assembling highly fit segments of chromosomes (potential solutions), called building blocks. The hBOA enhances the efficiency of this process by using a Bayesian network to create models of the building blocks. The building blocks are nodes on the network, and the algorithm uses the network to generate new solutions, retaining the best building blocks of the parents. This work compares the performance of hBOA to a simple genetic algorithm (SGA) in solving a case study to determine if any benefit can be gained through the use of this approach. This work demonstrates that hBOA more reliably identifies the optimal solution to this groundwater remediation design problem.

Select this Article		Expert Knowledge in Long‐Term Groundwater Monitoring Optimization Process: The Interactive Genetic Algorithm Perspective Meghna Babbar, Barbara Minsker, and Hideyuki Takagi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)340 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In most practical water resources optimization applications, a number of important subjective issues exist that cannot be represented in numerical optimization procedures. Considering these issues only in a post‐optimization analysis of solutions by the expert (engineers, stakeholders, regulators, etc.) does not ensure that the final set of optimal designs address all qualitative issues important to the problem. The Interactive Genetic Algorithm (IGA) promises to overcome these hurdles by involving the expert directly in the online search process to steer the genetic algorithm to a solution or set of solutions that address both quantitative and qualitative criteria. This paper investigates the effect on the overall search process when a single user interacts with the IGA system. Some of the salient control parameters that affect performance of such a framework are algorithmic control parameters (i.e. the GA settings, visualization interfaces, etc.), human control parameters (i.e. the user's cognitive perception, user's degree of risk aversion, human fatigue, etc.), and external control parameters (i.e. environmental noise and uncertainty, etc.). This work begins a rigorous assessment of the effects of different control parameters on the IGA search process by simulating the human decision making process using fuzzy logic models of human preferences as ‘pseudo humans’. Comparison of such a system with a conventional optimization framework (that lacks progressive user feedback) is made for a long‐term groundwater monitoring optimization problem, and related ramifications are highlighted.

Select this Article		A Genetic Programming‐Based Surrogate Model Development and Its Application to a Groundwater Source Identification Problem Emily Zechman, Baha Mirghani, G. Mahinthakumar, and S. Ranji Ranjithan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)341 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This paper investigates a groundwater source identification problem in which chemical signals at observation wells are used to reconstruct the pollution loading scenario. This inverse problem is solved using a simulation‐optimization approach that uses a genetic algorithm to conduct the search. As the numerical pollution‐transport model is solved iteratively during the heuristic search, the evolutionary search can be in general computationally intensive. This is addressed by constructing a surrogate modeling approach that is able to predict quickly the concentration profiles at the observation wells. A genetic program is used in the development of the surrogate models that provides an acceptable prediction performance. The surrogate model, which replaces the numerical simulation model, is then coupled with the evolutionary search procedure to solve the inverse problem. The results will illustrate 1) the performance of the surrogate model in predicting the concentration compared with the predictions using the original numerical model, and 2) the quality of the solution to the inverse problem obtained using the surrogate model to that obtained using the numerical model.

Select this Article		Hybrid Evolutionary Search Methods for Training an Artificial Neural Network Elias G. Bekele and John W. Nicklow, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)342 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent decades, hydrologic models have become increasingly complex in order to better simulate the physical processes that occur in watersheds. Highly detailed modeling, however, comes only at the expense of increased computational requirements. Such computational demand is typically not problematic while simulating hydrologic responses of a watershed for predefined land management policies; however, it is a major drawback when repeated simulations are required as part of an iterative, decision management approach. This paper presents a hybrid evolutionary search method for training an Artificial Neural Network (ANN) that will simulate hydrologic responses (e.g., flows, sediment and nutrient yield) and economic profits that can be generated as a result of particular watershed landscapes. The ANN is trained to mimic outputs of the comprehensive, but computationally intensive, hydrologic model known as Soil and Water Assessment tool (SWAT). The hybrid search method is derived by combining a Particle Swarm Optimizer (PSO) and the Back Propagation algorithm (BP). Test results indicate that the developed data‐driven models are capable of simulating SWAT outputs with greatly reduced computational demands. The ultimate goal of this study will be to integrate this SWAT‐based ANN for use in a watershed management decision model.

Select this Article		The Impact of Objective Function Formulations on the Optimal Calibration of QUAL2E R. K. Goktas and A. Aksoy, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)343 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Successful calibration and verification of a model is important to confirm its usage for water quality predictions. Instead of trial‐and‐error approach, optimization techniques can be used to adjust the biological, chemical, and kinetic parameters in a more efficient way. In this study, a genetic algorithm (GA) is used to calibrate and verify QUAL2E for the reaeration coefficient (K₂) and the sediment oxygen demand rate (K₄) with reference to dissolved oxygen (DO) observation data. Three different objective functions were used to investigate the impact of formulation itself on the performance of the optimization models. The results show that for the river system considered in this study, objective function formulation may have an impact for a successful outcome.

Select this Article		Integrating Ecological Flow Regimes in Water Resources Management Using Multiobjective Analysis Jian‐Ping Suen, J. Wayland Eheart, and Edwin E. Herricks ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)344 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water resources management has shifted from flow regulation applications designed to protect public health to applications that include restoration of natural flow regimes and protection of aquatic ecosystems. The ecological flow regime uses a regime‐based approach that considers hydrologic variability instead of focusing on identifying flows or flow targets for aquatic ecosystems. It determines environmental flow by embracing the multitude of species within an ecosystem rather than emphasizing a single species. In addition, the ecological flow regime recognizes that flow magnitude, duration, frequency, timing, and predictability must be incorporated into any flow management strategy. This paper provides a multi‐objective approach to integrating ecosystem and human needs in water resources management. The ecological flow regime analysis provides a surrogate for ecosystem needs in analyzing the trade‐offs with human water usage. The non‐dominated sorting genetic algorithm (NSGA II) is used to find the Pareto set of operating rules for evaluation of reservoir operation for the Dahan River basin in Taiwan. It provides decision makers with the trade‐offs between shortages in water available for human needs and ecological flow regime maintenance.

Select this Article		Interactive Genetic Algorithms for Inverse Groundwater Modeling: Issues with Human Fatigue and Prediction Models Abhishek Singh, Barbara Minsker, and Hideyuki Takagi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)345 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents an interactive multi‐objective evolutionary optimization based approach to solve the inverse problem of estimating heterogeneous aquifer parameters (in this case ‐ hydraulic conductivity) for a groundwater flow model. A hypothetical aquifer, for which the ‘true’ parameter values are known, is used as a test case to demonstrate the usefulness of this method. It is shown that using automated calibration techniques without using expert interaction leads to parameter values that are not consistent with site knowledge. In such cases, it is desirable to incorporate expert knowledge in the estimation process to generate more reasonable estimates. An interactive approach is proposed within a multi‐objective framework that allows the user to evaluate trade‐offs between the expert knowledge and other measures of numerical errors. For the hypothetical aquifer, this type of expert interaction is shown to produce more plausible estimates. A major issue with interactive approaches is ‘human fatigue’. One way of dealing with human fatigue is to use machine learning to model user preferences. This work presents some initial results that show that machine learning models can be used to augment user interaction, allowing the IGA to find good solutions with much less user effort.

Select this Article		Investigation and Demonstration of an Evolutionary Computation‐Based Model Correction Procedure for a Numerical Simulation Model Emily Zechman, G. Mahinthakumar, and S. Ranji Ranjithan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)346 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Traditional model calibration attempts to correct a model so that the model output will match a set of system observations by tweaking a set of model parameters. Potential model structural error limits, however, the effectiveness and accuracy of calibration, undermining the predictive capabilities of the calibrated model. An evolutionary computation‐based model error correction procedure that couples an evolutionary algorithm and a genetic program was previously developed and tested for two analytical models. Due to nonuniqueness in the solution space, numerous forms of correction terms that similarly fit the observation data were found. This procedure is further investigated to explore and identify alternative correction terms that not only provide a good fit but also results in good prediction performance. This approach is then demonstrated using a numerical groundwater contaminant transport simulation model.

Select this Article		Multiobjective Tools and Strategies for Calibrating Integrated Models Yong Tang and Patrick M. Reed ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)347 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Although integrated models provide a more realistic representation of the water balance within a watershed, their nonlinearity and large numbers of physical parameters necessitate new tools and strategies for automatic model calibration. There is a need to extend prior work on calibrating hydrologic models to the multiobjective domain because single objective measures are unable to account for distinctly different responses within a watershed's hydrograph (e.g., high flow, low flow, average flow). This paper is investigating the computational efficiency and effectiveness of a suite of evolutionary multiobjective optimization algorithms in calibrating a multi‐state semi distributed hydrologic model for the Shale Hills watershed located within the Valley and Ridge Province of the Susquehanna River Basin in north central PA. In this study, the impacts of parameter dimension and alternative formulations are being assessed. Different metrics for assessing algorithmic convergence and solution diversity are evaluated based on the optimization results. This study will provide the first comprehensive assessment of evolutionary multiobjective tools' relative effectiveness in calibrating integrated hydrologic models.

Select this Article		Optimal Groundwater Remediation Design Using Trust Region Based Metamodels within a Genetic Algorithm Shengquan Yan and Barbara Minsker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)348 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Computational cost is a critical issue for large‐scale water resource optimization problems that often involve time‐consuming simulation models. Less accurate approximation (“meta”) models can be used to improve computational efficiency. We propose a novel trust‐region‐based metamodel framework, in which hierarchically trained metamodels are embedded into a genetic algorithm (GA) optimization framework to replace time‐consuming numerical models. Numerical solutions produced from early generations of the GA, along with solutions dynamically sampled from later generations, are used to retrain the metamodels and correct the GA's converging route. A bootstrap sampling technique is used to cluster the collected numerical solutions into hierarchical training regions and then multiple metamodels are trained based on these clustered regions. The hierarchically trained metamodels are then used to approximate the numerical models. A trust region testing strategy selects the most appropriate metamodels for prediction. This allows the local regions (particularly those near the optimal solution) to be approximated by smoother and smaller metamodels with higher accuracy. This can speed up GA's convergence when the population moves into local regions. The technique was tested with artificial neural networks (ANNs) and support vector machines (SVMs) on a field‐scale groundwater remediation case in a distributed network computation environment. Our preliminary results show that the adaptive meta‐model GA (AMGA) with the trust region based training technique converges with higher accuracy with the same computation effort.

Select this Article		Optimal Load Allocations by Linkage of Evolutionary Optimization Algorithms with Inductive Models of Watershed Response Mohammad Tufail and Lindell Ormsbee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)349 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Two separate optimization strategies (genetic algorithm and box complex method) are compared in the development of optimal nutrient load allocations for the water quality‐impaired Beargrass Creek Watershed in Louisville, Jefferson County, Kentucky. The optimal load allocations are determined by linking the optimization algorithms with receiving water inductive models developed for the lower reaches of the watershed. The inductive models are developed from (1) a synthesis of both input and output response variables as derived from a continuous simulation of the watershed using a calibrated HSPF model, and (2) a synthesis of the continuous and discrete water quality data sampled over the last 2 years in the watershed. Inductive model construction is performed by use of artificial neural networks and the use of functional fixed‐set genetic programming. The use of inductive models provides a more computational efficient framework for linkage with an optimization model for use in developing an optimal loading strategy.

Select this Article		Salient Issues in Comparing Performance of Multi‐Objective Evolutionary Algorithms Joshua B. Kollat, M.ASCE, Yong Tang, M.ASCE, and Patrick M. Reed, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)350 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Numerous performance metrics have recently been developed to assist in evaluating the relative effectiveness of evolutionary multi‐objective optimization (EMO) algorithms. Comparison of EMO algorithms is extremely challenging because performance metrics must account for both convergence (distance from true objective tradeoffs) and diversity (representation of full extent of objective tradeoffs). This paper demonstrates how to effectively compare the performance of different EMO implementations using two state‐of‐the‐art performance metrics (ϵ‐performance and the binary ϵ‐indicator metric) and identifies some of the difficulties that arise in assuring that the chosen metric is as informative as possible. Two EMO performance comparison case studies are presented: (i) a performance comparison on a suite of two‐objective test functions and (ii) a performance comparison of a hydrologic model calibration problem. Results of the first case study indicate that the ϵ‐performance metric can provide a great deal more run‐time information concerning algorithm performance than the binary ϵ‐indicator metric which only provides comparative information regarding final performance. Case study two demonstrates a different problem type whereby the computational constraints of the problem limit the ability of the ϵ‐performance metric in providing sufficient performance information. In this case, the binary ϵ‐indicator metric is more robust at providing the most information concerning algorithm performance.

Select this Article		Stochastic‐Lagrangian Model (SLAM) for NAPL Remediation Felipe P. Espinoza and Carl G. Enfield ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)351 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Mass removal technologies are widely used to remediate sites contaminated with NAPLs. These technologies work by injecting fluids that modify the properties of the contaminant facilitating its removal from the soil matrix. Numerical models are a useful tool in evaluating and designing NAPL remediation systems. Traditional constitutive finite difference and finite element models are complex and expensive to apply. For this reason, this paper deals with the application of a simplified stochastic‐Lagrangian model (SLAM) for advective dominated transport. The model is calibrated using tracers (partitioning and non‐partitioning). For the application of this model, the hydraulic properties are defined as a random variable and the NAPL structure by four different configurations: uniform, lognormal, uniform correlated to the velocity field, and lognormal correlated to the velocity field. The problem is formulated in two ways: coupled, evaluating hydraulic and NAPL properties simultaneously; and uncoupled, evaluating hydraulic properties in first place (with non‐partitioning tracer) and then the NAPL properties (with partitioning tracer). The parameters of the model are evaluated by means of a genetic algorithm designed explicitly to solve the problem. The results show that the new algorithm takes one average 90% less effort to solve the problem when compared with the traditional Simple Genetic Algorithm (SGA).

Select this Article		Stream Flowrate Prediction Using Genetic Programming Model in a Semi‐Arid Coastal Watershed A. Drunpob, N. B. Chang, and M. Beaman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)352 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Effective water resources management is a critically important priority across the globe. The availability of adequate fresh water is a fundamental requirement for the sustainability of human and terrestrial landscapes, and the importance of understanding and improving predictive capacity regarding all aspects of the global and regional water cycle is certain to continue to increase. One fundamental component of the water cycle is stream discharge. Stream flowrate prediction is not only related to regular water supply for human, animal, and plant populations, but also relevant for the management of natural hazards, such as drought and flood, that occur abruptly resulting in economic loss. Efforts to improve existing methods and develop new methods of stream flow prediction would support the optimal management of water resources at all scales in space and time. Recent advances in genetic programming technologies have shown potential to improve the prediction accuracy of stream flow rate in some river systems by better capturing the non‐linearity of the features embedded in a system. This study elicits microclimatological factors in association with the basin‐wide geological environment, exhibits the derivation of a representative genetic programming model, summarizes the non‐linear behavior between the rainfall/run‐off patterns, and conducts stream flow rate prediction in a river system given the influence of dynamic basin features such as soil moisture, soil texture, vegetative cover, air temperature, and precipitation rate. Three weather stations are deployed as a supplementary data‐gathering network in addition to over 10 existing gage stations in the semi‐arid Nueces River Basin, South Texas. An integrated database of physical basin features is developed and used to support a semi‐structure genetic programming modeling approach to perform stream flowrate predictions. The genetic programming model is eventually proved useful in forecasting stream flowrate in the study area where water resources scarce issues are deemed critical.

Select this Article		Two‐Dimensional Modeling of Tidally Influenced Ground Water Level Fluctuations I. M. M. Hemmings, M.A.Sc. and S. M. Harris, M.A.Sc., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)353 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A two‐dimensional groundwater flow model was developed to evaluate potential groundwater remedial alternatives for a site located on a peninsula along the northwest coast of Washington State. The peninsula is flanked on either side by tidal estuaries. The model was developed using the saturated‐unsaturated groundwater flow model MODFLOW‐SURFACT99. Tidal fluctuations of up to approximately 4 meters (m) twice daily induce significant groundwater level fluctuations within the peninsula requiring that transient groundwater flow conditions be represented in the model to provide a reasonable assessment of alternative remedial designs. Challenges encountered during model calibration are presented and discussed. In particular, differing results were obtained using the pseudo‐soil water retention functions implemented in MODFLOW‐SURFACT99 versus the relationships of relative permeability versus water phase saturation and pressure head versus water phase saturation described by van Genuchten. Further, although borehole stratigraphy indicates the absence of a continuous low permeability layer in the shallow portion of the peninsula, the model calibration demonstrated that the numerous discontinuous silt and clay lenses that are observed throughout the deposit impart a confining to semi‐confining effect on groundwater flow conditions at depth. Following model calibration, the model was applied to evaluate the performance of various groundwater remedial designs. The simulation results for a potential remedial alternative are presented.

Select this Article		Using Sequential‐Self Calibration Method to Identify Conductivity Distribution: Conditioning on Tracer Test Bill X. Hu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)354 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Based tracer tests, a geostatistically based iterative inverse method is presented for mapping spatial distribution by conditioning on nonreactive/reactive tracer breakthrough data. A streamline‐based, semi‐analytical simulator is adopted to simulate solute movement in a heterogeneous aquifer. The simulation is used as the forward modeling. In this study, the hydraulic conductivity is assumed to be a deterministic or random variable. Within the framework of the streamline‐based simulator, an efficient semi‐analytical method is developed to calculate sensitivity coefficients of the solute concentration with respect to the changes of conductivity. The calculated sensitivities account for spatial correlations between the solute concentration and parameters. The performance of the inverse method is assessed by a synthetic tracer test conducted within an aquifer with distinct spatial feature of heterogeneity. The study results indicate that our iterative inverse method is able to identify and reproduce the large‐scale heterogeneity patterns of the aquifer.

Select this Article		Analysis of the Primal and Dual Problem for Long‐Term Groundwater Monitoring Spatial Optimization Yuanhai Li and Amy B. Chan Hilton ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)355 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Long term monitoring (LTM) can be costly given the large number of sampling locations monitored at given site. Redundant monitoring wells in the existing LTM network make it possible to remove some of them while maintaining data reliability from the remaining wells. We can optimize a monitoring network design by maximizing cost‐effectiveness without compromising data quality. Alternatively, decision makers may define their LTM goal depending on the budget; they may set a low number of monitoring wells and identify the best combination of sampling points among all remaining monitoring wells. The problem of LTM spatial optimization is a non‐linear one. We formulate the LTM optimization problem in two ways: one is to minimize the number of remaining wells given constraint rules on data quality and estimation errors; the other is given the number of remaining wells, the objective is to determine the optimal combination of a reduced set of wells from among the original ground water monitoring network. Here we reverse the role of the number of remaining wells from objective function to constraint, and we call the former optimization formulation the primal problem and the latter the dual problem. An ant colony optimization (ACO) method is developed to solve these problems based on field data. The ACO method is inspired by the fact that ants are able to find the shortest route between their nest and a food source. Individual ants can contribute their own information by pheromones; and the shorter the path, the higher the density of pheromones. Increased pheromones will attract the ant colony to choose the shortest route. Two ACO algorithms for LTM optimization are developed in this work — one based on a binary combinatorial formulation and the other is analogous to the traveling salesman problem (TSP).

Select this Article		Analytical Tools for Modeling Natural Attenuation Processes at Chlorinated Solvent Contaminated Sites T. P. Clement, K. K. Lee, and V. Srinivasan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)356 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The current version of the USEPA model BIOCHLOR cannot be used to predict transport involving different retardation factors. In addition, BIOCHLOR also cannot describe non‐sequential biodegradation reactions. Both these limitations are associated with the assumptions involved in the multi‐species analytical solution strategy employed by the BIOCHLOR model. In this study, we use a novel analytical solution framework that can help avoid these limitations. Two example problems are solved to demonstrate the robustness of the analytical strategy to model natural attenuation processes at chlorinated solvent sites.

Select this Article		Aquifer Parameters in Confined Porous Media Kristi Bayless and Avdhesh K. Tyagi, F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)357 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper is part of a series of topics that will be included in a manual currently compiled by Task Committee on Aquifer Parameters in Porous and Fractured Media. The purpose of the manual is to present the state‐of‐the‐art methods available to evaluate aquifer parameters under various flow conditions in porous and fractured media. This paper presents the development of Theis and Jacob methods to evaluate storativity and transmissivity in confined aquifers.

Select this Article		Carbon Capture and Sequestration Options for Power Sector Ram G. Narula, Harvey Wen, and Kenneth Himes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)358 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper addresses carbon dioxide (CO₂) removal and storage options. It also examines three major fossil fuel technologies used in bulk power generation and assesses the impact on cost of electricity (COE) of CO₂ removal, transport, and storage for each of these technologies.

Select this Article		Comparison of Multi‐Objective Evolutionary Algorithms for Long‐Term Monitoring Design Joshua B. Kollat, M.ASCE and Patrick M. Reed, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)359 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Long‐term groundwater monitoring (LTM) design is an extremely challenging problem, which requires that engineers capture an impacted system's governing processes, elucidate human and ecologic risks, limit monitoring costs, and satisfy the interests of multiple stakeholders (e.g., site owners, regulators, and public advocates). Prior studies have shown that evolutionary multi‐objective optimization (EMO) tools can aid decision makers by providing rapid assessments of the tradeoffs between conflicting design objectives (e.g., minimizing sampling costs and minimizing uncertainty). This study compares the performance of several EMO algorithms (the NSGAII, the ϵ‐NSGAII, and the ϵMOEA) for supporting LTM design. The EMO algorithms are used to quantify tradeoffs for a four‐objective LTM test case. Optimization objectives include: (i) minimize sampling cost, (ii) maximize mapping accuracy while (iii) minimizing uncertainty, and (iv) minimize contaminant mass estimation error. A 25‐well LTM test case has been enumerated to provide a reference Pareto‐optimal solution set to facilitate rigorous testing of the EMO algorithms. The performances of the three algorithms are assessed and compared using three published performance metrics (convergence, diversity, and ϵ‐performance). Results of the analysis indicate that the ϵ‐NSGAII performs the most reliably and ultimately attains the highest performance on this application. In addition, the ϵ‐NSGAII's ability to adaptively size its population and automatically terminated its run make it an appealing algorithm to the water resources practitioner by simplifying EMO search.

Select this Article		Conjunctive Use of Surface and Groundwater Resources with Emphasis on Water Quality M. Karamouz, M. Mohammad Rezapour Tabari, R. Kerachian, and B. Zahraie ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)360 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a methodology for conjunctive use of surface and groundwater resources with emphasis on water quality is developed using Genetic Algorithms (GAs) and the Artificial Neural Networks (ANNs). Water supply with acceptable quality, reduction of pumping costs, and controlling the groundwater table fluctuations are considered in the objective function of the model. In the proposed methodology, the results of a groundwater simulation model are used to train the ANNs based simulation model. This model is then linked to the GA based optimization model to develop the monthly conjunctive use operating policies. The proposed model is applied to the surface and groundwater allocation in the irrigation networks in the southern part of Tehran, the capital city of Iran. Tehran metropolitan area has annual domestic water consumption close to one billion cubic meters. The sewer system is mainly consisted of the traditional absorption wells. Some part of this sewage is drained into local rivers and drainage channels and partially contaminates the surface runoff and local flows. These polluted surface waters are used in conjunction with groundwater for irrigation purposes in the Southern part of the Tehran. The results of the proposed model show the significance of an integrated and systems approach to surface and groundwater resources allocation in the study area. For example, the cumulative groundwater table variations in each zone, which has experienced a total fluctuation of more than ±20 meters in the last 20 years, is limited to ±5 meters over the planning horizon

Select this Article		Cost‐Effective Sampling of Groundwater Monitoring Wells: A Data Review & Well Frequency Evaluation Maureen Ridley and Don MacQueen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)361 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Lawrence Livermore National Laboratory (LLNL) uses the Cost‐Effective Sampling (CES) program for reviewing groundwater data and optimizing the site's groundwater monitoring plan. The CES program produces a data assessment sheet and a lowest‐frequency sampling schedule for each groundwater monitoring location. The assessment sheet and recommended sampling schedule greatly streamline the data review process and provide useful information for regulatory and remedial decision‐making. The determination of sampling frequency for a given location is based on trend, variability, and magnitude statistics. The underlying principle is that a location's schedule should be determined primarily by the rate of change in concentrations observed there in the recent past. The larger the rate of change, whether upward or downward, the greater the need for frequent sampling. Conversely, where little change is observed, less sampling is recommended. In 1992, CES was approved by the U.S. EPA — Region IX and the local regulators for use at LLNL, and became part of the LLNL's approved compliance monitoring plan. Applying the CES methodology produced, initially, a 40% reduction in the annual number of required groundwater samples, and with recent optimization of the program a 55% reduction has been produced. This reduction saves LLNL $530,000 annually in sampling, data management, and analysis costs.

Select this Article		Development of a Remediation Optimization Model for Fort Ord Site OU2 Omar Beckford and Amy B. Chan‐Hilton ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)362 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The former Fort Ord is located approximately 80 miles south of San Francisco near Monterey Bay in Monterey County, California. Fort Ord was placed on the EPA's National Priorities List (NPL) mainly due to the VOCs found in groundwater under the site. Fort Ord contains two landfills which were used for residential and commercial waste disposal. Fort Ord's Site OU2 is currently using pump‐and‐treat remediation with granular activated carbon (GAC), and the system has been in operation since 1995. It is anticipated that the existing pump‐and‐treat system will need to be in place for an extended period in order to reach the aquifer cleanup levels (ACLs). In an effort to reduce the time to cleanup while meeting regulatory restrictions, a mathematical optimization model is developed for this site. This work applies Groundwater Modeling Software (GMS) version 5.1 to Fort Ord's Site OU2 for optimal groundwater remediation under uncertainty. GMS version 5.1 contains a Geographic Information System (GIS) module that facilitates the import and export of aquifer data. Additionally, GIS tools from the map module of GMS are used to develop hydraulic conductivity and boundary conditions for the site. GIS tools will also be used as a post‐optimization procedure to compare solutions based on concentration contours, total pumping, total remediation period and costs. The research presented here will be used to develop a tool for identifying optimal remediation strategies for site OU2 using GMS version 5.1 with the enhanced multi‐objective robust genetic algorithm (EMRGA). This research will begin a new path of research for multi‐objective GAs, GMS, and GIS. The combination of an optimization algorithm with GMS has great potential to bring valuable new insights on groundwater characterization, contaminant transport, and remediation optimization.

Select this Article		Development of Novel Tracer Techniques for Better Understanding of Karst Transport Characteristics and Surface Water Influences Randall W. Gentry, Larry McKay, Alice Layton, and John McCarthy ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)363 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The primary concern for surface water influenced systems is to limit the risk associated with Giardia cysts and Cryptosporidium oocysts. Published research indicates that Cryptosporidium and Giardia can survive for months in some aquatic environments, are resistant to chlorination, and may cause infection in small numbers. Karst aquifers are generally expected to be the more susceptible to this type of contamination than granular aquifers, because of the rapid flow velocities and lower potential for filtration in these systems. However, even in karst aquifers, flow rates and recharge characteristics can vary greatly, so not all wells or springs in these settings may be considered as groundwater under the direct influence (GWUDI) of surface water. The purpose of this research is to develop and test alternative methods for assessing GWUDI in karst aquifers using advanced microbial (PCR‐based molecular) and isotopic techniques. The study will include a comparison of the efficacy of these methods with current EPA protocols and other common indicators of microbial contamination. These new techniques will also be evaluated for consideration in describing the transport characteristics of microbial organisms in a karst subsurface environment. This is an on‐going study in the very early stages. This paper will present the experimental design and conceptualization.

Select this Article		Direct Electrolytic Reduction of Energetic Compounds (hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine and 2,4,6‐trinitrotoluene) in Groundwater Altaf Wani, Brenda O'Neal, David Gilbert, David Gent, and Jeffrey Davis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)364 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Electrolytic reactive barriers (e‐barriers) consist of closely spaced permeable electrodes installed across a groundwater contaminant plume in a permeable reactive barrier format. Application of sufficient potential to the electrodes results in sequential oxidation and reduction of the target contaminant. The objective of this study was to quantify the mass distribution of compounds produced during sequential electrolytic oxidation and reduction of ordinance related compounds (ORCs) in a laboratory analog to an e‐barrier. In this study, a series of column tests were conducted using RDX (hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine) and TNT (2,4,6‐trinitrotoluene) as representative ORCs. The experimental setup consisted of a plexiglass column packed with quart‐feldspar sand to simulate aquifer conditions. A single set of porous electrodes consisting of expanded titanium‐mixed metal oxide mesh was placed at the midpoint of the soil column as a one‐dimensional analog to an e‐barrier. Constant current of 20 mA (variable voltage) was applied to the electrode set. Initial studies involved quantification of reaction products using unlabeled RDX and TNT. The results indicated approximately 70% of the influent concentration was transformed, in one pass, through sequential oxidation‐reduction for both contaminants. Following the unlabeled studies, ¹⁴C labeled ORCs were introduced to conduct the mass balance. An activity balance of up to 95.5% was achieved for both ¹⁴C‐RDX and 14C‐TNT. For both contaminants, approximately 21% of the influent activity was mineralized to ¹⁴CO₂. The proportion of the initial activity in the dissolved fraction was different for the two test contaminants. Approximately 30% of the initial ¹⁴C‐RDX was recovered as unreacted in the dissolved phase. The balance of the ¹⁴C‐RDX was recovered as non‐volatile, non‐nitroso transformation products. None of the ¹⁴C‐RDX was sorbed to the column sand packing. For ¹⁴C‐TNT approximately 51% of the initial activity was recovered in the dissolved phase, the majority of which was unreacted TNT. The balance of the ¹⁴C‐TNT was either sorbed to the sand packing (approximately 23.7 %) or dissolved/mineralized as unidentified ring cleavage products (4.5%).

Select this Article		Efficient Data Management Strategies for Large MODFLOW Models N. L. Jones, A. M. Lemon, and M. J. Kennard ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)365 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Recent advances in graphical user interfaces and geographic information systems have resulted in increasingly complex MODFLOW files. Complex source/sink data, including transient stages and pumping rates can result in a single MODFLOW simulation taking as much as one gigabyte of space on disk using the standard MODFLOW text file format. In this paper we present a new binary format for MODFLOW arrays and MODFLOW stress packages. The format is based on the HDF5 library developed by the National Center for Supercomputing Applications at the University of Illinois at Urbana‐Champaign. MODFLOW data can be saved/retrieved from this format using an API built on top of the HDF5 object code. This results in a set of MODFLOW input files where the bulkier parts of the files are stored in a compressed, platform independent binary format. MODFLOW files written in this format can be read in a few seconds and the resulting file sizes are typically less than 1–2% of the original text file format.

Select this Article		An Efficient Method for Assessing Uncertainty in Forecast of Computationally Intensive Groundwater Models Pradeep Mugunthan and Christine A. Shoemaker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)366 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An efficient method that combines the results of automated calibration using function approximation based optimization and importance sampling is presented for assessing parametric uncertainty in the outputs of computationally intensive models. A function approximation based algorithm is used for automated calibration of parameters. Parameter sets that meet a predetermined error threshold are identified as suitable simulators of the model and importance weights are assigned to such parameter sets. These parameter sets are then used in the model to simulate forecast. The importance weights are used to estimate the empirical quantiles of the output of interest. The method is applied to two illustrative groundwater bioremediation examples of differing complexity, and the results are compared to more frequently used Monte Carlo based uncertainty assessment method such as Generalized Likelihood Uncertainty Estimation (GLUE). The results indicated that the proposed method identifies more parameter sets that qualify as suitable simulators of the system than GLUE for a given error threshold and a given number of model simulations. Further, the proposed method enables the use of more stringent thresholds thereby reducing the uncertainty in model forecast.

Select this Article		Field Experiments in Transport of Pesticides in Tropical Soils in Hawaii Martin Sanda, Chittaranjan Ray, Jaromir Dusek, Joseph Lichwa, Martina Sobotkova, Helena Pavelkova, and Binh Loo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)367 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Past incidences of ground water contamination from nematicides and herbicides has focused on a progressive approach to pesticide registration in Hawaii. The state of Hawaii, in the early 1990's made an assessment of the pesticides used in Hawaii and their potential to leach into ground water. Since there is increased pressure to bring new agricultural chemicals to Hawaii, the state and the University of Hawaii worked together to evaluate five EPA‐registered chemicals for their leachability in Hawaii soils. Three herbicides (s‐metolachlor, sulfometuron methyl, and imazaquin), a fungicide (trifloxystrobin), and an insecticide (imidacloprid) were tested for their leachability in various tropical soils. In addition, the herbicide atrazine and bromide ion were used as two reference chemicals in the study. All chemicals were applied to tilled soils at label rates for agriculture or insecticidal use of these chemicals, except for bromide applied at the rate of 21.9 kg Br⁻/ha. Five test sites at differing topographic, climatic and soil conditions were selected on three Hawaiian islands: three on Oahu, one on Maui and one on Kauai. Each site had four test plots; two for herbicides and two for insecticide/fungicide. No crops were grown and the soil surface was covered with a thin layer of mulch to prevent weed growth and decrease water evaporation from the soil surface. An irrigation system was set up at each site to apply water at close to potential evapotranspiration rate to induce leaching. Loose soil samples were collected on the day after pesticide application and in one to four week intervals for four months. Soil hydraulic and climatic data from each site were collected during the same period. Soil samples collected in the field to a depth of 2.1 m were analyzed for the content of the pesticides and bromide, yielding concentration profiles for elapsed times of 1 day to 16 weeks. Prior to pesticide application, soil profiles were also characterized for pH, organic carbon content and basic soil nutrients: P, K, Mg, Ca. Undisturbed soil core samples were taken and sets of water‐retention curves were developed in the laboratory. Field tests for unsaturated and saturated hydraulic conductivity using tension disc infiltrometer were carried out at all sites. To duplicate the complexity of processes in the field, laboratory tests on the sorption and degradation of the chemicals were carried out for all 5 sites and 6 pesticides using appropriate analytical methods. Selected degradation products were tested for their competitive sorption to soils. The physico‐chemical properties of soils and pesticides, evaluated in this study, will be used to determine whether these compounds will be permitted for unrestricted use, or with some restrictions. This information will be used by the state of Hawaii to classify this group of chemicals for intra‐state sale and use.

Select this Article		Groundwater Quantity and Quality Management: A Case Study of Kashan Aquifer, Central Iran N. Mahjouri, F. Ghazban, and M. Ardestani ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)368 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The city of Kashan is one of the major cities located in the central part of Iran next to great Kavir and has annual domestic water consumption close to 24 million cubic meters. The sewer system mainly consists of the traditional absorption wells and 70 percent of domestic allocated water returns to water resources as wastewater. Thus, the return flow from the domestic and agricultural consumptions has been one of the main sources of groundwater recharge. These return flows have contaminated the groundwater resources in the Kashan aquifer, which is the main water resource in the study area. The Kashan aquifer suffers from considerable overdraft of water and it has resulted in an annual groundwater table drawdown close to 1 meter. In this paper, a systematic approach to surface and groundwater resources in the study area, with its complex system of water supply, groundwater pollution, recharge and discharge is discussed. A genetic algorithm‐based optimization model is developed for groundwater quantity and quality planning. The objective function of this model is developed to supply the agricultural water demands; to control the existing severe groundwater table fluctuations and to improve the quality of allocated water. To develop the response function of the aquifers located in the study area a mathematical model for simulation water quality in Kashan Aquifer as well as the groundwater table fluctuations has been developed and calibrated with the available data. The results show the significance of an integrated approach for groundwater resources operation in the Kashan Aquifer.

Select this Article		Identification of Principal Directions of Anisotropy in Porous Media R. M. Neupauer, K. L. Powell, D. A. Villhauer, and D. H. Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)369 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Permeability anisotropy affects the magnitude and direction of groundwater flow and the movement of contaminants in groundwater. We developed a technique that uses wavelet analysis on regularly‐spaced permeability data to identify principal directions of anisotropy and dominant scales in the porous medium. Wavelet analysis is an increasingly popular tool for image analysis because it can extract local information at multiple scales. Because of this capability, wavelet analysis can be used to identify dominant scales of permeability in a statistically heterogeneous porous medium. Certain wavelets are directional and therefore can also extract information about dominant orientations. We use three different wavelets—fully anisotropic Morlet wavelet, anisotropic Mexican hat wavelet, and Cauchy wavelet—to identify the dominant orientations in spatial distributions of permeability in synthetic heterogeneous and anisotropic media. We compare the effectiveness of the three wavelets in identifying dominant orientations at each position in the medium and in identifying boundaries between regions with different dominant orientations.

Select this Article		Impact of Sea Level Rise on Saltwater Intrusion in Coastal Aquifers A. K. Tyagi, F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)370 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This investigation concerns the hydrodynamics of the intrusion and dispersion of a fresh‐salt water interface in coastal ground water systems. Primary attention is focused on developing a model to predict the rate of dispersion of the interface in natural aquifers. Mathematical models including the density and viscosity effects are incorporated. Since the fresh and salt water are miscible, a transition zone is created due to dispersion of the interface, caused by the secular flow and tidal fluctuations. A field example using realistic parameters from a natural aquifer is presented to determine the extent of intrusion of the interface for a given secular variation of flow in the aquifer. Then the growth of the transition zone is predicted on a space and time basis, utilizing the finite element solution. The digital model is capable of generating the entire dispersion pattern in a two‐dimensional vertical aquifer.

Select this Article		Improving Site Characterization and Classifying Attenuation Processes Using Microbiological Profiles, Geochemistry, and Artificial Neural Networks from Landfill‐Leachate Contaminated Groundwater Paula J. Mouser and Donna M. Rizzo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)371 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Groundwater geochemistry and microbiology were sampled from a shallow aquifer contaminated by municipal landfill leachate in northeastern New York. Polymerase chain reaction (PCR) of the 16S rDNA molecule and sequencing was used to identify organisms associated with clean and leachate‐contaminated monitoring wells. Groundwater samples were tested for general water quality parameters (pH, temperature, redox, turbidity, and specific conductance), metals, inorganic, and organic compounds. A principal component analysis revealed three groups of samples; highly contaminated, leachate‐influenced, and uninfluenced groundwater monitoring locations. Microorganisms could also be classified into three groups, those typically found in extreme environments, those found in zones with changing redox conditions, and those typically found in agricultural or glacial soils corresponding to contaminated, leachate‐influenced, and uninfluenced locations, respectively. The combined use of principal component scores and microorganism community for depicting the zone of leachate‐influence gives managers a better estimate of the extent of contamination and attenuation processes. We will also show how an artificial neural network (ANN) can be trained to predict the geochemistry based on the microbiological profile for the purpose of improving site characterization using multiple types of data. Testing and validation was performed using data from subsequent sampling events.

Select this Article		Investigation of Permeability Upscaling Experiments Using Deterministic Modeling and Monte Carlo Analysis Thomas S. Lowry and Vince C. Tidwell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)372 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Numerical groundwater model parameters are typically derived from field measurements where the quantity of porous media measured is generally a minute fraction of the site under investigation (e.g. core sampling) and/or represents a spatially averaged quantity (e.g. pump tests). For these measurements to be mapped to a numerical grid, parameters must be scaled to the cell size of the model and, in most cases, extrapolated to unsampled locations. This process represents the universal problem of parameter upscaling. Previous to this study, laboratory experiments were performed to physically explore permeability upscaling. The experiments make use of a gas permeameter that has been specially adapted for acquiring permeability measurements over a range of discrete sample supports (scales) subject to consistent flow and boundary conditions. Thousands of permeability measurements were made at four discrete sample supports for various rock samples. The experimental results exhibited strong, consistent trends in the mean, variance, and semivariogram of the permeability as a function of sample support. These distinct trends provide physical evidence of the dependency between measurement sample support and parameter values. This work uses numerical modeling to investigate the conditions necessary to reproduce the experimental trends. Using a Monte Carlo approach, the model simulates a gas‐permeameter at four different scales across variations of three deterministic heterogeneous permeability fields: 1) a horizontally layered system, 2) a vertically layered system, and 3) a system of vertical columns. Statistical trends in the calculated permeability are plotted as a function of the measurement scale and are compared to the experimental trends as well as to linear and theoretical models based on the same permeability fields. Results show that for all permeability fields, the model is able to match the trends in the variance but only for certain combinations of tip‐seal size and heterogeneity length‐scale can it match the trend in the mean.

Select this Article		Management Alternatives for River‐Alluvial Groundwater Supply Systems A. Naghibi‐Beidokhti, M.A.Sc. and B. J. Lence, Ph.D., A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)373 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An integrated approach for evaluating water supply and treatment options for a river‐alluvial groundwater supply system is presented. Such systems are important because they are commonly used for drinking water supplies due to their proximity to large populations. However, there is limited understanding of the natural mechanisms that impact water quality and of the options for managing these impacts. The combinatorial problem of selecting water supply sources and treatment options is complicated by this lack of information, the interrelationships between these options, the urgent need for a sound public health decision, and other institutional and historical constraints. A framework is developed for evaluating tradeoffs among alternative combinations of source and treatment in the short‐term and for addressing the management of such systems over time. The alternatives will be evaluated with respect to the following objectives: the cost of the various treatment alternatives, as well as pumping and monitoring costs; the risk of contamination due to pathogens and the resulting risks to human health; and the available water yield. The framework decomposes the classical groundwater supply system into three subsystems: the source water, water treatment and water distribution network subsystems, and uses reliability‐based optimization models to determine operations in each subsystem considering output from adjacent subsystems as constraints. The uncertainties related to information and mechanisms that drive each subsystem are accounted for in the reliability analyses. This approach is developed considering the water supply conditions for the City of Fredericton, New Brunswick; however, it may be generalized for the many similar hydrologic settings that exist in North America.

Select this Article		Modeling of Redox Zonation Downgradient of Landfill Sites M. Rolle, A. Di Molfetta, R. Sethi, and T. P. Clement ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)374 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The release of landfill leachate, with its load of organic material, gives rise to a succession of redox zones in the contaminated aquifer. Indigenous microbial populations can couple the oxidation of the organic compounds to the reduction of a number of electron acceptors. The sequence of TEAPs (terminal electron acceptor processes): aerobic respiration, denitrification, Mn(IV)‐reduction, Fe(III)‐reduction, sulfate‐reduction and methanogenesis is determined by the energy yield of each redox reaction. This study presents a kinetic description of these processes using the multispecies reactive transport code RT3D. A user‐defined kinetic was developed in order to take into account the principal biogeochemical processes that are likely to occur downgradient of a landfill. This model was tested on simple batch, 1D and 2D problems before applying to a field data set collected at a mixed municipal and industrial landfill site located close to the city of Turin in Italy.

Select this Article		Monitored Natural Attenuation and Enhanced Attenuation for Chlorinated Solvent Plumes—It's All about Balance Karen A. Adams, Karen M. Vangelas, Brian B. Looney, Frank Chapelle, Tom Early, Tyler Gilmore, and Claire H. Sink ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)375 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Nature's inherent ability to cleanse itself is at the heart of Monitored Natural Attenuation (MNA). The complexity comes when one attempts to measure and calculate this inherent ability, called the Natural Attenuation Capacity (NAC), and determine if it is sufficient to cleanse the system to agreed upon criteria. An approach that is simple in concept for determining whether the NAC is sufficient for MNA to work is the concept of a mass balance. Mass balance is a robust framework upon which all decisions can be made. The inflows to and outflows from the system are balanced against the NAC of the subsurface system. For MNA to be acceptable, the NAC is balanced against the contaminant loading to the subsurface system with the resulting outflow from the system being in a range that is acceptable to the regulating and decision‐making parties. When the system is such that the resulting outflow is not within an acceptable range, the idea of taking actions that are sustainable and that will bring the system within the acceptable range of outflows is evaluated. These sustainable enhancements are being developed under the Enhanced Attenuation (EA) concept.

Select this Article		Numerical Simulation of Saltwater Intrusion in Response to Sea‐Level Rise C. D. Langevin and A. M. Dausman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)376 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A two dimensional numerical model of variable‐density groundwater flow and dispersive solute transport was used to predict the extent, rate, and lag time of saltwater intrusion in response to various sea‐level rise scenarios. Three simulations were performed with varying rates of sea‐level rise. For the first simulation, sea‐level rise was specified at a rate of 0.9 mm/yr, which is the slowest rate of sea‐level rise estimated by the Intergovernmental Panel on Climate Change (IPCC). After 100 years, the 250 mg/L chloride isochlor moved inland by about 40 m, and required an additional 8 years for the system to reach equilibrium. For the next simulation, sea‐level rise was specified at 4.8 mm/yr, which is the central value of the IPCC estimate. For this moderate rate of sea‐level rise, the 250 mg/L isochlor moved inland by about 740 m after 100 years, and required an additional 10 years for the system to reach equilibrium. For the fastest rate of sea level rise estimated by IPCC (8.8 mm/yr), the 250 mg/L isochlor moved inland by about 1800 m after 100 years, and required more than 50 years to reach equilibrium.

Select this Article		Optimizing Long Term Monitoring at a BP Site Using Multi‐Objective Optimization Barbara Minsker, Peter Groves, and Dennis Beckmann ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)377 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract BP (formerly British Petroleum) incurs significant costs associated with monitoring subsurface remediation sites. The purpose of this project is to evaluate whether these costs could be reduced by identifying and eliminating both spatial and temporal redundancies in the monitoring data at a BP site without significantly increasing monitoring errors. The project also aims to demonstrate the potential for multi‐objective optimization approaches to improve monitoring decision making at the many sites at BP and elsewhere with long‐term monitoring records. The first step in the optimization process is to identify monitoring objectives and constraints, and express them in mathematical form. In this case, the initial objectives were to minimize the number of samples collected and to minimize relative BTEX interpolation error. The BTEX interpolation error for trial sets of sampling plans are calculated by comparing the concentrations interpolated using all sampling locations and times with those interpolated using only reduced sampling frequencies or locations. Historical data from the wells that are currently being sampled are used to develop a suite of interpolation models, which are then tested using a cross‐validation approach. Adaptive Environmental Monitoring System (AEMS) software, developed at the University of Illinois and RiverGlass Inc., is then used to search through the billions of sampling plans to identify the optimal tradeoffs between the number of samples collected and the relative error.

Select this Article		On Prior Parameter Structure Investigation to Parameter Uncertainty Frank T.‐C. Tsai, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)378 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This study investigates the significance of the prior parameter structure, which is used as a regularization term in the inverse problem, to estimate the parameter heterogeneity over a field. It has been demonstrated that estimating parameter heterogeneity at all computation nodes are achievable even though the number of observation data is less than that of the unknown nodal parameter values if a regularization term is used in the inverse procedure. However, the quality of heterogeneity estimation at all nodes heavily depends upon the quantity of quality observations and how close the prior parameter structure is to the true heterogeneity. In this study, we use the generalized parameterization (GP) method to find the optimal prior parameter structure with a set of measured data. The estimation error of the prior parameter structure is characterized using a geostatistical method. The parameter value at each node is estimated through the Bayesian approach and the regularization of the prior parameter structure. We investigate the quality of nodal value estimation with different prior parameter structures made by a zonation structure, the ordinary kriging (OK) method, and the GP method. The GP method, in this study, is the combination of the zonation structure and the OK method through a set of weighting coefficients. The best prior parameter structure is obtained by searching for the optimal weighing coefficient values in the GP method via a set of observation data. We use the beta probability function to approximate all possible prior probability density functions of weighing coefficients in the Bayes rule. The proposed methodology is demonstrated at a synthetic confined aquifer, where the true transmissivity heterogeneity is unknown. The GP method is able to provide a good prior transmissivity structure which is better than the zonation structure and the kriged heterogeneity. As a consequence, the GP method is able to uncover the true transmissivity heterogeneity and shows better results than the other two methods.

Select this Article		A Process‐Based Transfer Function Approach to Model Tile Drain Hydrographs Mazdak Arabi, Jennifer S. Schmidt, and Rao S. Govindaraju ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)379 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Tile drain response to rainfall events is determined by unsaturated vertical flow to the water table, followed by horizontal saturated water movement. In this study, unsaturated vertical movement from redistribution of water is modeled using a sharp front approximation, while the saturated horizontal flow is modeled by an approximate solution to the Boussinesq equation. The unsaturated flow component models the fast response that is associated with the presence of preferential flow paths. By convoluting the responses of the two components, a transfer function is developed that predicts tile drain response to unit amounts of infiltrated water. Since the approach is process‐based, model parameter definitions are easily identified with soil properties at the field scale. It was shown that transient tile drain response to arbitrary amounts of infiltrated water can be constructed using superposition principles. Comparison with data measured from the Water Quality Field Station show that this approach provides a promising method for generating tile drain response to rainfall events.

Select this Article		Stormwater Runoff Supplied to Subsurface Infiltration Areas for Groundwater Recharge, Dane County, Wisconsin Robert J. Montgomery, Stephen J. Gaffield, and Nancy R. Zolidis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)380 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Stormwater runoff is being infiltrated to recharge groundwater as part of a strategy to mitigate the impacts of cooling water withdrawal from Lake Mendota for a new cogeneration facility on the University of Wisconsin‐Madison campus. Lake Mendota is one of five lakes in the Yahara River watershed, which includes most of the City of Madison and central Dane County, in southern Wisconsin. Withdrawals from the watershed are primarily from groundwater, for potable and industrial water supply, and have been increasing in recent years, resulting in reduction of base flow in the Yahara River. Although the cooling water demand for the cogeneration facility will be small compared to other withdrawals from the basin, heightened concern regarding low‐flow reduction resulted in the requirement that construction of the cogeneration facility be accompanied by a compensatory groundwater recharge system. The capacity requirement for the system is 305,000 m³ per year (80.4 million gallons per year). An initial screening study evaluated 14 sites for potential use as recharge facilities, based on subwatershed land use, available stormwater runoff volume, presence of storage, surficial soils and hydrogeologic conditions, cost, and logistical and implementation constraints. Site selection for implementation depended on technical issues, landowner requirements, and watershed stakeholder and public policy considerations. The seleted site, at Odana Hills golf course , was extensively investigated for surface water, hydrogeologic, and water quality characteristics. The recharge design draws stormwater runoff from an existing pond and discharges it to a subsurface infiltration system. An analysis of rate‐limiting mechanisms concluded that clogging of the infiltration trenches by fine particulates is likely to control the long‐term capacity of the system. The design includes use of a comprehensive filtering system for the water drawn from the pond, which will virtually eliminate suspended solids in the recharge water. System construction will be complete in 2005, with operation starting by early 2006. System operation will include water quantity and quality monitoring, which will provide data for use in continuing efforts to supplement recharge in the Yahara River watershed and beyond.

Select this Article		Transport of Selected Pesticides in Hawaii Soils: Results from Laboratory Column Experiments Michal Snehota, Chittaranjan Ray, Joseph Lichwa, and Martina Sobotkova ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)381 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Past incidences of ground water contamination from nematicides and herbicides in Hawaii has focused on a progressive approach to pesticide registration in Hawaii. The state of Hawaii, in early 1990's made an assessment of the pesticides used in Hawaii and their potential to leach to ground water. Researchers at the University of Hawaii looked into 40 commonly used pesticides in Hawaii and compared their leachability using soil and pesticide properties, recharge rates, and depth to water. Since there is increased pressure from users to bring these chemicals to Hawaii, the state and the University of Hawaii worked together to evaluate five EPA‐registered chemicals for their leachability in Hawaii soils. Three herbicides, one fungicide, and one insecticide were selected. In addition, atrazine and bromide ions were used as two reference chemicals in the column leaching study. Undisturbed soil monoliths were collected from the Poamoho experimental site (Oahu, Hawaii). Soil cores were taken by inserting a stainless steel cylinder into the soil using a hydraulic jack. Soil cores were equipped with three microtensiometers inserted at different heights. Infiltration‐outflow and evaporation experiments were performed on each soil core to obtain its soil hydraulic properties. Solute displacement experiments were conducted on soil cores. The near‐saturated flow was secured by maintaining small tension (up to 10cm water tension) at the bottom end of the column while constant water flux was supplied to the column's top surface. Initially inflow rate was adjusted to achieve uniform vertical distribution of suction head. After steady flow rate was achieved, the input was switched from background solution to an aqueous solution of pesticides and bromide and the same constant flow rate was maintained. The effluent was regularly collected and analyzed for the presence of pesticides and bromide. The flow interruption technique was used to test the presence of non‐equilibrium transport of pesticides in the soil under study.

Select this Article		French Drains to Mitigate Groundwater in Residential Areas Robert A. Cooper, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)382 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Since 1995, french drains have been installed at the lip of gutters and parallel to the street centerline in certain residential areas in Sacramento, California. The purpose of the french drains has been to control the occurrence of groundwater at the surface. The residential areas are all improved and have concrete curb, gutter, and sidewalks, and an asphalt concrete pavement street. The storm drainage system captures all gutter flow through the underground pipe system to a series of canals and finally to pump stations that discharge to the Sacramento River. These areas are severely impacted by the intrusion of groundwater that causes the formation of algae and moss on the sidewalks. These conditions may be potentially unsafe and interfere with common activities such as pedestrian activity and mail delivery. Additionally, groundwater intrusion degrades the structural section of the street and causes base failures and premature failure of the asphalt concrete and the concrete curb, gutter, and sidewalk. All of the affected neighborhoods are within one kilometer of the Sacramento River. Observations show a strong correlation between levels of the Sacramento River and the number of neighborhoods affected by excessive groundwater. The french drains intercept groundwater and route that flow into the city's existing storm drainage system. The construction of french drains along these streets has significantly mitigated problems in those neighborhoods that historically were affected with high levels of groundwater.

Select this Article		Groundwater Behaviour in a Fractured Basalt Aquifer under Existing and Future Climate and Land Use in Auckland City (New Zealand) Parviz Namjou, Gerald Strayton, Alan Pattle, Matthew, D. Davis, Peter Kinley, Paul Cowpertwait, M. Jim Salinger, A. Brett Mullan, and Greg Paterson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)383 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Existing and expected future groundwater behaviour in a fractured basalt aquifer system is presented for Auckland City (New Zealand), considering current and future climate scenarios (using historic and stochastic rainfall) and impervious surface land use changes. The Auckland Isthmus is comprised of unconfined basalt aquifers and semi‐confined Waitemata and Tauranga Groups (sandstone and mudstone) aquifers. The basalt aquifers are used to dispose stormwater via drilled soakholes, serve as groundwater supply in the Onehunga aquifer and disperse industrial and commercial sites across the city, and feed important springs in Western Springs and Onehunga. Regional groundwater models were developed in Visual MODFLOW and MIKE‐SHE, covering approximately 45 km² with a north‐south grid alignment and 100 × 100 m grid cells. Vertically the models are divided into a single basalt aquifer hydrogeological unit. Three scenarios were investigated with combinations of rainfall and land use: (1) existing conditions (current climate and existing land use), (2) future wet year (most probable 2050 climate and maximum possible 2050 land use), and (3) future dry year (most probable 2050 climate and maximum probable 2050 land use). Model results indicate that the aquifer has spare capacity to accommodate recharge under all scenarios examined. Base flows in principal streams and springs will not be compromised unless many dry years occur in succession. A major issue to resolve will be to find practical ways of capturing and injecting large volumes of stormwater generated over short, high intensity storms.

Select this Article		Identifying Optimal Sampling Design for Monitoring Multiple Contaminants under Uncertain Hydrogeology Pradeep Mugunthan and Christine A. Shoemaker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)384 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A method for identifying cost effective sampling designs for long term monitoring is presented when multiple contaminants are involved over several time periods. Monitoring costs are minimized under a constraint to meet an acceptable level of error in the estimation of total mass for multiple contaminants simultaneously over many equiprobable realizations of hydraulic conductivity field. A myopic heuristic algorithm (MS‐ER) that combines an error‐reducing search neighborhood is developed to solve the optimization problem. The method is applied to design sampling locations and frequency for a hypothetical case study. The results showed that MS‐ER algorithm consistently performed better in multiple trials when compared to simulated annealing and genetic algorithm. The best design of MS‐ER algorithm produced a savings of nearly 25% in project cost over a conservative sampling plan that uses all possible locations and samples.

Select this Article		Impacts of Sea‐Level Rise on Groundwater Environment in Coastal Areas: Laboratory Experiments, Numerical Analyses, and a Case Study in Turkey K. Fujinawa, M. Furukawa, T. Nagano, and T. Watanabe ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)385 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The impacts of sea‐level rise in low lands and the effect of barrier walls for reducing saltwater intrusion were investigated by laboratory experiments. The experiments revealed that sea‐level rise induce saltwater intrusion into coastal aquifers, which in turn reduces fresh groundwater resources, causes water logging, and accumulates salt on ground surface in arid regions. A numerical method, called SIFEC, for a variable‐density flow model, which couples the saturated‐unsaturated flow equation with the dispersive‐convective equation, was also developed to apply for the problem. A Galerkin‐finite element method was applied for fluid flow and a characteristic finite element method for mass transport. Numerical results were compared with the experimental results and the accuracy of the numerical scheme was examined.

Select this Article		Investigation of Seawater Intrusion in Coastal Wetland through a Numerical Study Hwai‐Ping Cheng, Hsin‐Chi J. Lin, Earl V. Edris, Clarissa M. Hansen, and Jing‐Ru C. Cheng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)386 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. This paper presents an investigation of seawater intrusion in a coastal wetland area and aims at providing useful information as a reference for setting adequate boundary conditions in future wetland modeling work. Seawater intrusion modeling involves density‐driven flow, where water flow and salinity transport are coupled. In addition to seawater intrusion, surface‐subsurface interaction and tidal effects may play key roles in determining salinity distribution in the coastal wetland area and the underlying subsurface system. In this investigation, we will use WASH123D, a numerical model that accounts for both density‐driven flow and surface‐subsurface interaction, to simulate seawater intrusion for various scenarios, where different domain shapes and boundary conditions are applied. For each scenario, we will conduct water flow and salinity transport simulations of 2D overland only, 3D subsurface only, and coupled 2D/3D system. The computational results between simulations and between scenarios will be compared and discussed. Useful conclusions will be drawn.

Select this Article		Method for Evaluating Groundwater Contaminant Plume Stability Joe A. Ricker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)387 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes a method to evaluate the stability of a groundwater contaminant plume. Spatial and temporal changes in contaminant plume area, average concentration, and mass were evaluated using the mathematical features of Surfer, by Golden Software, Inc. and statistical analysis techniques. This method is relatively simple and inexpensive to implement when compared to other methods of contaminant plume stability evaluation such as mass flux analysis and fate and transport computer modeling. The plume stability evaluation method described in this paper was used as a basis for recommending the cessation of a groundwater pump and treat system at a chemical wood treating facility in Mississippi. This action resulted in annual cost savings of $150,000 to the client.

Select this Article		Recycling Effects on TN and TP Mass Removal Rates in a Full‐Scale Subsurface Flow Constructed Wetland Steven C. Reese, S.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)388 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Natural treatment systems, including constructed wetlands, have grown in popularity as wastewater treatment options since the mid 1980s. Research efforts on constructed wetlands increased from the 1970s through the 1990s. However, there is a lack of quality data of sufficient detail on full‐scale constructed wetlands. The main objective of this study was to use a full‐scale subsurface flow constructed wetland to examine the effects of effluent recycling on total nitrogen (TN) and total phosphorus (TP) removal. Weekly water samples and flow data from the inlet and outlet of wetland channels were analyzed for 10‐weeks during late summer, 2004. Repeated measures analysis of variance demonstrated that average percentage mass removal of TN and TP was similar between recycling and single‐pass channels.

Select this Article		Analysis and Design of Infiltration Seawater Intakes S. W. Taylor and L. C. Headland ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)389 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the development and application of a model for the analysis and design of infiltration seawater intakes. A three‐dimensional, finite‐difference groundwater flow model is used to simulate the steady‐state flow of water through the seafloor and to the collector laterals. The model considers the physical characteristics of the porous medium, and the diameter, depth, spacing and length of the collector laterals. The primary output from the model is the intake capacity (i.e., the flow rate the infiltration seawater intake is capable of delivering on a sustained basis). A sensitivity analysis is conducted to identify the parameters that govern intake capacity. By varying key design parameters, intake capacity is determined as a function of the number and length of collector laterals, and the physical characteristics of the porous media bed. Using representative seafloor characteristics, the feasibility of the intake concept is demonstrated for a typical industrial application.

Select this Article		Applicability and Experimental Verification of a Dam‐Break Flood and Sediment Transport Model Christina W. Tsai, Ken Z. Kuai, Marcus Bursik, and Dale Hess ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)390 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The propagation of a flood wave in the water‐sediment morphological system is investigated. A refined nonlinear mathematical model composed of a fully coupled system of flow‐sediment continuity and momentum equations and two closure formulas for sediment discharge and friction slope is proposed. Using dimensional analysis, dominating dimensionless variables are identified and investigated. The matched asymptotic perturbation expansion is applied to explore the analytic‐numerical solution of this model. The model is then validated with experimental data from the literature. Based on the model results, the influence of bed slope, Manning roughness coefficient and the Froude number on this water‐sediment morphological system is examined.

Select this Article		Application of Acoustic Doppler Current Profilers for Measuring Three‐Dimensional Flow Fields and as a Surrogate Measurement of Bedload Transport J. S. Conaway ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)391 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Acoustic Doppler current profilers (ADCPs) have been in use in the riverine environment for nearly 20 years. Their application primarily has been focused on the measurement of streamflow discharge. ADCPs emit high‐frequency sound pulses and receive reflected sound echoes from sediment particles in the water column. The Doppler shift between transmitted and return signals is resolved into a velocity component that is measured in three dimensions by simultaneously transmitting four independent acoustical pulses. To measure the absolute velocity magnitude and direction in the water column, the velocity magnitude and direction of the instrument must also be computed. Typically this is accomplished by ensonifying the streambed with an acoustical pulse that also provides a depth measurement for each of the four acoustic beams. Sediment transport on or near the streambed will bias these measurements and requires external positioning such as a differentially corrected Global Positioning Systems (GPS). Although the influence of hydraulic structures such as spur dikes and bridge piers is typically only measured and described in one or two dimensions, the use of differentially corrected GPS with ADCPs provides a fully three‐dimensional measurement of the magnitude and direction of the water column at such structures. The measurement of these flow disturbances in a field setting also captures the natural pulsations of river flow that cannot be easily quantified or modeled by numerical simulations or flumes. Several examples of measured three‐dimensional flow conditions at bridge sites throughout Alaska are presented. The bias introduced to the bottom‐track measurement is being investigated as a surrogate measurement of bedload transport. By fixing the position of the ADCP for a known period of time the apparent velocity of the streambed at that position can be determined. Initial results and comparison to traditionally measured bedload values are presented. These initial results and those by other researchers are helping to determine a direction for further research of noncontact measurements of sediment transport.

Select this Article		Application of the Upwind Scheme to the Discontinuous Flow in Natural River Won Kim, Kun‐Yeun Han, and Hyoseop Woo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)392 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The upwind model is well known to simulate the shockwave, but it is not commonly applied to natural rivers because of the problems related to the source terms. Although several kinds of methods dealing with the source terms have been developed, currently there is no method applied to natural rivers. This paper deals with application of the upwind model to the natural river. The implicit upwind model is applied to natural river with very irregular bed, width, and hydraulic structures. Furthermore, many kinds of flow, steady state and unsteady state are simulated to prove the accuracy and applicability of the implicit upwind model. As the results of the application, this model is proved to be able to simulate many kinds of flows in the natural river with high accuracy and robustness.

Select this Article		Applications of 3D Hydrodynamic and Particle Tracking Models in the San Francisco Bay‐Delta Estuary P. E. Smith, J. M. Donovan, and H. F. N. Wong ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)393 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Three applications of three‐dimensional hydrodynamic and particle‐tracking models are currently underway by the United States Geological Survey in the San Francisco Bay‐Delta Estuary. The first application is to the San Francisco Bay and a portion of the coastal ocean. The second application is to an important, gated control channel called the Delta Cross Channel, located within the northern portion of the Sacramento‐San Joaquin River Delta. The third application is to a reach of the San Joaquin River near Stockton, California where a significant dissolved oxygen problem exists due, in part, to conditions associated with the deep‐water ship channel for the Port of Stockton, California. This paper briefly discusses the hydrodynamic and particle tracking models being used and the three applications.

Select this Article		Applying the Energy‐Momentum Method to Radial Gate Discharge Calibration Tony L. Wahl and Albert J. Clemmens ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)394 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Bureau of Reclamation (Reclamation), the Agricultural Research Service (ARS), and the Salt River Project (SRP) are collaborating to produce a practical means for applying the Energy‐Momentum method to the problem of calibrating canal radial gates for the measurement of discharge. A new series of experiments conducted at the ARS hydraulic laboratory in Phoenix is being used to refine the submerged flow energy correction, a key parameter of the method, and empirical factors in the momentum equation. The experiments are also examining the feasibility of measuring the pressure in the vena contracta jet, which might simplify application by alleviating the need for applying the momentum equation. The results of the laboratory tests will be incorporated into a new computer program that will make radial gate calibration practical for a variety of situations.

Select this Article		Bridge Abutment Collar as a Scour Countermeasure Hua Li, Brian Barkdoll, and Roger Kuhnle ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)395 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract To mitigate abutment scour various flat, horizontal, steel collars were attached around a wing‐wall abutment ending at the main channel edge under clear‐water flow conditions in laboratory experiments. It was found that the collars were able to protect the bridge abutment efficiently by eliminating secondary vortices that ordinarily would cause local scour. The minimum collar dimensions that eliminated local scour were those with a width of 0.23L (L is the abutment width perpendicular to the flow direction) for elimination of local scour, a length of 0.8L_a for maximum reduction of scour at the edge of the collar, and having the collar located at a vertical location of 0.08y_m below the mean bed sediment elevation (y_m is the main channel flow depth). In addition, the collar not only reduces scour magnitude near the abutment, but also retards the scour hole development.

Select this Article		Burial of Short Cylinders Induced by Scour and Bedforms under Waves Plus Currents Yovanni A. Cataño‐Lopera and Marcelo H. García, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)396 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Experiments were conducted to study burial of cylinders placed on a sandy bed under combined waves and currents. The burial of a finite‐length cylinder was determined by local scour around the cylinder and by a more global process associated to the formation and evolution of ripples and sandwaves. Experimental tests covered cylinder Reynolds wave numbers and Keulegan‐Carpenter numbers within the ranges 10⁴ ≤ R_e ≤ 9.1×10⁴ and 2 ⩽ KC ⩽ 26, respectively. Observations indicate that existing semi‐empirical formulae for prediction of equilibrium burial depth for pipelines are not completely suitable for the case of a cylinder having a finite length. In these experiments burial depth shows a strong dependency on both the Shields parameter (θ) and the Keulegan‐Carpenter number (KC) combined.

Select this Article		Calibration of Bulk Aquifer Parameters of Regional Models Using Hydraulic Disturbances A. M. Wasantha Lal and Randy Van Zee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)397 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Calibration of integrated hydrologic models of managed systems just using historical data is a difficult task because these systems have a large number of structures and pumps operated by multiple government agencies, utilities and the public based on a variety of rules and guidelines that change over time. The operations of the facilities are too complex and unrecorded at times. Water level and discharge data collected for such managed systems with mixed urban‐agricultural‐natural land use types often contain unrecorded local effects that are considered as errors if the model is not intended to simulate it. Data collected for such systems have a high level of noise that cannot be easily traced to the source. A method is proposed in the paper to solve the problem of the calibration of such systems by using the existing pumps and structures to generate specific identifiable hydraulic signatures in the system that also have analytical solutions. If data related to causal stress and the resulting hydraulic signal are collected free of noise, they can be used to calculate parameters directly using analytical methods or optimization methods. The paper describes such a test carried out in South Florida, and the use of an analytical method to obtain the parameters.

Select this Article		CFD Modeling of Spillway Performance Dan Gessler, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)398 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In reviewing the hydraulic performance of the overflow spillways for a dam it was found that the pool elevation during the newly computed probable maximum flood (PMF) was projected to be 10 feet higher than the design level and 26 feet above the crest of the spillways. The spillways were tested by use of a physical model in 1960 for flows up to the design flow. The objective of this study was to determine the spillway performance during the PMF. A three dimensional computational fluid dynamics (CFD) model of a portion of the lake and the two spillways was developed using FLOW‐3D®. For the computational mesh, three levels of successive grid refinement were used to minimize computational time and to provide adequate resolution of the final model results. A total of about 13,000,000 computational cells were used in the models. Results of the CFD model were validated against the 1960 model study. A grid resolution study using three different grids was used to determine the sensitivity of model results to changes in grid resolution. The validated CFD model was used to predict the free falling jet trajectory and performance of the spillways under flow rates which were more than double the design the design flow.

Select this Article		Characterization of Particle Cluster Bedforms in a Mountain Stream K. B. Strom, A. N. Papanicolaou, B. Billing, L. L. Ely, and R. R. Hendricks ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)399 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Small‐scale bedforms, such as particle clusters, have been shown to affect sediment transport and flow characteristics when present in laboratory experiments. However, little extensive documentation of such naturally occurring features has been presented in the literature. This research presents descriptive information regarding cluster microtopography shape for clusters naturally occurring in a mountain stream. At the site, reach‐scale stream morphology, stream slope, grain size distribution, cluster type, and geometric properties were recorded. Five main types of clusters where identified. Namely the comet, heap, line, pebble, and ring shaped clusters. These cluster types can be roughly correlated to other cluster types noted in the literature from field and laboratory studies. Descriptive cluster geometry ratios are presented to aid in defining artificial cluster creation in numerical and analytical modeling of flow over a clustered bed.

Select this Article		Coherent Structures in a Channel with Groyne Fields: A Numerical Investigation Using LES Andrew McCoy, George Constantinescu, and Larry Weber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)400 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The flow fields around two vertical spanwise groynes (spur dikes) in an open channel with lateral walls are investigated using Large Eddy Simulation (LES). The interest in this flow is motivated by its similarity to flow around groyne fields in natural rivers which are used to stabilize river banks and play and an important role in restoring fish habitat and enhancing the bio‐diversity of flora and fauna in rivers. This work focuses on the investigation of the main phenomena present at flow around groynes from the point of view of the dynamics of coherent structures. This flow is characterized by massive separation, high adverse pressure gradients and presence of highly unsteady vortices. Simulation of the dynamically important flow structures encountered around groyne fields require methods that are capable of accurately capturing the wide range of eddies present in such flows such as LES which is used in the present investigation. The main flow features include the formation of a horseshoe vortex (HV) system at the base of the upstream groyne that plays an important role in the scouring process, the coherent structures in the area between the groynes (embayment), the detached shear layers originating at the groyne tips, the recirculation regions upstream the first groyne and downstream the second one. The simulations capture the structure of the HV system as it wraps around the groyne including the complex dynamics of the unsteady vortices that are part of the HV system. The formation and subsequent merging of vortices emanating from the detached shear layer originating at the upstream groyne tip and their subsequent interaction with the vortical structures inside the embayment is investigated and their spectral content is analyzed. The statistically averaged 3D vortical structures located in the upstream recirculation zone, within the embayment and detached shear layer, and downstream of it are visualized using 2D and 3D streamlines. The flow dynamics in these areas is described. The differences between the instantaneous coherent structures observed in LES and the mean structures are also highlighted and explained. It is shown that trying to understand the flow physics just based on the mean structures (this is all what we get from a steady RANS simulation) may be insufficient, some important vortices may not be captured as a result of the averaging process, while some other averaged flow structures do not really exist in the instantaneous flow, rather they are just a reflection of the averaging process when unsteady vortices are present.

Select this Article		Dam Break Flood Routing Using HEC‐RAS and NWS‐FLDWAV D. Michael Gee and Gary W. Brunner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)401 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Although the numerical algorithms for solution of the St. Venant Equations are similar; substantial differences exist between these two commonly used models with respect to how the river geometry is sampled, interpreted and represented digitally for model use. HEC‐RAS utilizes cross section descriptions in distance‐elevation format, with associated transverse roughness distribution. NWS‐FLDWAV utilizes a cross section description based upon user‐input tables of top width and Manning's n values as functions of elevation. This paper reports the procedures used to prepare comparable NWS‐FLDWAV data from an existing HEC‐RAS dam break flood routing application and the differences and similarities in the resulting simulations. The results demonstrate that the computed breach outflow hydrograph is similar for the two models. It is concluded that the differences in the interpretation and approximation of river geometry is the primary source of the differences in the model simulations. The two models employ numerous different assumptions regarding formulation of the finite difference approximations to the various terms in the governing unsteady flow equations. A number of data representations were examined to identify and evaluate the differences in the models for computations, data handling and model features.

Select this Article		Dam Break Modeling for Tandem Reservoirs—A Case Study Using HEC‐RAS and HEC‐HMS Christopher R. Goodell, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)402 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Creekside Development Project is located in Southern Oregon on land owned by the Cow Creek Band of the Umpqua Tribe of Indians. The new development includes the construction of two tandem high‐head earth embankment dams for water supply to infrastructure downstream. The two dams are located on an unnamed ephemeral stream in a steep, relatively small watershed. The crest of the lower dam (Dam 1) is about 0.5 miles downstream of the crest of the upper dam (Dam 3). An initial consideration for Dam 1 was that it should provide enough storage capacity and a large enough spillway to be able to safely pass a dam break event from Dam 3. The 1‐dimensional unsteady flow hydraulic routing model HEC‐RAS and the hydrologic routing model HEC‐HMS were used to model this unique dam break application. This paper will discuss the efforts required to construct and successfully run both of these models, the benefits and drawbacks of each of these models for this type of study, and the results of the study.

Select this Article		Design for Fish Passage for Bridges and Culverts Christopher M. Frei, Rollin H. Hotchkiss, and Bart Bergendahl ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)403 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Federal Highways Administration and Washington State University are collaborating to produce Hydraulic Engineering Circular 26: “Design of Fish Passage for Bridges and Culverts”; a comprehensive manual for the design or retrofit of a stream crossing to meet fish passage requirements. Input from State Departments of Transportation, non‐governmental organizations, and other interested parties will be combined with new research and an extensive literature review to compile design methods, culvert and stream assessment techniques, case studies, and design examples. The manual will provide a set of guidelines to any party interested in the design or retrofit of culverts and bridges to meet fish passage requirements, and is intended to streamline the design process.

Select this Article		Determining the 2‐D Surface Velocity Field around Hydraulic Structures with the Use of a Large Scale Particle Image Velocimetry (LSPIV) Technique D. C. Dermisis and A. N. (Thanos) Papanicolaou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)404 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this investigation is to employ the state‐of‐the‐art large scale particle image velocimetry (LSPIV) technique for free surface flow measurements around and within the vicinity of hydraulic structures (e.g. weirs, ladders) used for fish passage in the loess region of Western Iowa, USA. Knowledge of the 2‐D free surface velocity allows engineers and biologists to determine the hydraulic performance of the above structures as it relates to fish passage. The magnitude of the velocity will provide unique information about the level of turbulence around and within the vicinity of the structures, the approach velocity magnitude, the dissipation rate and the forces acting on juvenile and adult fish passing through the structures. The LSPIV technique is founded on similar principles with those of the particle image velocimetry (PIV). LSPIV is a powerful and efficient technique for measuring river surface velocities especially in natural ‐large scale‐ systems which are of the primary interest of this research. It is a cheap method as it needs, basically, an inexpensive video equipment (camera) and a geodetic survey to describe the region of interest (ROI). The water velocity vector magnitude and direction are calculated by dividing the estimated displacement of the particles with the time interval between two sequential images. The LSPIV technique does not require calibration and it is well‐suited for measuring in very shallow flows quickly and accurately; also can be used to estimate the discharge in conjunction with bathymetry information and assumed velocity distribution over the depth. Validation of the LSPIV measurements will be attained with the use of a SonTek flow tracker.

Select this Article		A Direct Solution to Normal Depth in Open Channels Ravi C. Shrestha and Brian Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)405 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Normal depth is an important parameter in open channel analysis and has ramifications for flood prediction. Calculation of normal depth can be done by various methods but there is no simple analytical solution. All of the existing methods either have a complex chain of equations or are iterative. A regression equation is presented here that is computationally more efficient than the existing methods and introduces little additional error.

Select this Article		Dynamics of Sediment Release in a Hypereutrophic Lake Mamta Jain ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)406 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The dynamics of fine sediment resuspension in Newnans Lake in north‐central Florida was examined as part of a study to identify the mechanism by which sediment is released from a pliant, muck‐laden bottom. The lake has a surface area of 27 km², mean depth of about 1.6 m, and the organic‐rich muck is also rich in nutrients (P and N). At a dedicated platform in the center of the lake, physical and water quality parameters were measured from December 2003 to September 2004. Due to short wind‐fetches and low wind speeds, the maximum wave height was 0.18 m and the wave modal frequency on the order of 1 Hz. The time‐variation of the total suspended solids concentration (TSS) was conveniently divided into a diurnal component dependent on wind‐wave induced muck entrainment, and a sub‐diurnal component having a period of days and dependent on wind‐driven circulation and tributary runoff. The ratio of diurnal to sub‐diurnal TSS amplitudes was on the order of 10, suggesting that direct wave‐induced resuspension may play a weak role in loading the water column with nutrients. Nutrient transport appears to depend on water current induced advection of the entrained matter, which may have a residence time on the order of tens of hours in the lake.

Select this Article		Earth Dam Overtopping and Breach Outflow Darrel M. Temple, P.E., M.ASCE and Gregory J. Hanson, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)407 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Over the past half‐century, the USDA has assisted in the design and construction of approximately 11,000 flood control and multipurpose dams. As these dams approach the end of their planned service life, sediment pools fill and sediment deposition in the flood pool reduces flood storage. Simultaneously, development in the watershed may increase runoff while development downstream of the dam increases the consequences of failure. Therefore, there is an increased need for improved procedures for predicting performance of overtopped earth embankment dams. Field experience and laboratory experiments indicate that the erosion process for overtopped earth embankment dams can be divided into sequential stages or phases for computational purposes. These stages include: 1) an initial stage prior to the failure of the vegetal cover or other protection on the downstream slope, 2) a breach development stage during which the resulting headcut or overfall moves from the point of formation through the dam crest, 3) a breach stage during which the headcut advances into the reservoir, and 4) a drawdown stage during which the breach continues to widen as the stored water in the reservoir is released. The flow geometry and the relations describing the discharge and erosion processes vary with stage. This report discusses the dominant characteristics of the identified stages of the progressive breach process and the impact of the resulting geometry on discharge prediction. Results of an idealized study of breach outflow during headcut entry into the reservoir are briefly discussed.

Select this Article		Effect of Channel Bed Corrugations on Hydraulic Jumps Nuray Denli Tokyay ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)408 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There have been many investigations on the effect of roughness elements on physical parameters of hydraulic jump. In practice, baffle blocks and sills are commonly being used to stabilize the location of a jump and shorten the length of a stilling basin. On the other hand, corrugations which cover the entire length of the basin may be an alternative. In the present study, hydraulic jumps on corrugated channel beds are studied experimentally. Values of 0.20 and 0.26 were used as the wave steepness of corrugations in the experiments. The range of Froude number was between 5 and 12. The tailwater depth‐initial depth ratio was determined as a function of the Froude number. The length of the jump and the energy dissipation occurring in the jump were also determined. The results are compared with the data available in literature for corrugated beds and those of the hydraulic jumps forming on a smooth channel bed. It was determined that the tailwater depth required to form the jump and the length of the jump on corrugated bed were appreciably smaller than those of the corresponding jumps on a smooth bed. It was also found that the head loss for jumps on corrugated beds were higher than those occurring on smooth beds and corrugations were efficient in stabilizing the location of the jump. Therefore corrugations should be considered as an effective alternative of accessory devices such as baffle blocks and sills.

Select this Article		Effects of Fluidization on the Sedimentation Process A. N. Papanicolaou, A.M.ASCE and A. R. Maxwell, S.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)409 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract One of the difficulties inherent in batch tests is developing a mixing approach that allows repeatable answers for detecting the onset and evolution of self‐weight fluidization without masking the fluidization process itself. The overarching objective of this research is to examine the effects of mixing on the detection on self‐weight fluidization. For this purpose, two mixing methods were considered, namely, pneumatic and rotary. Through a series of carefully controlled batch sedimentation experiments the authors examined the fluidization behavior of a pure kaolinite mixture under different initial concentrations and initial suspension heights. Observations of the descending mudline interface (batch curve) and of the fluidization features (i.e., fluidization pipes and craters) were made by means of a digital camera, naked eye and gamma radiation source through repeated runs. These observations were necessary in order to examine the efficacy of the mudline interface to detect the onset of fluidization process of the kaolinite mixture as it has been reported in the literature. In addition the gamma radiation source provided unique information about the ascending sediment‐suspension interface (L‐curve) and the meeting point of the batch and L‐curves, which can not be easily detected by naked eye. The results of this research show that pneumatic mixing does not provide repeatable experimental runs (i.e., batch and L‐curves), especially for larger suspension heights due to uneven mixing and possible air entrapment. Subsequently, rotary mixing was considered as the most suitable mixing approach for investigating self‐weight fluidization. The experimental results obtained, using rotary mixing, were compared against the results obtained via the use of a 1‐D sedimentation code developed by Diplas and Papanicolau. The comparison shows a close agreement between the predicted and experimentally obtained batch and L‐curves. For all tests described herein, the onset of self‐weight fluidization was recorded to occur at an earlier period, during the first falling rate than the second falling rate. Despite the upward propagation of fluidization pipes no inflection points Were recorded anywhere atop the mudline interface for the kaolinite mixture. These findings agree with the batch sedimentation results reported by Gaudin who noticed no inflection points at the mudline interface despite recording the eruption of small flocs. Based on the results of this investigation, the efficacy of the mudline interface to detect fluidization appears to be questionable.

Select this Article		Estimating the Dispersion Coefficient with an Acoustic Doppler Current Profiler Meredith L. Carr and Chris R. Rehmann ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)410 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract We evaluate the use of river velocity and bathymetry data measured with an acoustic Doppler current profiler (ADCP) to estimate the longitudinal dispersion coefficient K. If shear dispersion controls the mixing, the dispersion coefficient can be estimated from a theoretical formula involving velocity measurements in a cross section. The dispersion coefficient has typically been measured by costly and time consuming tracer studies rather than by evaluating the theoretical formula because the velocity field could not be resolved sufficiently before the flow changed. However, ADCP transects, which now are routinely used to measure discharge, provide detailed velocity and bathymetry data quickly. We use ADCP velocity and bathymetry measurements from the United States Geological Survey to estimate the dispersion coefficient and compare with estimates from historical dye studies to explore the accuracy of this method and determine the error range. Half of the estimates of K fall within 50% of the values from tracer studies, and 75% are within a factor of three. The ADCP method is at least as accurate as the best formula considered. Both the comparison of field data and an analysis with theoretical velocity profiles suggest that error in K will be largest when the velocity profile is nearly uniform.

Select this Article		Evaluation of Oceanographic Microstructure Methods for Hydraulics Problems Danielle J. Wain and Chris R. Rehmann ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)411 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract We evaluate oceanographic methods to estimate dissipation of turbulent kinetic energy and eddy diffusivity for use in hydraulics. In the temperature microstructure method, dissipation is computed by fitting theoretical forms of the temperature gradient spectra to measured spectra. Eddy diffusivities are then computed from simplified budgets of turbulent kinetic energy and temperature variance. Dissipation from the temperature microstructure method matches that from acoustic Doppler velocimetry within a factor of 2 over the range 10⁻⁸ < ε < 10⁻⁶ m²/s³. An evaluation of terms in the temperature variance budget suggests that the dissipation of temperature variance dominates the budget, though terms neglected in the production‐dissipation balance contribute to uncertainty. Also, comparing the eddy diffusivities estimated with the two methods suggests that the dissipation coefficient Γ is not constant and smaller than 0.2 in the flow driven by a bubble plume.

Select this Article		Flooding Analysis Using HEC‐RAS Jon E. Zufelt, P.E., PhD, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)412 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The New York District of the US Army Corps of Engineers is currently conducting three Section 205 Studies for Ice Jam Flooding Reduction in central New York State. DuBois & King, Inc. and the US Army Cold Regions Research and Engineering Laboratory (CRREL) are conducting the flooding analysis for open water and ice jamming conditions. The three small watersheds all flow into the Mohawk River between Utica and Herkimer, NY. Each of the watersheds has its own unique design issues. This paper concerns some of the difficulties that required innovative analysis for Moyer Creek which flows through the Village of Frankfort, NY.

Select this Article		Graphical User Interface for ADCP Uncertainty Analysis D. Kim, M. Muste, J. A. Gonzalez‐Castro, and M. Ansar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)413 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A rigorous engineering methodology based on the American Institute of Aeronautics and Astronautics specialized standard has been implemented to conduct Acoustic‐Doppler‐Current‐Profiler (ADCP) measurement uncertainty analyses. Because the methodology for estimating ADCP measurement uncertainty is quite complex and requires laborious calculations, a stand‐alone software has been developed to facilitate this task. The software is controlled by a graphic user interface (GUI) containing extensive explanatory information, graphical and numerical reports, and straightforward menus that require minimum user preparation. The software is linked to an extensive library containing information compiled from specialized literature. A distinct feature of the software is the automated archiving of information relevant to ADCP uncertainty analysis from field data as soon as it is collected by the users. The newly added information is organized using uncertainty analysis considerations (error type, uncertainty analysis approach) and stream characteristics. The archived data continuously improves the reliability of the uncertainty analysis, because one of the most important aspects of error estimation is the collection of ample amount of data in various measurement conditions and environments to be able to account for as many potential sources of errors as possible.

Select this Article		The Horseshoe Vortex System around a Circular Bridge Pier on Equilibrium Scoured Bed Gokhan Kirkil, George Constantinescu, and Robert Ettema ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)414 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Large eddy simulation (LES) is used to investigate the horseshoe vortex (HV) system around a circular bridge pier located on scoured bed corresponding to equilibrium conditions. The deformed bed bathymetry is obtained from experiments. Simulation is performed for two different inflow boundary conditions, one in which the upstream flow is fully turbulent including the turbulent fluctuations obtained from a precalculated LES simulation in a periodic channel (Re=18,000) and one in which the mean streamwise velocity profile corresponding to the first simulation is used (Re=5000, no turbulent fluctuations). The former case corresponds exactly to the experimental conditions, the latter serves to highlight the effect of incoming turbulence on the HV system. The dynamics of the instantaneous coherent structures associated with the HV system around the cylinder and the spectral content of the flow in this region are analyzed. Special attention is given to the interaction between the legs of the horseshoe vortices and the flow behind the cylinder and to the distribution of the bed shear stress. The statistics of the flow are calculated. It is found that the bed shear stress fluctuations around the local mean values can be very high, especially in the scour and near wake regions. The mean flow fields show that for the given scour bathymetry and flow conditions, the mean HV system contains one primary eddy situated fairly close to the cylinder. Inside this eddy the mean pressure fluctuations and resolved kinetic energy levels are very high. Maximum mean bed shear stress levels are observed beneath this eddy as well as close to the small corner vortex at the base of the cylinder.

Select this Article		Hydraulic Model Study of Delta‐Mendota Canal Raymond Walton, Mark Jonas, Alan Stroppini, and Bob Martin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)415 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The flow capacity of the Delta‐Mendota Canal (DMC) from the San Francisco Bay Delta to the O'Neill Forebay is restricted due to the original telescoping design flow requirements, freeboard, and changes in water delivery patterns, and possible ground subsidence over the past 50 years. The Bureau of Reclamation is considering various alternatives including the construction of an Intertie between the DMC and the California Aqueduct. To determine the feasibility of these alternatives, the capacity of the existing conveyance system and the areas where conveyance restrictions occur need to be determined. A one‐dimensional hydraulic model, HEC‐RAS, was development and calibrated to the upper 70 miles of the canal. The model has about 1,000 cross sections, and includes 13 check structures, 9 inverted siphons or inline culverts, and numerous bridges and other crossings. As the canal was designed and built in sections using “template” cross sections for each reach, a spreadsheet was developed to automatically create the HEC‐RAS geometry file from the template sections and individual station invert elevations. The model was calibrated to nearly 600 observed water surface elevations surveyed during August and September 2003. The calibration was complicated because of the extremely flat slope of the canal (0.00005) and water surface, which meant that small changes in flow (which may occur daily) resulted in significant changes in water surface elevations.

Select this Article		Hydraulic Modeling beyond HEC‐RAS Dragoslav L. Stefanovic, Ph.D., P.E., Thomas R. Grindeland, P.E., and Christine Jenkins ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)416 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A drainage swale hydraulic analysis was conducted by WEST Consultants, Inc. as part of a dispute regarding a proposed subdivision. The primary purpose of the study was to evaluate the adequacy of the proposed drainage improvements. The downstream portion of the flow system consisted of: a steep triangular channel discharging into a debris basin, a chute‐like flow over a retaining wall, and a hydraulic jump (formed on the adverse slope of the street) combined with a distributed lateral (sheet) outflow along the road. Due to the complex nature of the flow (steep slope, lateral spreading, hydraulic jump with distributed outflow), standard hydraulic modeling tools, such as the HEC‐RAS program, could not be used to accurately determine flow characteristics. A straightforward numerical procedure, which overcomes present limitations of HEC‐RAS, was developed instead to solve flow resistance equations using a simple Excel spreadsheet. The elements of this procedure and the hydraulic modeling results are presented here.

Select this Article		Impact of Converging Chute Walls for RCC Stepped Spillways S. L. Hunt, E.I.T., A.M.ASCE, K. C. Kadavy, P.E., S. R. Abt, P.E., F.ASCE, and D. M. Temple, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)417 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Roller compacted concrete (RCC) stepped spillways are growing in popularity as a method for providing overtopping protection for many aging watershed dams with inadequate spillway capacity. Land rights are often not obtainable for widening existing earthen spillways, and in other cases, topographic features and land use changes caused by urbanization limit the ability to modify the dimensions of the embankment or spillways. An advantage of stepped spillways is that they can be placed over the top of an existing embankment dam without increasing the height of the dam or without widening the existing auxiliary spillway. Furthermore, stepped spillways provide considerable energy dissipation in the chute, potentially reducing stilling basin size. The U. S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) has proposed to design a converging RCC stepped spillway for Big Haynes Creek watershed dam site 3 in Georgia. The design calls for a 100 m (330 ft) ogee crested weir section, with a 3(H):1(V) spillway chute converging 52° to the stilling basin located at the toe of the structure. The peak runoff from a probable maximum precipitation (PMP) event is expected to generate a spillway discharge of 763 m³/s (26900 cfs). To assist with the design of this spillway and with future designs based on similar design parameters (i.e. chute slope, step height, etc.), a study utilizing a three‐dimensional, 1:22 scale, physical model was conducted to evaluate the flow characteristics in the spillway. This study is the first known attempt at developing generalized design criteria for vertical training walls for converging stepped spillways. The results of the study will be discussed herein.

Select this Article		Improving Performance of Low‐Head Labyrinth Weirs B. P. Tullis, C. M. Willmore, and J. S. Wolfhope ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)418 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Design criteria are presented for optimizing the design of labyrinth weirs operating at low heads. The design data were developed as part of a model study of the Brazos Dam (Waco, TX). A labyrinth weir spillway was proposed as a replacement for the existing gated spillway. One performance criterion was a strict limitation on upstream head rise to minimize flooding of the City's river walk, as well as other private and public property. The labyrinth weir design was constrained by the width of the river channel and the fact that it had to fit within the footprint of the existing structure. Based on these constraints, a labyrinth weir with a sidewall angle in the 7‐to 8‐degree range was required to obtain sufficient weir length. Laboratory tests were conducted to optimize the performance of 7‐ and 8‐degree labyrinth weirs at low heads featuring different crest shapes. An 8‐degree weir with an ogee‐type crest proved to be the most efficient design for this application.

Select this Article		The Integrated Hydrologic Model: A Field‐Scale Application Alaa Aly, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)419 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The integrated hydrologic model (IHM) has been applied to a small basin (450 acres) in west‐central Florida. The basin has been intensively monitored at a local scale for about 2 years. Data were recorded at five‐minute intervals for relevant hydrologic parameters including: stream flow into, and out of the basin, precipitation, soil moisture vertical profiles and water table depths along flow path transects, runoff rates from a controlled plot and complete meteorological conditions. The basin includes isolated pothole wetlands and alluvial wetlands with some stage monitoring. The model application had three objectives: (1) to test the validity of the conceptual model from which the code is developed, (2) to understand the relative importance of different model parameters and how their range of values could be derived based on observations, and (3) to provide guidelines for calibrating the model for larger applications. Preliminary application results indicated that IHM shows considerable promise in simulating the short‐term fluctuations in water table depth, soil moisture conditions, and evapotranspiration fluxes from the vadose zone and the water table in humid, shallow water table conditions. Sensitivity analyses results were used to evaluate the reasonable range of parameters for some of influential parameters.

Select this Article FREE		Integrated Modeling and Hydraulic Engineering Sam S. Y. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)420 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This Panel Session is to provide an open forum to discussion on how to apply the integrated modeling methodology to hydraulic engineering research, analysis and design at the present state of the art and in the future. Considerations of many different and conflicting factors in the solution of contemporary problems in our society, such as engineering effectiveness, economics, environmental/ecological constraints, sonetal acceptance, etc are needed. Optimization of multiple objectives under numerous constraints is an effort and time demanding process. The integrated modeling has the potential to be the cost‐effective tool for solving this problem. It is hoped that this Panel Session shall gather together professionals with different expertise and experience in this topic area to exchange their knowhow and opinions so that the advancement of application of integrated modeling to hydraulic engineering can be accelerated.

Select this Article		Investigation of Flood Hazards on Alluvial Floodplains Philip J. Shaller, Douglas Hamilton, Macan Doroudian, Parmeshwar L. Shrestha, Jene Lyle, and Andrea Cattarossi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)421 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Investigations were carried out to delineate the 100‐year flood hazard for a project area located in the upper Coachella Valley of Southern California. A multi‐disciplinary approach was adopted, integrating elements of geologic mapping, mapping of geomorphic features, detailed topographic data, hydrologic inputs, and numerical simulations of flood propagation. The San Andreas Fault dominates the geology, groundwater conditions, landforms and surface water hydrology in this area. Splay faulting between the major faults may be responsible for the formation of aligned channels and ridges on the floodplain northwest of the project area. Active uplift and a shift to intermittent stream flow during the Holocene have resulted in incision of Morongo Wash into the alluvial plain. As a result, most of the flooding in this area is confined to the existing channels, particularly Mission Creek and Morongo Wash. In contrast, the alluvial fan at the mouth of the neighboring Long Canyon watershed is the result of a typical desert watershed dominated by occasional flash‐flood type activity. Historical aerial photo coverage of three floods that struck the area indicate that flooding on the Long Canyon fan follows typical alluvial fan flooding patterns, and that associated with Morongo Wash and Mission Creek follows typical riverine flooding patterns. A two‐dimensional flood routing model was applied to assess the potential risk of future 100‐year flooding at the subject property from Morongo Wash, including a forced overflow scenario. To adequately characterize flood propagation and flood routes, it is critical that subtle topographic features be accounted for in the numerical model. For preliminary flood routing investigations, the USGS DEM data are generally a good source of topographic information. However, the relatively coarse resolution of the USGS DEM data and the significant age of the source survey measurements suggested the need for more accurate topographic data. Elevation data from Light Detection and Ranging (LiDAR) technology were therefore used. Model simulations were evaluated to predict the maximum discharge entering the project area as a result of temporal flood inflows from Morongo Wash, as well as the maximum water depths and extent of flooding in the interim floodplain.

Select this Article		Laboratory Evaluation of a Shallow‐Water Acoustic Doppler Profiling Flowmeter Tracy B. Vermeyen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)422 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A laboratory evaluation was conducted to determine if a newly developed acoustic Doppler flowmeter could be used for a canal seepage reduction project that required flowmeters to continuously measure flowrate through a series of 1.2‐ to 1.8‐m diameter culverts. A set of laboratory tests were designed to determine the uncertainty in the velocity and stage measurements used by the flowmeter to compute discharge. Tests were performed in a section of 1.2‐m‐wide flume and in a length of 0.45‐m diameter plastic culvert. The scope of this evaluation did not include a verification of the vertical velocity profile measurements or the algorithms used by Sontek's Argonaut‐SW for the discharge computations for open channels or closed‐conduits.

Select this Article		Large Eddy Simulation and Reynolds Averaged Navier‐Stokes Simulations of Flow in a Realistic Pump Intake: A Validation Study T. E. Tokyay and S. G. Constantinescu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)423 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract It is well known that the flow inside pump‐bays is characterized by the formation of sub‐surface and free‐surface vortices due to poor design or due to operating those structures outside their design range. These vortices are observed to be highly unsteady and intermittent. The presence of these vortices and the high level of non‐uniformity in the approach flow can produce high levels of unsteady swirl inside the pump column which in turn can result in uneven impeller loading and adversely affect the performance of the pumps. Numerical prediction of these flows characterized by the formation of unsteady (meandering) intermittent vortices and massive separation is very challenging. Successful prediction of these phenomena requires numerical methods and turbulence models that can accurately capture the dynamics of the main coherent structures in these flows. The present paper describes such a model that is based on using Large Eddy Simulation (LES) techniques in conjunction with an accurate non‐dissipative Navier‐Stokes massively parallel solver to predict the flow and vortical structures in pump intakes. The numerical solver can use unstructured hybrid meshes which allows flexibility in meshing very complex geometries while maintaining high quality of the computational mesh which is essential in obtaining accurate solutions. Some recent PIV data collected on a laboratory model of a realistic geometry pump intake is used to validate the newly developed LES model. To better put in perspective the predictive performances of the LES model, results from simulations employing the SST RANS model performed using a state‐of‐the‐art commercial Computational Fluid Dynamic (CFD) software are presented and compared with LES. The LES model is intended to be used as a design tool to remediate problems at existing pump intakes or test new design ideas without need to perform expensive scaled‐model studies.

Select this Article		Management Practice for Control of Erosion and Sediment (MPCES) Standards Committee M. L. Clar, W. J. Heatherman, and K. F. Holbrook ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)424 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This committee was established to develop standard guidelines, and/or practice documents (s) for the design, construction, rehabilitation, installation, and/or operation & maintenance of erosion control systems and/or best management practices for sediment control. To date the committee has organized three subcommittees which are addressing the following topics: Performance based BMPs; development of erosion and sediment control guidance; identification of regulatory tools

Select this Article		Model Study of Lock Extension for J. T. Myers Locks and Dam, Ohio River J. E. Hite, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)425 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Navigation improvements are planned at J. T. Myers Locks and Dam on the Ohio River main stem. The existing navigation project consists of a gated dam, an overflow weir, and a 365.8‐m‐long by 33.5‐m‐wide long (1,200‐ft‐long by 110‐ft‐wide) main lock chamber adjacent to a 182.8‐m‐long by 33.5‐m‐wide (600‐ft‐long by 110‐ft‐wide) auxiliary lock chamber. The improvements include developing a 365.8‐m (1,200‐ft) lock chamber from the existing 182.8‐m (600‐ft) lock chamber, which is referred to as a lock extension. The existing filling and emptying system for the 182.8‐m (600‐ft) chamber is a bottom lateral system with the culvert located within the lock wall. The requirements for the lock extension were that it be cost‐effective and an efficient lock filling and emptying system. This paper summarizes the results of a laboratory investigation performed to determine the hydraulic efficiency of the filling and emptying system proposed for the lock extension. A unique design for the additional filling and emptying system was evaluated. The design consisted of adding a lateral system in the extended lock chamber that was similar to the design in the existing 182.8‐m long (600‐ft long) lock. The water for the additional lateral system was supplied from through‐the sill intakes located beneath the existing upper miter gate sill. The intakes connected to two culverts that ran inside the chamber along the existing lock walls and over the top of the existing laterals. The culverts curved to the outside of the lock after passing over the existing empty culvert and then transitioned into a single culvert that fed the additional laterals in the extended chamber. The additional laterals emptied through a landside diffuser located in the lower lock approach. The filling and emptying times with the initial design were considered acceptable although minor modifications were made to the design that significantly improved the hydraulic efficiency. The recommended design filled the lock chamber in 11.3 min and emptied the chamber in 9.6 min with the design lift of 5.49 m (18.0 ft).

Select this Article		Modeling and Model Validation of Wind‐Driven Circulation in Upper Klamath Lake, Oregon Ralph T. Cheng, Jeffrey W. Gartner, and Tamara Wood ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)426 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The hydrodynamics in the Upper Klamath Lake (UKL) plays a significant role in the water quality conditions of the lake. In order to provide a quantitative evaluation of the impacts of hydrodynamics on water quality in UKL, a detailed hydrodynamic model was implemented using an unstructured grid 3‐D hydrodynamic model known as the UnTRIM model. The circulation in UKL is driven primarily by wind. Wind speed and direction time‐series records were used as input, the numerical model reproduced the wind “set‐up” and “set‐down” at down wind and upwind ends of the lake, respectively. Of the two acoustic Doppler current profiler (ADCP) records, the UnTRIM model reproduced the measured velocity at the deep station. At the shallow station, the model results showed diurnal patterns that correlated well with wind variations, but the measured velocity showed water velocity sustained at 3 to 5 cm/sec or above. Discrepancies between the model results and observations at the shallow ADCP station is discussed on the basis of correct physics. If the field measurements are inconsistent with the known physics, there exists the possibility that the field data are suspect or the field data are revealing some physical processes that are not yet understood.

Select this Article		Modeling Steep Channels with Lateral Inflow Richard L. Stockstill ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)427 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The main concern in the design of high‐velocity channels is the depth of flow in the channel for the design discharge. The depth must be known to determine sidewall heights and minimum bridge soffit elevations. Determining the depth of flow is complicated by side inflows and boundary features such as contractions, expansions, curves, and obstructions to the flow such as bridge piers, and vehicle access ramps. These boundary features in a supercritical channel, cause flow disturbances, which can result in a significant increase in the local flow depth. An accurate prediction of the water surface shape (i.e. variations in local depth) is essential in the successful design of a high‐velocity channel. Confluences of supercritical flow are complicated by the fact that standing waves are generated at any and all boundary alignment changes. Peak flows in the side channel and the main channel may not occur at the same time during a storm event. Therefore, analysis and design must be conducted at all probable combinations as well as at the design flow conditions. The design flows may not produce the largest water‐surface elevations because large standing waves that result from unequal water‐surface elevations can result in locally high water‐surface elevations. The confluence addressed in this paper is the case where culvert flow is introduced into the main channel in a lateral. These storm‐water drains are usually located near roadway intersections where the right‐of‐way is limited and the utilities are numerous. These place constraints on geometric flexibility in routing the culverts. The culvert discharge is only 10 percent or less than the main channel flow, but the momentum effects can produce significant bulking of the main channel flow. That is, locally, the main channel water‐surface elevation can be raised due to the introduction of lateral culvert flow. An understanding of the flow conditions in the vicinity of laterals is essential in the economic design of these structures. This paper presents a two‐dimensional (2D) model applied to supercritical flow with lateral inflow from a pressurized culvert. Model results are compared with laboratory data.

Select this Article		Net Transfer of Sediment from Floodplain to Channel on Three Southern U.S. Rivers J. W. Lauer and G. Parker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)428 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Eroding streambanks play an important role in the transfer of fine sediment between temporary storage in a floodplain and active transport by a river. Quantifying this transfer rate is important both for developing sediment budgets for fine sediment and for describing of the fate of contaminants that are bound to sediment particles. Many studies have measured gross bank retreat rates without also measuring the volume of material deposited in point bars on the opposite accreting bank. However, the net transfer of material from a floodplain to a river channel cannot be computed without accounting for deposition in point bars. Since the local geometry and channel migration rate determine the net transfer at any given location, and since both of these vary in the streamwise direction, computing net transfer rates is more difficult than computing gross bank erosion rates. This study presents net transfer rates for portions of three U.S. rivers: a 91 km reach of the Pearl River in Louisiana, a 62 km reach of the Bogue Chitto River in Louisiana, and a 35 km reach of the Neuse River in North Carolina. Channel migration rates taken from sequences of historic aerial photographs, together with detailed topography obtained using LIDAR, allow both the local erosion rate from cut banks and the local deposition rate on point bars to be estimated approximately every half channel width down the channel. These rates are used to develop system‐wide net transfer rates. The datasets can be used to optimize surveying strategies for measuring net transfer rates on streams where high‐resolution digital elevation data does not exist.

Select this Article		Noncohesive Sediment Transport Modeling with Multiple Size Classes Scott C. James, Parmeshwar L. Shrestha, and Jesse D. Roberts ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)429 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Contemporary three‐dimensional sediment transport models are computationally expensive and thus a compromise must be struck between accurately modeling sediment transport and the number of effective size classes to represent in such a model. The Environmental Fluid Dynamics Code (EFDC) was used to model the experimental results of Yen and Lee who investigated sediment erosion and gradation around a 180‐degree bend subject to transient flow. The EFDC model was first calibrated using the eight distinct size classes reported in the physical experiment to find the best erosion formulations to use. Once the best erosion formulations were ascertained, numerical simulations were carried out for each experimental run using a single effective particle size. Four techniques for evaluating the effective particle size were investigated. Each procedure yields comparable effective sizes, each within a factor of 1.5 of the others. Model results indicate that particle size as determined by the weighted critical shear velocity most faithfully reproduced the experimental results for erosion and deposition depths. Subsequently, model runs were conducted with different numbers of size classes to determine the optimal number that yields an accurate estimate for noncohesive sediment transport. Results from this study indicate that using three effective size classes to estimate the distribution of sediment sizes is optimum. In addition, when modeling only one non‐cohesive size class, the best technique for calculating effective particle size is to use a weighted critical shear velocity.

Select this Article		Numerical Modeling of the Phosphorus Cycle in a Shallow Oxbow Lake Xiaobo Chao, Yafei Jia, Charles M. Cooper, and F. Douglas Shields, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)430 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A three‐dimensional model was developed for simulating the phosphorus concentration in a shallow oxbow lake. The processes of mineralization, settling, adsorption, desorption, bed release (diffusion), growth and death of phytoplankton, etc, were considered, and the concentration of organic phosphorus, orthophosphate and phytoplankton were simulated. The adsorption and desorption of phosphorus from suspended sediment particles, as well as its release from bed sediment were verified using results obtained from laboratory experiments. The model was calibrated and applied to Deep Hollow Lake in the Mississippi alluvial plain. Simulated trends and magnitudes are generally in good agreement with field observations. Simulation indicates strong interactions between sediment‐related processes and phosphorus concentration.

Select this Article		Numerical Simulation of In‐Stream Sediment Capture Structures B. W. Hobbs and A. N. Papanicolaou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)431 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Sediment transport in a regulated river can be irregular and challenging to deal with due to the presence of large control structures, artificial channelization, and flow regulation. This study focuses on the Spokane River, Washington, USA, and specifically the entrapment of sediment well upstream of the Monroe Street Head End Diversion (HED). Throughout the operational lifetime of the diversion dam, sediment deposition behind the dam has been a serious problem, at times fouling the penstock intake and costing significant amounts of money and time to remove. A proposed solution to the problem is to capture sediment well upstream of the HED by placing artificial rock weir structures in the channel. Rock weirs are aesthetically pleasing and have been found to work effectively in trapping sediment. Numerical flow simulation is utilized in this study to examine the flow around the rock weirs and to examine the performance of those weirs under a wide range of flow conditions. Computer models are becoming an increasingly popular engineering tool as advancements in numerical modeling and data presentation drive the method forward. The commercial Surfacewater Modeling System (SMS) software package is utilized here to perform the necessary calculations. Using SMS, it is possible to resolve the in‐stream flow field velocity vectors, which can be used to calculate shear stress and examine the kinetic energy and dissipation. The model was calibrated using field data and the results compared to previous physical models. The resulting data can eventually be used to describe the sediment transport properties of the river and around the structures. It will be possible to give an estimate of the sediment capturing ability of the rock weirs and predict a useful lifetime for the structures.

Select this Article		Numerical Simulation of the Flow in Black Lake, Alaska J. Sanford, B. W. Hobbs, and A. N. Papanicolaou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)432 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Black Lake, Alaska, USA has historically been a significant juvenile salmon habitat. More recently, increase sediment transport down the Allec River system has forced a change in the sediment inflow to Black Lake. Over the past 50 years, the Allec River has carried enough sediment to build a sandbar across a portion of the lake and effectively reduce the recirculation and volume in the lake. This sandbar has also caused a major shift in flow from the north channel of the Allec River to the south channel near the lake outlet, ths bypassing most of the lake volume. This reduced volume and circulation poses a severe threat to juvenile salmon and overall salmon population in the region. Numerical flow and sediment simulation in the Allec River and Black Lake system utilized here to predict future changes based on recent field data. With the advancements in numerical modeling and data presentation, computer models are an attractive engineering tool. Two models will be used here in combination to produce an overall picture of the system. First, the Steep Stream Sediment Transport 1D (3ST1D) model will be used to predict the flow and sediment transport of the Allec River. Then, the commercial SMS package will be used to model the Lake. Using the results of the 3ST1D as inputs for the SMS model, it will be possible to examine the velocity vectors, recirculation patterns, and shear stresses in the lake. The resulting sediment transport parameters will be examined in order to predict further loss of lake volume and juvenile salmon habitat.

Select this Article		Peeking over the Computational Horizon: Numerical Simulation of a Swimming Fish Rollin H. Hotchkiss and Patrick J. Flanagan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)433 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In 2000, the first author presented a report on the ability to simulate a swimming fish using numerical solutions to the equations of motion. This paper is a report of significant progress towards the solution of this complex problem. The propulsion mechanism of a 10 cm rainbow trout (oncorhynchus mykiss) swimming steadily in undulatory mode was investigated. A 2‐D laminar unsteady incompressible Navier‐Stokes computational model was developed which utilized a moving adaptive mesh (Fluent 6.1). The simulated wake was dominated by a reverse von Karman vortex street previously observed experimentally. Thrust and drag forces acting on the trout were quantified and the equilibrium condition was satisfied within 5%. To better evaluate the models' ability to investigate swimming mechanisms, a logical next step would be a comparison of a wider variety of swimming cases. This could be accomplished by varying the wave speed, the swimming speed, the amplitude function, and several other parameters. Body thickness should be added to the model since it will most likely increase drag and better simulate the equilibrium condition for steady swimming. Adding turbulence and creating a 3‐D simulation would provide the most accurate and realistic numerical simulation of a rainbow trout.

Select this Article		Radar Stage Uncertainty Janice M. Fulford and William J. Davies ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)434 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Geological Survey is investigating the performance of radars used for stage (or water‐level) measurement. This paper presents a comparison of estimated uncertainties and data for radar water‐level measurements with float, bubbler, and wire weight water‐level measurements. The radar sensor was also temperature‐tested in a laboratory. The uncertainty estimates indicate that radar measurements are more accurate than uncorrected pressure sensors at higher water stages, but are less accurate than pressure sensors at low stages. Field data at two sites indicate that radar sensors may have a small negative bias. Comparison of field radar measurements with wire weight measurements found that the radar tends to measure slightly lower values as stage increases.

Select this Article		Recent Development in Hydraulic Design of Power Plant Cooling Water Intake Structures Kit Y. Ng, Yifan Zheng, and Stewart W. Taylor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)435 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The hydraulic guidelines traditionally used in the design of large cooling water intake structures for power generation stations have taken some fundamental changes recently. These changes were brought about by the promulgation of the recent U.S. Environmental Protection Agency Phase I and Phase II final rules under Clean Water Act, Section 316(b) in 2004. The new rules affect both cooling water systems and intakes of existing power plants and proposed new plants. By requiring cooling water intakes to adopt the best technology available to protect all stages of aquatic life, the new 316(b) rules impose more stringent hydraulic requirements on the design of intake systems. The impact of the rules can be considerable, especially for large intake structures such as those serving power plants with a once‐through cooling system. This paper summarizes the new requirements and assesses the changes on the hydraulic design criteria and design concepts of large cooling water intakes in the United States as driven by the Phase I and Phase II 316(b) rules.

Select this Article		Results of Near‐Term Forecasting of Surface Water Supplies Janice Lantrip, Mitchell Griffin, and Alaa Aly ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)436 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Tampa Bay Water developed a set of goals and objectives aimed at improving water supply source planning, rotation, and utilization through the development of Tampa Bay Water's Decision Support System (DSS). One of the tools developed as part of Phase I of the DSS project was a prototype hydrodynamic computer simulation model of the Hillsborough River and Tampa Bypass Canal (HRTBC). This model provides Tampa Bay Water with short‐term predictions of surface water available for withdrawals from the HRTBC system (one week, daily forecast). The complete HRTBC prototype model package includes several Artificial Neural Network (ANN) flow generation models and a hydraulic routing model (HEC‐RAS). Tampa Bay Water used these prototype models during WY2004. This paper discusses the analysis of the accuracy of the flow generation model component during the first year of operation. Tampa Bay Water believes that the lag time in collecting hydrologic data is leading to a lag in the forecast during periods of high flow which is providing unacceptable results. The near‐term effort will be toward improving the timeliness of these input data. Given better data, these ANN models may be re‐trained with additional data in the future.

Select this Article		River Water Quality Management: Application of Stochastic Genetic Algorithm R. Kerachian, M. Karamouz, F.ASCE, and A. Vejdan Naseri ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)437 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A stochastic GA‐based optimization model is proposed to determine the operating policies for river water quality management. This model, which is called Stochastic Genetic Algorithm (SGA), considers the state variables of the system such as the discrete values of upstream flow and the spatial variation of the concentration of water quality variables along the river. This multi‐objectives optimization model is linked to WQRRS (Water Quality for River‐Reservoir Systems) model for simulating water quantity and quality. As different decision‐makers and stakeholders with conflicting objectives, are involved in river water quality management, in this study the Nash conflict resolution theory is used. The proposed model maximizes an objective function which is based on the expected value of the Nash product which includes different utility functions related to the pollution reduction costs and the water quality deviations from the standards. The main idea of the proposed optimization model adopted from the Stochastic Dynamic Programming (SDP) by utilizing the recursive function and the transition probability matrix in the objective function. This GA‐based optimization model does not have the dimensionality problem of the SDP. To assess the efficiency of the proposed methodology, the model is applied for waste load allocation in the Aras River basin in north western part of Iran. The results show that the proposed model can effectively reduce the computational deficiencies of using an alternative optimization model such as SDP for waste load allocation problem. It is also shown that the number and duration of violating the standards can be significantly reduced using the waste load allocation policies.

Select this Article		Rough Wall Flow Using k − ω Turbulence Model in FLUENT K. B. Strom, A. N. Papanicolaou, and G. Constantinescu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)438 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The ability the k − ω SST model in the CFD package FLUENT to accurately predict open‐channel turbulent flows over rough porous walls is examined. Numerical results are compared to laser Doppler velocimetry and well established relations for ΔB = F(ks+) for validation. Results show that if low Reynolds number modeling is used, the k − ω SST model in FLUENT is capable of predicting accurate mean flow distributions of velocity.

Select this Article		Scaling Dispersion Model for Pollutant Transport in Natural Rivers Zhi‐Qiang Deng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)439 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Scaling dispersion is hypothesized as the mechanism underlying the non‐Fickian longitudinal dispersion process in natural streams. Using this mechanism, a new model, called scaling dispersion model, is developed to simulate pollutant transport in natural rivers and streams. The model is comprised of (1) a fractional advection‐dispersion‐reaction equation, (2) a parameter estimation method based on the Laplace transform of fractional order differential equations, and (3) a semi‐Lagrangian F.3 central difference scheme devised to evaluate the solution of the fractional differential equations. Dispersion characteristics computed by the scaling dispersion model were in good agreement with those observed by 20 dye tests conducted in natural rivers, thereby demonstrating the efficacy of the scaling dispersion model for prediction of the non‐Fickian dispersion process in natural rivers and streams.

Select this Article		Scour in Non‐Cohesive Soil Due to the Impact of Jet Spillway out of Ski Jump Elsa V. Minaya Espinoza and Julio M. Kuroiwa Zevallos, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)440 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A number of researchers have studied the scour phenomenon in non‐cohesive soils. Several of these studies are empirical due to the complexity of the physical processes involved. The physical model presented in this paper consists of an impinging jet released from a ski jump with a takeoff angle of 35°. The jet impacts on a scouring plunging pool made up of non‐cohesive soil. The area of the physical model was 10.0 m. long and 5.0 m wide. The maximum scour depth (h_s) in the impingement zone is estimated using different parameters such as H: difference between water level at the reservoir and the tailwater level, θi: the angle of attack (measured from the x‐axis) that the jet forms when impacting the plunging pool, q: the discharge per unit area (0.033, 0.0667 and 0.1 m²/s), d₅₀ and d₈₅: the representative sediment diameter used in the tests (coarse sand: d₅₀ = 1.60 mm, d₈₅ = 4.81 mm, medium gravel: d₅₀ = 17.88 mm, d₈₅ = 23.43 mm, and rounded cobbles: d₅₀ = 49.08 mm, d₈₅ = 70.53 mm) and h_tw: tailwater depth: 0.05m, 0.10m, 0.25m and 0.50m. A dimensional analysis (Pi‐Buckingham theorem) and linear multiple regressions are performed to obtain a mathematical equation that predicts the final depth of scour. During the tests, it was evident that a tailwater practical limit exists for which scour does not occur. The need of additional tests is assessed.

Select this Article		Sediment Investigation and Stable Channel Design for the Lower Mud River Martin J. Teal and Phillip E. Anderson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)441 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Army Corps of Engineers, Huntington District (COE or the District) is currently developing a feasibility level investigation to determine viable alternatives for local flood protection for the town of Milton and vicinity in Cabell County, West Virginia. The principal flooding source is the Lower Mud River. In the current investigations several alternatives are being evaluated to determine the most cost effective project. These alternatives consist of a levee (with varying levels of protection) and channel widening/channel diversion as well as combinations of these options. A detailed stable channel and sediment transport analysis for the project was warranted to determine the aggradation/degradation tendencies that may have adverse impacts on the operational and functionality characteristics of the local protection project. The objectives of this study were to define both the long‐term and short‐term aggradation/ degradation tendencies associated with the project. This information would be used as a basis for determining expected channel maintenance. Part of the scope for this study was to perform initial design of the new channel such that, on average, it would neither aggrade nor degrade over time. Design of the new channel using an innovative combination of geomorphic and sediment transport analyses is described in the paper.

Select this Article		Sediment Transport Modeling in HEC RAS Gary W. Brunner, P.E. and Stanford Gibson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)442 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Sediment transport capabilities have been added to the Hydrologic Engineering Center's River Analysis System program (HEC‐RAS). HEC RAS can perform mobile bed sediment routing computations with quasi steady (histogram) flow series data. For each flow in the time series a water surface profile is calculated. Hydraulic parameters required for sediment processes are also calculated. The model calculates sediment transport capacity by a number of available methodologies. The sediment continuity equation is then solved in conjunction with sorting and armoring algorithms to solve for the actual volume of deposition or erosion. Additionally, temporal entrainment and deposition functions similar to those employed in HEC‐6 have been adapted. This paper discusses the equations and methodologies that have been added to HEC‐RAS for the inclusion of sediment transport modeling. Additionally, the graphical user interface, which is used to enter sediment data and visualize results, will be shown.

Select this Article		Simple Methods for Energy Dissipation at Culvert Outlets Rollin H. Hotchkiss and Emily A. Larson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)443 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Experiments were performed to investigate the energy dissipation realized at the outlet of a culvert using two simple design alternatives: (1) Design I, a simple weir near the culvert outlet, and (2) Design II, a weir with a drop upstream in the culvert outlet barrel. The two designs are intended to reduce the flow energy at the outlet by inducing a hydraulic jump within the culvert barrel, without the aid of tailwater. This paper examines the jump geometry, the effectiveness of each jump type, and proposes a design procedure for practicing engineers. The design procedure is applicable to culverts with approach Froude numbers from 2.6–6.0. Both designs are effective in reducing outlet velocity 0.7 to 8.5 ft/s (0.21–2.59 m/s), momentum 10–48%, and energy 6–71%. The design layouts allow easy access for maintenance activities.

Select this Article		Spur Dikes as an Abutment Scour Countermeasure Hua Li, Roger Kuhnle, and Brian D. Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)444 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Experiments using spur dikes as a countermeasure to local scour at wingwall abutments were made in a laboratory flume channel. Flow velocity ratios of 0.9, 1.5 and 2.3 times the incipient motion of the bed material sediment were used in a compound channel with a model abutment. The bed material was sand with a median diameter of 0.8 mm and a standard deviation of 1.37. A series of configurations of spur dikes with varying lengths, spacings, number, and positions with respect to the abutment were tested. The most effective configuration to prevent local scour at the abutments consisted of three spur dikes composed of rock located upstream of the abutment and at the two corners.

Select this Article		Study on Turbidity Outflow Problems at the Shimokodori Dam Jian Liu, M.ASCE and Peng Lou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)445 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The turbidity outflow problems at the Shimokodori Reservoir in central Japan were discussed in this study. A two‐dimensional numerical model was used for predicting the water temperature distributions and turbidity variations in the reservoir. The model calibration and verification were made by the measured data in the reservoir and at the tailrace channel of the power station in 1999 and 2002. The predictions were performed for different operational modes such as rapid discharging, selective withdrawal, fence, and fence plus selective withdrawal. The calculated results show the selective withdrawal method is the best option from the viewpoint of decreasing the turbidity outflow days.

Select this Article		A Systematic Procedure for Flow Model Verification and Validation Sam S. Y. Wang and Yafei Jia ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)446 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper is to report some recent progresses of the ASCE‐EWRI Task Committee on 3D Free Surface Flow Model Verification and Validation. A general procedure has been developed for verifying and validating numerical models for simulating 3D free surface flows. This procedure consists of three major steps, namely, the Mathematical Verification, the Physical processes Validation and the Site‐Specific Case Validation, which includes calibration. Typical examples are given during the presentation for demonstration of the applications of these three major steps of a selected numerical model, CCHE3D. The results of these tests can be used by the model developers to confirm the correctness and refine the capabilities of their models and by the prospective users to determine a model's capabilities and accuracy before their decision to adopt it.

Select this Article		Task Committee on Experimental Uncertainty and Measurement Errors in Hydraulic Engineering: An Update Brian Wahlin, Tony Wahl, Juan A. Gonzalez‐Castro, Janice Fulford, and Michael Robeson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)447 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract As part of their long range goals for disseminating information on measurement techniques, instrumentation, and experimentation in the field of hydraulics, the Technical Committee on Hydraulic Measurements and Experimentation formed the Task Committee on Experimental Uncertainty and Measurement Errors in Hydraulic Engineering in January 2003. The overall mission of this Task Committee is to provide information and guidance on the current practices used for describing and quantifying measurement errors and experimental uncertainty in hydraulic engineering and experimental hydraulics. The final goal of the Task Committee on Experimental Uncertainty and Measurement Errors in Hydraulic Engineering is to produce a report on the subject that will cover: (1) sources of error in hydraulic measurements, (2) types of experimental uncertainty, (3) procedures for quantifying error and uncertainty, and (4) special practical applications that range from uncertainty analysis for planning an experiment to estimating uncertainty in flow monitoring at gaging sites and hydraulic structures. Currently, the Task Committee has adopted the first order variance estimation method outlined by Coleman and Steele as the basic methodology to follow when assessing the uncertainty in hydraulic measurements. In addition, the Task Committee has begun to develop its report on uncertainty in hydraulic engineering. This paper is intended as an update on the Task Committee's overall progress.

Select this Article		Tests of Capability and Reliability of a Model Simulating Coastal Processes Yan Ding and Sam S. Y. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)448 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Integration of processes‐based models is an effective approach to simulate complex multi‐scale coastal processes in estuaries and coasts. In general, coastal process modeling aims at predicting irregular wave deformations, wave‐induced currents, sediment transport, morphological processes, and/or other concerned physical processes like fresh water exchanges and ecological responses. Although modelers can validate individually each submodel related to a single process like wave, current, or sediment transport, it is still difficult to verify and validate highly integrated multi‐process models, due to the interactions of submodels in the multi‐scale processes. In the paper, several numerical examples for validation of each process submodel in the integrated coastal process model are presented. The interactions of these submodels for modeling wave deformations, currents, and seabed changes, are also discussed. Moreover, a long‐term simulation result about the seabed change of a coastal zone with installation of coastal structures is presented; and an application of the numerical model to select a plan of a groin in a harbor is demonstrated. The results indicate that this comprehensively validated coastal process model can insure the capabilities and reliabilities in the applications to the marine environmental impact assessment for coastal zone sediment management and coastal structure planning.

Select this Article		Two‐Dimensional Model Simulation of Flow Field around Bridge Piers Jennifer G. Duan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)449 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Two‐dimensional (2D) depth‐averaged hydrodynamic model was applied to simulate flow field around a circular pier in clear water. A correction factor was included in the friction term to take account the effect of streamline curvature due to flow separation and vortex shedding. In this study, 2D model simulate not only the vortex shedding in the turbulence wake but also bed shear stress distribution. The simulated bed shear stress contours were close to experimental measurements and three‐dimensional (3D) modeling results. Since 2D model is much simpler and requires significantly less computational time than three‐dimensional model, these results demonstrated that an improved 2D model is a capable tool of simulating bed shear stress distribution around bridge piers. Research in enhancing and applying 2D model to simulating the initiation and development of local scour is still a challenging topic for hydraulic engineers.

Select this Article		Uncertainty of Index‐Velocity Measurements at Culverts Juan A. González‐Castro and Zhiming Chen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)450 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The flow through uncontrolled and partly‐controlled culverts in environmentally sensitive areas is often monitored based on index‐velocity measurements by time‐of‐travel ultrasonic velocity meters (UVM). Index‐velocity monitoring consists of measuring the velocity of the flow in a limited region of the flow cross‐sectional area—so‐called index‐velocities—at time intervals on the order of 15 minutes. Index‐velocities are then used to estimate the mean velocities of the flow using site‐specific index‐velocity ratings, which are established based on index‐ and mean‐velocity data concurrently measured at the site within the expected range of flows. Water stages are also monitored at the culverts' ends and, together with the culvert geometry, are used to estimate the flow cross‐sectional area. The discharge through the culvert is then computed from the estimated mean velocity and respective flow cross‐sectional area. The quality and reliability of index‐velocity‐based discharge records depends directly upon the measurement uncertainty of the data used for developing the rating and the measurement uncertainty of the index‐velocity and stage data from which the discharges are estimated. To estimate the total uncertainty of index‐velocity‐based discharge records, the total uncertainty of the index‐velocity and mean‐velocity measurements of each data pair used for establishing the index‐velocity rating need to be estimated first. These measurement uncertainties are then combined for estimating the total uncertainty of the index‐velocity rating throughout the range of index velocities. The rating uncertainties and the uncertainties of the monitored index‐velocities and stages from which the discharge record is estimated are subsequently combined to compute the uncertainty of each mean discharge estimate. Moreover, since time‐average discharges are typically estimated from measurements collected at time intervals on the order of minutes and the uncertainty of each discharge estimate varies as a function of the flow velocity, the uncertainties of the individual values need to be combined for estimating the total uncertainty of daily, monthly, and annual mean discharges. The evaluation of uncertainty of discharge records is not yet a common practice in flow monitoring. In this paper, we present an evaluation of UVM‐measurement uncertainty based on the First‐Order Taylor Series Expansion (FOTSE) method for propagation of uncertainty for an uncontrolled culvert site in the South Florida Water Management District (SFWMD). In this evaluation, we show that the precision uncertainty of the index‐velocity measurements is not only a function of the frequency of the samples and the sampling time span, but also of the time scale of the turbulence intermittency of the flow. Moreover, we show that since the characteristic time scale is a function of the maximum velocity in the culvert, the precision uncertainty of UVM measurements is a function both the sampling time in the monitoring protocol and the time span over which the data for determining the precision uncertainty are collected.

Select this Article		Validation of a 3D RANS Model to Predict Flow and Stratification Effects in River‐Dam Forebays Md. Manjurul Haque, George Constantinescu, and Larry Weber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)451 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Flow and temperature distributions within the powerhouse units and the forebay of McNary Dam on the Columbia River are predicted using a fully coupled non‐hydrostatic 3D Reynolds Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) model. The parallel pressure based solver of FLUENT is employed and the Boussinesq approximation is used to account for temperature stratification effects. The model is validated with hydrodynamics data from a 1:25 scaled model laboratory study of a single turbine powerhouse unit and temperature data collected in the forebay of the McNary Dam by the U.S. Army Corps of Engineers (USACE) in summer 2004. Excellent agreement for the velocity distributions inside the model intake unit is observed. The unstructured mesh of the full forebay simulation contains close to 6 million cells. This large size was needed to incorporate all the relevant geometrical details of the hydraulic structures and forebay bathymetry over a length of 13,000ft and to accurately resolve the large temperature gradients present near the free surface under strong stratified conditions. Overall, a good agreement is found between the simulated temperature profiles and corresponding field data inside the forebay.

Select this Article		Velocity and Suspended‐Sediment Measurements over Mobile Sand Dunes in a Laboratory Flume Daniel G. Wren, Roger A. Kuhnle, and Christopher Wilson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)452 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Knowledge of the flow structure over mobile sand dunes is important for modeling flow resistance and sediment transport in fluvial systems. Many previous studies of flow over dunes in laboratory channels have utilized some type of immobile dunes. In the current work, a Laser Doppler Velocimeter (LDV) and an Acoustic Backscatter System (BSS) were maintained at a fixed point relative to a given dune by using a motion control system to track bedforms over a 1.7 meter test section. A second BSS continually traversed the test section to map the bed profile. Under similar hydraulic conditions, isokinetic samples of the water‐sediment mixture were collected simultaneously from 4 depths to assess suspended sediment characteristics and to calibrate acoustic backscatter measurements of concentration. Two different flow stages were used: Fr≈0.15 and 0.3. Preliminary results from the velocity and suspended‐sediment concentration measurements are reported.

Select this Article		Velocity Profile Characteristics in Open Channel Flow over Two‐Dimensional Dunes with Small Relative Submergence C. Polatel, T. Stoesser, and M. Muste ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)453 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Turbulent open channel flow over a two‐dimensional dune with small submergence is investigated numerically by Large Eddy Simulation (LES) and experimentally with Laser Doppler Velocimetry (LDV). Experiments are used for validating the simulations, which in turn provide an ideal complement to the experiments to investigate the flow properties with a high spatial resolution. In this paper we discuss flows over large roughness elements with low submergence by analyzing the spatially averaged profile. As expected, it is found that the roughness is affecting the flow throughout the depth, and a more substantiated roughness characterization is needed for describing these types of flows.

Select this Article		Analysis of ENSO Impacts in Southwest Virginia Ethan Knocke, Eric LaRocque, Vinod Lohani, and G. V. Loganathan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)454 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper provides a correlation analysis between El Niño and La Niña events and Roanoke annual precipitation. Roanoke annual precipitation is compared with the NOAA and JMA‐ SST, and SOI indices. Also, precipitation behavior is reported during the 6‐phases of El Nino. Preliminary results indicate that the decay phase of an El Niño event may lead to increased precipitation for Roanoke. In addition, the SOI anomaly can be a potential predictor of Roanoke precipitation for the year following an El Nino year.

Select this Article		Analysis of Streamflow Trends in the Upper Midwest Using Long‐Term Flowrecords H. Vernon Knapp ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)455 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This study examines trends in the longest‐term streamflow records in the Upper Midwest, with periods of record in excess of 90 years. Results from long‐term flow records from other locations in the eastern United States are also provided for comparison purposes. Emphasis is given to identifying comparative changes in the flow regime relative to total runoff (mean flow), rather than focusing solely on univariate trend analyses for individual flow parameters. Results indicate that significant trends in total runoff for the longest streamflow records in the eastern half of the United States are mostly limited to the Upper Midwest, defined primarily by the Upper Mississippi River Basin. This region also displays increases in median and low flows that are well correlated to coincident increases in total runoff. Two different patterns appear regarding trends in high flows. First, for roughly 60 percent of the region, changes in the magnitude of the annual maximum flows are accordant with coincident changes in total runoff. However, these trends in maximum flows typically have lower statistical significance as determined by the Kendall trend test, primarily because of the higher variance of the annual maximum flow series as compared to the annual mean flow series. For the remaining 40 percent of the Midwest, streamflow records have detectable decreases in the annual maximum flows relative to total runoff. For certain regions the reduction in the maximum flow appears to be related to seasonal changes in precipitation amount. Additional factors contributing to the decreases in high flows are being investigated.

Select this Article		Analysis of the Relations between Climatic Variability and Groundwater Level Variations in Wisconsin, USA Reza Namdar Ghanbari ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)456 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Singular Spectrum Analysis (SSA) toolkit is used to analyze the groundwater level time series in frequency domain. Frequency domain analysis of the groundwater level time series enables us to estimate and reconstruct different frequencies from groundwater level time series. The comparison of reconstructed frequency components of different data types leads us to identify the existing relations between them. Regional groundwater and surface water models are usually used to assess the effects of management practices on sustainability of these resources while climatic variability effects are neglected. Considering the importance of climatic variability effects shown in this paper we must include these effects in the assessment of the water resources sustainability. Groundwater level time series from Wisconsin are used in this study as input data. The results reveal the relations between these time series and climate cycles such as Pacific Decadal Oscillation and the El Nino‐Southern Oscillation. Groundwater level is affected by different hydrologic processes such as precipitation and surface water bodies' interaction. To include the relations between hydrologic time series and climate cycles (climatic variability effects) in water resources studies results in better water resources management.

Select this Article		Application of DSPM and HEC‐HMS in the Upper Red River of the North Basin Watershed Modeling Henry H. Hu, M.ASCE, Leo R. Kreymborg, M.ASCE, and Scott A. Jutila ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)457 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In order to reduce future flood damage in the Red River of the North basin, the U.S. Army Corps of Engineers, St. Paul District, is developing a Corps Water Management System (CWMS) to assist in real‐time operation of reservoirs to regulate reservoir outflows. This paper presents an application of Distributed Snow Process Model (DSPM) and Hydrologic Engineering Center's Hydrologic Modeling System (HEC‐HMS) in distributed snowmelt and rainfall‐runoff modeling for reservoir operational forecasting, which is an essential component of the CWMS system. The model setup, calibration, and verification are described. The paper particularly focuses on information requirements of DSPM and HEC‐HMS for model setup/calibration and continuing forecast operations and shows how these requirements could be met in a practical and operational setting. Elements of the modeling process that are challenging for an operational forecasting are discussed and are expected to benefit similar CWMS operational forecasting in other watersheds both in cold and warm regions.

Select this Article		Automated Hydrologic and Hydraulic Modeling E. James Nelson and Robert M. Wallace ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)458 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The US Army Corps of Engineers (USACE) through the Engineering Research and Development Center (ERDC) has developed automated hydrologic and hydraulic modeling tools for more than a decade. These tools have been widely used by engineers in government, university, and private sectors for automated basin delineation and model parameterization. This paper summarizes the latest automated hydrologic and hydraulic modeling tools available from ERDC with a focus on the ability to link H&H models for the purpose of considering uncertainty in model parameters as a part of the final solution for a floodplain delineation.

Select this Article		Bayesian Spectral Analysis of Climatic and Hydrologic Time Series En‐Ching Hsu and A. Ramachandra Rao ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)459 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Many hydrological time series are periodic and can be modeled by sinusoidal functions and random noise. By fitting the data with sinusoidal functions, the fundamental frequencies, amplitudes, and stochastic properties of noise can be estimated. However, when more frequencies are considered, large number of parameters needs to be estimated. Such a situation may result in solving a high dimensional problem with a consequent reduction in accuracy. An alternative to this situation is the Bayesian spectral analysis developed by Bretthorst which enables removal of uninteresting or needless parameters. Long‐term series of different types of climate and hydrological data are analyzed in this study by using the Bayesian spectral analysis. There are more than two hundred years of daily temperature data available in Europe and these allow assessment of the long‐term trend and climate variability. Several unregulated streamflow records in US are also analyzed to examine the performance of the Bayesian method. The results by the Bayesian method are compared to those by discrete Fourier transform, Burg's and the multi‐taper methods.

Select this Article		Climate Change and Feedbacks from Vegetation Succession: Evidence from Long‐Term Ecological Research Sites Julia Jones, Barbara Bond, Georgianne Moore, and Kevin McGuire ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)460 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Long‐term ecological research (LTER) sites, many of which are U.S. Forest Service Experimental Forests, have unique, long‐term records of climate, streamflow and vegetation that illustrate many aspects of vegetation effects on hydrology and suggest implications for climate change. Because vegetation, and vegetation water use, are changing over time, changes in streamflow and the climate:streamflow relationships are not sufficient to demonstrate climate change. This study investigates the hypothesis that vegetation change effects on streamflow can be quantified and separated from pure climate change effects on streamflow. Long‐term paired watershed experiments involving forest removal and regrowth have been conducted at sites in the eastern and northwestern United States. These experiments show that streamflow increases after forest removal, and then decreases as forests regrow. However, the rates and timing of these changes depend upon the type of vegetation (deciduous or evergreen forests), the climate (seasonally concentrated v. year‐round rainfall), and the history of disturbances (fire, hurricanes, pests and diseases, prior forest harvest or agriculture) at the sites. Detailed examination of vegetation water use at these sites indicates that transpiration rates of trees also vary by the type of vegetation (broadleaf or conifer), the age of the tree (young plantation v. old‐growth), and climate (wet/dry seasons, wet/dry years). Detailed study of hillslope hydrology at these sites shows that the transport of water through vegetation to soils and thence to streams depends upon preferential flow pathways that are in part related to soil depth, slope angle, and changes in permeability with depth. These findings imply that as vegetation undergoes succession, water fluxes to the atmosphere and streams will change. This study utilizes streamflow and climate records from multiple LTER sites to examine the changing relationship between streamflow and climate over periods of up to 6 decades in the course of forest vegetation succession. Results indicate that in early succession (0 to 50 yr‐old stands) vegetation water use increases rapidly and is decoupled from water availability, whereas in old‐growth stands (450 to 500 yr‐old stands) vegetation water use may decline and is coupled to water availability. Understanding how vegetation responds dynamically to climate fluctuations over decadal time scales improves predictions of climate change effects on streamflow over very long time scales.

Select this Article		Climate Change Impacts on Missouri River Basin Water Yields: The Influence of Temporal Scales Mark C. Stone, S.M.ASCE, Rollin H. Hotchkiss, M.ASCE, and Asako B. Stone ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)461 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Global climate change will likely modify the availability of surface and ground water. It is necessary to evaluate the potential impacts of climate change on water resources to assist in policy decisions. Water resources impact assessments are often completed with hydrologic models. This draws into question the temporal and spatial scales over which these models are developed and evaluated. The objective of this paper was to evaluate the impacts of climate change on Missouri River Basin water yields at multiple temporal scales. This was accomplished by developing a hydrologic model of the basin. The model was conducted for baseline and changed climate conditions. The climate change data was provided by a Global Circulation Model and downscaled with a Regional Climate Model. Water yield increased significantly under the changed climate simulation for all temporal scales. The insensitivity of results to temporal scale was likely due to the large sample size and the strong effects of climate change on water yield. Future research will expand this work to include assessment of spatial model scales.

Select this Article		Climate Change in Texas: Fact or Fiction James P. Amick, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)462 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The climate in Texas is changing — or is it? This paper will analyze over 100 years of climatologic data in an attempt to answer this question. The data was available from the U.S. National Weather Service. Records from several locations around the state of Texas were used to determine annual precipitation and annual average temperature. Locations for annual precipitation included Austin (dating to 1856), Abilene, Del Rio, Fort Worth/Dallas, Lubbock, Midland/Odessa, San Antonio and Waco. Records for annual precipitation from all eight locations were available starting in 1931. Locations for annual average temperature included Austin (dating to 1854), Del Rio, Fort Worth/Dallas, Midland/Odessa, San Antonio and Waco. Records for annual average temperature from all six locations were also available starting in 1931. These records were analyzed in a standard XY Scatter Chart with a linear regression. The trends were subtle, but measurable. Four locations indicated increasing annual precipitation and four locations indicated decreasing annual precipitation. Four locations indicated increasing average annual temperature and two indicated decreasing average annual temperature. Averaging the regression results from the eight annual precipitation locations produced an answer to the question, are we getting more rain. Averaging the regression results from the six annual average temperature locations produced an answer to the question, are we getting hotter.

Select this Article		Climate Impacts on Inland Navigation J. Rolf Olsen, Laura J. Zepp, and Chrisman A. Dager ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)463 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The availability of barge transportation has benefited the national economy by providing a more fuel‐efficient alternative to rail and highway transport for many commodities, including grains, coal, petroleum and chemicals. Cost savings from barge transport on the Middle Mississippi are estimated to exceed one billion dollars per quarter, but these savings depend upon the reliability of inland waterways. Shipping interruptions due to low flows, floods, or traffic congestion increase the time and costs required to transport a quantity of goods. In such cases, the cost savings associated with barge transport decrease as the per ton costs of barge transportation increase. Climate conditions are a crucial determinant of navigation system reliability. Temperatures, soil moisture, humidity, cloudiness, wind, and the timing and duration of precipitation events interact to determine the river conditions under which barges operate, including river flows and channel depths. Changes in the magnitude and frequency of low flows or floods could affect the costs of barge transportation by impairing or enhancing the navigability of the waterway. This paper models the frequency of shipping interruptions caused by hydrologic variability on the Middle Mississippi River associated with past and projected climate conditions. The economic consequences of changes in inland navigation system reliability are calculated.

Select this Article		Climate Variability and Ecosystem Response: Concept Transfer from Natural to Agricultural and Hydrological Systems David Greenland ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)464 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Long‐Term Ecological Research (LTER) program recently completed a major study on climate variability and ecosystem response at the (then) 24 LTER study sites. Most of the study sites are in natural ecosystems. Several recurrent principles emerged from this study. In light of possible future climate changes there is value in investigating the applicability of these principles to agricultural and hydrologic systems. The principles of the LTER study are organized here under the themes of separation of time scales, legacies of climatic events and episodes, physiological links and climate redundancy, legacies and lags, gateways, filters, and catalysts, and buffering, simple response, and resonance. This paper suggests: 1) agricultural and hydrological systems potentially have faster adaptive response times to climate change or changes of climate variability but it is not guaranteed that the potential will be realized; 2) the concept of “buffering capacity” has important cross‐over implications and biological, agricultural and hydrological engineers must work to increase the buffering capacity of their respective systems to climate variability and change; 3) the concept of resonance has more application to the shorter time scales of the agricultural ecosystems, and crop and hydrologic models can be used to optimize the tuning of the systems. There is a degree to which agricultural and hydrological systems potentially can be “forced” by human manipulation to come into resonance with climate change and variability, although such forcing may not be possible because of political and/or economic reasons. Overall, it is important to recognize that climate is a dynamic and not a static phenomenon.

Select this Article		Climate Aspects of Water Supply Planning Derek Winstanley, D.Phil. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)465 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Illinois withdraws about 19 billion gallons of water per day from Lake Michigan, reservoirs, rivers, lakes, and aquifers. As population grows, the economy expands, recognition of the needs of aquatic ecosystems increases, and water supply systems age, there is a need to look to the future to determine possible changes in water availability and water demand. Foresight and planning provide a sound basis for water supply management that includes consideration of constructing new reservoirs, expanding existing and constructing new water supply systems, water allocations, increasing withdrawals from surface waters and groundwater, and water conservation and reuse. Using the water cycle as a framework, a reference water budget for Illinois was produced for the period 1971–2000. Examples are provided of how variations and possible changes in precipitation and temperature may change the water budget in Illinois in the future. The historical climate records for the past 150 years and output from climate models provide the means to examine possible future climate conditions and their impacts on surface water and groundwater availability. Special focus is given to characterizing drought conditions and drought frequencies. The Illinois Department of Natural Resources plays a lead role in water supply planning and management, and this role is explained.

Select this Article		Climatology of Extreme Precipitation at Long Term Ecological Research Sites D. G. Goodin and M. Losleben ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)466 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Forecasts for global climate change agree that a greenhouse‐warmed world will be characterized by an increase in climatic extremes. In order to understand the effect of these extremes on various ecosystems, we have undertaken an investigation of extreme precipitation events within the Long Term Ecological Research (LTER) network. Currently, the emphasis within this program is on defining and quantifying precipitation extreme events from a climatological, rather than meteorological perspective. Using data from a subset of terrestrial LTER sites, we are testing two methods for quantifying extremes: 1) an intensity based method where an extreme is defined by a significant deviation from the long‐term mean, and 2) a duration based method where the distribution of runs of consecutive values over or under the mean are used to develop statistical thresholds of extremity. Preliminary results suggest that unusual events are detected using these methods. The spatial pattern of extremes at LTER sites shows little recognizable structure. Currently, we are in the process of refining the methods for detecting extremes, and testing the relationship between climatic extremes and ecological productivity at the LTER sites.

Select this Article		Coupling of PnET‐II3SL and SWAT for Modeling the Combined Effects of Forests and Agriculture on Water Availability Jason T. Kirby and S. Rocky Durrans, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)467 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The earth's climate is governed by a series of complex interactions between the sun, oceans, atmosphere, land‐cover, and all living things. Natural variations in the global climate have occurred irregularly throughout history. Modern climatic models suggest that not only will this phenomenon continue in the future, but larger magnitudes and higher frequencies of variability are likely due to human influences. Furthermore, it has been postulated that the increasing concentration of atmospheric greenhouse gases could result in regional changes of soil moisture, runoff, mean sea level, and the potential for severe climatic events (extreme hurricanes, floods, droughts, etc). The climate change / variability phenomenon, because of its potential to exert significant influence on water availability, the economy, and human society as a whole, has drawn considerable attention from the scientific community and government agencies worldwide. In response to growing concerns, we are attempting to expand our understanding of the relationship between land‐use heterogeneities, water availability, and climate change / variability in the southeastern United States. Specifically, this paper describes the coupling and validation of a hydrologic / forest productivity model (PnET‐II3SL) with a hydrologic / agricultural productivity model (SWAT) to better represent the hydrologic response characteristics of large spatial areas. The resulting model is capable of generating more scientifically sound predictions of the effects of climate change / variability, with regards to water availability, in the heterogeneous watersheds of the southeastern United States. Validation efforts are described, utilizing long‐term historical records, for 15 experimental watersheds. Selected sites represent a diversity of climatic regimes, topographic conditions, soil types, area, and vegetal species. Furthermore, validation efforts focus on evaluations of model robustness to changes in management practices and factors such as biological adaptation.

Select this Article		Decision Support for Water Planning: The ZeroNet Water‐Energy Initiative Paul M. Rich, Laura H. Z. Weintraub, Mary E. Ewers, Thomas L. Riggs, and Cathy J. Wilson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)468 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Rapid population growth and severe drought are impacting water availability for all sectors (agriculture, energy, municipal, industry…), particularly in arid regions. New generation decision support tools, incorporating recent advances in informatics and geographic information systems (GIS), are essential for responsible water planning at the basin scale. The ZeroNet water‐energy initiative is developing a decision support system (DSS) for the San Juan River Basin, with a focus on drought planning and economic analysis. The ZeroNet DSS provides a computing environment (cyberinfrastructure) with three major components: Watershed Tools, a Quick Scenario Tool, and a Knowledge Base. The Watershed Tools, based in the Watershed Analysis Risk Management Framework (WARMF), provides capabilities 1) to model surface flows, both the natural and controlled, as well as water withdrawals, via an engineering module, and 2) to analyze and visualize results via a stakeholder module. A new ZeroNet module for WARMF enables iterative modeling and production of “what if” scenario libraries to examine consequences of changes in climate, landuse, and water allocation. The Quick Scenario Tool uses system dynamics modeling for rapid analysis and visualization for a variety of uses, including drought planning, economic analysis, evaluation of management alternatives, and risk assessment. The Knowledge Base serves simultaneously as the “faithful scribe” to organize and archive data in easily accessible digital libraries, and as the “universal translator” to share data from diverse sources and for diverse uses. All of the decision tools depend upon GIS capabilities for data/model integration, map‐based analysis, and advanced visualization. The ZeroNet DSS offers stakeholders an effective means to address complex water problems.

Select this Article		A Decision‐Support‐System for Integrated Water and Land Management in Agriculture‐Dominated Watersheds: A Conceptual Study to Faria Watershed, Palestine Ammar Jarrar, Niranjali Jayasuriya, Maazuza Othman, Mohammad N. Almasri, Anan Jayyousi, Jagath J. Kaluarachchi, and Mac McKee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)469 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Arid and semi‐arid regions are generally characterized by water scarcity and low per capita water allocation. This situation is further exacerbated when such areas are agriculturally dominated and encounter a high population growth rate. Faria watershed, Palestine, is one of these semi‐arid regions where lack of proper management of natural resources, accompanied with the recent prolonged drought periods in the watershed have negatively affected the existing obtainable surface water and groundwater resources. This situation has compelled the motivation for developing optimal water allocation policies that consider the available water resources under the climatic changes in the watershed such that the socio‐economic revenue is maximized. This paper conceptually demonstrates a decision‐support‐system to integrate different work plans and components in order to assess the conjunctive use of the different water resources in the watershed under different management scenarios driven by climatic changes and land use planning. The framework incorporates an assessment of the existing data and future needs, a GIS framework to facilitate processing and visualization, mathematical models of surface water and groundwater a planning model to evaluate the economic ramifications for different management options, and a multi‐criteria decision analysis module.

Select this Article		Distributed Modeling of Extreme Floods on Large Watersheds John F. England, Jr., Pierre Y. Julien, Mark L. Velleux, and James A. Smith ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)470 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Estimates of extreme floods and probabilities are needed for hydrologic engineering and dam safety risk analysis. Physically‐based, distributed watershed models are used as an avenue to estimate extreme floods, and as a basis to extrapolate frequency curves. The main elements of this research include improving and using a two dimensional, physically‐based rainfall‐runoff model (CASC2D) to estimate extreme floods and probabilities for dam safety on a large (12,000 km²) watershed, the Arkansas River above Pueblo, Colorado. New tools have been developed so the model can be applied at this scale. CASC2D can be successfully used to model extreme floods based on observations of extreme rainfall (from both rain gage networks and weather radar) for large watersheds. Future research will focus on the storm transposition concept and linkages with radar.

Select this Article		Effect of Soil Condition on Channel Transmission Loss during Ephemeral Flow Events — Part 2 Steve A. Mizell, Julianne J. Miller, and Richard H. French ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)471 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Transmission losses along ephemeral channels are an important, yet poorly understood, aspect of predicting runoff rates. Channel transmission loss research has been conducted at the U.S. Department of Energy/National Nuclear Security Administration's Nevada Test Site, where two transmission loss field experiments have been completed using water discharged from unrelated drilling activities. The first experiment, conducted in 2001, used an incised channel created by water discharged during drilling of well ER‐5‐3. The second experiment, conducted in 2003, used Cambric Ditch, a channel constructed several decades ago for radionuclide induced migration studies. Transmission losses were quantified during well development and aquifer pump test discharges. Results of the first experiment were presented in Miller in 2003. This paper describes preliminary results of the second experiment related to transmission losses estimates and hydrologic response of channel soils to multiple flow events. Transmission losses are quantified using three different methods. Method 1 uses discharge measurements at three flumes located along Cambric Ditch. As this channel traverses the alluvial basin floor, near Frenchman Lake playa, flume locations were chosen based upon channel geometry, as there were no variations in geomorphic surfaces as during the first experiment. Method 2 uses heat as a subsurface tracer for infiltration. Numerical modeling is used to estimate infiltration from soil temperature data. Method 3 uses hydraulic gradient and water content in a Darcy's Law approach to calculate one‐dimensional flow rates. Heat dissipation and water content data were collected for this analysis. This paper describes initial transmission loss calculations and soil hydraulic property responses for the second field experiment. Preliminary results indicate that up to approximately 40 % of flow is lost in an overall reach of 1,100 m (3,300 ft). Transmission loss is less in the lower reach, closer to the playa, suggesting fine material has been intermixed, but not well‐layered, in the sandy soil either by shoreline movement or aeolian transport. The introduction of fine material closer to the playa is also supported by the temperature and soil tension data. Thermal gradients correspond well with channel and surficial geomorphology and measured losses. Small thermal gradients, suggesting advection‐dominated heat transfer and higher infiltration rates, are observed in the younger geomorphic surface found at Cambric Ditch, which is similar to the results in the lower reach of ER‐5‐3; rather than the larger thermal gradients that were measured in the older geomorphic surfaces in the upper reaches of ER‐5‐3, which suggest heat transfer by conduction, and lower infiltration rates.

Select this Article		The Effect of Urbanization‐Induced Rainfall Variability on Hydrologic Response: Linking Mesoscale Meteorological Model Output to an Urban Watershed Model Shannon Reynolds, Steven Burian, J. Marshall Shepherd, and Michael Manyin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)472 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper reports the preliminary results of a study of the relative effect of urban‐induced precipitation variability on the hydrological response of a large urban watershed. The study involves (1) developing a mesoscale meteorological model centered on the Houston metropolitan area to simulate urban effects on meteorological fields, particularly precipitation, (2) developing a stormwater runoff model for a large urban watershed in the Houston metropolitan area, and (3) using the simulated rainfall fields as input to the watershed model. Meteorological simulations were performed to elicit the urban effect on a case study precipitation event and the simulated rainfall fields are being used as input to the stormwater runoff model to study the differences in runoff response caused by the urban rainfall modification. This paper describes the development and verification of the models and outlines the concept of the use of the simulated rainfall fields as input to the runoff model. Results of the linkage and analysis of urban rainfall modification effect on runoff response will be presented at the conference.

Select this Article		ENSO Impacts on Taiwan's Water Supply Nian She, Jan‐Tai Kuo, and Ming‐Han Hsieh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)473 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract 53 years monthly precipitation data in Taipei City were used to examine relationship between climate and variations in Southern Oscillation Index (SOI), Pacific Ocean Sea Surface Temperature (SST) and Pacific Decadal Oscillation (PDO). It was found that there exists a thirteen month lag of ENSO events associated with February, and August precipitation, especially summer precipitation (July, August and September) in Taipei is significantly higher in cool phase or La Nino (p‐value < 0.05). This relationship leads to a possibility of developing a long range forecast to water supply to Taiwan. ENSO predictors (SOI, SST and PDO) of previous seasons were used with persistence together to forecast summer precipitation using support vector machine (SVM) method. The forecast results are compared with commonly used methods such as logistic regression and discriminant analysis. It shows that SVM is superior to other two methods in predictability at about two‐year lead‐time. Thus, decision information is available for government agencies ahead of critical typhoon season.

Select this Article		Evaluating Effects of Climate Change on Source Water Quality of Lake Cachuma, California Joseph A. Drago, M.ASCE, P.E., Ph.D and Levi Brekke, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)474 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Climate change is an important and well‐studied phenomenon and historical data tracking changes in weather and climate are readily available. Climate change could induce shifts in mean values for weather variables and/or cause new patterns in climate variability, both of which could cause impacts on water demands, supplies, and source water quality. Water suppliers are beginning to consider the potential impacts of climate change on future water supplies. However, the focus of past work has been on water quantity impacts (e.g., flooding and droughts) rather than on changes in water quality. This paper focuses on an assessment of how various climate change scenarios would affect lake hydrology and selected source water quality parameters for Lake Cachuma; which provides water supply to the Goleta Water District and several other water agencies in Santa Barbara County, California. The climate change assessment indicates that under a variety of scenarios of a warming climate, the likelihood of taste and odor events during the dry season would increase and turbidity and apparent color events would be more likely if precipitation rates increase.

Select this Article		Evaluating Uncertainty in Regional Hydrologic Impacts of Climate Change Using Different Global Models: A California Case Study Edwin P. Maurer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)475 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Quantifying the uncertainty, and source of uncertainty in the projected impacts of climate change on hydrology will help decision‐makers interpret the confidence in different projected future hydrologic impacts. In this study the focus is on California, which is vulnerable to hydrologic impacts of climate change. Temperature and precipitation projections from the suite of GCMs participating in the Coupled Model Intercomparison Project are downscaled statistically to allow a regional analysis of hydrologic impacts using a distributed hydrologic model. These GCM simulations include a control period (unchanging CO₂ and other forcing) and perturbed period (1%/year CO₂ increase). The hydrologic model is forced with the downscaled GCM meteorology to generate streamflow estimates. While the different GCMs predict significantly different regional climate responses to increasing atmospheric CO₂, hydrological responses are robust across models: decreases in summer low flows and increases in winter flows, and a shift of flow to earlier in the year.

Select this Article		Flood Peaks Distribution in a Tide‐Affected River Basin Chintu Lai, M.ASCE and Tsan‐Wen Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)476 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract For a river basin with interconnected channels and prevailing unsteady flow, it is very difficult to determine the location and the magnitude of the peak flood flow for each tributary as well as for the whole basin. A comprehensive numerical model for simulation of basin‐wide unsteady river‐channel flow has been developed, and has subsequently been applied to the Tamsui River System in Northern Taiwan. The 1996 Typhoon Herb was first used for basin‐wide flood flow analysis and evaluation. An ensuing series of simulation studies has confirmed that the flood discharge in each tributary would keep attenuating until a confluent point is reached, at which a resurge of the peak may occur, that the maximum discharge for the entire basin, the grand peak, wouldake place at the confluence of the two largest tributaries, Tah‐han Stream and Hsin‐tain Stream, and that the irrationality of the traditional practice of hydrologic flood peak allocation for a river basin, in which the peak values monotonously increase from uppermost points toward the river mouth. The peak stage, or wave crest, likewise, has exhibited the similar trends as the flood peak, but with dissimilar phases. From such dynamic hydrology analysis, a reference data set, e.g., the magnitude and place of the grand peak, of a particular river basin can be set up for each major flood event, and systematic comparative studies can be carried out. A series of useful basin‐wide flood‐hydrology data are expected to be generated.

Select this Article FREE		Flood Risk under Current and Future Climate Scenarios in Auckland City (New Zealand) K. G. Dayananda, Jagath Pathirana, M. Jim Salinger, A. Brett Mullan, Matthew D. Davis, Peter Kinley, and Greg Paterson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)477 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Rainfall is one of the principal inputs in rainfall‐runoff and floodplain delineation investigations In this study, the relationship between rainfall input and flood risk were investigated using current and 2050 climate scenarios in Auckland City (New Zealand). The Building Act and Resource Management Act, and related statutory documents require local government to provide flood protection to specified annual exceedance events. Long term planning horizons and potential large investments necessitate consideration of climate change as part of good planning. Sensitivity of flood levels to future climate scenarios was examined in three of 38 catchments in the city. Auckland City catchments are urbanised, small, and characterised by quick response and runoff (Metrowater 2004).

Select this Article		Hydraulic Modeling of PPCP Discharges in the Detroit River C. J. Miller, Ph.D., P.E., S. Kumar, S. Jasim, Ph.D., and L. Schweitzer, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)478 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The occurrence and fate of pharmaceutically active and personal care products (PPCPs) in surface waters originating from urban sources is the focus of this paper. At least 80 PPCPs (e.g., analgesics, antibiotics, antiepiletics, antidepressants, and blood lipid regulars) have been identified in outflows from sewage treatment plants (STPs) and surface waters worldwide. Of these, the endocrine‐disrupting chemicals (EDCs) are especially of concern because of their broad range of potential health effects. Endocrine disrupting compounds (EDCs) can alter the endocrine system of animals and have been linked to a number of adverse effects in both humans and wildlife. The Detroit River receives a considerable loading of urban and agricultural runoff, as well as sewage treatment plant (STP) discharges at the head of the river. The river is the source of drinking water for approximately 4.5 million residents of the greater Detroit metropolitan area and Windsor, Ontario, Canada. Windsor's main intake for its drinking water treatment plant (WTP) is downstream from Little River Sewerage Treatment Plant (STP), City of Windsor. The contribution of PPCPs from STPs and other sources are of interest to Windsor and other surrounding communities. This paper describes the use of the SMS series of hydraulic models, especially RMA2 and RMA4, in the analysis of the fate and transport of the PPCPs from point of discharge to water treatment plant intake. Measured concentrations are used to validate the model. The present investigation refines the modeling strategies developed by both the U.S. Army Corps of Engineers and the U.S. Geological Survey for the Detroit River waterway, and employs these strategies for contaminants not previously investigated.

Select this Article		Increasing HSPF Model Performance by Improving FTABLEs: Case Studies on the Illinois River Basin Yanqing Lian, Ph.D., Misganaw Demissie, Ph.D., P.E., and I‐Chi Chan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)479 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Using the U.S. Environmental Protection Agency (USEPA) Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) system, a Hydrologic Simulation Program ‐ Fortran (HSPF) model for the Illinois River basin was developed. Values of the HSPF model parameters were based on calibrations for three representative watersheds within the basin. Over the 1985–1995 simulation period, monthly and annual mass balances correlated well with observed discharges at three gaging stations along the Illinois River. However, the correlation for daily flows was poor due largely to the inability of the HSPF model to route dynamic flows through the complicated Illinois River system. In particular, the HSPF model uses the depth, area, volume, outflow relationship (FTABLE) for channel flow routing. River reach data used in the BASINS 3.0 system for developing the FTABLE contains only rudimentary channel characteristics and does not adequately describe the hydraulic behavior of channels and reservoirs. The goal of this study was to examine effects of FTABLE improvements on HSPF modeling accuracy for the Illinois River basin. Three sets of FTABLEs were developed. The first set created by the BASINS modeling system uses the rudimentary reach file (RF1); the other two sets were based on the natural channel geometry data. The second set FTABLEs used the Manning's equation to compute flow, volume, and water depth relations. The third set of FTABLEs used flows and stages simulated from the one‐dimensional unsteady state flow model UNET for computations. The HSPF simulations using these three sets of FTABLEs were performed from 1985 to 1995. This study suggests that FTABLE modifications can increase HSPF modeling accuracy. The FTABLEs can be improved with minimal additional data on the channel geometry and stage‐flow relation.

Select this Article		Interdecadal and Interannual Oceanic / Atmospheric Variability and United States Seasonal Streamflow Glenn A. Tootle and Thomas C. Piechota ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)480 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A study of the influence of interdecadal and interannual oceanic / atmospheric influences on seasonal streamflow in the U.S. is presented. Unimpaired streamflow was identified for 639 stations in the U.S. for the period 1951 – 2002. Pacific Ocean [El Niño‐Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO)] and Atlantic Ocean [Atlantic Multidecadal Oscillation (AMO)] oceanic / atmospheric phases (e.g., warm or cold) were identified for the year (or season) prior to the year of the winter‐spring season streamflow (i.e., long lead‐time). Statistical significance testing of the difference in means (and medians) of streamflow, based on the interdecadal and interannual oceanic / atmospheric phase (warm or cold), was performed applying the two‐sample t‐test and the rank‐sum test. Additionally, the coupled effects of the oceanic / atmospheric influences were evaluated, based on the long‐term phase (warm or cold) of the interdecadal variables (PDO and AMO) and ENSO, and streamflow regions in the U.S. were identified that respond to these climatic couplings. The results show that, in addition to the well‐established ENSO signal, the PDO and AMO influence streamflow variability in the United States. Additionally, the phase (warm or cold) of the PDO and AMO enhance (or dampen) the ENSO signal in several streamflow regions in the United States. By utilizing the winter‐spring streamflow season (e.g., typical period of peak runoff) and the long lead‐time for the oceanic / atmospheric variables, useful information can be provided to streamflow forecasters and water managers.

Select this Article		Long Range Forecast of Streamflow Using Support Vector Machine Nian She and Daniel Basketfield ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)481 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Long‐range streamflow forecasting along the Western slopes of the Cascade mountain range of the United States is difficult due to the effects of complex climate variability. In this paper we use machine learning techniques from pattern recognition called support vector machine (SVM) to forecast spring and fall season streamflows in selected locations in Pacific Northwest region. The method uses El Niño Southern Oscillation (ENSO) and regional variables as predictors for various lead times ranging from one month to six months. Our method is also compared with existing methods such as linear discriminant analysis and multinomial logistic regression. The results show that the skill scores obtained from support vector machines are better than ones obtained from these existing methods.

Select this Article		Modeling Response of Soil Erosion and Runoff to Changes in Precipitation and Cover M. A. Nearing, V. Jetten, C. Baffaut, O. Cerdan, A. Couturier, M. Hernandez, Y. Le Bissonnais, M. H. Nichols, J. P. Nunes, C. S. Renschler, V. Souchere, and K. van Oost ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)482 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Global climate has changed over the past century. Precipitation amounts and intensities are increasing. In this study we investigated the response of seven soil erosion models to a few basic precipitation and vegetation related parameters using common data from one humid and one semi‐arid watershed. Perturbations were made to inputs for rainfall intensities and amounts, and to ground surface cover and canopy cover. Principal results were that: soil erosion is likely to be more affected than runoff by changes in rainfall and cover, though both are likely to be significantly impacted; percent erosion and runoff will likely change more for each percent change in rainfall intensity and amount than to each percent change in either canopy or ground cover; changes in rainfall amount associated with changes in storm rainfall intensity will likely have a greater impact on runoff and erosion than simply changes in rainfall amount alone; changes in ground cover have a much greater impact on both runoff and erosion than changes in canopy cover alone. The results do not imply that future changes in rainfall will dominate over changes in land use, since land use changes can often be drastic. Given the types of precipitation changes that have occurred over the last century, and the expectations regarding changes over the next century, the results of this study suggest that there is a significant potential for climate change to increase global soil erosion rates unless offsetting conservation measures are taken.

Select this Article		An Overview of Hydrology and Water Resources Studies on Climate Change: The California Experience J. A. Dracup and S. Vicuna ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)483 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There is an increasing threat of potential climate change impacts on water resources. The California water system is especially vulnerable to these impacts due to its dependence on snow accumulation and snowmelt process. Since 1983 there have been almost 50 studies related to the field of climate change impacts on hydrology and water resources in California. These studies can be categorized in three major areas: 1) Those studies that look at the historical trend of streamflows and other geophysical variables in order to determine if there is any evidence of climate change in the historical record; 2) Studies of the potential future effect of climate change on streamflow and; 3) Studies that use those changes in natural runoff to determine their economic, ecologic, or institutional impacts. In this paper we provide a review of these studies explaining at each step the methodological aspects involved. We provide for each category of studies their significant conclusions and potential areas for future work.

Select this Article		Paired Watershed Study of Land‐Use and Climate Change Impact on Small Streams T. G. Schade and W. D. Shuster ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)484 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The United States Environmental Protection Agency (EPA) installed flow monitoring stations on three tributaries to the Shepherd Creek (Cincinnati OH). The western and central tributaries are on the fringe of circa 1960's suburban development where flows derive from these suburban storm water systems. The eastern tributary is entirely contained within a mostly undeveloped city park, and it functions as an undeveloped reference site. All three sites share similar hilly topology, except for borrow and fill areas in the subdivisions of the western and central tributaries. EPA implemented and calibrated a rainfall‐runoff and hydraulic system model (SWMM 5.0) for these subcatchments. We derived long‐term statistics of the impact on direct runoff from the suburban development. We then extend the analysis for climate change scenarios by applying and perturbing synthetic storms to the same SWMM model. This preliminary study draws conclusions about relative impacts between land‐use and climate change for a mixed land‐use study area.

Select this Article		Policies Directions and Political Dynamics in the Future of Water Resources Management in the Midwest Gary R. Clark and Nani G. Bhowmik ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)485 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Policy directions and programs for water resources management continue to be revised as new issues and technologies come into play in the fields of water resources, civil engineering and environmental management. Issues such as water law and water use regulation; dam removal and modification; flood plain remapping; and large rivers flood plain management; will be discussed in consideration of competing needs for budgets and staff along the political realities of balancing local needs with statewide responsibilities. Added to this is the uncertainty of climate change which must also be addressed to adequately plan for the management and development of future programs and projects involving limited water resources. The management tools are available if current institutions are willing to direct the necessary long‐term commitments to staff and funding. Regional water supply planning will be key area of need in the Midwest which should direct the development of future regional water supply systems and functional regulatory programs. Innovative regional management measures such as the Great Lakes Annex 2001 water management initiative will also shape the future management of water resources in the Midwest.

Select this Article		Potential Effects of Climate Change and Variability on the Surface Water Resources of the Upper Midwest H. Vernon Knapp, Jaswinder Singh, Hua Xie, Yanqing Lian, and Misganaw Demissie ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)486 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Simulated effects of potential climate change on the surface‐water resources in the Upper Midwest are compared to the region's historical variability in climate and streamflow, and implications of both climate change and variability on water supply are discussed. Hydrologic models developed for watersheds in Illinois were used to evaluate the response in simulated streamflow to various climate scenarios. The climate scenarios used in the hydrologic simulation are based on outputs from global climate models, and represent a range of potential future climatic conditions. The driest climate scenarios result in a considerable reduction in the simulated flows. The wetter and more moderate climate scenarios generally cause relatively small amounts of change in simulated streamflow amounts, with most estimated streamflow frequency values falling within 15 percent of the simulated record using the 1950–2000 historical climate data. For 5 of the 6 climate scenarios examined in this study, the potential change in average flow is less than 25%. In contrast, there has been considerable historical variability in climatic and hydrologic conditions in the Upper Midwest since the mid‐1800s, with variability in the 30‐year average precipitation of 10–15 percent and associated changes in average streamflow in excess of 40 percent. Midwestern precipitation and streamflow, in particular, have increased substantially over the last 30 years. It is not known whether the 1971–2000 increase in precipitation and streamflow is a regional manifestation of climate change, or is instead part of the natural variability in the climate. But for now, the recent increasing trends in precipitation may give more credence to the GCM predictions that suggest moderate increases in future precipitation and streamflows.

Select this Article		Quickbird Satellite Imagery for Riparian Management: Characterizing Riparian Filter Strips and Detecting Concentrated Flow in an Agricultural Watershed S. Volkman, B. Barkdoll, and R. Bingner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)487 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Riparian ecology plays an important part in the filtration of sediments from upland agricultural lands. The focus of this work makes use of multispectral high‐spatial‐resolution remote sensing imagery (Quickbird by Digital Globe) and geographic information systems (GIS) to characterize significant riparian attributes in the USDA experimental watershed, Goodwin Creek, located in northern Mississippi. Significant riparian filter characteristics include the width, vegetation properties, soil properties, topography, and upland land use practices. The land use and vegetation classes are extracted from the remotely sensed image with the supervised Maximum Likelihood classification algorithm. Accuracy assessments resulted in an overall accuracy of 84 percent. In addition to sensing riparian vegetation, this work addresses the issue of concentrated flow bypassing a riparian filter. Results indicate that Quickbird multispectral remote sensing is capable of determining riparian spatial impact on filtering sediment. Quickbird imagery is a viable solution for land managers to monitor the effectiveness of riparian filtration.

Select this Article		Regional Rainfall Frequency Analysis Based on Generalized Logistic Model Woo‐Sung Nam, Hong‐Joon Shin, Jun‐Haeng Heo, and Kyung‐Duk Kim ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)488 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract At site analysis is not appropriate if the record length is shorter than the target return period T. If the record length is longer than 2T years, then at‐site analysis may be sufficient. However, in such a case, regional analysis is recommended for purpose of comparison. Sample sizes of annual maximum rainfall data in Korea are usually shorter than 50 years. Therefore, it is essential to use regional frequency analysis for estimating rainfall quantiles of more than 100 years return period. In this research, regional rainfall frequency analysis is performed for hourly rainfall data of South Korea. The identification of homogeneous regions is very important and requires subjective judgments in regional frequency analysis. Cluster analysis is used to form homogeneous regions for regional frequency analysis. An appropriate distribution is chosen by goodness‐of‐fit test. GLO is found to be an appropriate distribution as a result of goodness‐of‐fit measure. Simulation experiments are performed to check the performance of frequency analysis techniques. The effects of discordant sites on quantiles are considered.

Select this Article		Risk Analysis Methods for Water Resources Studies Jeff Harris, Beth Faber, Ph.D., P.E., and Robert Carl, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)489 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In today's world, the trend for comparing project alternatives, analyzing project impacts and evaluating solutions is to apply risk analysis methods. Risk analysis provides methods for quantifying differences in projects by incorporating the key factors including the economic, hydraulic and hydrologic uncertainties related to a project. These economic, hydraulic and hydrologic uncertainties can be related to many causes ranging from conveyance modifications to climactic changes. Currently, Corps of Engineers policy dictates the use of risk analysis to evaluate project alternatives. This procedure aids in the identification of the most economically feasible project. Detailed economic, hydrologic and hydraulic data are needed for this analysis. These H&H data are used to compute the Annual Exceedance Probability (AEP) and the Conditional Non‐Exceedance Probability (CNP) of a project alternative.

Select this Article		Software Integration for Watershed Studies: Hydrologic Engineering Center's Watershed Analysis Tool (HEC‐WAT) Christopher N. Dunn, P.E., Gary W. Brunner, P.E., and Jeff Harris ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)490 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Army Corps of Engineers conducts watershed and water resources management studies. In many cases, hydrologic, hydraulic, economic, environmental, and social impact analyses are performed independently and the reporting and visualization of modeling results is not coordinated. For a project study, modelcoordination, data and file sharing, reporting of modeling results, and status reporting are often a problem for the modeling and project management teams. To address this issue, the Corps' Hydrologic Engineering Center (HEC) is developing the Watershed Analysis Tool (HEC‐WAT or the WAT). The WAT is an interface designed to streamline and integrate the planning process using software commonly applied by multi‐disciplinary teams. HEC‐WAT will help perform comprehensive watershed scale studies by creating procedures and capabilities that allow integrated modeling using risk analysis. The tool would improve coordination and communication across Project Delivery Teams (PDT) thus encouraging a team approach. Management would benefit by being able to track project status through each modeling component and being able to display results during public and project status meetings. HEC WAT will streamline the analytical process, while producing more consistent results, and shared displays. This paper will discuss the functionality, capabilities, benefits, and requirements of the WAT. The paper will also discuss the status of the WAT's development and its application to water resources studies.

Select this Article		Trends in Precipitation, Runoff, and in Channel Vegetation on the USDA‐ARS Walnut Gulch Experimental Watershed M. H. Nichols, M. Nearing, and C. Shipek ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)491 \| Cited 1 time Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Precipitation and runoff play a critical role in adjustments to channel morphology and in channel vegetation establishment in semiarid regions. In southeastern Arizona, more than 60% of the precipitation occurs during July, August, and September, and almost all of the runoff is produced during these months. Data collected from the network of raingages and runoff measuring flumes on the USDA‐ARS Walnut Gulch Experimental Watershed were analyzed to quantify trends in rainfall and runoff. Since the mid 1950s there has been an increase in precipitation during non‐summer months. There was a decrease in annual runoff and a decrease in the magnitude of the maximum annual runoff event during the same time period. Air photos and field measurements were combined to quantify vegetation changes in the main Walnut Gulch channel. In channel vegetation was found to have increased since the mid 1930s. The vegetation increase may be a response to a combination of increased available moisture during non‐summer months and fewer large magnitude flow events during the summer months. Although the trends identified may represent short term fluctuations in rainfall and runoff, an improved understanding of the relationships among precipitation, runoff, and channel vegetation establishment is important for understanding the potential impacts of larger‐scale climate changes on water quality and quantity.

Select this Article		Use of Radar‐Based Precipitation Estimates for Runoff Prediction Rafael G. Quimpo and Matthew Swensson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)492 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The distributed modeling of watersheds has been facilitated by the availability of geographic information systems and of hydrologic information at scales which can be integrated into models of moisture retention and runoff generation. Information on land use, topography and soils has become relatively abundant so that with a suitable mass balance approach, one can investigate how runoff is generated from a small hydrologic unit. Until recently, one key variable that was not available at a scale commensurate with topographic, soils and land use information is precipitation. NEXRAD has narrowed this gap and more comprehensive integration of the factors affecting runoff is now feasible. As part of its program to address the issue of combined sewer flows, Allegheny County in Pennsylvania has made data on near real‐time distributed precipitation available to the public. The program makes available calculated rainfall amounts at 15 minute intervals distributed at one‐square‐kilometer resolution. This paper examines how the increased resolution improves the prediction of runoff and how it reduces the modeler's dependence on unreliable parameter estimates of watershed characteristics. We examine the use of WSR‐88D radar reflectivity data converted into estimates of rainfall rates on one‐square‐kilometer grids as input to a distributed model of watershed response. Incremental rainfall data is applied to a small watershed and the runoff hydrograph is generated by applying a loss function based on soil and land use characteristics determined on a pixel basis. The watershed is also subdivided into smaller subwatersheds in order to examine the effect of watershed size of prediction accuracy.

Select this Article		Watershed Modeling for Mining Impacts in the Muskeg River Basin in Northern Alberta, Canada P. Grover, A. S. Donigian, Jr., X. Chen, J. Love, and K. Foster ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)493 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes an application of the U.S. EPA Hydrological Simulation Program‐FORTRAN model (HSPF) in the Muskeg River basin in northern Alberta, Canada. The Muskeg River basin has significant deposits of oil sands that are the focus of mining and development over the next few decades. There are two oil sands mines currently operating in the basin and other mines and in‐situ projects are in the planning stages. Regulatory agencies require rigorous environmental impact assessments for all mining permits. The HSPF model is a comprehensive watershed hydrology and water quality model that is being used to assist in the environmental analysis and the design of the water management infrastructure for Syncrude's Aurora South project. This paper describes the calibration, validation and use of the hydrology component of the model. A ‘weight‐of‐evidence’ approach was followed in the model application, which included multiple graphical and statistical analyses of observed and simulated values to evaluate model performance. Sensitivity analyses were performed as part of the model testing process to assess the impacts of important watershed characteristics. Significant challenges in applying HSPF in such a northern setting included simulating the unique characteristics of the muskeg soils, harsh winter climate conditions at this latitude, and a relative scarcity of climate and flow data compared to typical southern watersheds. Despite these challenges, a calibrated/validated model was developed that has physically realistic model parameters and can be used to represent the hydrology of the Muskeg River basin to assess potential impacts of proposed oil sands development.

Select this Article		Effectiveness of High Resolution GCM Simulation for Water Resources Prediction in Korea Chang Sam Jeong and Jun Haeng Heo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)494 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Effectiveness of high and low resolution GCM information was analyzed using probabilistic diagnostic method for Korean water resources managements. The formulation based on the significance probability of the Kolmogorov‐Smirnov test for detecting differences between target (observation) and indicator variable (GCM). AMIP‐II (Atmospheric Model Intercomparison Project‐II) type GCM simulations done by ECMWF (European Centre for Medium‐Range Weather Forecasts) were used for high resolution indicator variable and SMIP(Seasonal Prediction Model Intercomparison Project) type GCM simulations named Metri‐AGCM(4°×5°) done by Korean Meteorological Agency (KMA) were used for low resolution indicator variable. The former has 2 and 2 degrees in longitude and latitude respectively and the latter has 4 and 5 degrees. Nodal surface precipitation and temperature values of both GCMs near 7 major river basins in Korea were used as indicator variables with analysis window concept. Observed mean areal precipitation and discharge values on each watershed were used for target variable. Monte Carlo simulations were used to establish the significant threshold of the estimator values. The results show that high resolution GCM is more significant to discriminate the extremes from target variables. It means that high resolution GCM can give more helpful information for water resources planning and managements. Considering this effectiveness, high resolution simulations are suggested for the future water resources management application in spite of various limitations of the present GCM simulations.

Select this Article		Intra‐ to Multi‐Decadal Terrestrial Precipitation Regimes at the End of the 20^th Century Steven A. Mauget ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)495 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Intra‐ to multi‐decadal (IMD) variation in terrestrial precipitation during 1901–98 was evaluated here by sampling annual precipitation rankings over 6–30 year moving time windows and converting those rankings to Mann‐Whitney U statistics. Those U statistics were then used to identify the most significant sequences of wet and dry years relative to a null hypothesis that assumes stationary climate variability. This time series analysis approach was used to evaluate IMD variation in time series of annual precipitation spatially averaged over specified areas. The method showed a highly significant incidence of wet years over North America during 1972–98, with 8 of the 10 wettest years of 1901–98 occurring during that 27‐year period. A comparably significant incidence of late century wetness was also found over a northern European grid region, with 7 of the 10 wettest years occurring during 1978–98. While wet regimes were also found over other continental areas in the final decades of the 20^th century, the late century North American and European wet periods stood out in terms of being the most statistically significant found here during 1901–98. It is suggested that these recent wet periods are terrestrial evidence of a single multi‐decadal precipitation mode extending across the North Atlantic. The potential effects of this wet regime on North Atlantic climate are discussed.

Select this Article		The LP3 Distribution and Its Use for Flood Frequency Analysis V. W. Griffis and J. R. Stedinger ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)496 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper explores the characteristics of the LP3 distribution in both log space and real space, and their relationship. The analysis reveals that the LP3 distribution provides a reasonable model of annual flood series for log space skews ∣γ_x∣ ≤ 1.414 and standard deviations in the range 0–3.6 with base e logarithms. A wide range of alternative parameter estimation methods for the LP3 distribution are explored in the hydrologic literature, including the method of moments (MOM), maximum likelihood estimators (MLEs), and mixed moments. While the method of mixed moments does very well in comparison to MOM and MLE in the absence of regional information, the Monte Carlo analysis demonstrates that the MOM estimators with regional skew information as recommended by Bulletin 17B is more attractive, and the more precise the regional skewness estimator the more precise are flood quantile estimators.

Select this Article		Agreements and Questions on Water Apportionment in the St. Mary and Milk Rivers Lisa Bourget and Murray Clamen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)497 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The International Joint Commission (IJC) was established under the Boundary Waters Treat of 1909 to help Canada and the United States prevent and resolve disputes over the use of the waters they share. Article VI of the Boundary Waters Treaty provides that the measurement and apportionment of water from the St. Mary and Milk Rivers be made by Accredited Officers, one from each country, under the direction of the IJC. In 1921, the IJC issued an Order directing how the measurement and apportionment of these waters would take place. In 2003, the IJC received a letter from the State of Montana requesting that the IJC review its 1921 Order. The IJC also received letters from the Provinces of Alberta and Saskatchewan that were supportive of the existing Order. It held informal public consultation meetings in 2004 to receive further information. The IJC is considering the information it has received to decide how best to proceed on all of the matters that have been raised in light of its responsibilities under the Treaty regarding the St. Mary and Milk Rivers. This paper will describe existing agreements, questions raised to the IJC, and the IJC's actions.

Select this Article		Assessment of Adaptation Capacity of a Large Irrigation District Towards Social and Climatic Changes: A Case Study of Lower Seyhan Basin in Southern Turkey T. Nagano, K. Hoshikawa, S. Donma, T. Kume, and T. Watanabe ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)498 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Many large‐scale irrigation projects in the arid and semi‐arid regions are now facing structural changes. Water management responsibilities are being transferred from governments to end‐users; water distribution management of gravity irrigation networks, designed for mono‐cropping system, is becoming more complicated by diversifying cropping patterns; and predicted climate change may further bring constraints on water resource availability and management options. Therefore an assessment of the existing irrigation systems' capacity is important if existing irrigation systems were to adapt to social and climatic changes. In 2002, the Research Institute for Humanity and Nature (Japan) and the Scientific and Technical Research Council of Turkey initiated a research project, ‘Impact of Climate Changes on Agricultural Production System in the Arid Areas.’ Seyhan Basin in southern Turkey was selected as a study area. One of the largest irrigation districts in Turkey extends on the delta plain of Lower Seyhan with a total irrigable area of 133,000 ha. With the water supply from the big reservoirs in the upper stream, gravity irrigation is conducted with water efficiency lower than 50%. However, climate change experiments predict a decrease of precipitation in the upper basin. The plain has potential drainage and salinity problems, which may deteriorate either with saltwater intrusion caused by sea level rise, or with a change of water use in the district. For analyzing the irrigation district's adaptation capacity, we are applying a quasi three‐dimensional irrigation water balance model that can simulate the effect of cropping patterns and distribution management on water balance. The model is coupled with a GIS database of soil classes, irrigation networks, groundwater levels, salinity, and cropping patterns. The model is composed of 3 modules. The Water Distribution Module represents water distribution rule, canal capacity, and losses from the canals. The SWAP Module calculates in‐field soil water balance. The Spatial Water Balance Module calculates inter‐field groundwater balance and drainage flow out, which would feed back lower boundary conditions to the SWAP Module. In the EWRI 2005, we will show possible impacts on the district, predicted under climate changes in the future, with several scenarios of water availability, land use and adaptive management options.

Select this Article		Changing Policies in the U.S. Mexico Border Region: Effects on Water, Wastewater, and Other Environmental Projects under the Expanded Border Definition Mark W. Killgore, P.E. and David Eaton, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)499 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The US Congress recently passed legislation redefining what was a 100‐km limit on either side of the US‐Mexico Border to now include up to 300‐km on the Mexican side only. The boards of the North American Development Bank (NADB) and the Border Environmental Cooperation Commission (BECC) were combined to streamline the development of new water and wastewater infrastructure in the border region. This paper explores the potential impacts of these recent developments on a region that has experienced increasing population growth and water demand. Recent approvals of water conservation funding for irrigated agriculture in both Mexico and Texas may reduce the Mexico‐U.S. tension with respect to water resources allocations from the Rio Grande/Rio Bravo river basin.

Select this Article		Devastation of the Indus River Delta Altaf A. Memon, Ph.D., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)500 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Indus River Delta plays a central role in the lives of the people, economy, environment, and ecological well being of the region. Waters of the River Indus have been dammed or diverted upstream. Only a fraction of water and most of the times no water is released to the Delta region. This paper shows the impact on the Indus Delta that has brought the Delta to the brink of death and destruction.

Select this Article		Drought Frequency Analysis and Prediction in Sonora, Mexico M. Hallack‐Alegria and D. W. Watkins, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)501 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Sonora is located in northwestern Mexico, an arid region which has suffered from drought for the last nine years. Using available precipitation data, we conduct a drought frequency analysis and investigate teleconnections with recurrent atmospheric anomalies such as El Niño/Southern Oscillation and the Pacific Decadal Oscillation. Upon completion of these analyses, we will investigate how drought intensity‐duration‐frequency estimates and seasonal drought forecasts can be useful to farmers and other water managers in Sonora.

Select this Article		Environmental Problem of Drainage Congestion in Mahanadi Delta, India: Case Study of a Remedial Direct Cut Bishnu P. Das ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)502 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Orissa, a coastal state of India, has five major rivers — Mahanadi and others that have their deltaic plains adjoining and overlapping on each other stretching almost 250 km along the coast and 80 km across. This fertile alluvial zone of 20,000 km² is extremely flat with a gradient of 1 in 5000–10000, and gets affected by floods almost annually, which cause drainage congestion and submersion up to 1 meter. Orissa receives during the monsoon (June–October) a rainfall of 1200 mm. One‐day storm rainfall even up to 500 mm during severe cyclones has been recorded on several occasions. The largest river Mahanadi draining a basin area of 1, 43, 000 km² has a deltaic plain of 7000 km² built up by the main river and its six branches‐Birupa, Chitrotala, Kathjuri‐Devi, Kusabhadra, Bhargavi and Daya. Almost 3000 km² is irrigated draining their supply from two barrages‐one built on the river 100 km up stream of its out fall to sea (at delta head) and the other 20 km down stream. All the deltaic branches are ridge channels and embankments protect the irrigated command with escapes (high level spills) built on both the banks of each deltaic branch. The ground level at the delta head slopes from 20 m to sea level over a 100 km stretch longitudinally. In the flattest doabs (area between two deltaic branches covering Kusabhadra‐Bhargavi and Bhargavi‐Daya rivers, 600 km² saucer shaped land in close proximity to the coast was remaining perpetually water‐logged affected by flood spills. Also drainage outflow to the river Bhargavi by the central drain Ratnachira and to the river Kusabhadra by the central drain Dhanua was not feasible because of locking effect along the main river. The 110 km long, river Kuakhai‐Bhargavi (which carries 3000 m³sec⁻¹ over 80 km length in high flood) with a slope of 1 in 10,000 for the terminal 50 km was simply unable to discharge into the Chilika lake to eventually join the sea. To manage the complex and problematic drainage system in the Mahanadi delta command an innovative solution for the 600 km² lowland was evolved by providing a 12 km long straight cut to sea from Bhargavi river at the 40^th km. Thereby the main river shortened its length by 40 km. This direct cut 300 m wide and 2 m deep has been operational for the last 30 years and has diverted up to 2000 m³sec⁻¹ of high flood (almost 70%) directly to the sea. The cut has been helpful in restoring and sustaining agriculture by improved drainage over 30,000 Ha of totally unproductive ill drained land in the tail reach. The flood level has lowered by 2 m thereby facilitating surface drainage of over bank lands into the river. The straight cut however, has deprived the tail reach of the environmental in stream flow and has itself experienced degradation in its hydraulic regime. The river has also experienced aggradation below the cut. The experience of coordinated irrigation and drainage management over the last 30years by improving surface runoff and the need to integrate sub‐surface drainage over the entire deltaic stretch of 7000 km² are presented as a case study. The efficacy of the cut for four major storm events is also analysed. During October 1999, a super‐cyclone with wind speed up to 300 km hr⁻¹ accompanied with 600 mm of rainfall in three days devastated the basin causing the worst ever drainage problem. Details of this catastrophic event are also discussed. The Mahanadi delta is typical of the drainage problem experienced in India where the deltaic agricultural land covers almost 20 Mha. Reference to the problems of other major delta and remedial interventions are also presented.

Select this Article		Evaluation of Water Sector Performance: A Case Study Banafsheh Zahraie, Mohammad Karamouz, F.ASCE, Reza Kerachian, and Masoud Asadzadeh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)503 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a methodology is developed for evaluating the performance of water sector in the 3^rd 5‐year development program in Iran is presented. A hierarchy framework is developed based on a set of criteria developed in this study and also a number of criteria used by the Water Resources Management Organization (WRMO) and Management and Planning Organization (MPO). In this study, the water sector is divided into Regional Water Authorities (RWA). The Analytical Hierarchy Process (AHP) is used to rank the RWAs' performance based on a set of 97 criteria to quantify different aspects of water supply reliability and social, economic, and cultural effectiveness of the activities in the area of water resources development, planning, and management. A method developed by the United Nations Environmental Program (UNEP) based on the distance from the ideal point is also used to quantify the relative performances of RWAs. Each criterion is estimated based on the existing information and engineering judgments and is normalized based on the target values defined in this study. In order to estimate the overall performance of the sector and its distance from the ideal point, the country has been divided into a number of homogenous zones based on different indicators regarding the share, variability, and accessibility of surface and groundwater resources. The results have shown that the developed methodology can provide useful information for the managers and the decision makers in order to better allocate financial resources to the activities with more positive impact on the overall performance of the water sector in Iran. It can also assist the policy makers in planning the 4^th 5‐year development program and beyond.

Select this Article		Irrigation Adaptation to Changing Water Supply: Palestine as a Case Study Marwan Haddad ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)504 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Israel's decided in April 2002 to establish unilaterally a permanent barrier diverting from internationally acknowledged armistice lines between the Occupied Palestinian Territory (OPT) in the West Bank and Israel. Identifying and considering the impact and vulnerabilities of wall construction on Palestinian farmers was done through field questionnaire. The Palestinian farmers found to be able of and already resist abandoning their farming land and adapt to newly imposed conditions evolved from wall construction. Several adaptive and mitigation measures were practiced since the start of wall construction of which (1) increasing water availability by increasing irrigation water storage capacity and home water storage capacity by building home rain fed cisterns (2) Increasing searching for and documenting data and information about land and water resources, its ownership, use, and distribution and (3) increasing media involvement in informing and educating public on the negative impacts of the wall and its illegality.

Select this Article		Regional Climate Change Impact Perspective on the Future Particulate C‐N‐P Flux in the Indo‐Tibetan Brahmaputra Basin C. Mahanta, R. K. Goswami, and U. Dutta ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)505 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Climate change impact on the colossal water (1.6 × 10¹² m³/y) and sediment (1.4 × 10⁹ tons, one of the highest in the world) injected from the Brahmaputra‐Ganges during the southwest monsoon is phenomenon of critical consequence to the ecosystem of the watershed. Strategic watersheds like the Brahmaputra are such that early signs of global climate change would appear earlier in such places of most sensitive nature. The thermal and dynamic influence of the Tibetan Plateau affects the climatic modulation of dissolved and particulate material fluxes through the Brahmaputra and also impacts upon the relationship between spatial distribution of water and ecosystem diversity. As a result, basic characteristics of water circulation, especially geomorphologic influences on water movement and land‐water‐atmosphere interactions can be severely affected. The present study shows that the Brahmaputra system carries almost 5% of the global particulate C‐N‐P input (computed as 6.3 × 10⁶ tons C/year, 8.5 × 10⁵ tons N/year, 3.4 × 10⁴ tons P/year) due to its enormous sediment load. The open sea connection to this high nutrient flux is of particular importance as time‐series studies revealed sediment load fluctuations of an order of magnitude over two decades indicating one of the highest variability in the world. Distribution of C‐N‐P and DO in the deep Indian Ocean suggests that the sediment flux serves as a major nutrient source and oxygen sink. Thus, the current uncertainty about the future climate change effect on the hydrological, ecological and biogeochemical processes of the watershed is increasing, having potential implications for a range of ecosystems from the highlands (5300 m) of the Himalayas to the coastal zone of Bay of Bengal. There are indications that the future of C‐N‐P biogeochemistry of the entire basin is likely to be impacted significantly by the modified nutrient flux of the Brahmaputra.

Select this Article		Resilience and Vulnerability of Water Resources Management in the Conchos River Basin to Climate Change Javier González, Juan B. Valdés, F.ASCE, and Luis J. Mata ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)506 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The Conchos River Basin is one of the most important river systems in northern Mexico, and the most important tributary of the Lower Río Bravo/Rio Grande. The Conchos contributes approximately 2/3 of the total inflows to the Lower Rio Bravo/Rio Grande. As such, the flows are subject to the 1944 International Treaty between the United States and Mexico. Irrigation is the largest consumptive use in the basin, followed by industrial and municipal use. In addition there are flows required to satisfy the treaty. The region had a significant population growth in the last two decades, which combined with a severe drought in the 1990s, significantly impacted management of the water resources in the basin. The flows are regulated by a system of multiple reservoirs, one of them as large as Elephant Butte. In this work, an optimal water resources policy management is developed for a complex multi‐reservoir system in a semi‐arid region like the Conchos. The policy is adjusted for current climate conditions. To analyze its resiliency, this policy is simulated under predicted climate change scenarios. Using the MAGICC software package, variations in mean precipitation and temperature are estimated for several GCMs models, with different greenhouse emission scenarios, and for the following time horizons: 2025, 2050 and 2100. For each time horizon, the probability of variation in precipitation and temperature are estimated. The study evaluates the resilience of the current optimal policy to predicted climate changes. It also analyzes the adaptability of the policies as a function of the rate of climate change, allowing the quantification of the vulnerability of the system.

Select this Article		Small Island States in Indian and Atlantic Oceans: Vulnerability to Climate Change and Strategies for Adaptation William B. Mills and Katherine Hancock ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)507 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Small Island Developing States (SIDS) are among the world's nations that are most vulnerable to climate change. SIDS have neither the resources nor the expertise to effectively evaluate the risks associated with climate change, nor the ability to adapt to potential changes. Compared to islands in the Pacific Ocean and the Caribbean Sea, SIDS in the Indian Ocean and eastern Atlantic Ocean off of the west coast of Africa are among the poorest and least studied of the SIDS. In this United Nations supported study, five Indian Ocean SIDS (Comoros, Madagascar, Mauritius, Seychelles, and Maldives) and two Atlantic Ocean SIDS (Cape Verde, and the Republic of Sao Tome & Principe) are evaluated for their vulnerability to climate change, with an emphasis on impacts on water resources and coastal zone resources. Due to significant differences between the SIDS studied in terms of size, topography, geology, precipitation, population density, storm patterns and intensities, relative sea level rise, indicators of wealth (such as GDP/capita), and other island characteristics, each SIDS faces its own unique challenges. This paper describes the major findings of the study. One important finding is that relative sea level rise at present appears most significant on one of the SIDS (Maldives), and a number of other SIDS appear to be emerging slightly at a rate high enough to presently offset the effects of global sea level rise. However, analysis shows that at sometime during the 21^st century, should sea level rise accelerate as climate models now suggest, that all the SIDS will become vulnerable to sea level change. Further, an existing stress on most of the SIDS is the human population density and tourism that have increased dramatically at most SIDS over the past several decades. Tourism provides both economic benefits to the islands, while at the same time tourists consume resources at rates typically far in excess of the native population. Therefore, stresses on water resources and the coastal zone due to human population are factored into the climate change stresses that are projected to increase over this century. Finally the paper describes capacity building efforts and strategies for adaptation that are intended to bring attention, resources, and expertise to the aid of the SIDS. One vehicle to do this is through the development of an Internet portal, eventually to be hosted and maintained by one of the SIDS.

Select this Article		Socio‐Economic Devastation of Orissa Coast, India: Caused by Unprecedented Sea Level Rise during October 1999 Super Cyclone Bishnu P. Das ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)508 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The torrential rainfall, consequential high flood in major rivers from Ganjam in the south to Balasore in the north accompanied by super cyclone gale caused unprecedented damage to the entire coastal belt comprising of 2.5 million ha arable land. A major cause for the crippling blow to agricultural production (which would have been otherwise good due to a normal monsoon) is the continuous submergence of flat medium and low land for 10 to 15 days due to impeded drainage. The Super Cyclone was considered by the Government of India as a calamity of rare severity, which is comparable to the recent Tsunami Devastation of Dec. 26, 2004.

Select this Article		EWRI's Visiting International Fellowship Panel Discussion on Climate Change H. E. Cardwell and L. S. Saito ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)509 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The Visiting International Fellowship panel discussion will feature EWRI's Fellowship recipients in a panel discussion of climate change challenges in their countries. The panel discussion will combine the perspectives of the fellows with those of other experts. The expected areas of discussion include the possible impact of climate change on water resources, opportunities in environmental and water resources management afforded by the adoption of Kyoto Protocol, and policies in developing countries for mitigating or adapting to climate change.

Select this Article		WEAP as a Participatory Tool for Shared Vision Planning in the River Njoro Watershed in Kenya Marion W. Jenkins, Guilherme F. Marques, Francis K. Lelo, and Scott N. Miller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)510 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a preliminary study of the Water Evaluation And Planning System (WEAP) as a decision support tool (DST) for local stakeholders and communities in addressing shared water issues in the River Njoro watershed. Located in the semi‐arid Rift Valley of Kenya, the watershed includes important downstream habitat at Lake Nakuru, a large shallow saline lake designated a RAMSAR wetlands site of international importance, and a broad mix of water uses and users. A complex web of possible causes has been put forth by different groups for the growing water quality and quantity problems. Most attention has been focused on recent deforestation in the upper catchment. The magnitude, extent and duration of water shortage problems and their causes, however, have been poorly documented and poorly understood, hindering pursuit of more sustainable and effective options for water resource management and development. Lacking is a common understanding of the water system and a clear definition of the problems faced by different stakeholders, in part because no comprehensive quantitative assessment of the water supply and demand system has been undertaken. In this exploratory study, a model of the Njoro watershed using WEAP was created and a workshop held with a multi‐disciplinary group of Kenyan researchers involved in local water and environmental issues. The workshop explored WEAP's potential as a participatory modeling tool to support Njoro watershed stakeholders to develop a shared vision of water management solutions. Modeling capabilities and features of WEAP are assessed and its usefulness as a DST considered for a developing country watershed such as the Njoro. Outcomes of the workshop included new information and increased common knowledge about the current water resources system, and new shared insights into the causes of water problems and potential solution strategies. These represent important stakeholder educative and attitudinal changes that support a shared vision of solutions and consensus on sustainable and cooperative water management.

Select this Article		Adapting to Irrigation Water Scarcity Due to Climate Change in Eastern England T. T. de Vries and E. K. Weatherhead ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)511 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Climate change in England is expected to result in higher temperatures, less summer rainfall and more evaporation. Irrigation demands are predicted to rise 20 percent by the 2025s and even more after that. Water demands from industry, urban areas and the environment are also on the increase. Many catchments are already over‐licensed or worse over‐abstracted. As conflicts over available water rise, adaptation to changing water availability becomes crucial. Stakeholder interviews were used to assess how water users might try to adapt and how they would react to potential restrictions, higher charges and/or water trading opportunities. Initial results show that most agricultural water users, although aware of the problem, have not yet focussed on the problem of climate change; current and short term issues such as introduction of new legislation and changing markets require more immediate attention. They see climate change as a gradual process that they will adapt to as it occurs. Most users report they have a wide range of adaptation options available to them, such as constructing on‐farm reservoirs, adopting water conservation techniques and changing cropping patterns. Some may stop growing crops that need irrigating. The adaptation routes appear likely to vary between farm types. Policy changes may be required to encourage appropriate adaptation. Irrigated agriculture may not be a long‐term option for all current irrigators.

Select this Article		Adapting to Long Term Water Shortages in the Lower Rio Grande River Basin Guy Fipps ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)512 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. For over 10 years, the water supply in the Lower Rio Grande River Basin has been at historic low with no end in sight. This is affecting Texas' most intensively irrigated region, the Lower Rio Grande Valley located at the Southeast tip of Texas, as well as the adjoining areas in Mexico. Population and industrial growth in this border region is expected to continue to fuel increased water usage in these sections. Irrigation districts who have historically enjoyed nearly unlimited water supply are being forced to adopt water conservation practices and programs. The situation has also prompted serious regional water planning efforts as well. This paper will provide an overview of the water supply situation in the Lower Rio Grande River Basin including past, present and future projections and recent funding initiatives through the NAD Bank and US Congress, and Mexican government to support irrigation scheme rehabilitation. The paper will also detail the other dramatic changes in district operations, including mandatory metering, water fines and incentives, and facility renovation. The irrigation districts were successful at getting approval from Congress for funding of a small number of projects. The paper reviews the types of projects implemented so far and evaluates how well they meet the objective of meeting continued water shortages. Some problems have already occurred with questionable project design and construction, raising the question about a need for standards. The economic evaluation of these projects will also be discussed and reported in terms of project cost per volume of water saved. The need for a regional approach to irrigation scheme rehabilitation planning will also be examined.

Select this Article		An Advisory Service for Regulated Deficit Irrigation Marshall English, Brett Isbell, John Bolte, and Greg Perry ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)513 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Conventional irrigation practices are designed to avoid crop stress in order to maximize yields. With the world demand for fresh water approaching the limits of readily accessible supplies, steady expansion of irrigated lands for increased food production, accelerating economic competition for water and rising environmental concerns, this most fundamental precept of irrigation is no longer rational. A new approach to irrigation based on maximizing total benefits rather than yields must inevitably be adopted. This approach will often involve deliberate under‐irrigation of crops, but managing deficit irrigation for maximum benefit is intrinsically more complex and challenging than conventional irrigation. Farmers employing this approach will need technical advice tailored specifically for deficit irrigation strategies. A pilot program discussed in this paper has begun development of an advisory service for optimum irrigation on cooperating farms. The project, begun in October, 2003, will develop a computer based decision support program operated by professional analysts working interactively with client farmers. Key elements of the program will include: (i) simulation of the relationship between irrigation management and application efficiency; (ii) crop‐specific yield models; (iii) economic modeling of production costs, opportunity costs, and net returns to irrigation, and (iv) a systematic and efficient procedure for evaluating alternative strategies and identifying those that are optimal.

Select this Article		Assessing Irrigation‐Induced Selenium and Iron in the Lower Arkansas River Valley in Colorado Joseph P. Donnelly, M.ASCE and Timothy K. Gates, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)514 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An intense field investigation was performed in an irrigated alluvial valley along a 61.6 km portion of the Arkansas River in Colorado. 54 monitoring wells and 21 surface water locations (including six locations in the Arkansas River) were sampled twelve times over the past twenty months. Results indicated selenium concentrations (C_Se) in the ground water ranging from less than 0.4 to approximately 3760 μg/L with a median concentration of about 17 μg/L. Ground water C_Se samples taken from wells located in alluvial material ranged from less than 0.4 to 166 μg/L with a median concentration of 12.2 μg/L while samples taken from monitoring wells located in slopewash and shale derived material ranged from less than 0.4 to 3760 μg/L with a median concentration of 30.8 μg/L. The surface water C_Se samples ranged from approximately 1.6 to 43.2 μg/L with a median concentration of about 11 μg/L. Iron concentration (C_Fe) ranged from less than 5 to about 1560 μg/L; however, only about 25 percent of the samples indicated dissolved Fe above the analytical detection limit. Total recoverable Fe concentration (C_Fe‐tree) in samples in the surface water ranged from about 25.4 to 118,000 μg/L, with a median concentration of about 361 μg/L. A non‐linear single‐variant relationship was developed between C_Se and EC in the surface water (r² = 0.34) and in the ground water (r² = 0.39). In the surface water samples, a linear multi‐variant relationship was developed to predict C_Se from C_SO4 and C_NO3 (r² = 0.55). Also, a non‐linear relationship was developed between C_Se from C_SO4 in the ground water (r² = 0.55). About 40 independently monitored surface water locations and 55 monitoring wells were sampled to test the reliability of these models. A preliminary Se mass balance for the Study Area was completed over a one‐year period from approximately April 1, 2003 to March 31, 2004. The total Se load to the Arkansas River was estimated at approximately 15.6 kg‐Se per km per year. The total Se load from irrigation canals in the Study Area was estimated at approximately 1086 kg‐Se per year while about 959 kg‐Se per year was returned to the river.

Select this Article		Can Irrigation Scheduling Improve the Yield/Consumptive Use Ratio? Ronald D. Bliesner, MS, M.ASCE, Daniel Spare, MS, and Aaron M. Beutler, BS ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)515 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract An irrigation scheduling program based on FAO‐56 Penman‐Montieth evapotranspiration estimation and neutron probe soil moisture measurement has been in operation on a 28,000 hectare center‐pivot irrigation project located in northern New Mexico for the past 5 years. The program has resulted in a reduction in applied water of about 20% compared to the average for the ten years prior to implementation of irrigation scheduling. Reduced groundwater discharge as a result of the reduced deep percolation has reduced phreatophyte growth and consumptive use. Reduced water ponding and runoff in the fields has allowed increases in yields and reduced consumptive use in some crops as a result of scheduling. Yields also have improved for most crops as a result of better farming practices not directly attributable to irrigation scheduling. While the yield/consumptive use ratio has improved with scheduling it has not been possible to quantify the improvement with the available data.

Select this Article		Combining a River Basin Network Flow Model and Artificial Neural Networks for Salinity Control in an Irrigated Valley Enrique Triana, John W. Labadie, and Timothy K. Gates ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)516 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A comprehensive decision support system (DSS) is presented that combines the MODSIM river basin network flow model with geographic information systems (GIS) and an artificial neural network (ANN) for basin‐wide water management and salinity control under appropriative water rights and other legal, institutional, and administrative structures. The MODSIM graphical user interface and/or GIS provide for display and editing of spatially distributed river basin network topology and other GIS layers, including basin DEMs, irrigated fields, NEXRAD precipitation data, basin hydrography, finite‐difference groundwater grids, pumping wells, diversion and water use data, water rights database, water quality data, and hyperlinked display of GPS‐located basin features. MODSIM embeds a VB.NET coded ANN for modeling of stream‐aquifer interactions that is interpreted at runtime rather compiled with MODSIM. The ANN is trained using weekly modeled aquifer responses to historical events from a calibrated regional‐scale finite difference groundwater model that would be computationally intractable if directly linked with MODSIM for management studies. A water quality module for characterizing salinity in the basin is also scripted in MODSIM using VB.net. The DSS is applied to evaluating remediation strategies in the Lower Arkansas River Basin in Colorado, where increased salinization in agricultural areas and intensified competition with expanding urban areas for limited available water supplies have threatened the viability and sustainability of agriculture in the basin.

Select this Article		Concepts in Deficit Irrigation: Defining a Basis for Effective Management Dan R. Upchurch, James R. Mahan, Donald F. Wanjura, and John J. Burke ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)517 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Deficit irrigation can be defined as an agricultural water management system in which less than 100% of the potential evapotranspiration can be provided by a combination of stored soil water, rainfall and irrigation, during the growing season. As water supplies decline and the cost of water increases, it is clear that producers are being driven toward deficit irrigation management. The implication of this management system is that some level of plant water stress is unavoidable. The challenge is to define a management system that will minimize the negative impact of the expected stress. Irrigation management requires choosing the timing and amount of water to be applied. Deficit irrigation management requires optimizing the timing and degree of plant stress, within the restriction of available water. This third, critical, concept greatly increases the complexity of the decision process. This presentation will incorporate a wide discussion of deficit irrigation concepts, with a focus on emerging technologies that can be applied to the detection and management of plant stress, within production environments.

Select this Article		Considerations for the Design and Installation of SDI Systems in Humid Areas Garry L. Grabow, Kerry Harrison, Michael D. Dukes, Earl Vories, W. Bryan Smith, Heping Zhu, and Ahmad Khalilian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)518 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Humid areas, such as the southeastern and midsouthern United States, have particular climate, topography, soils, cropping systems, and water sources that require special consideration when considering and implementing a subsurface drip irrigation (SDI) system. Design criteria are generally the same in humid areas as in arid or semi‐arid areas, but these factors are normally different enough in value or type to result in a different system design. Irregularly shaped fields commonly found in humid areas can result in a system layout that differs greatly from a “normal” layout. Installation is best done when the soil moisture is within an optimal range, which may seriously limit installation windows in humid areas. As fewer systems have been installed in humid regions, availability of professional installers and installation equipment can be problematic. This paper presents both design and installation considerations for SDI systems, with particular emphasis placed on conditions found in humid areas. It is condensed from two publications in a series designed to provide guidance on SDI systems in humid regions in an “extension‐like” format. Topics include: design criteria; pumps; filtration; chemical injection; valves; main and submain, dripline, and flushing manifold design; instrumentation and control systems; design implementation; installation tips; and locating an installer.

Select this Article		Cotton, Corn, and Peanut Yield under Subsurface Drip Irrigation Ronald B. Sorensen and Christopher L. Butts ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)519 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Long term yield response with various crop rotations of corn (M) (Zea mays L.), cotton (C) (Gossypium hirusutum L.) and peanut (P) (Arachis hypogeae L) is unknown when irrigated with subsurface drip irrigation (SDI) in the humid southeast. A SDI system was installed in 1998 on a Tifton loamy sand (Fine‐loamy, kaolinitic, thermic Plinthic Kandiudults) with five crop rotations, two drip tube lateral spacings, and three irrigation levels in south west Georgia. Crop rotations were continuous peanut (PP), alternate year rotations with corn and peanut (MP) and cotton and peanut (CP), three year rotation (CMP), and four year rotation (CMMP). Laterals were installed underneath each crop row (narrow) and alternate row middles (wide). Crops were irrigated daily at 100, 75 and 50% of estimated crop water use for each crop. There was no yield reduction in corn or peanut when irrigating at 75% of the estimated water use compared with the 100% irrigation level. The narrow spaced laterals had over 6 and 7% increase yield for peanut and corn, respectively, compared with the wider spaced laterals. Corn yield with MP and CMMP rotations had 8% higher yield compared with the CMP rotation. In cotton, longer rotations of CMP or CMMP had 18% higher lint yields when compared with alternate year CP rotation. Peanut pod yield increased over 12% with a CP rotation compared with MP rotation with highest peanut yields achieved with the CMP rotation (5579 kg ha⁻¹). Crop yield response indicates that crop rotation is a valid management decision even when using SDI. Economic simulations would need to be performed for individual growers to identify best economical irrigation level, lateral spacing, and crop rotation when irrigating with a SDI system.

Select this Article		Critical Management Issues When Using SDI in Humid Areas Dorota Z. Haman, Ronald B. Sorensen, David S. Ross, Robert O. Evans, and Phil Tacker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)520 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Proper irrigation scheduling, system maintenance and chemigation is imperative to the successful implementation of SDI (Subsurface Drip Irrigation). Because working components of an SDI system are underground, it is important to establish baseline operational performance standards while the system is relatively new. Future declines in operating performance can often be diagnosed by comparing real time performance with baseline criteria. Irrigation scheduling is the process of determining when and how much water to apply. Weather, crop models, and various soil and/or plant sensors can be used to determine when to irrigate and a water balance can be used to decide how much water should be applied. Very small amounts of water can be applied on demand through SDI to increase water application efficiency. SDI can be used to efficiently apply chemicals such as pesticides and crop nutrients. These systems can deliver frequent fertilizer applications at low concentrations, resulting in increased nutrient use efficiency and lower cost per unit of harvested product. Chemical application through the lines is also used for protection of the tubing from rodents, insects, and obstructions cause by root intrusion or mineral precipitates.

Select this Article		Downstream Response of Runoff, Sediment, and Phosphorous to Spatial Variations in Conservation Practice Implementation Michael W. Van Liew, John A. Daniel, and Jeffrey G. Arnold ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)521 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years watershed scale hydrologic models have been developed to assess the environmental conditions of a watershed and evaluate the impact of Best Management Practice (BMP) implementation. In this study the Soil and Water Assessment Tool is used to simulate the impact of BMP implementation on runoff, sediment yields, and total phosphorous yields for the 136 km² Lake Creek watershed in Southwestern Oklahoma. Changes in cultivated crops from winter wheat, sorghum‐wheat, and peanut‐wheat to Bermuda grass at upper, middle, and lower locations in the watershed are implemented at three BMP levels, representing 2.5%, 5.0%, and 7.5% of the total watershed area. Changes in runoff, sediment, and phosphorous are simulated by the model for each of the three BMP levels. Of the three types of cropping system conversions, test results show that the largest percent reductions in sediment occur for a change in wheat to Bermuda, followed by changes in sorghum‐wheat and then peanut‐wheat. A 2.5% level BMP implementation in the upper portion of the Lake Creek watershed results in a 15.3%, 9.6%, and 7.1% reduction in sediment for wheat, sorghum‐wheat, and peanut‐wheat, respectively. Model simulations show that sediment reductions resulting from BMP implementation are most pronounced in the upper reaches of the watershed where topographic and soils conditions more strongly influence erosion rates than in the middle and lower reaches of the watershed. Of the three types of cropping system conversions, results of this study indicate that the largest percent reductions in phosphorus occur for a change in sorghum‐wheat to Bermuda, followed by changes in peanut‐wheat and winter wheat. With BMP implementation at the 2.5% level in the upper portion of the Lake Creek watershed, percent reductions are 6.8%, 5.1%, and 2.0% for sorghum‐wheat, peanut‐wheat, and winter wheat systems, respectively. Unlike changes in sediment, the effect of BMP location on reductions in phosphorous is nearly negligible. This investigation provides preliminary information that quantifies the relative changes in runoff, sediment yield, and phosphorous yield that might be expected to occur if conservation practices were implemented in the upper, middle, or lower portions of the watershed.

Select this Article		Drainage Challenges in Developing North Natomas Basin in Sacramento, California Rosa M. Ulloa, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)522 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The North Natomas Basin covers approximately 7,400 acres (3,000 hectares) of land and is about 4 miles (6.4 kilometers) long in the north/south direction. It is situated in the northwestern region of the corporate limits of Sacramento, California. Up until 1998, this area was undeveloped farmland situated in a flood plain. Originally, the existing system of drains and seven pump stations worked in combination with agricultural field storage to provide flood control to the basin. The planning behind the development of this area was not only a lengthy process (approximately 10 years), but also complicated and challenging. There were many restrictions and requirements that needed to be satisfied before the area could be developed. There were many challenges to the development of North Natomas: drainage and flood control issues, geology of the area, high groundwater, environmental concerns, water quality requirements, multi use facilities, pump station design, potable water and financing, but this report will only touch on the issues related to drainage and flood control.

Select this Article		Enhancing Evapotranspiration Prediction to Improve Regional and Local Estimates of Agricultural Consumptive Water Use in Florida Jennifer M. Jacobs, Xinhua Jia, and Michael D. Dukes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)523 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Irrigated agriculture is the primary consumer of water in the United States accounting for 80% of water use. In Florida alone, irrigated agriculture accounts for over 45% of the total freshwater withdrawals. As competition for freshwater rises, the demand for refined estimates of water requirements increases. In the Southeast U.S., regional scale water management has historically relied on relatively coarse approaches to estimate crop water requirements. In this study, we review the approach used to prioritize data and experimental needs, describe an experiment conducted to address these needs, and provide preliminary crop coefficient experimental results necessary to enhance estimates of agricultural consumptive water use. The results from a regional modeling study showed that crop water estimates are highly sensitive to crop coefficients. Based on this finding, we prioritized experimental data collection to determine crop coefficients for regionally significant crops. To develop crop coefficients, an eddy flux system was installed in a Bahia grass field. Here, we present preliminary results from the eddy flux system at the grass plot.

Select this Article		Enhancing WUE in Irrigated Agriculture T. A. Howell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)524 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Irrigated agriculture is a vital component of total agriculture and supplies many of the fruits, vegetables, and cereal foods consumed by humans; the grains fed to animals that are used as human food; and the feed to sustain animals for work in many parts of the world. The objectives of this paper are to review irrigation needs to meet our growing needs for food production, to discuss various concepts that define water use efficiency (WUE) in irrigated agriculture from both an engineering and agronomic view points, arid to discuss the impacts of enhanced WUE on water conservation. Scarcely one‐third of our rainfall, surface water, or groundwater is used to produce plants useful to mankind. Without appropriate management, irrigated agriculture can be detrimental to the environment and can endanger sustainability. Irrigated agriculture is facing growing competition for low‐cost, high‐quality water. WUE in irrigated agriculture is broader in scope than most agronomic applications and must be considered on a watershed, basin, irrigation district, or catchment scale. The main pathways for enhancing WUE in irrigated agriculture are to increase the output per unit of water (engineering and agronomic management aspects), reduce losses of water to unusable sinks and reduce water degradation (environmental aspects), and reallocate water to higher priority uses (societal aspects).

Select this Article		Estimating Cotton Crop Water Use from Multispectral Aerial Imagery, 2003 G. J. Fitzgerald, D. J. Hunsaker, E. M. Barnes, T. R. Clarke, R. Roth, and P. J. Pinter, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)525 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Current numerical models used for irrigation scheduling rely on single point measurements to predict irrigation needs for entire fields. To incorporate the spatial dimension, remotely‐sensed imagery was investigated as a tool for estimating water use by cotton in central Arizona. This report presents the second year of a study situated in a furrow‐irrigated field with large variation in soil texture. Aerial imagery was obtained every two to three weeks using a high resolution camera system equipped with narrow band‐pass filters and calibrated with ground‐based reference tarps. The normalized difference vegetation index (NDVI) was used to estimate the crop coefficient (K_cb) for cotton via a previously defined relationship. The K_cb plus estimated soil evaporation coefficients were multiplied by reference evapotranspiration (ET_o) determined from a nearby weather station and summed during each irrigation interval to provide a seasonal water use map of the field. The map was validated using soil water balance with periodic soil moisture measurements. Areas of the field with less vigorous canopy were poorly predicted in 2003, although ET in areas with more robust growth was well characterized. Although ET predictions in 2003 were not as accurate as in 2002, the study demonstrated that if relationships between imagery and ET can be developed, maps showing the spatial and temporal dynamics of crop water use can be created. Water use maps can offer insight into spatially‐variable crop response and help define and manage zones in surface irrigated fields.

Select this Article		Estimating Spatially Distributed Cotton Water Use from Thermal Infrared Aerial Imagery A. N. French, G. Fitzgerald, D. Hunsaker, E. Barnes, T. Clarke, S. Lesch, R. Roth, and P. Pinter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)526 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract High resolution thermal infrared (TIR) observations of irrigated lands have the potential to retrieve spatially distributed estimates of evapotranspiration (ET) and thereby assess crop stress and refine water scheduling. To assess this possibility we use a remote sensing data set from a 2003 central Arizona cotton experiment in combination with ground‐based observations to estimate instantaneous ET. The spatially distributed estimates are compared with those derived from soil neutron probe water observations. We retrieve ET from TIR observations using a two source energy balance (TSEB) approach, which models surface energy fluxes from distinct soil and vegetation sources. This distinction of energy sources is important for heterogeneous and sparsely vegetated surfaces since soil and plant ET processes are significantly different. TSEB requires radiometric surface temperatures, vegetation densities from Normalized Difference Vegetation Index (NDVI) and near surface meteorological observations. Incorporation of TIR observations into other remote sensing surveys could help realize near‐real‐time water use monitoring at local and regional scales.

Select this Article		Evaporation from American Falls Reservoir in Idaho via a Combination of Bowen Ratio and Eddy Covariance Richard G. Allen and Masahiro Tasumi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)527 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Evaporation and energy balance components were measured and estimated for the American Falls reservoir of SE Idaho during 2004. The energy balance for this reservoir that stores snow‐melt is dominated by water heat storage that consumes more than one‐half of net radiation during the growing season. Evaporation fluxes from the reservoir average less than 40% of alfalfa reference ET, which indicates relatively efficient water storage. Some general relationships between albedo as sensed by satellite and water turbidity and among air and water temperature are presented that may be useful in satellite‐based simulation of the energy balance and evaporation processes from the reservoir.

Select this Article		Evapotranspiration and Crop Water Productivity: Making Sense of the Yield‐ET Relationship Andrew Keller, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)528 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract When water is the limiting resource crop production should focus on maximizing return per unit of water consumed rather than return per unit of land watered. Maximizing crop water productivity requires both an accounting of consumed water and an understanding of the crop yield‐evapotranspiration relationship. Plots of crop production versus evapotranspiration (ET) from multiple locations appear to indicate there is little correlation between yield and ET. This paper demonstrates that for grain corn the apparent lack of correlation between multiple location yield and ET is due primarily to two factors: 1) differences among locations and seasons in saturation vapor pressure deficit (Δe); and 2) variability in the evaporation component of ET. A strong correlation is shown between corn yield and transpiration normalized for Δe, with evaporation explaining most of the remaining variability in the yield‐ET relationship. An important and interesting conclusion for corn is that water productivity is maximized by full irrigation of a smaller area rather than by deficit irrigation of a larger area with the same volume of water consumed. Thus, for corn, maximizing crop water productivity is consistent with maximizing crop yield per unit of land area. It is hypothesized that this is true for other grain crops.

Select this Article		Evapotranspiration of Turfgrass Located Adjacent to a Fallow Desert Soil: A Quantitative Assessment of the “Edge Effect” P. W. Brown, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)529 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A field study was conducted using microlysimeters (ML) to assess the impact of advection on evapotranspiration (ET) of turfgrass in Tucson, AZ. A rectangular block (70 m × 45 m) of irrigated turfgrass [‘Tifway’ bermudagrass (Cynodan dactylon L. × C. transvaalinsis Davy) in summer overseeded in winter with ‘Charger II’ perennial ryegrass (Lolium perenne L.)] was planted in a 1.8 ha fallow agricultural field. Wind flow at the site was typically parallel to the long dimension of the block and decidedly periodic due to a mountain‐valley flow regime. Parallel rows of ML were installed in the turf at varying distances from the two edges of the field subjected to advection. ET along the edge of the field subjected to afternoon advection averaged 10.8 and 8.2% higher than ET in the middle of the field in summer and winter, respectively. Enhancement of ET relative to the field middle was smaller for the turf edge subjected to evening and morning advection and averaged 6.8% in summer and 4.7% in winter. ET from MLs located 7 m from the edge of the field were typically within 5% of ET measured in the field middle, indicating the impact of advection diminishes rapidly with distance. A simple advective index computed from wind speed and vapor pressure deficit may prove useful in quantifying the impacts of advection.

Select this Article		Feasibility of Water Management Strategies for the Declining Ogallala Aquifer Thomas Marek, Stephen Amosson, Lal Almas, Fran Bretz, Bridget Guerrero, Dustin Gaskins, and DeDe Jones ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)530 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Ogallala aquifer level in the intensively irrigated northern region of Texas continues to decline with this portion of the aquifer having no appreciable rate of recharge. New Texas water planning requirements warranted a feasibility analysis of water management strategies that could be potentially implemented over the next 60 year horizon to reduce the rate of aquifer pumpage for irrigation water use. The assessment of the strategies deal with ET network scheduling, changes in crop variety, irrigation equipment improvements, changes in crop type, implementation of conservation tillage methods, precipitation enhancement, and conversion from irrigated to dryland farming. Results indicate that while water is conserved with implementation of the strategies, several are devastating to the regional economy. Assuming that water savings are the principle objective, the strategies of changing crop variety and the use of conservation tillage should be dropped from consideration. The two strategies of changing crop type and conversion of irrigated to dryland production generate the largest water savings, but they negatively impact the regional economy. The strategies of precipitation enhancement and irrigation scheduling provide both a substantial water savings and have a positive impact on the regional economy, but do not meet the extent of the water savings desired over the 60 year horizon. Thus, tough choices will ultimately have to be made by water planners and groundwater district managers to attain a balance of allocation versus demand.

Select this Article		Field Studies of Water Requirements for Rice Production and the Effect on Water Quality E. D. Vories, P. L. Tacker, and I. Chaubey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)531 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water has been an abundant and relatively inexpensive input for agriculture in the lower Mississippi River valley. However, as groundwater levels decline in portions of the watershed, production practices that conserve water in ways that aren't prohibitively expensive and don't worsen existing water quality problems must be developed and refined. This report describes the on‐farm methods employed to quantify the water budget and water quality for rice fields as one part of a multidisciplinary project to develop an integrated water quality ‐ water management program in the Arkansas Delta. Two pairs of rice fields were selected in the L'Anguille River watershed in eastern Arkansas. One field from each pair was managed conventionally, while the other field employed multiple inlet rice irrigation as a water conservation treatment, with inflow and outflow monitored on both fields. The initial year of the study (2004) was used to test equipment and experimental procedures. Problems were encountered with both inflow (disagreement between analog and electronic measurements) and outflow (submergence of outflow weir, stage sensor and datalogger data loss) measurements. Procedures were modified to address the problems, primarily more frequent site visits, more rigorous data integrity checking, using existing flashboard risers to monitor outflow whenever possible, and ensuring that dataloggers are protected from moisture. The study will expand to additional fields in 2005 and 2006.

Select this Article		Genetic Programming of Crops to Sustain or Increase Yields under Reduced Irrigation John J. Burke ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)532 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Crop productivity is determined by the plant's capacity to convert energy, nutrients, and water into harvestable yield of high quality and high value. The challenge is to sustain or enhance the outputs with a declining land base, reduced water supplies, and a changing global environment. The process of crop adaptation to the environment is restricted by the genetic potential of the plant. Improving the capacity of crops to overcome or adapt to factors that limit growth would increase yield and quality, while reducing demand for irrigation. Research identifying the molecular and biochemical factors underlying crop productivity, adaptation to stressful environments, and production of high‐value end products is providing new insights into strategies for germplasm improvement. Characterization of existing genetic diversity within U.S germplasm collections for water‐deficit and temperature stress resistance; and the use of biotechnology to enhance yield stabilization in water limited environments will ensure farming sustainability in the future.

Select this Article		Global Mapping of the Moisture Availability Index: Using the World Water and Climate Atlas George H. Hargreaves and Andrew A. Keller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)533 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract There is an increasing concern relative to the adequacy of food and water to meet future needs of the increasing global population. There is a need to increase sustainable development using renewable resources. A moisture adequacy index (MAI) was developed for use in natural resource inventories. MAI has been used in numerous studies at the country and global level to evaluate the climate resource for agricultural production. MAI was also used in water fertility interaction research to determine the influence of water adequacy on yields and the yield response to fertilizers. The World Water and Climate Atlas presents data and computed values for evapotranspiration, rainfall, temperature, and agricultural parameters. The Atlas is used to compute and map MAI and crop yield potential. These mapped parameters can be used for determining when and where irrigation is required, identifying drainage needs, determining when and where it is profitable to use fertilizer, estimating relative yields from rainfed agriculture, estimating depth of fall for extreme rainfall events, agro‐technology transfer and crop selection, estimating stream flow probable amounts, and strategic planning. Various books and papers describe an impending world water shortage. However, there is little effort made to obtain reliable measurements of water adequacy. More research is recommended on the relationships of rainfall and runoff. Publication of a world streamflow atlas is strongly recommended.

Select this Article		Globalization — What's in It for the Poor in Terms of Water and Food Security? Claudia Ringler ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)534 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, a greater level of integration of the world economy and an opening of national markets to trade has impacted virtually all areas of society. At the same time, water scarcity and the phenomena of a ‘global water crisis’ have become part of our vocabulary. With most of the water worldwide being used for irrigated agriculture, and an increasing share of irrigated production being traded, trade policy has become intrinsically linked with both water and food security. While the process of globalization has the potential to generate long‐term benefits for developing‐countries, the distribution of those benefits is lessclear. Whereas countries with competitive (agricultural) production sectors and strong export potential have called for more open markets, those less competitive and fearful of adverse consequences on their farmers have been reluctant to increased liberalization efforts. Moreover, while the implications from changes in trade policy on national food production levels are often analyzed—albeit result of studies sometimes differ—impacts on water supply and demand, and water security are seldom studied and usually not known. This paper will analyze various alternative trade scenarios and their impact on food supply, demand, and water and food security using the recently enhanced IMPACT‐WATER modeling framework.

Select this Article		Impact of Agricultural Water Conservation on Water Availability A. J. Clemmens and R. G. Allen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)535 \| Cited 1 time Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Agricultural water diversions in the U.S. in 2000 were roughly 189 million MegaLiters (153 million acre‐feet) per year, representing 65% of the freshwater diversions (excluding thermoelectric power). The market value of crops sold from irrigated agriculture in the U.S. exceeds $38 billion/year, representing 40% of the market value of all harvested crops on only 9% of the crop land. Thus while agriculture is an attractive target for obtaining water for other segments of the economy and environment, large shifts in water away from irrigated agriculture may eventually have a negative impact on the economy. Agricultural water conservation is touted as a good method for reducing water diversion while minimizing the impact on production. However, very few studies have documented the actual amount of water saved from agricultural water conservation efforts. In some hydrologic settings, reducing water diversions to agriculture does not automatically save water, since the extra water not consumed may be used downstream. Further, there is evidence that water conservation programs that target improved application efficiency can actually increase water consumption as the result of improvement in irrigation uniformity. There are situations under which improvements in the irrigation systems will reduce the amount of water that is irrecoverably lost or will result in less water quality degradation. In arid environments, water is required for leaching salts brought in with the irrigation water. More water is needed for leaching as the salinity of the water increases. Thus reducing the water salinity can result in less irrigation water demand, potentially making more water available for other uses. In the paper, we provide a framework for examining the impact of water conservation practices and programs on water availability and present examples where water conservation efforts have been successful.

Select this Article		Impact of Net Radiation Estimation in Accurate Determination of Reference Evapotranspiration in Central Florida Xinhua Jia, Michael D. Dukes, and Jennifer M. Jacobs ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)536 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Florida's rapidly increasing population requires the efficient use of natural water resources. Accurate determination of reference evapotranspiration (ET_o) is essential to the estimation of a key water balance component. Data collected from automatic weather stations can be used to determine ET_o following standardized methods, such as ASCE‐EWRI. Net radiation (R_n) is one of the most important parameters in ASCE‐EWRI. To evaluate the impact of net radiation on ET_o, two weather stations were setup in large Bahia grass fields (Paspalum notatum) in central Florida. Meteorological data were collected at 15 min and 30 min intervals for ET_o calculation. Daily average values were used in the analysis. The data were used to examine the impact of R_n determined by three different methods, R_n measured (R_n‐meas), R_n estimated from solar radiation (R_n‐EWRI), and R_n simplified from Irmak et al. (2003a) (R_n‐Irmak). ET_o calculated from R_n‐EWRI and R_n‐Irmak agreed very well with one another. ET_o calculated from R_n‐meas was substantially lower than the other two methods. The R_n‐meas was 10–30% lower than the estimated R_n‐EWRI. This resulted in 6–20% lower ET_o if using the measured R_n. This suggests that either the use of the ASCE‐EWRI R_n equation in a humid region is questionable or the net radiometer needs to be examined.

Select this Article		The Imperial Irrigation Decision Support System — Evolution from Project Planning to Operations David W. Miller, Ph.D., P.E., John R. Eckhardt, Ph.D., P.E., and Andrew A. Keller, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)537 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Imperial Irrigation Decision Support System (IIDSS) is a comprehensive tool for evaluating structural and operational modifications to the Imperial Irrigation District's delivery and drainage systems. The IIDSS toolkit contains several modules including the MODSIM hydrologic model. IIDSS was originally developed as an analysis tool for use in preparation of the environmental documentation for the water transfer between the Imperial Irrigation District and the San Diego County Water Authority. Specifically, the model was used to investigate how various scenarios for meeting the water conservation requirements of the transfer would affect flows and water quality throughout the District's irrigation and drainage system and impact discharges to the Salton Sea. Now that the transfer is in the process of being implemented, the IIDSS is evolving from a planning tool to an operational aid. This paper begins with background on IID and on the water transfer agreement. The paper then discusses the original formulation of the IIDSS and how the system is being modified to improve its functionality as a planning and operational tool.

Select this Article		Implementation of FAO‐56 Penman‐Monteith Evapotranspiration in a Large Scale Irrigation Scheduling Program Aaron M. Beutler, BS and Andrew A. Keller, PhD,M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)538 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Scientifically based irrigation scheduling programs are valuable tools to assist farmers in improving on‐farm water management. Program effectiveness is dependent upon the accurate computation of crop evapotranspiration (ET). The Penman‐Monteith equation is widely accepted as the most accurate method to estimate reference crop ET where the climatic data it requires are available. The FAO‐56 implementation of this ET estimation method has been used for the past five years in an irrigation‐scheduling program for a 28,000‐hectare irrigation project in northern New Mexico. This paper uses water balance data, including neutron probe soil moisture measurements, to evaluate the accuracy of the method on a large‐scale center pivot project.

Select this Article		Implications of Irrigated Agriculture with Growing Water Scarcity, Increasing Food Requirements, Environmental Sustainability, and Changing Climate Panel Discussion Ronald Bliesner, (Moderator), M. Salah Darghouth, Michael Hanneman, PhD, and Tom Gohring ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)539 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Dialog is critical to the development of solutions to world water supply problems. The issues are complex and single disciplines do not typically understand the scientific foundation of others. This panel discussion will use the material presented by the three panelists as a catalyst for discussion of key issues important to the group. There will be a set of prepared questions and ample opportunity for questions and input from the floor.

Select this Article		Implications of Irrigated Agriculture with Growing Water Scarcity, Increasing Food Requirements, Environmental Sustainability, and Changing Climate Panel Presentation M. Salah Darghouth, Michael Hanneman, PhD, and Tom Gohring ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)540 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Irrigated agriculture is the largest user of fresh water in the world. With increasing municipal and domestic demands, environmental demands for restoration of aquatic ecosystems and the potential for shrinking fresh water supply in some regions as a result of global warming, there is an increasing tendency to look to irrigated agriculture to reduce water use. At the same time, the growth in world population brings with it a need to increase agricultural production in the future. Heated controversy is developing among groups whose interests lie in the various competing demands for this precious resource. The objective of this panel discussion is to promote a more holistic and scientifically sound basis for solving these critical problems. Reducing water demands per unit of crop produced will be critical to the solution of present and future water supply problems. However, this is not a simple task. Some believe that it is a simple matter of becoming more efficient. While this seems an obvious solution, understanding what happens to the losses from irrigation in a river basin context is important. Losses from irrigation processes may return to the stream and meet a portion of downstream demands. Reducing these losses may not result in any increase in overall water supply. When looking for real water savings it is important to find those efficiency improvements that result in reduced consumption per unit of production or that reduce losses that are not usable downstream or do not perform an important environmental function. Understanding the world‐wide relationship between irrigated agriculture, food production and future food demand is also critical. In some areas of the world today, it may be tempting to take the water for the use that can pay the most. While including economics in the assessment of water supply allocation is important, it is crucial to examine future conditions as well as present. Past water supply projects have often included benefit‐cost analysis as part of the basis for justification. Some argue that not all impacts, particularly those to the environment, are considered in such analyses. While present environmental laws in some countries attempt to deal with these issues, including values in the cost‐benefit equation is rarely attempted. Understanding the economic value and cost of non‐market impacts becomes important for the fair and intelligent allocation of water. While much is heard about heated disputes over water, there are processes at work to bring together proponents of competing interests in a scientifically sound way to solve these water management problems. The California Bay‐Delta process is one such example where solutions to these competing demands for a limited water supply have a broad scientific basis, applied in a cooperative process. These three panelists will present their individual perspectives on these issues in a thought‐provoking way.

Select this Article		Irrigation Management in an Irrigation District of the Veneto Region: A Case Study in the Berici Hills M. Borin, L. Bortolini, and G. Bonaiti ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)541 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Since agriculture is an important water user, given the amounts involved and the uneven demand during the year, it has to develop all the strategies allowing to avoid losses and misuses. This is particularly important in the hilly areas, where, if there are not reservoirs in the upper zones, water has to be pumped up from the valley, thus requiring also energy consumption. In the paper, a case study of collective automated irrigation in a district located at the Berici hills (North‐east Italy) is presented. The irrigation district, having a surface of 57 hectares, is mainly cultivated with grape, cherry and olive. It is served by an automated pipe distribution network, capable to distribute more than 63 000 m³ of water per year. At present, in spite of the water availability, more than one third of the cultivated surface is not irrigated. Among irrigation methods, sprinkler systems are the more diffused, and still a significant percentage of surface is irrigated by hand. Micro‐irrigation is applied on slightly more of 20% of the territory. Among the possibilities of amelioration to enhance the overall water use efficiency and the economic income of irrigation, the following can be pursued: 1) stimulate farmers towards irrigation, in the perspective of use water in all the district served by the system; 2) apply water balances calculated for single farms or fields to better determine timing and depth of irrigation; 3) select the irrigation methods more adequate to fully take advantage of the potential of the automated distribution system and to offer the best water use efficiency. To gain useful information for these purposes, a research programme is stared in 2005 and is briefly presented in the paper.

Select this Article		Landscape and Turf Irrigation Auditing for Small Communities D. L. Thomas, K. A. Harrison, M. D. Dukes, and J. W. Branch ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)542 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Landscape irrigation is one of the first water resource uses to be affected by designated drought or water restriction conditions. In large cities, personnel and funds may be allocated to help encourage improved approaches to outside water use. However, many small communities typically lack the funds and infrastructure to hire personnel to help with their landscape irrigation water management. As water use rises during drought periods, system‐wide bans of outside water use are typical approaches to addressing water shortages. Obviously, outside watering bans have a direct and long‐term impact on some of our most dynamic and thriving industries tied to landscape plant materials (retailers, nurseries and turf/sod producers). Landscape irrigation is notoriously inefficient because irrigation systems can rarely be designed, installed, and maintained at the highest level attainable (unless available funds are not limited and the owner is very conscientious and knowledgeable). A comprehensive, community‐wide approach to addressing landscape irrigation via a mobile laboratory can provide small communities with a way to address these issues efficiently and effectively. A pilot study in the community of Douglas, Georgia was used in the development process. Representative landscape and turf irrigation (home, business, and municipal) withdrawals were audited to determine system and management alternatives for potential water savings. Results from that pilot study indicate that a 20% water savings could occur during peak water use periods if approaches were implemented system wide. Additional recommendations were provided on working with the community, auditing and analysis procedures, and report options for individuals and groups.

Select this Article		Lysimetric Evaluation of Single‐ and Two‐Source Energy Balance Models for Alfalfa, Grain Sorghum, and Cotton in the Southern High Plains P. D. Colaizzi, S. R. Evett, T. A. Howell, and J. A. Tolk ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)543 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The performance of a single source energy balance (SSEB) model was compared to a two source energy balance model described by Norman et al. and Kustas and Norman, which has formulations using parallel and series resistances in the soil‐canopy‐atmosphere continuum (TSEB‐pr and TSEB‐sr, respectively). Sensible (H) and latent (LE) heat fluxes predicted by each model were compared to H and LE derived from precision weighing lysimeters for several seasons of fully irrigated alfalfa, dryland grain sorghum, and deficit irrigated cotton in Bushland, TX, USA. Each model requires surface temperatures, which were provided by infrared thermometers that viewed the lysimeter surface. Although the TSEB‐sr requires additional assumptions in computing the resistance in the canopy boundary layer and some approximations in solving the resulting non‐linear system of equations, its predictions of H and LE were better than those predicted with the SSEB or the TSEB‐pr for all crops, which represented a variety of surface roughness and height characteristics. This implied that energy exchange between the soil and canopy could be significant, and this is considered by resistances in series. All models tended to underestimate the magnitude of H, which led to LE being overestimated, especially during periods of regional advection that commonly occurs at the study location.

Select this Article		Microclimate Corrections for Urban Landscape Evapotranspiration Richard L. Snyder and Simon O. Eching ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)544 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Landscape evapotranspiration (ET) can be estimated using reference evapotranspiration and “landscape” coefficient (K_L) factors that adjust for differences between the vegetation and the reference surface. Difficulties in estimating ET of well‐watered vegetation in urban settings result from local advection and edge effects, wide variations in radiation resulting from undulating terrain and buildings, wind blockage or funneling and differences in temperature due to spatial variation in radiation, wind, etc. Estimating the ET of urban vegetation that is water stressed is even further complicated because of stomatal closure and reduced transpiration. The Landscape Irrigation Management Program (LIMP) was developed to help landscape professionals improve their estimates of ET by accounting for microclimate, vegetation type, plant density and water stress. The output from the LIMP is helpful for professionals and homeowners to set controllers and fine‐tune their irrigation management. In this paper, we present the basis for how microclimate corrections are made in the LIMP relative to the ASCE‐EWRI Penman‐Monteith equation for short canopies (ET_o). The first step to adjust for microclimate is to input monthly climate data that represent the area and calculate a “regional” estimate of ET_o. Then climate data for the local microclimate are input to calculate ET_m, which is an estimate of ET_o for the local microclimate. Monthly K_L values are computed as the ratio of the local ET_m to the regional ET_o. Local solar radiation measurements can be adjusted upward to account for reflection from buildings or lowered for shaded areas. In addition, differences in radiation due to slope and aspect can cause variations in water requirements. To account for these differences, the LIMP uses solar collector algorithms to convert daily direct solar radiation on a horizontal surface to that of a surface with known slope and aspect. Then, assuming the same diffuse radiation and long wave radiation balance, a net radiation adjusted for the slope and aspect is determined. This is then used to calculate the local microclimate ET_m. In this paper, microclimate corrections and the methodology to adjust for slope and aspect are presented.

Select this Article		Mini‐Irrigation Technologies for Smallholders Jack Keller, M.ASCE and Andrew Keller, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)545 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Several water technologies that have been designed specifically for and are being marketed to resource poor farmers (smallholders) with small land holdings are presented. Both the market creation approach to development and the appropriate technologies are described. The water technologies include: treadle pumps and storage tanks to supply water for crop irrigation; and low‐cost drip and mini‐sprinkle irrigation systems to apply water to high value crops. The development of these efficient and affordable water technologies provides smallholders with an essential tool for intensifying their farming practices. This allows them to grow high value crops and significantly boost their farming income while also increasing crop production per unit of water used and consumed.

Select this Article		A New Low‐Pressure Subsurface Drip Irrigation (LPSDI) System: Measurement of Irrigation, Yield, Evapotranspiration and Crop Coefficients for Soybean Suat Irmak and Derrel L. Martin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)546 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. A new form of low‐pressure subsurface drip irrigation (LPSDI) system has been introduced in 2003 by the Netafim‐USA company. It is a relatively low‐cost system to irrigate irregular‐shaped and/or relatively small fields with limited water supplies. The system is operated under low pressure (approximately 20.7 to 34.5 kPa). The pressure to operate the system is maintained using a 3‐m standpipe. An experiment is currently being conducted to research soybean yield response to irrigation water and to quantify crop evapotranspiration (ET_c) and crop coefficients (K_c) using the LPSDI system in south central Nebraska. In addition to the results of the first year of field research, challenges, issues, and experiences associated with using LPSDI system and practical solutions to the issues will be discussed.

Select this Article		Nitrogen, Phosphorus and Salt Transfers at the Landscape Scale in the Upper Klamath Basin of Oregon and California S. R. Kaffka ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)547 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Upper Klamath Basin (UKB) is a high desert region straddling the California‐Oregon border east of the Cascade Range. Irrigation and other agricultural practices in the region may result in impaired surface water quality for wildlife and anadramous fish. To investigate the relationships among agricultural practices and surface water quality in the UKB, a multi‐year (1995–2000) reconnaissance survey of surface water and agricultural tile drain locations was conducted, focusing on total dissolved solids, N, and P concentrations and mass transfers. Data were collected at 18 surface and 10 tile drain locations every ten days during the irrigation season (March through October) and one or two times a month during the remainder of the year. Water samples were analyzed for N, P, temperature, pH and electrical conductivity (EC_w). Climate and water balance data were available over a multi‐decade time interval. These data were used together with concentrations derived from sampling to estimate transfers of salts and nutrients within the UKB. The salt content of surface waters increased nearly threefold as water moved through the watershed. Mean EC_w levels in water entering the region were 250 μS cm⁻¹, while water sampled at the main irrigation drain increased to 600 μS cm⁻¹ over the sample period and to 700 μS cm⁻¹ by the time water reentered the Klamath River. The EC_w values observed in subsurface tile drains were higher on average than in input and other surface waters in the region (2,500 μS cm⁻¹). Total N increased from 2.3 mgL⁻¹ on average for the years reported in input waters to 4.0 mg L⁻¹ in outflows at the Klamath Straits Drain. For total P (TP), input waters averaged approximately 0.27 mg L⁻¹ to 0.40 mg L⁻¹ over the same pathway. Atomic ratios (TN:TP) of surface water samples remain constant at approximately 10:1 throughout the system, suggesting that the amount of small particulate matter in surface waters affects the values observed. In spring or early summer large NO₃‐N values (range: 1 to 40 mg L⁻¹) were observed in shallow (1.1m) subsurface tile drains, leading to the inference that some N from fertilizer and soil organic matter is lost in drainage. More N is removed in crop biomass than is applied as N fertilizer in the region, but less P. More efficient fertilizer use can help bring P inputs and outputs into balance in local farming systems. Since surface waters entering the region are already enriched with N and P, it appears unlikely that further reducing N and P losses from farming, if possible, would make surface waters significantly less eutrophic. Reusing some drainage water for irrigation would reduce nutrient loads in the Klamath River.

Select this Article		Penman‐Monteith Estimates of Reservoir Evaporation Marvin E. Jensen, Hon.M.ASCE, Avry Dotan, and Roland Sanford ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)548 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Weather and Lake Berryessa (LB) temperature profile data were collected from May 2003 through September 2004 to enable estimating lake evaporation using the Penman‐Monteith equation. Current evaporation estimates from LB by the U.S. Bureau of Reclamation (USBR) are based on Class A pan evaporation and the original pan coefficients developed in the 1960s. Since then, the location of the pan has been moved several times and measured pan evaporation measured at the current or old site is much lower than that measured at a new site that is fully exposed to solar radiation. USBR calculated inflow to LB is based on measured lake elevation, estimated evaporation, and measured releases from the reservoir. The estimated lake evaporation based on the pan data and original pan coefficients are too low. Because of the method of calculating lake inflow, calculated daily negative lake inflows commonly occur from mid‐July until fall‐winter rains begin. Estimates of evaporation from the lake were made using the Penman‐Monteith (P‐M) equation, estimates of daily change in heat in the water, and advection of heat energy into or out of the lake. Estimates of P‐M evaporation were reduced by a factor of 0.95 because a small part of the lake surface area is shaded part of the day, and weather data were measured at a location near the lake instead of over the lake. The P‐M evaporation estimates and estimates using pan evaporation at the new site with Lake Elsinore monthly pan coefficients indicated that USBR evaporation estimates are about 20% too low mainly because of pan site conditions. A computer model was developed to process, store, and calculate estimated daily or monthly evaporation from the lake.

Select this Article		Policies to Address Asymmetric Externalities in Groundwater Extraction: The Case of Cherokee Strip in Butte County, California Siwa Msangi and Richard E. Howitt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)549 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract While water markets have been shown to be beneficial to users, the transfers made through sales can have serious third‐party impacts, as has been addressed in the water resources literature. Potential asymmetries arising from the hydrological characteristics of the groundwater basin could seriously affect the distribution of the impacts resulting from these transfers, when taken into account. In this paper we seek to extend the water resources management literature by examining the depletion problem experienced on the Cherokee Strip, in the hills of Butte County, and account for asymmetric external effects in a model of strategic groundwater pumping. The results of this model show that current ordinance restricting water transfers from Butte County does not serve the interests of promoting efficiency, and that volumetric limits on groundwater pumping is the preferred policy instrument. These results were robust to behavioral assumptions. This paper also highlights the need to move beyond simple single‐cell aquifer modeling and to find appropriate institutional arrangements that can mitigate the kind of asymmetric third‐party impacts seen in Butte County, especially during drought periods, when third‐parties are most vulnerable and the market incentives for making transfers is greatest.

Select this Article		Quantifying Water Quality and Other Environmental Benefits of Agricultural Conservation Practices D. A. Bucks, M. A. Weltz, and C. A. Richardson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)550 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. The Farm Security and Rural Investment Act of 2002—referred to as the 2002 farm bill—substantially increased funding levels of conservation programs—up nearly 80 percent above the level set for conservation under the 1996 farm bill. While it is widely recognized that these conservation programs will protect millions of acres, the environmental benefits have not previously been quantified for reporting at the national scale. Moreover, while an extensive body of literature exists on the effects of conservation practices at the field level, there are few research studies designed to measure the larger effects. The Natural Resources Conservation Service (NRCS) and the Agricultural Research Service (ARS) are working together on the Conservation Effects Assessment Project (CEAP) to quantify the environmental benefits of conservation practices at the national and watershed‐scales as a measure for how the money being spent is meeting the goals. There are two main components of CEAP—a national assessment provides modeled estimates of conservation benefits for annual reporting, and the second component quantifies the environmental benefits from specific conservation or best management practices at a watershed scale. The watershed assessment studies component of CEAP complements the national assessment by providing more in‐depth assessment of water quality and other benefits at a finer scale of resolution than is possible for the national assessment. The first set of watersheds is the ARS “benchmark” watersheds, where ARS has conservation effects research projects underway, became fully operational in 2004. The 12 ARS benchmark watersheds are located near Ames, Iowa; Tifton, Georgia; El Reno, Oklahoma; Temple, Texas; Oxford, Mississippi; University Park, Pennsylvania; Columbia, Missouri; West Lafayette, Indiana; and Columbus, Ohio. In addition to these ARS locations, scientists from Ft. Collins, Colorado are assisting with a portion of the modeling activities. Environmental effects will be estimated for water quality, soil quality, and water conservation. One of the goals of the ARS benchmark watersheds is to develop a set of USDA Watershed Assessment Models that can address environmental quality assessments for specific regions of the nation. This national effort will advance the knowledge of how watershed scale assessments should be done and provide additional research findings and insights on the expected off‐site effects of conservation practices. Annual reports that document the environmental benefits of conservation practices will be published beginning in 2006. Tracking the progress of conservation programs in terms of the outcomes achieved will allow policymakers and program managers to improve the effectiveness of existing programs and design new programs to increase the conservation of our nation's natural resources.

Select this Article		Recent Great Lakes Evaporation Model Estimates Thomas E. Croley, II ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)551 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract NOAA's lumped‐parameter Great Lakes continuous evaporation model solves for each day's over‐water and over‐ice surface fluxes (which in turn are functions of heat storage and ice and water surface temperatures). They include incident short‐wave radiation, reflection, evaporative heat transfer (both latent and advected), sensible heat transfer, precipitation heat advection, long‐wave radiation exchange, and surface flow advection. The model simultaneously finds daily heat storage and surface temperature with a heat balance, a model of linear temperature rise (or loss) with volume beneath the water surface, an empirical wind mixing model, and a one‐dimensional (vertical) superposition of past aged heat additions or losses. The model couples ice formation and loss to lake thermodynamics and heat storage by utilizing both heat and mass balances for the ice pack and boundary conditions of ice‐water existence. It simultaneously finds ice temperatures, pack size, and heat transferred between ice pack and both the atmosphere and the water. Since measured whole‐lake evaporation is unavailable, the model is calibrated to existing daily water surface temperatures and ice cover, and compared with measured temperature‐depth profiles and independently estimated or measured water surface thermodynamic fluxes. Two calibrations are used to apply the model; the first minimizes error with observed water surface temperatures to determine parameters for superposition heat storage, wind mixing, and radiation exchange. The second minimizes error with observed ice cover to determine ice cover parameters. The calibrations alternate until changes in all parameters are insignificant. Presented calibrated parameters result in 1.1–1.6°C root mean square error with water surface temperatures and verify well over a time period independent of the calibration. Example results of the evaporation model include estimated temperature‐depth profiles over a year on Lake Michigan, and both a year's worth of daily evaporation and five years' worth of monthly evaporation on Lake Superior. Deep water evaporation characteristics are readily seen and described. Turnovers occur as a fundamental behavior of the model. Hysteresis between heat in storage and surface temperature, observed during the heating and cooling cycles on the lakes, is preserved. The model also correctly depicts lake‐wide seasonal heating and cooling cycles, vertical temperature distributions, and other mixed‐layer developments.

Select this Article		Reference Evapotranspiration of Grass—Southern High Plains T. A. Howell, S. R. Evett, J. A. Tolk, and K. S. Copeland ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)552 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Evapotranspiration (ET) from a cool‐season grass with a height of 0.12 m and a surface resistance of 70 s m⁻¹ has become a standard reference surface as the basis for crop coefficients and for modeling water use from many crops. Although many data sets were used in developing and verifying this standard, few of them are subject to strong regional advection like that found in the Southern High Plains of the U.S. Our objectives were to measure water use from a fescue grass (Festuca arundinacea Schreb.), to determine if differences existed in computed reference grass ET from several widely used methods in this environment, and to examine methods for estimating irrigated fescue grass water use rates. ET of the subsurface irrigated fescue was measured at Bushland, TX, in the latter half of 1995 through 1997 using a weighing lysimeter (1.5 m by 1.5 m and 2.3 m deep) with an ET resolution exceeding 0.1 mm. The lysimeter was situated in an irrigated 0.3 ha grass weather station adjacent to other irrigated crops. Routine daily agricultural weather parameters (maximum and minimum air temperatures, mean daily barometric pressure, and mean daily dew point temperature in a cotton belt shelter at 1.5 m above the ground, wind speed at a 2‐m height, and precipitation at 0.76 m height) were measured at the site together with specific data for the lysimeter — mass, net radiation, and soil heat flux. The lysimeter was manually vacuum drained periodically to remove excess water due to the slight over irrigation needed to sub moisture across the subsurface drip lines. The grass was regularly mowed to a 0.11 m height (weekly and even semiweekly if needed), and the clippings were bagged and removed. Nutrients were supplied mainly through the irrigation water and occasional surface applications to maintain strong vigor and health. Only days without significant rainfall (0.1 mm or less), drainage, mowing, or irrigation events were used in this analysis. After grass establishment in the fall of 1994, data collection began in late May of 1995. The Food and Agriculture Organization Penman Monteith (FAO‐PM) methods estimated net radiation well, but an assumption of zero soil heat flux was better than using the FAO‐PM daily air temperature method. The data set contained a few days with ET rates exceeding 10 mm d⁻¹, but most of the midsummer ET rates were in the 6–10 mm d⁻¹ range. Winter time ET rates varied, but often were in the 1–3 mm d⁻¹ range. The 1948 Penman combination equation closely paralleled ET calculated with the more recent FAO‐PM equation. The former FAO Penman equation over estimated the ET computed by the FAO‐PM, while both the Priestley‐Taylor and the Hargreaves and Samani equations under estimated the ET computed by the FAO‐PM equation. The FAO‐PM estimated ET was larger than that measured at low rates (mainly in the late fall, winter, and early spring) and tended to underestimate the ET for the higher rates (> 8 mm d⁻¹). Surprisingly, the 1948 Penman combination appeared to be slightly better correlated to the measurements and had a lower standard error of estimate. Both reference ET methods predicted higher grass ET rates than measured in the fall and spring. The FAO‐PM computed “hypothetical” grass reference ET accurately estimates irrigated fescue ET in mid to late summer in this environment, but it did not perform any better than the 1948 Penman combination equation.

Select this Article		Regulated Deficit Irrigation to Optimize Water Application in a Commercial Viognier Vineyard Samuel Ortega‐Farias and César Acevedo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)553 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Irrigation scheduling holds the potential to play a vital role in ensuring wine quality and increasing water use efficiency. Therefore, this requires farmers to schedule irrigation of vineyards accurately. Accurate irrigation, however, depends on understanding the complex, non‐linear interactions between soil, climate, and vineyard conditions. Knowledge of these interactions is thus essential in the practical application of regulated deficit irrigation (RDI), to realistically achieve the practical outcomes desired in vineyard production. For this reason, a study was carried out during the 2002/03 growing season in a commercial Viognier vineyard located in the VI region, Chile. The results of this study showed that RDI did indeed successfully reduce the amount of water applied to vineyards without affecting significantly the yield and grape composition. In this case, RDI reduced the water application by about 52 % and increased the water use efficiency from 6.2 kg m⁻³ to 12.7 kg m⁻³.

Select this Article		Remotely Sensed ET Computed by SEBAL—Implications for Water Resource Planning in California Bryan Thoreson, Scott Matyac, Tom Hawkins, and Mark Roberson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)554 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Quantitative estimates of consumptive water use by crops, landscape, and natural vegetation are necessary for water resource planning. Availability of satellite remotely‐sensed data offers an alternative to current estimating techniques. Evapotranspiration (ET) is predicted as a residual of the energy balance by the Surface Energy Balance Algorithm for Land (SEBAL) using routine weather data and satellite sensed thermal radiances. The California Department of Water Resources (CDWR) is required by state law to develop a state‐wide water plan every five years. Computations of consumptive water use are an integral part of the water planning process. Remotely‐sensed ET computed by SEBAL offers potential advantages compared to the current labor‐ and data‐intensive estimates techniques. For 2002, annual actual ET for California was computed by SEBAL using MODerate‐resolution Imaging Spectroradiometer (MODIS) satellite images (1 km by 1 km square pixels) and California Irrigation Management Information System (CIMIS) weather data. The annual ET of irrigated, agricultural lands computed by SEBAL is compared to the CDWR current water plan estimates. The hydrologic implications of these different estimates to the recommendations and options discussed in the plan are explored. The advantages, disadvantages and estimated accuracy of the current ET computation method and the remotely‐sensed based SEBAL method are compared and contrasted.

Select this Article		A Review of Evaporation Research on Japanese Lakes Masahiro Tasumi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)555 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a brief history of lake evaporation studies in Japan. The results of the studies indicate that evaporation from deep lakes peaks during winter, while evaporation from shallow lakes peaks during summer like evaporation from a wet soil surface or evaporating pan. These differences in evaporation patterns are due to the difference in lake energy storage. Deep lakes have high heat storage capacities. Since the thermal conductivity of water is high, deep lakes store energy during spring and summer, and release the stored energy during fall and winter. Shallow lakes have less heat storages and therefore evaporation peaks at summer when solar radiation is highest. These characteristics of lake energy storages need to be accounted for in estimating lake evaporation.

Select this Article		Satellite‐Based Evapotranspiration by Energy Balance for Western States Water Management Richard G. Allen, Masahiro Tasumi, Anthony Morse, and Ricardo Trezza ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)556 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract METRIC™ (Mapping Evapotranspiration at high Resolution and with Internalized Calibration) is an image‐processing model comprised of multiple submodels for calculating evapotranspiration (ET) as a residual of the surface energy balance. METRIC is a variant of SEBAL, an energy balance process developed in the Netherlands by Bastiaanssen. METRIC was extended for application to mountainous terrain and to provide tighter integration with ground‐based reference evapotranspiration. METRIC has been applied with Landsat images in southern Idaho, southern California, and New Mexico to predict monthly and seasonal ET for water rights accounting and for operation of ground water models. ET “maps” (i.e., images) via METRIC provide the means to quantify, in terms of both the amount and spatial distribution, the ET on a field by field basis. The ET images generated by METRIC show a progression of ET during the year as well as distribution in space. Comparisons between ET by METRIC, ET measured by lysimeter and ET predicted using traditional methods have been made on a daily and monthly basis for a variety of crop types and land‐uses. The results suggest that METRIC or similar methods hold substantial promise as efficient, accurate, and inexpensive procedures to predict the actual evaporation fluxes from irrigated lands throughout a growing season.

Select this Article		SDI for Conserving Water in Corn Production Freddie R. Lamm, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)557 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract On‐farm water savings of 20–25% can be obtained with subsurface drip irrigation (SDI) for corn production on the deep silt loam soils of the semi‐arid Great Plains (United States) through a combination of reducing non‐beneficial water balance components and better usage of precipitation. The conjunctive use of SDI with appropriate nitrogen fertigation strategies resulted in optimization of corn yield, nitrogen uptake and water use efficiency at an irrigation level of approximately 75% of normal. A field study indicated a differential response in corn yield and water use for SDI and low energy precision application (LEPA) sprinkler irrigation as affected by weather conditions. SDI had approximately 6% yield advantage (0.9 Mg/ha) over LEPA in three normal to wet years while reducing crop water use by 4% (30 mm). Conversely, LEPA had approximately 7% yield advantage (1.0 Mg/ha) over SDI in four extreme drought years but with increased crop water use of 4% (27 mm). More research is needed to explain the differential response of the two system types.

Select this Article		Site Selection for Subsurface Drip Irrigation Systems in the Humid Region Michael D. Dukes, Dorota Z. Haman, Freddie Lamm, John R. Buchanan, Carl R. Camp, and ASCE‐EWRI Task Committee on Subsurface Drip Irrigation ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)558 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Site selection for subsurface drip irrigation (SDI) in the humid region must be carefully considered to ensure optimum system performance and crop yield while minimizing unnecessary expenses. SDI has been shown to result in similar or higher crop yields on many crops while reducing water use. However, characteristics of the field, soil, crop, cropping system, water resource available, managerial and farm labor resources, economic factors, and industry support infrastructure affect decisions about the appropriateness of SDI in a given situation. These topics are discussed with emphasis on their effect on the humid regions of the United States.

Select this Article		Stochastic Net Profit‐Water Functions: Assessing Changes in Irrigation Needs and Farm Profits to Public Policy and Climate Variability Kelly Brumbelow ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)559 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Changing economic and social priorities have significantly affected water availability for irrigation in recent years. Exacerbating this situation has been apparently increased climatic fluctuations and potential climatic change. Public policy responses have included in various cases newly opened water markets, compensation schemes for irrigation reduction or elimination, and statutory limits on irrigation application, among other options. These changes in climate and economic incentives have also changed the farm profit calculus. A technique for determining the stochastic relationship of farm net profits to irrigation application is the focus of this paper. By formulating crop‐water production functions for long climatic records, the crop yield versus irrigation relationship is determined in a probabilistic manner incorporating historical climate variability. This probabilistic yield versus irrigation function can then be incorporated into a net profit calculus that includes new public policy effects such as irrigation limits and water sales opportunities. Preliminary results from ongoing work are presented.

Select this Article		Strategies for Attenuating Hypoxia in the Lower San Joaquin River, California A. T. O'Geen, E. E. Van Nieuwenhuyse, and R. A. Dahlgren ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)560 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The San Joaquin River is a highly fertile and productive tributary of the Sacramento‐San Joaquin Delta, the hub of California's water supply system. Dissolved oxygen concentration (DO) frequently (>50%) violates water quality objectives in the river's deepwater ship channel, in part because of high algal biomass loading from the watershed. Recent modeling indicates that reducing this upstream algal load, in combination with artificial oxygenation, a reduction in point source ammonia loading and increased flow, could help eliminate hypoxia in the ship channel. There is uncertainty; however, as to how effective algal biomass reduction might be in improving DO conditions in the ship channel and especially about how best to attain this reduction. A notable symptom of this uncertainty is the difference of scientific opinion concerning the role, if any, phosphorus load reduction should play in reducing the river's yield of algal biomass to the ship channel. Readily available forms of nitrogen (NH₄ + NO₃ mean = 1.8 mg N/L; range=0.7 to 2.8 mg N/L) and phosphorus (soluble‐reactive mean PO₄ = 0.12 mg P/L; range = 0.06 to 0.24 mg P/L) in the lower San Joaquin River are much higher than those levels suggested to limit phytoplankton growth rates (N limitation <0.1 mg N/L; P limitation <0.01 mg P/L). This suggests that mineral N and soluble‐reactive P concentrations would have to be reduced by more than an order of magnitude to effectively decrease algae biomass in this eutrophic aquatic ecosystem. However, P load reduction in other highly eutrophic rivers (e.g., Rhine River) has resulted in appreciable reductions in algal biomass loads in spite of nutrient concentrations being considerably above the threshold values reported to limit growth rates. The primary objective of this paper is to examine the causes and potential solutions to hypoxia in the lower San Joaquin River.

Select this Article		Technologies to Minimize Water Quality Impacts of Irrigated Agriculture David L. Bjorneberg, Robert E. Sojka, and April B. Leytem ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)561 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Irrigation transformed arid land in the Pacific Northwest into productive agricultural land. However, much of this land is prone to erosion during irrigation, which can cause problems on and off of the field. Management practices have been developed to control soil erosion on irrigated land and improve the quality of water returning to streams and rivers. Applying polyacrylamide (PAM) with irrigation water can reduce erosion from furrow irrigated fields more than 90%. Using PAM in combination with other practices, such as applying straw mulch in furrows and installing small sediment ponds on fields, can virtually eliminate sediment loss fromfields. Once soil runs off a field, it can be removed by settling in sediment ponds, although soluble nutrients remain in the water. Applying 20 mg/L alum to irrigation return flow water can remove about 50% of the soluble phosphorus that will not be removed as suspended sediment settles in ponds. Using these management practices allows irrigation to continue with minimal impact on water quality.

Select this Article		USDA Develops a Plan to Address Agricultural Water Security Issues Dale A. Bucks, Mike O'Neil, Allen R. Dedrick, Daniel E. Kugler, James P. Dobrowolski, Margriet F. Caswell, and Richard A. Kestle ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)562 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. As population continues to increase across the United States and around the world, there is a growing demand for safe, reliable sources of water to meet the needs of the expanding population. Farmers, ranchers, and rural communities are particularly susceptible to the mounting pressures to provide more water to urban and urbanizing areas at the expense of water supplies in rural and agricultural communities. Agricultural water security is used here to describe the need to maintain adequate water supplies to meet the food and fiber needs of the expanding population — maximizing the efficiency of water use by farmers, ranchers, and rural communities. Drought and the reliability of water supplies for agriculture and rural communities historically have been linked to western states. However, issues surrounding agricultural water security have expanded beyond western states and now represent a national crisis. On June 5, 2003 Interior Secretary Gale A. Norton and Agriculture Secretary Ann M. Veneman signed a Memorandum of Understanding (MOU) aimed at promoting improved water management and rapid response to emerging water supply shortages in the West. This MOU highlights the need for expanding the research and education programs focused on better management of water resources. On September 9–10 2004, the U.S. Department of Agriculture (USDA)‐Research Education, and Economics (REE) agencies conduced an Agricultural Water Security Listening Session in Park City, Utah, to determine the relevance of current USDA‐REE efforts and to develop the basis for future research, education, extension, and economics programs within USDA that take full advantage of partnerships with other federal and state agencies. These REE agencies include the Agricultural Research Service (ARS), the Cooperative State Research, Education and Extension Service (CSREES), the National Agricultural Statistics Service (NASS), and the Economic Research Service (ERS). Approximately 90 representatives from federal and state agencies, universities and colleges, non‐profit and private sector firms and local municipalities participated in the listening session. Six key topic areas were identified for REE involvement through the listening session: drought preparedness and mitigation, irrigation efficiency, general water conservation, urban and rural water reuse, biotechnology, and economics and water marketing. Participants in the listening session identified 19 “Bold Steps” that USDA and particularly the REE Mission Area could take to move closer to solutions for agricultural water security. The presentation will discuss the results of this listening session and describe the progress being made to expand research, education, extension, and economic efforts within USDA related to water supply, allocation, and distribution problems throughout the nation.

Select this Article		Water Quality Issues and Nutrient Management in the Nanticoke Watershed William F. Ritter and A.E.M. Chirnside ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)563 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Water quality trends were monitored in eight subwatersheds in the Broad Creek watershed over a four‐year period as best management practices (BMP's) were implemented. The BMP's consisted of nutrient management plans and construction of manure storage sheds. There were a total of 227 poultry houses in the subwatersheds. Nitrate concentrations were related to the percentage of cropland. The highest average seasonal nitrate concentration was 19.1 mg/L. There was no general decrease in nitrate concentrations over the four‐year period. Average seasonal ortho phosphorus concentrations ranged from <0.010 to 0.19 mg/L.

Select this Article		Alameda Creek Flood Control and Wetland Restoration Project Stephane Asselin, P.E., Francesca Demgen, and Ralph Johnson, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)564 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Alameda Creek is the largest watershed in Alameda County, CA with a total drainage area of approximately 695 square miles (1,800 square kilometers). Alameda County maintains the Alameda Creek flood control project, constructed by the U.S. Army Corps of Engineers after flood events in 1955 and 1958. The Creek was designed to contain the Standard Project Flood (SPF) flow of 52,000 cfs (1,472 cubic meters per second), which roughly corresponds to a 500‐year event. No desilting has occurred in the tidal portion of the channel since 1975 when construction was completed. Current topographic surveys suggest that the tidal reach's bathymetry has returned to close to its original pre‐construction configuration. Based on previous work conducted, it has been determined that Alameda Creek is now severely under capacity compared to its commissioned design flow due to heavy siltation. The straightforward solution of desilting the creek was deemed expensive and potentially damaging to the wildlife habitat that has established itself in the creek over the years. Accordingly, Alameda County decided to study different alternatives to restore the original flood control capacity while improving habitat values via the restoration of adjacent salt ponds to the North of Alameda Creek. The total areas comprised by the salt ponds amounted to about 4,000 acres (16 square kilometers). The selected approach consisted in first performing a LIDAR survey of the entire study area comprising over 100 km² to obtain detailed topography. The detailed LIDAR survey was then used to develop a 1‐dimensional model for Alameda Creek linked to a 2‐dimensional model in the salt ponds north of the creek. The combined model was used to study different levee reconfiguration alternatives that would meet the flood control and wetland restoration requirements. Three alternatives, each consisting of a different pond configuration, number and size of breaches and channels, were simulated for normal tidal and flood control conditions. The study resulted in a conceptual design layout for two (2) feasible restoration alternatives. A significant reduction in the total cost of the project compared to the original channel desilting option was estimated.

Select this Article		Allison Creek Dam Removal and Stream Restoration near Valdez Alaska Christopher H. Roach, P.E., P.H., M.ASCE and MacNamara C. Shoulders ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)565 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Allison Creek flows from Allison lake adjacent to the Valdez Marine Terminal near Valdez, Alaska. It is an anadromous fish stream flowing into Port Valdez. A 40′ wide in‐stream concrete dam was installed in 1976 in association with a raw water intake structure in the stream bed. By 2003, the bed elevation downstream of the dam had lowered sufficiently that the dam was undermined and the stream breached under the dam. This project involved removal of the concrete dam and restoration of the stream through the site to provide unimpeded fish passage and protect the water intake system. The channel was re‐constructed as a step‐pool channel system to distribute a drop of approximately 11 feet over a distance of 280 lf. The design was based on the morphology of a stable reference reach adjacent to the project site. Design and construction was tailored to accommodate the close proximity of several utilities in the stream bed, including four water intake pipes, a 48″ diameter buried crude oil pipeline, and a buried fiber optic cable. In addition to restoring the stream channel, the floodplain was reconstructed and the site re‐vegetated. This project has been highly successful in restoring the stream bed to a stable morphology while re‐establishing fish passage and accommodating the location of multiple buried utilities.

Select this Article		Alternatives for Riverine Backwater Restoration by Manipulation of Severed Meander Bend F. D. Shields, Jr., M.ASCE, Scott S. Knight, and John M. Stofleth ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)566 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Current thinking in stream ecology emphasizes the dependence of large riverine ecosystems on the materials and habitats provided by floodplain backwaters. However, these types of habitat are becoming increasingly rare as development is transforming floodplain landscapes in fundamental ways. Despite the large sums of money spent on control and management of water pollution, environmental quality continues to decline due to diminished hydrological connectivity between rivers and floodplain backwaters even as water quality improves. Along rivers with wide valley bottoms, functional values associated with floodplain water bodies such as abandoned channels, sloughs, severed meander bendways and borrow pits have been reclaimed by re‐opening relatively small connecting channels. Reconnection projects typically involve dredging connecting channels or installing weirs or other types of water control structures. Backwater inflow augmentation is sometimes necessary for reconnection due to changes in bed elevation that have isolated backwaters from the main channel. Flow augmentation may involve installing and operating pumps on a permanent or seasonal basis. Design approaches are illustrated using a case study from a 2.5‐km long severed bendway adjacent to the Coldwater River, Mississippi. Costs for project construction, operation and maintenance and benefits to fish habitats are projected and compared.

Select this Article		Assessment of In‐stream Processes in Urban Streams for Development of Sediment Total Maximum Daily Loads Joshua L. Robinson, M.ASCE and Terry W. Sturm, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)567 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Clean Water Act requires the establishment of Total Maximum Daily Loads (TMDLs) for quantifying allowable pollutant loads for stream reaches in which the biological integrity of the stream is threatened. Sediment TMDLs in urban streams are particularly difficult to establish because they require (1) reliable measurement of sediment loads and (2) the ability to locate sediment sources. The research presented in this paper has attempted to address these challenges through a field study of North Peachtree Creek located in metro Atlanta, Georgia, which has been sampled at the Century Boulevard crossing through automatic point sampling and depth‐integrated sampling. Storm events from October 2003 through October 2004 provided a field record of sediment concentration and turbidity data over a wide range of storm events. Bed and bank sediment samples were collected for comparison with the point samples and depth‐integrated samples. A methodology is presented whereby point sampling is used to calculate suspended sediment discharge and turbidity analysis is used to locate and characterize sediment sources. Point samples provide the boundary condition in the Rouse solution for the vertical distribution of suspended sediment to obtain suspended sediment discharge, which is then calibrated through comparison with depth‐integrated sampling. The computer model HEC‐RAS was applied to the stream reach to calculate the energy grade line slope throughout each storm event for input into the sediment discharge calculations. A favorable relationship between turbidity and suspended fine sediment was found at the sampling cross‐section and, through comparison with bed and bank sediment samples, was used to identify the contribution of eroded bank sediment to the total sediment discharge.

Select this Article		Channel‐Forming Discharge and Hydraulic Geometry Width Predictors in Meandering Sand‐Bed Rivers Ronald Copeland, Philip Soar, and Colin Thorne ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)568 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper defines channel‐forming discharge as a theoretical parameter commonly used to develop preliminary channel dimensions for natural channel design. The channel‐forming discharge concept is based on the idea that for a given alluvial channel geometry there exists a single steady discharge that given enough time would produce channel dimensions equivalent to those shaped by the natural long‐term hydrograph. This theoretical discharge therefore dominates channel form and process and may be used to make morphological inferences. Bankfull discharge, effective discharge and a designated flood peak frequency are three deterministic parameters commonly used to represent the channel‐forming discharge. Using this concept of channel‐forming discharge, data were collected from 57 meandering sand bed streams in the United States and the three deterministic discharges were compared. The estimated channel‐forming discharge was then used to develop generalized hydraulic geometry relationships for bankfull width. Statistically significant differences in the regression of bankfull width and bankfull discharge were determined based on a simple classification of bank vegetation density. These relationships are presented with both single response and mean response confidence limits.

Select this Article		Channel‐Forming Flow: Representations and Variability Philip J. Soar, Chester C. Watson, and Colin R. Thorne ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)569 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Determining the channel‐forming flow is a critical stage in the channel restoration design process. While there are several ‘representations’ of this flow (the bankfull, recurrence interval and effective discharges), previous research has revealed that they are not necessarily equivalent and further investigation based on a dataset of U.S. meandering sand‐bed streams supports further their differentiation under certain conditions. This uncertainty presents a challenge to the channel designer early in the design process. This paper explores the variability between the channel‐forming flow representations and provides an explanation based on flow variability to account for some of the differentiation. The paper closes with a discussion of a ‘sediment impact assessment’ as a closure loop to the design process, in order to better account for the full range of sediment‐transporting flows and ensure long term dynamic stability.

Select this Article		Conversion of Braided Streams to Stable Single Thread Channels—A Discussion of Design Principles, Applications, Benefits, and Limitations Christopher H. Roach, P.E., P.H., M.ASCE, MacNamara C. Shoulders, and Robert F. Carlson, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)570 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Braided channels are a common morphological pattern for rivers and streams. Four factors have commonly been attributed to the causes of braiding in gravel bed rivers: large and sudden variations in discharge, steep channel slopes, a high sediment supply, and highly erodible banks. Where braided stream are in close proximity to infrastructure and development there is often a need for river training works to mitigate the effects of bank erosion, aggradation, lateral migration, and similar impacts. Significant changes in climatic conditions will be reflected by associated changes in channel morphology. Thus the management of braided stream channels will continue to be an important subject long into the future. The state of knowledge for channel conversion projects is currently limited. Engineering principles for converting braided stream channels to stable single thread channels will be outlined. Applications, benefits, and limitations of the methodology will be presented and discussed. A failure mode analysis and associated measures to mitigate project risk will be outlined. Results and performance of previous channel conversion projects will be presented and discussed. Developing a discussion and framework for channel conversion projects will aid in advancing the state of knowledge by encouraging further discussion and research to refine engineering principles for this design method.

Select this Article		Depth‐Averaged Velocity in Channels with Submerged and Unsubmerged Rigid Vegetation G. V. Wilkerson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)571 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A willow post system is a type of bioengineering system used to reduce streambank erosion. In essence, a willow post system is a collection of rigid cylinders placed along a streambank. Herein, an analytical model that was developed to evaluate the hydrodynamics of newly constructed willow post systems is reviewed. The model is founded on wake theory and was originally developed for predicting depth‐averaged velocities in straight trapezoidal channels with unsubmerged rigid cylinders. The model was recently modified and now includes a parameter for evaluating submerged vegetation and is referred to as the submergence ratio. Observed depth‐averaged velocities from a physical model study are compared to predicted depth‐averaged velocities from the original and the modified version of the analytical model A comparison of coefficient of determination (r²) values shows that the submergence ratio significantly improves the accuracy of predicted velocities in channels with submerged and unsubmerged vegetation.

Select this Article		Design Discharge Procedures in the STREAMS Spreadsheet Tools A. D. Ward and D. E. Mecklenburg ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)572 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this paper is to provide an overview of a suite of spreadsheet tools that the author's have developed to aid in the analysis of stream form and processes. It is recommended that readers interested in using the STREAM modules contact the authors as not all of the modules are currently available on line and/or enhanced versions of the available modules might be in development.

Select this Article		Design Discharges as Described in the Draft USDA NRCS Stream Restoration Design Guide Jon Fripp, Jerry Bernard, and Kerry M. Robinson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)573 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The USDA Natural Resources Conservation Service (NRCS) is currently developing a stream design guide which will be a companion to the interagency document, “Stream Corridor Restoration: Principles, Processes, and Practices” (FISRWG, 1998). This comprehensive draft design guide includes a significant discussion of the use and assessment of design discharges. This paper will address the current status of the overall effort with a particular emphasis on sections of the draft design guide that describe design discharges.

Select this Article		Design Discharges for Arroyos in an Urban Setting Robert A. Mussetter and Michael D. Harvey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)574 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Perennial, mobile‐boundary streams tend to adjust their shape, planform, and gradient to the range of commonly occurring flows, and the hydrologic and sediment transport characteristics of these streams can be reasonably predicted through the use of flow duration curves, standard flood frequency analyses and sediment transport computations. As a result, design discharges for channel restoration might logically include the effective discharge (i.e., the range of discharges that carries the most sediment over the long term) for establishing the cross sections and planform of the primary channel, and consideration of larger flood flows in the 10‐ to 100‐year recurrence‐interval range to insure stability of critical project features and the required level of flood protection. Because of their ephemeral flow conditions and highly erodible boundary materials, a similar approach to identifying design discharges for restoration or habitat enhancement in arroyos may not be successful because the condition of the channel is often largely the product of the last major flood. In addition, arroyos tend to respond rapidly and dramatically to urbanization and other land‐use changes due to their effects on both runoff and sediment supply; thus, the long‐term conditions that will occur after implementation of a project may be very different from those leading up to the project. This paper discusses important issues associated with establishing appropriate design discharges for restoration or habitat enhancement in arroyos, with particular focus on the urban setting where the watershed discharge and sediment loads will undergo progressive change as urbanization continues.

Select this Article		Developing a Regional Engineering Model for Ecosystem Restoration H.‐P. Cheng, J.‐R. Cheng, E. V. Edris, C. A. Talbot, D. C. McVan, C. H. Tate, C. M. Hansen, H.‐C. Lin, D. R. Richards, and M. A. Granat ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)575 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the federally approved Comprehensive Everglades Restoration Plan, CERP (http://www.evergladesplan.org/), the restoration of the South Florida ecosystem is a major task for the U.S. Army Corps of Engineers and the South Florida Water Management District. Although CERP is comprised of 68 major components, which are grouped into over 40 projects, it is desired to construct a Regional Engineering Model for Ecosystem Restoration (REMER). The REMER model covers most of the South Florida area and contains various hydrologic processes and features, such as 1‐D canal flow, 2‐D overland flow, 3‐D subsurface flow, canal control structures, surface‐subsurface interaction, pumping wells, retention ponds, lakes, levees, culverts, roads, bridges, etc. The US Army Engineer Research and Development Center, ERDC, has been contracted to develop the REMER model for South Florida and is expected to accomplish model calibration and validation in Year 2006. This paper will provide an overview of the REMER model that includes the background information and the five critical technical tasks. It will also address challenges anticipated in the model development, including graphic user interface, GUI, development, computational code parallelization, and model calibration and validation approach.

Select this Article		Difficulties of Identifying Design Discharges in Steep, Coarse‐Grained Channels in the Arid Southwestern US Michael D. Harvey and Robert A. Mussetter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)576 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A study of three locations in a 16‐km reach of the lower Verde River in Arizona demonstrates the problem of identifying generalized design flows in the arid and semi‐arid regions of the southwestern US, where flow regimes are highly variable and often non‐continuous, where coarse bed material is supplied locally by steep ephemeral‐flow tributaries, and where channel morphologies are forced by large, infrequent floods, canyon walls, tributary fans and alluvial terraces. At the three sites, channel slopes vary from 0.0027 to 0.0041, and the median size of the surface bed materials ranges from 81 to 145 mm. Hydraulic analysis (HEC‐RAS) showed that, depending on the definition used, the bankfull discharge at the three sites ranges from 450 to 1,900 cms (1.7‐ to 8‐yr RI), the critical discharge (ϕ′ = 1) for bed‐material mobilization ranges from 398 to 811 cms (1.6‐ to 3.8‐yr RI), and significant sediment transport (ϕ′ > 1.5) occurs at flows between 989 and 1,740 cms (4‐ to 8‐yr RI). At any given flow above the critical discharge at one location, bed material can be immobile, in transport, or being deposited at any of the other two locations. Selection of flows for engineering design or restoration purposes in rivers with similar conditions is, therefore, highly constrained by local conditions, and site‐specific geomorphic, hydraulic and sediment‐transport analyses are required rather than generalized relations based on assumed relations between bankfull discharge, flood frequency, and effective discharge.

Select this Article		Ecosystem‐Based Restoration of the Illinois River: System Objectives, Vision, and Restoration Goals and Alternatives Nani G. Bhowmik, P.E., Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)577 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Illinois River, a major U.S. river in the Midwest, drains more than 75,000 square kilometers (sq km) of surface area in Illinois, Indiana, and Wisconsin. Illinois contains most of the Illinois River drainage basin which drains more than 40 percent of the state. Within the last 150 years, there have been many impacts on the river due to extensive land‐use changes, urbanization, water‐quality alterations, in‐channel and out‐of‐channel sediment deposition, and flow diversion from Lake Michigan. During the last decade, state and federal governments, with strong support from private entities, have embarked on restoring some river functions with the overarching goal of enhancing river ecosystems. The vision of this integrated management plan is a naturally diverse and productive Illinois River sustained by natural ecological processes. Seven goals have been developed: biodiversity, reduced sediment delivery, restored aquatic habitats of the main channel and side channels, improved floodplain habitats, increased longitudinal connectivity, naturalized river, and improved water and sediment quality. This paper outlines these basic concepts, presents some examples of what is being done, and also outlines future plans and activities.

Select this Article		Effects of Bendway Weir Characteristics on Resulting Flow Conditions C. I. Thornton, M. L. Heintz, S. R. Abt, D. C. Baird, and R. S. Padilla ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)578 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Natural processes associated with meandering river systems have been shown to lead to degradation of channel beds, erosion on channel banks, and bend migration. Attempts at mitigating the local instability associated with meandering systems, such as transverse and longitudinal structures, armor protection, and bio‐engineering techniques have been utilized worldwide. One type of structure, bendway weirs, are rock structures placed in series along the outer bank of a bend in an effort to alleviate stresses, as well as create habitat. Many aspects associated with the bendway weir indicate the structure to be a viable alternative to longitudinal stone toe for controlling migration and bank erosion. While bendway weirs have been successfully used in many applications, quantifiable design guidance has not been available. Past projects utilizing bendway weirs have relied heavily on field experiences, site‐specific flume studies, and engineering judgment, but have lacked general design guidelines. To accurately model flow conditions resulting from the placement of bendway weirs, an undistorted 1:12 Froude scale, hard boundary model was constructed at the Hydraulics Laboratory of the Engineering Research Center at Colorado State University. The model contained two bends, which exhibited unique geometric characteristics representative of those found in the Middle Rio Grande reach. Three‐dimensional velocities and water surface profiles were recorded for a series of tests including variations of weir length, spacing, and angle. Using the data obtained from the test series, a relationship of the reduction of velocities relative to pre‐weir conditions, due to the variation of bendway weir characteristics, was developed. The location of the strongest eddies found in a bend as a function of weir length was also examined. Bendway weir testing resulted in the creation of design criteria. Utilization of a known set of baseline conditions for a given bend and design parameters for bendway weirs, a designer is enabled to predict maximum velocities found in the bend after the installation of bendway weirs.

Select this Article		The Effects of Relative Submergence on Cluster Formation in Gravel Bed Streams C. M. Kramer and A. N. Papanicolaou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)579 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The formation of cluster microstructures in mountain gravel bed streams is examined. An emphasis is placed on the effects of large clast particles on the formation and evolution of cluster microforms. Specifically, two cases are examined in a laboratory flume; (1) when the relative submergence is less than 3 and (2) when the relative submergence exceeds 3. Results in the laboratory show that the relative submergence affects the geomorphic characteristics of clusters and bedload rates. For the low relative submergence the clusters form in streaks, indicative of a skimming flow regime. For the high relative submergence clusters form randomly and obtain a variety of geometric shapes. With the knowledge gained from these experiments, a practical application is to use these clast particles in a stream to help trap or entrain particles near spawning grounds, thus helping to make and sustain a cleaner habitat for fish and other aquatic organisms.

Select this Article		Enhancement of Stage Monitoring Network in the Florida Everglades Chandra S. Pathak, Alexandra Carvalho, and Michael J. DelCharco ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)580 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The South Florida Water Management District collects, validates, and archives hydrometeorological data that includes rainfall, water level (stage), water control structure operations, flow and others. A pilot project was undertaken to enhance stage‐monitoring network for a portion of the remnant Everglades of south Florida. This paper details the methodology employed to enhance a stage‐monitoring network for a specific area—the Shark River Slough basin in the Everglades National Park. The Shark River Slough basin comprises over 1,140 square kilometers (440 square miles) of wetlands that includes six landscape regions. Biological responses of the area's plant and biological communities to two hydrological criteria—water depth and inundation duration—provided the data grouping schemes for the hydrological data analysis. The daily mean water depth data from 1981 to 2000 were used for the analysis. The data were obtained from the results of the calibrated and verified spatially distributed hydrologic model (uses 3.2×3.2 kilometer [2×2 mile] grid)—South Florida Water Management Model. The methodology identifies similar hydrologic regions by combining analytical and geostatistical methodology, with GIS mapping and grouping techniques. The similar hydrologic regions were used in determining required optimal number of stage gage stations and their respective locations in the study area.

Select this Article		Experimental Study of Drag and Lift Forces on Prototype Scale Models of Large Wood Carlos V. Alonso, F. Douglas Shields, Jr., and Darrel M. Temple ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)581 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Prototype‐scale LW models were tested in a 1‐m deep, grass‐lined outdoor channel to measure drag and lift forces under flow conditions that accurately represent the turbulent regime encountered in natural streams. The tests were carried out with PVC, hackberry, and oak logs submerged in a steady, uniform flow to facilitate comparison with data from flume and wind tunnel investigations reported in the literature. Parametric charts are presented detailing the dependence of time‐mean drag and lift coefficients on log geometry and position. The findings show that (1) laboratory experiments conducted with careful attention to hydrodynamic scaling can be used to evaluate forces on LW pieces, (2) drag and lift coefficients evaluated in steady flows can be extended to LW subjected to transient stream flow events, (3) drag is affected by roughness, bed proximity, and free surface proximity, (4) lift decreases with increased roughness, and decays exponentially as bed proximity decreases, and (5) the effect of log orientation on drag at depth follows Hoerner's cosine‐law.

Select this Article		The Flooding and Drying Cycles in Rain‐Fed Seasonal Meadows, Central California H. A. Loáiciga and A. Huang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)582 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Wetlands are areas with hydric (poorly drained) soils or rocky substrate covered permanently or intermittently by shallow water that support predominantly hydrophytes. In a natural setting, they are created by the convergence of topographic, hydraulic, climatic, and hydrogeologic conditions favorable to maintaining saturated soils or ponding for extended periods. Wetlands serve important water‐quality and ecological functions. In this paper we present a method to quantify the water balance and flooding duration in rain‐fed wetlands with negligible overland drainage and a deep groundwater table. The method imposes Horton or Green‐and‐Ampt infiltration on design storms to determine the mechanics of wetland ponding and drying. The Green‐and‐Ampt infiltration analysis is based on a solution technique that considers variable rainfall supply, evapotranspiration, and ponding. The water balance method is useful in wetland creation and restoration, and particularly well suited to calculate the flooding‐drying cycle of vernal pools endemic to California and southern Oregon. The method is also applicable to the analysis of ponding in irrigated, flat, terrain.

Select this Article		A Guidance Manual for Restoring Streams through Fish Protection at Water Diversions Philip H. Burgi, P.E., Hon.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)583 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper provides a synopsis of a new technical manual soon to be available that summarizes planning and design guidance for fish protection at small dams and water diversion structures on Western U.S. rivers using exclusion screens and/or behavioral barriers. For years water resource planners, fishery biologists and engineers have been aware of the need for fish protection, but there has been inconsistent application of criteria and technology. More importantly, a lack of consensus among fishery resource agencies as to the scientific basis of past and present criteria has resulted. Recent advancements in the understanding of fish behavior and exclusion methods across a greater number of species and locations in the Western United States have greatly improved the application of new criteria to benefit restoration efforts. These recent advancements are the result of cooperative efforts among engineers and fishery biologists (bioengineering) in various government agencies and universities to bring consensus to the planning and design of fish exclusion facilities. It is evident that there is need for an application‐based manual to present alternatives and design guidelines for fish exclusion facilities at water diversions. The manual to be published in early 2006, will include these recent advancements in fish exclusion concepts and applications to both warm and cold water fish species at water diversions.

Select this Article		How Well Do the Rosgen Classification and Associated “Natural Channel Design” Methods Integrate and Quantify Fluvial Processes and Channel Response? A. Simon, M. Doyle, M. Kondolf, F. D. Shields, Jr., B. Rhoads, G. Grant, F. Fitzpatrick, K. Juracek, M. McPhillips, and J. MacBroom ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)584 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Over the past 10 years the Rosgen classification system and its associated methods of “natural channel design” have become synonymous (to many without prior knowledge of the field) with the term “stream restoration” and the science of fluvial geomorphology. Since the mid 1990s, this classification approach has become widely, and perhaps dominantly adopted by governmental agencies, particularly those funding restoration projects. For example, in a request for proposals for the restoration of Trout Creek in Montana, the Natural Resources Conservation Service required “experience in the use and application of a stream classification system and its implementation.” Similarly, classification systems have been used in evaluation guides for riparian areas and U.S. Forest Service management plans. Most notably, many highly trained geomorphologists and hydraulic engineers are often held suspect, or even thought incorrect, if their approach does not include reference to or application of a classification system. This, combined with the para‐professional training provided by some involved in “natural channel design” empower individuals and groups with limited backgrounds in stream and watershed sciences to engineer wholesale re‐patterning of stream reaches using 50‐year old technology that was never intended for engineering design. At Level I, the Rosgen classification system consists of eight or nine major stream types, based on hydraulic‐geometry relations and four other measures of channel shape to distinguish the dimensions of alluvial stream channels as a function of the bankfull stage. Six classes of the particle size of the boundary sediments are used to further sub‐divide each of the major stream types, resulting in 48 or 54 stream types. Aside from the difficulty in identifying bankfull stage, particularly in incising channels, and the issue of sampling from two distinct populations (beds and banks) to classify the boundary sediments, the classification provides a consistent and reproducible means for practitioners to describe channel morphology although difficulties have been encountered in lower‐gradient stream systems. Use of the scheme to communicate between users or as a conceptual model, however, has not justified its use for engineering design or for predicting river behavior; its use for designing mitigation projects, therefore, seems beyond its technical scope.

Select this Article		Hydrodynamic Investigation of Upper Mississippi River Freshwater Mussel Habitats Nathan Young, Andrew McCo, and Larry Weber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)585 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Human activities in the Upper Mississippi River Basin have caused a significant decline in freshwater mussel populations. One contributing factor is the construction of navigation dams and river training structures on the main stem of the Upper Mississippi. These structures have resulted in the slowing and redirection of flow through the braided channel system severely impacting mussel habitats. Ongoing research at IIHR — Hydroscience and Engineering is seeking to develop a more complete understanding of the hydrodynamics within mussel habitats in hopes of providing information useful in the preservation and restoration of imperiled Upper Mississippi River mussel populations. Freshwater mussel habitats in Pool 16 of the Upper Mississippi River are being studied using a combination of field data collection and numerical simulation. Field data are being used to characterize the physical habitat of Upper Mississippi freshwater mussels. Bathymetric, velocity, substrate, and mussel dispersal data are being collected to quantify physical variables influencing habitat quality. Bathymetric and velocity data are being used to generate computational fluid dynamics (CFD) simulations of flow in Pool 16. These models will provide information about the entire flow field in the river reach and will allow for simulation of historical high and low flows that may be an important factor in structuring the dispersal of freshwater mussels.

Select this Article		Hydrologic and Hydraulic Considerations for the Ecological Restoration of the Emiquon along the Illinois River Misganaw Demissie, Allen Wehrmann, Yanqing Lian, Geremew G. Amenu, Stephen Burch, and William Bogner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)586 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Nature Conservancy (TNC) has initiated a major ecological restoration project along the Illinois River to restore one of the largest levee and drainage districts that has been drained and farmed since 1924. The Thompson Lake Drainage and Levee District, located just upstream of the junction of the Spoon River with the Illinois River, was formed in the early 1920s by draining and leveeing a large floodplain area that included Thompson and Flag Lakes and diverse aquatic and terrestrial habitats that supported a wide variety of fish and wildlife. The restoration area known as the Emiquon is one of the largest floodplain restoration projects in the United States. The goal of the restoration effort is to restore ecological processes and habitats that could sustain the native aquatic and terrestrial species once found in the region prior to disturbance of the area. One of the key elements in the restoration effort is the proper understanding of the hydrology, hydraulics, and sediment transport processes in the Illinois River near the Emiquon area from a historical perspective, under existing conditions, and also for different management scenarios. Prior to making changes in the management of the area, TNC wisely initiated scientific investigations and analyses to guide the restoration effort. As part of this effort, the Illinois State Water Survey (ISWS) has collected hydrologic data and developed hydrologic and hydraulic models to assess existing conditions and evaluate different management alternatives that could be used during the restoration. This paper summarizes the results of those investigations.

Select this Article		Hyporheic and Total Storage Exchange in Small Sand‐Bed Streams John M. Stofleth, F. Douglas Shields, Jr., and Garey A. Fox ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)587 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Nutrient processing and carbon storage in stream ecosystems are linked to hydraulic retention. Hydraulic retention refers to the departure of stream flow from ideal “plug flow,” and reflects fluid movement through surface and hyporheic storage zones. Most existing information about hyporheic exchange is based on flume studies or field measurements in relatively steep streams with beds coarser than sand. Stream tracer studies may be used to quantify overall hydraulic retention, but disaggregation of surface and hyporheic retention components remains difficult. A stream tracer approach was used to compute the rates at which stream water is exchanged for water in storage zones (total storage) in short reaches of two small, sand‐bed streams. Tracer curves were fit to the one‐dimensional transport with inflow storage (OTIS‐P) model. Networks of minipiezometers were used to measure hyporheic exchange. The rate of exchange between main channel flow and surface storage zones was assumed equal to the difference between total storage exchange computed by the modeled tracer curves and hyporheic exchange. This technique was used to measure the effects of flow obstructions (large wood) and differences in bed morphology and grain size on surface and hyporheic exchange. Parameters describing total retention were in the upper 50% of data compilations published by others that represent a range of stream sizes and morphologies, but hyporheic exchange was only 0.01% to 0.49% of total exchange. Retention did not correlate to differences in median bed material size, but increased with flow obstruction. Hyporheic storage was an insignificant component of total hydraulic retention in the small sand‐bed streams studied.

Select this Article		The Influence of Successional Development on Periphyton Scour Resistance Mark C. Stone, S.M.ASCE, Rollin H. Hotchkiss, M.ASCE, and Ryan Morrison, S.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)588 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Disturbance is known to be a dominant variable in stream ecology. Disturbance can be the result of hydraulic or physical modifications to the environment. Periphyton assemblages are composed of attached algae, bacteria, and fungi growing on the streambed. The assemblages can be viewed as a necessity or a nuisance depending on stream productivity. Periphyton community structure is highly dependent on disturbance regime. The objective of this research was to investigate temporal variations in periphyton resistance to shear stress scour. The research was accomplished by colonizing clay tiles in a natural stream for various time periods. The tiles were periodically collected and subjected to increasing levels of shear stress in a laboratory flume. The tiles were then analyzed to determine the level of periphyton scour. It was found that periphyton ash free dry mass increased significantly with colony age and time of the growth season. Periphyton resistance to scour increased with colony development but was not significantly influenced by time. The results can be used to improve restoration and management of stream systems.

Select this Article		Investigation of the Excavation, Transport and Beneficial Use of Illinois River Dredged Material John C. Marlin and Robert G. Darmody ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)589 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Illinois River in central Illinois provides essential habitat for North American migratory birds and large river fish. The river's backwaters and side channels accumulated prodigious amounts of sediment during the past century, which severely degrading this resource. Restoration of the river the system will require removal of large quantities of sediment. Illinois is investigating the quality and characteristics of the sediment and methods of efficiently removing and placing it for storage or beneficial use. Part of this effort is focused on high solids dredging and long distance an transport to sites in need of soil or fill. Uses such as island creation and enhancement are also under consideration. Demonstration and pilot projects tested a variety of equipment types including clamshell buckets and a hydraulic clamshell on an excavator arm. Concrete pumps, both fixed and truck‐mounted, conveyors, and a variety of barges and trucks were used for sediment transport and handling. After weathering, the sediment is quite similar to central Illinois topsoil in its physical structure. Plant growth tests demonstrated that it performs as well as high quality topsoil. Urban renewal sites near waterways are likely candidates for use of sediment‐derived topsoil. Soil availability is often limited in these areas and the cost and inconvenience of moving large numbers of trucks through cities is a major consideration. A pilot project moved 94,300 tonnes of dredged material from Peoria Lake at East Peoria, IL to an old industrial site in Chicago, a distance of 270 km.

Select this Article		A Laboratory Study of the Effects of Groyne Height on Sediment Behavior in Rivers Kenneth Thiemann, Mohamed F. M. Yossef, and Brian Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)590 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Groynes are structures that extend from riverbanks out into the flow in order to protect from bank erosion and keep sediment from depositing and thereby blocking river transportation. If there is general bed aggradation or degradation, then the relative height of the groyne is changed. Little is known about the effects of this change in height on the flow or sediment behavior. A laboratory study was performed at the Technical University at Delft, The Netherlands to examine this issue for conditions of general bed aggradation. The flume recirculated water, while sediment was fed in upstream and collected downstream. A series of groynes were installed on one side of the flume. For all test cases the Shields parameter, θ was set at a value of 0.23, and the suspension number, Z was set to 1.87, so as to guarantee suspended‐load, as well as bed load, transport. The hydraulic conditions were chosen to replicate natural river conditions, i.e., constant mobility and suspension in all test cases. Furthermore, for all the test cases Froude number (F_r) was small enough (maximum = 0.28), and the Reynolds number (R_e) high enough to ensure subcritical, fully‐developed, turbulent flow in both the main channel (R_e ≅ 1.8× 10⁴) and the groyne fields (R_e ≅ 0.5 × 10⁴). Results are presented for the effect of groyne height on flow patterns, velocity, sediment exchange between main channel and groyne areas, and local scour. The results demonstrate the differences between the erosion and deposition patterns in the groyne fields for the different flow conditions and the dependency of the scour geometry on the relative height of the groynes.

Select this Article		Modeling the Impact of Riparian Buffer Systems on Bank Stability of an Incised Stream Eddy J. Langendoen, R. Richard Lowrance, Randall G. Williams, Natasha Pollen, and Andrew Simon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)591 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract A national project is underway within the U.S. Department of Agriculture to estimate the beneficial effect of conservation practices on environmental resources. The use of computer models is a major component of the project. Edge‐of‐field buffers are a core agricultural conservation practice, and installed along the stream are a proven technology to reduce sediment loadings from both hill slope and channel bank. This paper presents the initial effort to integrate the computer models CONCEPTS and REMM, which were developed to simulate stream channel morphology and riparian ecosystem function. The integrated model has been used to study the effectiveness of hypothetical woody and herbaceous riparian buffers in controlling streambank stability of an incised stream in Mississippi. Results show that the anchoring force provided by coarse roots of the woody vegetation greatly enhances streambank stability and therefore reduces streambank erosion. The roots of the herbaceous species have a negligible effect on the stability of the bank of the incised stream.

Select this Article		A New Approach to Modeling the Mechanical Effects of Riparian Vegetation on Streambank Stability: A Fiber‐Bundle Model Natasha Pollen and Andrew Simon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)592 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Riparian vegetation plays a number of roles in protecting stream banks from erosion by particle entrainment and mass wasting, with the impacts generally separated into those that are mechanical, hydraulic, or hydrological. This paper investigates the quantification of mechanical root‐reinforcement of streambanks using established perpendicular root‐reinforcement models and a newly constructed root‐reinforcement model, RipRoot. The root‐reinforcement estimates were tested against direct‐shear tests with root‐permeated and non‐root permeated soil samples and were then input to a streambank stability model to assess the impact of the differences between the root models on streambank factor of safety values. The new fiber‐bundle model, RipRoot, provided more accurate estimates of root reinforcement through its inclusion of progressive root breaking during mass failure of a streambank. In cases where bank driving forces were great enough to break all of the roots, the perpendicular root model overestimated root reinforcement by up to 50 %, with overestimation increasing an order of magnitude in model runs where streambank driving forces did not exceed root strength. For the highest banks modeled (3 m) the difference in factor of safety values produced by the two models varied from 0.13 to 2.39 depending on the riparian species considered.

Select this Article		One Wetland at a Time Michael G. Thalhamer and Nichole Baker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)593 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Carmel River Lagoon Enhancement Project is to restore and enhance the 100± acres west of Highway 1, just south of Carmel in Monterey County, owned and managed by California State Parks, from farmland to a more natural ecosystem, improve vegetation and wildlife habitat. The 100± acre site had been filled in and leveled to be used for artichoke production for many years. The project included grading of the agricultural land, lowering the access road to the Carmel Area Wastewater District Treatment Plant, expansion of the south arm of the Carmel River Lagoon, and restoration of natural habitats. The purpose of this paper will be to provide a pictorial journey through the engineering and construction process of this restoration process. The paper will emphasize the resource protection and restoration goals. This 100 ± acre site was historically a lagoon/wetland area. It then was landfilled and farmed for artichokes. When the state finally obtained ownership of the property, a unique opportunity arose to recreate the historical lagoon/wetlands. The authors now have a unique opportunity to present a photo log journey through this project. The photos will take us from historical photos, through the engineering process, and through the construction period. With the beginning of spring 2005, the last photos will show the emergence of the wetlands plant communities.

Select this Article		Overview of the Performance Optimization of the Everglades Construction Project Stormwater Treatment Area No. 3/4 Stephanie C. Otis, Ph.D., P.E. and Tracey T. Piccone, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)594 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Florida's 1994 Everglades Forever Act (EFA) established interim water quality goals designed to restore and protect the Everglades. The EFA also established a process for determining the long‐term water goal. Activities are currently underway to meet the interim goal of reducing phosphorus levels in discharges from the Everglades Agricultural Area (EAA) and other sources to a long‐term annual flow‐weighted mean concentration of 50 parts per billion (ppb). These activities include implementation of Best Management Practices (BMPs) throughout the EAA and the construction of Stormwater Treatment Areas (STAs). One of these STAs, STA‐3/4 is the world's largest man‐made wetland. Construction of STA‐3/4 was recently completed and its early performance has been very promising; average discharge concentrations to date have been well below the interim target. Concurrent with these activities, the South Florida Water Management District and other groups are conducting water quality research, ecosystem‐wide planning, and regulatory programs to ensure a sound scientific foundation for decision‐making related to the EFA requirements. Pursuant to the recommendations of the Long‐Term Plan, STA‐3/4 is currently being retrofitted with Advanced Treatment Technology (ATT) within its existing footprint to meet the long‐term water quality goals, and to include a large‐scale demonstration project for the ATT referred to as Periphyton‐based Stormwater Treatment Area (PSTA).

Select this Article		Panel Discussion of Stream Classification Systems Peter Klingeman, Donald Carpenter, EWRI River Restoration Committee, Douglas Shields, Jr., Sue Niezgoda, Andrew Simon, Munsell McPhillips, and James MacBroom ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)595 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Classification systems provide one means for generalizing, organizing, and categorizing sets of diverse items into groups. Stream channels tend to fit into broad categories (e.g., braided, meandering, sinuous, and straight) that suggest the utility of having some type of stream classification system. Recently, “natural channel design” has been advocated as a goal for stream alterations and has become the heart of some stream classification systems. Similarly, “channel evolution” has been recommended as one means for gaining insight to dominant channel processes. Both approaches rely on observations and comparisons of channel condition and geomorphic form. However, the physical appearances of streams can be misleading, as they often represent only fleeting glimpses at conditions, usually transitory, that reflect many different states of anthropogenic disturbance. This poses a particular difficulty in terms of stream channel restoration efforts, as there are few or no “undisturbed” streams in many regions of the country against which to make reference in order to understand what types of restoration goals and potentials may be relevant. Nevertheless, several classification systems have been developed that are used to assist in or even to guide stream alteration activities, including stream restoration. This panel reviews the features of classification systems and considers their “pros and cons” for various applications, including stream restoration.

Select this Article		Physical Habitat Assessment and Historical Water Quality Analysis on the White River, South Dakota Cory S. Foreman, Dan Hoyer, and Scott Kenner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)596 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract The White River was listed on South Dakota's 1998 303(d) list of impaired waterbodies for exceedances of water quality standards for total suspended solids (TSS) and fecal coliform bacteria. The White River flows out of northwest Nebraska into southwestern South Dakota and follows an easterly route until it discharges into the Missouri River. Shortly after it enters the State of South Dakota, the river flows through Badlands National Park, which is famous for its rugged, steep terrain with little to no vegetation on the loosely consolidated side slopes. Ten sites were established for assessment of physical habitat and biologic integrity following the Environmental Monitoring and Assessment Program (EMAP). These sites ranged in location from Crawford, Nebraska, near the headwaters of the river to the mouth of the river near Oacoma, South Dakota. An Index of Biologic Integrity (IBI) was created for the benthic macroinvertebrates and periphyton samples. A multimetric approach was used for the development of the IBIs with seven metrics being used for the benthic IBI and eleven metrics used for the periphyton IBI. A large amount of historical gage data are available for the White River, dating as far back as 1928, at a station near the mouth of the river. The White River has long been a river of special interest due to the Missouri River Reservoirs and the impact on reservoir storage. A statistical analysis of the historic data set was performed to characterize the conditions in the Watershed and to develop a Total Maximum Daily Load (TMDL) summary report. Downstream of the Badlands region, the median TSS concentration is 1,118 mg/1 with upper and lower quartiles of 154 mg/1 and 5,688 mg/1. At the same station, the fecal coliform median is 2,400 colony‐forming units (cfu)/100 ml with upper and lower quartiles of 350 cfu/100 ml and 7,500 cfu/100 ml. Because of the large natural background of TSS in this system, the TSS standard of 158 mg/1 is not attainable. Best management practices (BMP) are expected to reduce the TSS loading by a minimal amount. BMPs for fecal coliforms can be implemented to reduce concentrations to the water quality standard of 2,000 cfu/100 ml. We anticipate BMPs for fecal coliform reduction, such as a grazing management system, off‐site watering, and riparian vegetation stabilization, will also reduce the TSS loading slightly.

Select this Article		Predicting Watershed‐Scale Wetland Restoration Potential for Florida's Fisheating Creek Using Models Maria C. Loinaz, William R. Wise, Douglas T. Shaw, and Andrew I. James ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)597 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Abstract only available. Both GIS and the MIKE SHE model were applied to the 1100‐km² Fisheating Creek Watershed in Florida to develop a strategy for restoring basin hydrology. In particular, the restoration objective is to lower both water volume and nutrient inputs from the basin into Lake Okeechobee, in order to achieve specific goals of the Comprehensive Everglades Restoration Plan. GIS‐based modeling helped to identify wetlands that had been compromised by previous ditching and draining activities. Soil type, land use, and hydrography data, among others, were used to develop a map of potentially restorable wetlands in the basin. From the GIS‐based approach, restoration scenarios were identified. MIKE SHE modeling was performed for both existing conditions and for the restoration scenarios. Multiple year simulations revealed that under restored conditions, significant amounts of water should be retained on the landscape (ultimately lost as evapotranspiration) rather than rushing to Lake Okeechobee as currently occurs. Such storage on the landscape is among the most natural of the various restoration strategies that may ultimately be employed for the Comprehensive Everglades Restoration Plan.

Select this Article		A Process‐Based Ecological Model for River Network Management A. C. Marcinkevage and E. H. Herricks ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)598 Online Publication Date: 29 June 2005 Full Text: \| Download PDF
	+ -	Show Abstract Understanding the interactions of ecology and hydrology is essential for promoting effective watershed‐based river management. This paper considers the influences of watershed‐level landscape development on aquatic ecosystems within stream networks by using metrics of ecological connectivity and hydrologic condition. As landscape development shifts from downstream to upstream watershed locations, aquatic communities throughout the network will be affected by potential contaminant and sediment loading and changes in upstream source communities that are affected by landscape change. Although hydrologic effects propagate in the downstream direction, not all ecological effects are dependent on upstream to downstream mechanisms. Downstream to upstream processes are important in aquatic community maintenance and are critical concerns of a comprehensive management strategy. This research develops a model of species dispersion in a theoretical stream network based on fish movement potentials and associated hydrologic dispersion mechanisms. Management strategies can be modified to minimize adverse effects on aquatic communities. This is achieved by understanding mechanisms of community response to watershed‐scale landscape change along with the corresponding hydrologic changes at different points in the network. The use of this approach will promote understanding of the links between physical and ecological processes in ways that contribute to improved watershed management in human‐dominated areas.

Select this Article

Rapid Stream Assessments of the Illinois River Watershed

William P. White and Laura L. Keefer

ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40792(173)599

Online Publication Date: 29 June 2005

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Show Abstract

The Illinois River Basin Ecosystem Restoration Plan acknowledges that erosion by the Illinois River and its tributaries, as well as sediment deposition within the river valley, are significant problems. Naturalization of tributary streams and restoration of biodiversity are key, yet often missing components of traditional watershed planning and management efforts. Watershed plans often outline general problem categories and list potential conceptual solutions but rarely target specific problem sites for action. Conservation work on channel and near‐channel environments would significantly complement traditional soil conservation plans and programs in Illinois where sediment contributed from eroding streambanks and streambeds is extensive. Watershed assessments that rapidly, yet effectively, identify potential on‐the‐ground natural resource restoration sites are well received by the public and public institutions in charge of funding ecosystem restoration efforts. The Illinois State Water Survey (ISWS) has been working to assess and evaluate the Illinois River watershed to facilitate implementation of the larger goals of the Illinois River Basin Ecosystem Restoration Plan. Watershed assessments conducted by the Illinois Scientific Surveys under the auspices of this project include analysis of Geographic Information System (GIS) data, aerial reconnaissance of specific problem areas selected for survey by agreed upon criteria, and field data collection and analysis of geomorphological data and biological indicators. Those data and analyses are being used specifically to locate, characterize, prioritize, design, and construct actual multi‐objective restoration projects that reduce erosion, restore habitat, and protect overall ecosystem health. Assessment using a helicopter equipped with a Global Positioning System (GPS)‐synchronized aerial camera allows for rapid identification of potential restoration project site areas. After potential sites are identified, analyses will determine hydrological, hydraulic, geomorphological, and biological parameters before prioritizing where to proceed with design and construction of restoration work. This paper briefly describes the framework for the aerial assessment and data collection effort and acknowledges the usefulness of an accessible and integrated data retrieval and analysis system (Illinois Rivers Decision Support System) for tracking activities, evaluating project performance, and making adaptive management decisions.

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