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Critical Transitions in Water and Environmental Resources Management Proceedings of World Water and Environmental Resources Congress 2004

June 27 – July 1, 2004 Salt Lake City, Utah, USA

Editor(s): Gerald Sehlke, Donald F. Hayes, David K. Stevens

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ARID LANDS

Select this Article		Iraq's Marshlands — Demise and the Impending Rebirth of an Ecosystem Azzam Alwash, Suzanne Alwash, and Andrea Cattarossi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)1 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Mesopotamian Marshlands previously constituted the largest wetland ecosystem in the Middle East and Western Eurasia. They play a key role in the intercontinental flyway of migratory birds, support endangered species, and sustain fisheries of the Persian Gulf. In addition to these important ecological benefits, these marshlands represent a unique element of our global heritage and resources. They have been home to indigenous human communities for millennia and are regarded as the site of the legendary “Garden of Eden.” The marshlands once covered over 20,000 km² of interconnected lakes, mudflats, and wetlands within modern‐day Iraq and Iran. However, in the past thirty years, over 90% of the marshlands have been desiccated through the combined actions of upstream damming in Syria, Turkey and Iraq as well as the development of extensive downstream drainage projects within Iraq. Before the recently concluded war in Iraq, no close‐up monitoring of conditions in the marshlands has been possible for the international scientific community. Nevertheless, independent organizations have raised international awareness since 1991. After the end of major combat operation in the region in early May 2003, several reconnaissance surveys have been carried out and preliminary work has begun the long‐term restoration of the marshlands. The work currently being carried out includes modeling of flow regimes, ecological surveys and monitoring demonstration projects in various locations. Past and present marshlands conditions are described here along with an overview of the work currently being undertaken.

Select this Article		Iraq Water Resources Evaluation: An Overview of the Existing Conditions Marco Gonella, Augusto Pretner, Julien Lecollinet, and Andrea Cattarossi, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)2 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract On July 2003, the Italian Ministry of Environment financed a project called “New Eden” to the Iraq Foundation, an NGO active in the reconstruction effort in Iraq. The objective of the project focuses on the identification and prioritization of key water management problems, and on development of a comprehensive policy using a participatory process for water resources management in Iraq. Through resource planning, the project has identified actions to bring major improvements to the welfare of the Iraqi population and condition of their environment, both of which have significantly deteriorated over the last decade. The project would guide donor assistance for development and contribute beneficially to water management, including investments from other economic sectors. The first phase of the project was dedicated to data gathering to create an organized and comprehensive overview of the biophysical and socio‐economical data. On the basis of collected data, the development of an integrated water management model is important to understand Iraq's water needs and to prepare an action plan for the management of water resources in Iraq. A major objective of the project includes concrete proposals for immediate actions that do not require substantial financing, but which can bring significant and rapid results to the Iraqi people and their environment. These analyses define the Priority Action Plan in agreement with local authorities and stakeholders to outline the capital investment program of emergency water works in selected critical areas. Successful completion of this project entailed the collaboration and cooperation of the existing engineering and scientific community in Iraq through missions of Italian and U.S.A. technicians coupled with the efforts of local Iraqi Foundation experts. Our approach included collaboration with local experts to identify and assist in solving key water‐ and environment‐related problems.

Select this Article		Macro‐ and Micro‐Scale Circulation Modeling in the Mesopotamian Marshlands of Southern Iraq Andrea Cattarossi, M.ASCE, Douglas Hamilton, P.E., M.ASCE, Parmeshwar L. Shrestha, Ph.D., P.E., M.ASCE, and Paolo Polo, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)3 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This study focuses first on the macro‐scale modeling of marsh hydrodynamics. Simulation results have provided a preliminary look at overall circulation patterns arising from inflows/outflows to the system. Our analysis benefited from access to reasonably detailed topographic maps and exceptional satellite imaging products. This enabled us to include in our model most of the hydraulic structures that are responsible for causing the desiccation of the marshes. The model also provided the means to assess the effects of hypothetical water releases into the marshlands. The results of the macro‐scale circulation model are now used to develop micro‐scale models for pilot projects at a more detailed level. The objective is to examine the interaction of marsh conditions (e.g., bathymetric features, vegetation, etc.) and hydrodynamic forcing (freshwater inflows, meteorology, salinity and temperature gradients, the presence of hydraulic structures, etc.). With the aid of newly acquired, highly accurate topographic data, the micro‐scale analysis are providing insights on circulation patterns and velocity distributions and are applied to evaluate alternative restoration scenarios and to plan/design constructed wetlands to meet water treatment needs for villages in the region.

Select this Article		Desertification of Northeast Tibetan Plateau Grassland and Its Significance Qingwei Sun, Xian Xue, and Tao Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)4 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Tibetan Plateau plays an important role in past and present global climate; its modern environment change is both locally and worldwide significantly. In this article, we analyse the reason and consequences of the rapidly developing of desertification of Northeast Plateau grassland. It is found that the reason of desertification lies in the rapid growing population and under‐developed economy; the affect of local human factors may be magnified through the desertification process and air circulation; through the surface albedo change and increased dust emission, this local environmental change may affect East Asia, the north hemisphere or even the global climate.

Select this Article		Decadal‐Scale Precipitation Variations in Arid and Semi‐Arid Zones of Northern China during the Last 500 Years Tao Wang, Bao Yang, Achim Braeuning, and Dunsheng Xia ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)5 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Regional decadal precipitation reconstructions for the arid and semi‐arid zones of northwestern China were established by the use of different palaeoclimate archives such as ice‐cores, tree‐rings, lake sediments and written historical documents. Local rainfall reconstructions from single sites were averaged to obtain regional precipitation records for a western and eastern region of an arid and semiarid zone of northern China, respectively. All established regional precipitation curves display 5 dry periods, each lasting about 50 years. Meanwhile, precipitation reconstructions show regional dissimilarities. During the last 500 years, the trends of precipitation change in the eastern arid region are basically consistent with those in the western and eastern regions of the semiarid zone. Precipitation variations in the western arid region are unique, showing significant local patterns of rainfall variability. Maximum entropy method (MEM) spectral estimates show that each regional precipitation series contains stationary century‐scale periodicities of about 120a. Singular spectrum analysis was applied to isolate the century‐scale oscillation signals from the regional proxy precipitation series. Significant periods with wavelengths of 121.4a, 154.6a, 124.3a, 118.6a, 108.5a and 121.4a were found that explain 26.56%, 26.44%, 28.87%, 18.67%, 33.48% and 34.04% of the variances of the original series for the western arid zone, the eastern arid zone, the whole arid zone, the western semiarid zone, the eastern semiarid zone and for whole northern China, respectively.

Select this Article		Developmental Characteristics of Aeolian Sand Geomorphology and Their Environmental Changes in the Adjoining Region of Puruogangri Ice Sheet, North Tibet Plateau Weimin Zhang, Tao Wang, Xiaozhe Li, and Bao Yang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)6 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Large areas of moraine sediments and cryogenic weathering products, formed by glacial action and a cold environment, are the main source of aeolian sand in the high and cold region of the Qinghai‐Tibet Plateau in China. The evolution of aeolian sand geomorphology was closely related to the environmental conditions. Owing to freezen dune surface, the evolution of sand dunes was dominated by expanding dune bases and vertical accretion, and thereby forming huge barchan dunes. The migration rate of huge barchan dunes was very slow at an average rate of 1.8–0.5cm.a⁻¹, and their vertical accretion rate was 0.3–0.08cm.a⁻¹. The temperature mainly controls the environmental changes in the adjoining region of Puruogangri ice sheet. The dating of humus layers in studied sand dune was 10780±130, 9549±130, 8320±110, 7450±100, 5970±95, 5330±90, 4420±80, 3460±80, 2440±80, 2280±70, 1820±70, 980±70 aBP respectively. Viewed from the region's thermal mainly coming from the latent thermal of the summer monsoon, the changes of the Southwest monsoon intensity might be an important leading factor. As long as both water and thermal conditions are suitable, the plants will grow well, and sand dunes (land) will be in a stabilization state and form humus layers. Otherwise, sand dunes are bare and cause the re‐activation of stabilized sand dunes.

Select this Article		Measurements of Dust Deposition in Arid and Semi‐Arid Regions, China Wanquan Ta and Tao Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)7 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Dust samples collected monthly for 15 years from 50 sites in 10 urban cities in Gansu Province, China, provide information on modern rates of dust deposition in the desert/Gobi and loess areas. The dust deposition is highest during spring months and lowest during autumn months, in both the desert/Gobi and loess areas. There is a significant positive correlation between dust deposition and dust event, and an inverse correlation between dust deposition and precipitation. The 15‐year mean maxima in the desert/Gobi area and loess area are 498.64 and 327.02 t km⁻²yr⁻¹, respectively, and the mean minima 290.22 and 180.86 t km⁻² yr⁻¹, respectively. Drought may have a widespread, major influence on the modern rates of the dust deposition in the desert/Gobi and loess areas in Gansu Province, China.

Select this Article		Desertification in Sunite Steppe of Inner Mongolia, China Xian Xue, Qingwei Sun, Tao Wang, Guangting Chen, and Jianmin Feng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)8 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Results from remote sensing and field survey show that desertification of Sunite Steppe increased rapidly since the 1980s' and 26 percent of the 6092533 hectare grassland has become desertification land, of which there are 1073600 hectare slight desertification land, 311900 hectare moderate desertification land, 122700 hectare severe desertification land and 54700 hectare very severe desertification land. Three types of desertification land exist here: coarse gravel surface resulting from wind erosion, shrub‐coppice dunes and sand sheets from sand deposit, and fixed dunes reactivation. It is found that the cause of desertification in Sunite Steppe lies in the non‐equilibrium between changeful natural environments and human activities. In the arid and semi arid human‐nature ecological system, there exists some kind of hysteresis that people adjust actions themselves with the change of environment factors. That should be why desertification develops rapidly today in a flourish steppe at one time.

Select this Article		Uncertainty in Low‐Flow Data from Three Streamflow‐Gaging Stations on the Upper Verde River, Arizona D. W. Anning ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)9 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Decreases in streamflow, particularly in the lower flow regime in perennial streams, are a significant concern to water‐resource planners, especially in the Southwestern United States, where perennial streams are relatively few in number but provide valuable water supply, wildlife habitat, and recreational opportunities. Rapid population growth and the ensuing ground‐water development have created the potential for a decrease in low flows in the upper Verde River Basin, Arizona. As a result, the performance of three U.S. Geological Survey streamflow‐gaging stations at meeting low‐flow monitoring objectives was evaluated on the basis of uncertainty in the streamflow data. In downstream order, the stations are Verde River near Paulden, Verde River near Clarkdale, and Verde River near Camp Verde.

Select this Article		Estimating Stage Discharge Uncertainty for Flood Damage Assessment Iftekhar Ahmed and Gary E. Freeman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)10 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A flood damage assessment study was recently completed for the proposed North Levee at the confluence of Salt and Gila Rivers in Phoenix, Arizona under the U.S. Army Corps of Engineers' (Corps) Tres Rios environmental restoration project. This paper presents the methodology applied to estimate stage discharge uncertainty and levee freeboard under regulated flows. U.S. Army Corps of Engineers' Flood Damage Reduction Analysis software HEC‐FDA was used to obtain necessary freeboard for the proposed levee at a minimum 95% level, i.e., a non‐exceedance probability of 0.95, for levee overtopping. The knowledge of high discharges (> 100 year) was important for setting the levee heights. A rating curve was generated in HEC‐RAS using peak discharges of up to 500‐year return period, and stage uncertainties were computed per Corps of Engineers' Engineering Manual EM 1110‐2‐1619 at several locations along the study reach based on the 100‐year water surface elevations. Model uncertainty was computed based on Manning's n sensitivity analysis using HEC‐RAS. As a second step in the levee freeboard determination, graphical exceedance probability functions were introduced in HEC‐FDA. The levee freeboard was then calculated to be sufficient to maintain the minimum 95% reliability for the 100‐year event along the Salt‐Gila river being protected.

Select this Article		Hazard Zone Delineation for Urbanized Alluvial Fans R. García, J. J. Rodríguez, and J. S. O'Brien, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)11 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A method is proposed to delineate hazard maps for flooding and mud and debris flow events, based on the application of a two‐dimensional flood routing model FLO‐2D. The method defines hazard levels based on flood event frequency and intensity. The FLO‐2D model has been enhanced with pre‐ and post‐processor programs to automate data input and to generate hazard maps in ArcView GIS format. The proposed methodology was tested in twenty three sites in the Caracas and Vargas State region in Venezuela. This paper describes one application of the proposed method to the community of Tanaguarena on the Cerro Grande alluvial fan. The model results compare very well to the maximum flow depths and area of inundation observed during the December 1999 Vargas debris flow disaster. The hazard maps for the region are being used by local agencies to develop emergency plans and new land use policies. The methodology is being expanded to other flood hazard regions in Latin America.

Select this Article		Autorun Persistence of the Great Salt Lake Water Level Fluctuations Abdüsselam Altunkaynak and Mehmet Özger ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)12 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Planning, design, construction and operation of lakeshore structures require information about the future likely extremes of the lake levels at a given risk percentage. The estimation of average return periods of hydrological events and the corresponding risks of failure of hydraulic structures that are associated with such events are important aspects in many water resources studies. Small changes in the elevation of the lake surfaces can lead to enormous changes in the amount of land surface lost when the lake level rises or exposed when lake level falls. Persistence is the most important property in any hydrologic design concerning the storage capacity of reservoirs, average return periods, failure risks, drought properties. Its consideration in analytical derivations of design criteria presents difficulties and for this reason most often the analytical expressions are obtained on the basis of non‐persistent (independent) hydrological processes. Both return period and risk of failure can be easily calculated assuming the lake levels are independent. But it is well known that persistence is more important for lake level fluctuations. By using autorun function which is probability distribution free and robust parameter, return period and risk is determined. The application of the methodology is presented for the Great Salt Lake monthly water level data in western US.

Select this Article		Contrasting the Impact of the Natural Hydrologic Cycles and Legacy Highway Construction on Farmington Bay Wetlands of the Great Salt Lake Robb Edgar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)13 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Great Salt Lake wetlands are one of the most important inland wetlands in the United States. The playa lake topography of the Great Salt Lake basin and the climatic affects on the inflow and evaporation rates produce large fluctuations in the water surface elevations. These fluctuations produce cycles of destruction and regeneration of the adjoining wetlands that may have long term benefits to the overall diversity of the wetland habitats, especially for water birds. The limited land available in Davis County and subsequent development may impact the wetlands around Farmington Bay and have created some controversy over the proposed construction of a highway (Legacy Parkway) through the wetlands. The impact of the Legacy Parkway was assessed by analyzing the affects the highway may have on the wetlands with regards to the fluctuating lake and diversion of the water sources to the wetlands. The results indicate that the highway will not act as a dike since the drainage design of the Legacy Parkway requires that the inflow from the existing streams and channels from a 100‐year storm be conveyed under the roadway. This allows large flows in both directions. The water source for most of the wetlands in the area of the highway is groundwater. The legacy Parkway project will destroy 46 hectares (114 acres) of wetlands within the highway footprint and may have an adverse affect on the adjoining wetlands if the existing hydrologic conditions are not maintained with their hydraulic design. The major problems affecting the wetlands are water quality (pollution from surface water discharged into the bay), effluent from water treatment plants, unnatural vegetation and invasive species and hydrological modification.

Select this Article		Use of Remotely Sensed Data to Estimate the Flow of Water to a Playa Lake C. Dettling, R. H. French, J. J. Miller, and J. R. Carr ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)14 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The presence of water on Rosamond Dry Lake presents potential operational hazards and environmental issues for Edwards Air Force Base (EAFB). This research tests the utility of threshold precipitation in predicting inundation of Rosamond Lake, which is located within the boundaries of EAFB. Climatic data from the Western Regional Climate Center and remotely sensed data from the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratories were used to determine the correlation between winter precipitation events and surface water inundation of Rosamond Lake.

Select this Article		Model Performance Evaluation of Distributed Hydrological Modeling for Semi‐Arid Regions Irina Tcherednichenko, Luis A. Bastidas, and Kevin Lansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)15 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A performance evaluation of flow predictions from four semi‐arid watersheds in Arizona is presented and analyzed. The watersheds vary in size from 30 to 800 sq mi and belong to different climatic divisions with mean annual precipitation ranging from 9 to 19 inches. Daily streamflows were computed by the semi‐distributed USGS Modular Modeling System (MMS) that uses a conceptual bucket type model to represent the local water balance. GIS tools have been used to characterize all the watersheds in a similar and consistent manner using the same predefined criteria. Simulations have been carried out in continuous mode using a daily time step (daily mode).

Select this Article		An Approach to Estimating the Frequency of Playa Lake Flooding C. Dettling, R. H. French, J. J. Miller, and J. R. Carr ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)16 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The presence of water on Rosamond Dry Lake presents potential operational hazards and environmental issues for Edwards Air Force Base (EAFB). This research tests the utility of threshold precipitation in predicting inundation of Rosamond Lake, which is located within the boundaries of EAFB. Climatic data from the Western Regional Climate Center and remotely sensed data from the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratories were used to determine the correlation between winter precipitation events and surface water inundation of Rosamond Lake. The Poisson probability distribution was then used to estimate the probability of a specified number of precipitation events exceeding the threshold precipitation for the Rosamond Lake watershed in any given year. The Chi‐square test for goodness of fit was used to assess whether or not precipitation can be represented by the Poisson distribution. The statistical methods were used in concert with remotely sensed data to provide insight into the validity of the approach.

Select this Article		Real Time Rainfall‐Runoff Modeling on Alluvial Fans, Floodplains and Watersheds Jimmy S. O'Brien, M.ASCE, P.E. and Bing Zhao, M.ASCE, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)17 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Real time rainfall runoff modeling is rapidly advancing and soon will be the framework of a predictive early flood warning system. The Flood Control District of Maricopa County has supported the development of spatially and temporally variable rainfall simulation in the FLO‐2D model. FLO‐2D is a two‐dimensional flood routing model that can simulate rainfall‐runoff. Initially, FLO‐2D was designed to simulate uniform rainfall on a finite difference grid system of a watershed or floodplain. The model system has been expanded to interpolate ASCII grid file rain data (such as NEXRAD rain data or the Maricopa County rain gage data) to incorporate spatially and temporally variable rainfall data. FLO‐2D can also simulate a moving storm system. The variable rainfall‐runoff can be simulated with multiple inflow flood hydrographs routed over urbanized alluvial fans and floodplains. Spatially variable rainfall losses are computed with the Green‐Ampt model. The assignment of the Green‐Ampt parameters are automatically generated by a processor program. Simulating spatially and temporally variable rainfall enables monitored rain storms to be replicated, design storms to be predicted, or real time network rain gages data to be simulated as a projected flood event. The new rainfall components in the FLO‐2D flood routing model set the stage for integration for a predictive early flood warning system.

Select this Article		Climate Regionalizing for the Assessment of ENSO, NAO and SST Effect on Regional Meteorological Drought: Application of Fuzzy Clustering Mohammad Karamouz, F.ASCE, Shahab Araghinejad, and Amin Koorehpazan Dezfuli ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)18 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The effect of teleconnection climate signals on climate variability of different regions in the world has been the focus of interests of many investigations since early 90s. The feasibility of long‐term climate prediction through understating of how climate signals may affect the regional rainfall, have made these studies important for strategic watershed management. This study is consisted of a regional assessment of rainfall and the long‐term variation of climate in the southwestern part of Iran. In this region, there are considerable water resources in major rivers of Karoon, Dez and Karkheh. The climate regionalizing of the study area is done based on the long‐term variations of observed rainfall during dry spells at each station over the region. Drought characteristics such as duration and severity are considered as the main criteria in the regionalizing process. Fuzzy clustering by equivalence relation method is used to cluster 23 stations over the region. The clusters show the regions with similar pattern of drought events. The relation between extreme events of North Atlantic Oscillation (NAO) and El‐Nino Southern Oscillation (ENSO) and the seasonal rainfall at each station is assessed. This analysis is also done for the Sea Surface Temperature of Persian Gulf (PG‐SST) as an indicator of rainfall in the southwestern part of Iran. The method of Fuzzy clustering is also used for this purpose. This method provides three regional maps, each showing the regions with similar behavior during the extreme events of ENSO, NAO, and PG‐SST. Then clusters of similar signal‐affected stations are compared with the clusters of similar‐drought pattern. The similarity between these two kinds of clusters shows that drought pattern in which stations is affected by climate signals. The results show that the global circulation patterns such as ENSO, NAO, and PG‐SST could be indicators of meteorological drought in the study area.

Select this Article		Climate Change and Its Effects on California Water Resources Katherine Hancock, Chih‐Fang Chung, and William Mills ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)19 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract California is one of our nation's largest states, stretching from the arid and hot south at the Mexican border to the cooler and wetter state of Oregon (Figure 1). With a population of 34 million people, it is the most populous of any state in the Union. Its trillion‐dollar economy (the nation's largest) would rank it as the fifth largest economy of any nation on earth. Within the continental United States, Mt. Whitney (4418 meters (m) above mean sea level) is the highest mountain, and Death Valley (86 m below mean sea level) is the lowest point. Most of the water supply in the state comes from snow and rain that fall on the Northern coastal area and high mountains, particularly the Sierra Nevada. The statewide average precipitation is approximately 0.08 m per year (20 inches per year). Much of the runoff is conveyed by canals and pipelines to the more populated southern part of the state and to irrigate agricultural areas in the Central Valley. One of the earlier conveyance systems was built over 85 years ago to bring Owens Valley water to Los Angeles. Because of the diversity of ecosystems in California, the generally semi‐arid climate over much of the state, and the large and growing population (17 million people are expected to be added by 2030 to the 34 million people currently in California), California's water resources are particularly vulnerable to climate change. In this paper, an overview of the current and projected status of California's water resources is provided. Completed, ongoing, and anticipated work on climate change activities within the state are summarized. Then, the impact of projected climate change on water resources is discussed, along with potential adaptation strategies.

Select this Article		Linkages between Large‐Scale Climatic Variations and Seasonal Variations of Precipitation in the Colorado River Basin T.‐W. Kim, J. B. Valdés, B. Nijssen, D. Roncayolo, and K. K. Hirschboeck ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)20 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This study analyzes the influence of large‐scale climate patterns on precipitation variability in the Colorado River Basin. Large‐scale climate patterns, like ENSO and PDO, are associated with regional hydrologic variations. In order to link large‐scale climatic variations to the variations of precipitation in the basin, a conceptual influence index is developed, and its spatial variability in the basin is examined. Various possible combinations of teleconnections are examined using the conceptual climate phase representing extraordinary climatic fluctuation to investigate their influences on seasonal precipitation variations in the basin.

Select this Article		Forecasting of Lower Colorado River Basin Streamflow Using Pacific Ocean Sea Surface Temperatures and ENSO Glenn A. Tootle and Thomas C. Piechota ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)21 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The lower Colorado River basin is located in an area of known El Niño‐Southern Oscillation (ENSO) influence. A streamflow forecast is developed using Pacific Ocean Sea Surface Temperatures (SSTs) as predictors in addition to a traditional ENSO predictor, such as the Southern Oscillation Index (SOI). Significant regions of SST influence on streamflow were determined using linear correlations (LC). These significant SST regions are then used as predictors in a statistically based exceedance probability model previously applied to streamflow stations in Australia and the U.S. Long lead‐time (3 and 6 month) streamflow forecasts were developed for El Niño, La Niña and non‐ENSO years for the winter‐spring (January‐February‐March — JFM) season. The use of the SSTs resulted in improved forecasts, based on cross‐validated skill scores, when compared to forecasts using the SOI. Additionally, forecast lead‐times were increased when using the SSTs as predictors due to the inability of the SOI to provide an acceptable forecast. Also, the use of SSTs provided an improved forecast for all lead times for non‐ENSO seasons when compared to the SOI forecasts. Following the methodology presented, water resource planners in ENSO influenced areas are provided a useful tool for forecasting streamflow.

Select this Article		Physical Habitat and Sediment in the Lower Virgin River Robert T. Milhous ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)22 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Virgin River in southwestern Utah and adjacent Arizona and Nevada is habitat for a number of endangered and threatened species of fish. The river also has significant loads of sediment that change the characteristic of the stream channel with time. The Virgin River transports large quantities of sand. Some sections of the river store the sand in the stream bed following a high stream flow event; the sediment is then removed by lower streamflows that can cause a wave of sand to pass through river channels in other sections of the river. The Hurricane Bridge on the Virgin River had a sand wave that passed through the channel during a low flow event that followed a high flow event. This paper demonstrates that antecedent conditions are important in the analysis of physical habitat in sand‐bed rivers because the relation between the streamflows and habitat will change depending on these antecedent conditions.

Select this Article		Salt Balance in the Rio Grande Project from San Marcial, New Mexico to Fort Quitman, Texas Jerry H. Williams, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)23 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Using historical data, the purpose of this study was to determine the occurrence and distribution both temporally and spatially of salt in the Rio Grande within the Rio Grande Project (RGP) in New Mexico and west Texas. The concentration in the river of total dissolved solids (TDS), major ions, and flow were analyzed generally on a monthly time step for river metering stations at San Marcial, below Elephant Butte Dam, below Caballo Dam, at Leasburg Dam, and below Mesilla Dam (all in New Mexico), and at El Paso and Fort Quitman, Texas. In addition, time series models have been constructed that may assist in better understanding the behavior of the system and also be used for forecasting purposes.

Select this Article		Phosphorus Loading in Furrow Irrigation Tailwater A. J. Clemmens, D. T. Westermann, T. S. Strelkoff, and D. L. Bjorneberg ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)24 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Phosphorus (P) transport to streams from furrow irrigation tailwater is a significant water quality issue in the Pacific Northwest. Under this NRI funded research project, we have collected field data to document phosphorus loads that occur under furrow irrigation conditions in Kimberly, Idaho. Since the majority of phosphorus transported off the field is associated with eroded sediments, we have developed an erosion detachment, transport and deposition component for the surface irrigation model SRFR. This model has the ability to track particle‐size distributions in the furrow flow. A modification to the Laursen transport formula was required for small particle (silt and clay) sizes. Laboratory batch studies were conducted to determine the amount of phosphorus released when soil is entrained in water, as occurs under furrow erosion. There appear to be influences from both sediment:water mass ratios and P concentration in the water, as well as soil P indices. Flume studies were conducted to determine the amount of phosphorus released from the soil surface under non‐erosive conditions. Preliminary results suggest that soil P release is influenced by the flow regime (turbulent or laminar) at the interface between the soil and the water in the furrow. Turbulent flow results in more P released, and potentially desorbed and diffused from deeper soil layers. A phosphorus transport component is being added to SRFR to model the transport of P with eroded soil and the desorption of P into the irrigation water from both the eroded soil and the soil surface. Several new modeling approaches are being explored. This paper presents a status report on this modeling ‐ field verification effort on P transport from furrow‐irrigated fields.

Select this Article		Bird Use of Habitat Created by Irrigation and Drainage Practices in the Delta, Utah Area A. W. Peralta and W. R. Walker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)25 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Irrigation impoundments, canals, drainage ditches, irrigated fields, and the incidental wetlands created by irrigation and drainage, provide valuable habitat for birds in and around Delta, Utah. Documentation of the creation of these areas and observations of bird use from 1995–2004 during migration, breeding, and wintering are reported. 147 species of birds were observed using incidentally created habitat sites.

Select this Article		Optimization of Water Resources for the Salt Lake Valley Charles H. Call, Jr., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)26 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Salt Lake Valley (Valley) is the largest metropolitan area in Utah and is located along the front of the Wasatch mountain range. Wholesale domestic water supply is provided to the Valley by two main agencies, namely, Metropolitan Water District of Salt Lake City and Sandy (Metro) and Jordan Valley Water Conservancy District (Jordan Valley). Rapid growth and drought conditions have placed pressure on water supply and delivery. The cost of meeting the annual water supply demand of all agencies was analyzed to minimize the total cost.

Select this Article		Cache Valley: Optimizing Sustainable Water Use and Ecosystems while Considering Water Rights Rudolf Das, Richard Peralta, and Bassel Timani ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)27 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Population and urban water need increases in the Utah portion of Cache Valley is forcing restrictions on groundwater use. We compute maximum sustained yield pumping strategies for two management scenario groups, differing in constraints. We apply constraints to prevent unacceptable heads, spring flows, and river‐aquifer seepage (RAS). Scenarios differ in the limits imposed on head and/or pumping. Goals are to provide water for 18 municipalities using one new well for each. Computed maximum sustainable pumping can be as much as 38% greater than 1990 pumping, depending on applied bounds. However, imposing projected 2020 water needs as upper bound on pumping reduced the maximum total pumping rates. Optimal pumping is most sensitive to RAS restrictions. Significantly constraining RAS to the river significantly reduces the amount of sustainable pumping increase.

Select this Article		Evaluating Effects of Water Rights Diversions in Coastal California Streams over Spatial and Temporal Scales Matthew J. Deitch and G. Mathias Kondolf ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)28 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract While much of the western United States may be considered arid, some regions receive more water annually than most agricultural zones in the rest of the US. The problem inherent to agriculture in a region such as California's north‐central coast is that the timing of water availability is opposite that of need: roughly 45 inches of rain falls in the Russian River watershed, but all between November and March. Vintners (representing the most common form of agriculture in the region) therefore must meet water needs by obtaining it from supplies available during summer growing months, principally groundwater, surface streams, and artificial impoundments. Diversion of flow from small streams may conflict with flow needed by federally protected salmonids for spawning and rearing habitat. Historical stream flow data and water rights records highlight the disparity between stream flow and water needs: streams varying in size may dry at different points after the rainy season, but the demand for water from these streams continues throughout the summer. The difference between water demanded from small streams and the amount of water they can provide may be the primary hurdle to restoring coastal river fisheries.

Select this Article		Salt Lake City—Watershed Management Plan LeRoy W. Hooton, Jr., Thomas Ward, M.ASCE, and Charles H. Call, Jr., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)29 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract “Keep it pure” is the slogan for the Salt Lake City watershed protection program. The City has put effort into protecting the water quality of the watersheds east of the valley that provide much the potable water used in the developed areas along the Wasatch Front. This paper describes the history of watershed management over the past 150 years.

Select this Article		Texas Statewide Water Planning: The Regional Water Planning Concept T. C. Gooch, S. W. Griffin, and W. F. Mullican, III ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)30 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Texas began statewide water planning in response to the devastating effects of the drought that ended in the 1950s. The 1950s drought prompted the Texas Legislature to create the Texas Water Development Board (TWDB) for the purpose of implementing statewide water planning. Since its inception, the TWDB has produced seven statewide water plans — in 1961, 1968, 1984, 1990, 1992, 1997, and 2002. In the mid 1990s, the State of Texas endured a significant drought, with some areas entering a new drought of record. In 1997, the 75^th Texas Legislature responded to concerns about the adequacy of water supplies by passing Senate Bill 1 (SB1) to provide for a new approach to water supply planning in Texas. In the past, the State planners had been responsible for determining what strategies and projects each region or city should implement to meet future water supply needs. SB1 is a radically different approach to statewide water planning, setting forth a grass‐roots regional water planning process that calls for local representatives to develop strategies to meet water supply needs over a 50 year time period. SB1 emphasizes public participation in the planning process.

Select this Article		Well Spacing and Its Impacts on Surface Water Flow in El Paso Lower Valley Z. Sheng, L. S. Aristizabal, and Y. Wanyan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)31 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, the authors use an analytical model, GFLOW 2000, to simulate groundwater flow under different pumping conditions, with special emphasis on the analyses of well spacing and their proximity to canals and drains, and the effects of pumping on surface water flow. In the first pumping scenario, new wells and some of the existing wells were included in the model under pumping stresses of the year 2003. Additional simulations with different pumping stresses and different well spacing were then assumed to evaluate impacts of alternate pumping scenarios. Preliminary results indicate that wells located closer to canals and drains have strong impacts on surface water flow, whereas wells further away from the canals and drains have lesser impacts on surface water flow. When wells in close proximity to canals and laterals are pumped, seepage from unlined canals and laterals is significantly increased and some of drains can also dry up.

Select this Article		Erosion and Overbank Deposition: Effects on Mercury Transport in Thecarson River, Nevada R. W. H. Carroll, J. J. Warwick, A. I. James, and J. R. Miller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)32 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Work in progress is presented as part of an on‐going investigation of mercury transport in the Carson River in west‐central Nevada. The Carson River is one of the most mercury contaminated fluvial systems in North America. Most of its mercury is affiliated with channel bank material and floodplain deposits, with the movement of mercury through this system being highly dependent on sediment transport processes. In January 1997 a rare, high‐magnitude flood generated significant geomorphic change to the system and transported large quantities of mercury. Calibrated bank erosion functions developed for the US EPA water quality model (WASP5), suggest that bank erosion is significantly greater at flows above bankfull discharge when compared to flows confined to the main channel with a single major flood event transporting nearly 87% of the total mass eroded during the period from 1991–1997 (Carroll et al., submitted). Preliminary mercury transport results for the 1997 flood are encouraging as it over predicts the observed value by less than 20%. However, mercury is under predicted following the flood as flows recede back into the channel and highlights the need to revisit Hg transport at moderately high flows.

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BEST MANAGEMENT PRACTICES TECHNOLOGY

Select this Article		Why Is It so Difficult to Acquire Reliable BMP Performance Data? Jonathan E. Jones, P.E., Thomas Langan, Elizabeth A. Fassman, Ph.D., Ben Urbonas, P.E., Eric Strecker, P.E., and Marcus Quigley, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)33 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of this paper is to answer the question of why it is so difficult to obtain reliable performance data for urban stormwater best management practices (BMPs) such as retention/detention ponds, wetlands, swales, infiltration devices, proprietary devices, and others. Our assessment of this question is based on extensive experience developing, implementing, and conducting stormwater monitoring programs, as well as development and oversight of the U.S. Environmental Protection Agency (USEPA)/American Society of Civil Engineers (ASCE) National Stormwater BMP Performance Database, on behalf of ASCE's Urban Water Resources Research Council. The paper begins with a list of factors that contribute to the difficulty of BMP monitoring, and concludes with a review of representative problems that we have experienced when reviewing BMP performance data sets that have been submitted to the National BMP Performance Database Clearinghouse for integration into the database.

Select this Article		Analyses of the Expanded EPA/ASCE International BMP Database and Potential Implications for BMP Design Eric W. Strecker, P.E., Marcus M. Quigley, P.E., Ben Urbonas, P.E., and Jonathan Jones, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)34 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The US EPA/ASCE National Stormwater BMP Database has grown significantly since the first evaluation of BMP performance data in the database was completed in 2000. The project team has conducted a limited re‐evaluation of the data contained in the database to assess the overall performance of BMPs as well as compare BMP design attributes to performance. The evaluations have included the assessment of various BMP types as categorized in the database with regards to their ability to reduce runoff volumes as well as the effluent quality they can achieve. It is apparent that certain BMP types can reduce the volumes of runoff through soil soaking and resulting evapotranspiration and/or infiltration as opposed to BMPs that are more “sealed,” such as wet ponds, wetlands, vaults and hydrodynamic devices. Runoff reductions contribute to pollutant loadings reductions as does improved effluent quality. On average, dry detention basins were found to reduce runoff volumes by an average of 30 percent (comparison of inflow to outflow), while biofilters reduced volumes by almost 40 percent. As expected, wet ponds, wetlands, hydrodynamic devices, and retention ponds show little or no runoff volume reductions. BMP types vary with regards to effluent quality that is achieved. BMPs such as wet ponds and wetlands appear to achieve lower concentrations in effluent quality than other BMPs such as detention ponds (dry) and hydrodynamic devices for some parameters. These differences vary with pollutant type. Finally, analyses of BMP design vs. performance are beginning to result in statistically valid results. For example, a relationship (ratio) between the treatment volume of retention ponds (wet ponds) vs. the average size measured storm event volume monitored has been established, showing that those with a ratio of 1 or more have been observed to achieve better effluent quality. Based upon these findings, this paper discusses potential BMP selection, design, and BMP design standards implications. A set of potential recommendations for how communities develop and specify BMP requirements such that more local goals for improved water quality is discussed.

Select this Article		Modeling Concepts for BMP/LID Simulation Wayne C. Huber, Fu‐hsiung Lai, LaMarr Clannon, and Matt Stouder ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)35 \| Cited 1 time Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Enhancement of simulation options for stormwater best management practices (BMPs) and hydrologic source control is discussed in the context of the EPA Storm Water Management Model (SWMM). Options for improvement of various BMP representations are presented with emphasis on incorporation of fundamental unit processes from environmental engineering into the algorithms.

Select this Article		Hydrologic Characteristics Simulation for BMP Performance Evaluation Angela Brown and Wayne C. Huber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)36 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract So‐called “best management practice” (BMP) performance for urban runoff control may be characterized on the basis of BMP effectiveness for control of both hydrologic and water quality impacts of stormwater and urban dry‐weather flows. This paper deals with hydrologic impacts through the use of continuous simulation with the Storm Water Management Model (SWMM), in order to evaluate volume‐based and flow rate‐based controls. Case studies at sites in Greenville, NC and Austin, TX were used to demonstrate the methodology.

Select this Article		Modeling Effectiveness of Bioretention Cells for Control of Stormwater Quantity and Quality R. D. Christianson, B. J. Barfield, J. C. Hayes, K. Gasem, and G. O. Brown ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)37 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Bioretention is the process of using biological processes and rapid infiltration along with the storage of water to reduce contaminants. A bioretention cell creates an aesthetically pleasing water treatment area to help meet the National Pollutant Discharge Elimination System (NPDES) pollutant standards in, for example, the petroleum producing, refining, and distribution industry, parking lots of shopping centers, and residential homes. Pollutants that may be impacted consist of petroleum products (BTEX, cyclohexane, paraffins, and olefins), metals (cadmium, copper, lead, zinc), and nutrients (nitrogen and phosphorus). Currently there are no design models for bioretention cells that combine the removal of nutrients with infiltration, sorption of metals, and degradation of organic compounds. The model to be discussed will account for these constituents, as well as take into account specific site characteristics like climatic location, area drained, bioretention cell properties, and various loads of pollutants entering. The resulting output from the model would include the dimensions of an infiltration layer, an organic layer, and an anoxic layer, pollutant levels after moving through the cell with associated trapping efficiency, and water quantity leaving the cell. Results of preliminary column tests performed in the laboratory will determine the infiltration and sorption properties of various organic materials.

Select this Article		The Villanova Bio‐Infiltration Traffic Island: Project Overview Clay Emerson and Robert G. Traver ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)38 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Villanova Bio‐Infiltration Traffic Island is part of the Villanova Urban Stormwater Partnership Best Management Demonstration Park. The site has been in operation for three years. It was designed to capture the first inch of runoff from the 50,000 ft² watershed. The Traffic Island is the subject of a continuous monitoring project. The site is fully instrumented to monitor water quantity and has recently been modified to collect water quality data. Ongoing research has shown that the site infiltrates 69% of the annual runoff produced in its 52% impervious watershed. Data from the site will be used to support the implementation of similar innovative urban stormwater management practices.

Select this Article		Assessing TMDL's and Management of Phosphorous Pollution Using Data and Model for the Cannonsville Watershed, NY Christine Shoemaker and Bryan Tolson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)39 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This talk will discuss methodology for data analysis, modeling, and phosphorous management analysis in complex watersheds and describes the application of this methodology to the assessment of best management practices for phosphorous in the 1200 km² Cannonsville Watershed, which is a catchment for one of the City of New York's drinking water reservoirs. Our group has used the model SWAT2000 to model hydrology, sediment, and Phosphorous movement over the watershed. Calibration and independent validation results obtained were excellent given the difficult of measuring and modeling these constituents. Current results indicate Phosphorous loadings will increase substantially in the future, even if economic activities and phosphorous management program do not change. We evaluate practices for reducing the loading of phosphorous including source control methods like precision feeding. We discuss the importance of incorporating soil storage of phosphorous in analysis of phosphorous BMPs.

Select this Article		Design of a Decision Support System for Selection and Placement of BMPs in Urban Watersheds John Riverson, Jenny Zhen, Leslie Shoemaker, and Fu‐hsiung Lai ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)40 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Environmental Protection Agency (USEPA) has funded the development of a decision support system for selection and placement of best management practices (BMPs) at strategic locations in urban watersheds. The primary objective of the system is to provide stormwater management professionals with a BMP assessment tool based on sound science and engineering that helps develop, evaluate, select and place BMP options based on cost and effectiveness. The system is called the Integrated Stormwater Management Decision Support Framework (ISMDSF) and is being designed through a systematic review of modeling needs, technical requirements, current and emerging data management technology, and available watershed and BMP models. The ISMDSF will be applied to a real urban watershed to evaluate its ability. There are four major design aspects for the ISMDSF development. First, the system provides a robust computer platform for BMP selection, sizing, and placement in the context of several integrated watershed factors and influences. Second, it is applicable to mixed land use urban watersheds, and can perform watershed simulation based on watershed size, scale, anthropogenic, and natural characteristics. Third, it incorporates hydrologic/hydraulic and water quality modeling, integrating surface runoff and direct discharges to surface water bodies, based on relevant data collection. Finally, it will have the capability to objectively evaluate multiple solution alternatives based on cost and the desired water‐quality objectives.

Select this Article		Monitoring Data on Effectiveness of Sediment Control Techniques Michael E. Barrett and Joseph F. Malina, Jr., P.E., DEE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)41 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Silt fences are among the most common BMPs implemented for sediment control at construction sites. Field evaluation of the efficiency of silt fences in removing sediment in highway construction runoff showed that sediment removal was not attributable to filtration by the fabric, but was the result of particle settling in the pool of water behind the fence. The median concentration of solids discharged from the silt fence controls was approximately 500 mg/L. This concentration is significantly lower than the 3000 mg/L of TSS often reported in construction runoff and suggests that approximately 75% of the particles in the runoff were removed by sedimentation in the water impounded bythe fences. Geotextile silt fences proved to be ineffective in reducing turbidity. The particles responsible for creating turbidity are mainly silt and clay and the particle diameter normally is much smaller than the size of the openings in the fabric. The observed data indicated that silt and clay size particles comprised 92% of the total suspended solids that reach the face of the silt fence. High sediment removal efficiencies were achieved with silt fences in flume studies. The geometry of the flume created a large ponded area behind the controls resulting in long detention times and significant particle settling even with the fine grained sediment used in the tests. Mean efficiency for sediment removal in the flume ranged from 68 to 90% and was highly correlated with the detention time. These data indicate that silt fences should be sited in the field to maximize the volume of water impounded behind the fence. Flow rates through the silt fence fabric of sediment‐laden runoff were two orders of magnitude less than those typically specified by many regulatory agencies. The flow rates of a sediment slurry through geotextile fences are a function of apparent opening size as well as permittivity (or other measures of clean water flow rates). The fabric that resulted in the longest detention times in this series of flume tests had the highest reported permittivity, but the smallest apparent opening size, suggesting that clogging of the fabric with sediment affected the hydraulic performance.

Select this Article		Retention Pond Performance: Examples from the International Stormwater BMP Database Michael E. Barrett ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)42 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper explores the factors affecting pollutant removal performance of retention (wet) ponds using data contained in the International Stormwater BMP Database. 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.

Select this Article		Detention Basin Retrofit: Optimization of Water Quality Improvement and Flood Control Keith B. Marcoon and Qizhong Guo, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)43 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Retrofitting existing stormwater facilities is of critical importance to restoring impaired watersheds. Many existing storm water detention basins were designed solely for stormwater runoff peak discharge magnitude abatement or were under‐designed for current water quality control standards. These basins can be retrofitted to trap additional amounts of non‐point source pollutants. This study analyzed a detention basin in Morris Township, NJ as an example to demonstrate the tradeoff between water quality benefits and increases in flooding problems resulting from retrofit. As part of the first retrofit, an outlet structure with a small‐diameter circular orifice at the bottom and a rectangular weir on the top was placed in front of the existing large diameter outlet pipe. Diameter of the orifice and height of the weir were varied during hydraulic routing. Quantitative relationships were obtained between the increase in stormwater detention time (pollutant removal efficiency) for a defined, small, infrequent water quality storm and the maximum increase in peak outflow rate (flooding impact) for a full range of storms. It was found that beyond a specific weir height, the detention time no longer increased whereas the maximum peak outflow rate increased greatly. The longest detention time that could be achieved was also calculated for different orifice diameters. In addition, effect of different definitions of the water quality storm on the achievable detention time was quantified.

Select this Article		The Best Management Practices of Tea Farm on High Mountain Areas Ching Gung Wen, Jan Tai Kuo, Chih Hua Chang, Chih Sheng Lee, Shui Ping Chang, Su‐Maan Chuang, and Pao Wen Liu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)44 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Due to the considerable profit made by planting tea trees on the high mountains in Taiwan, farmers fertilized their tea farms with about 600 kg of N/ha/y and 210 kg of P/ha/y to maintain a high production. However, the tea trees utilized only 5% of the fertilizer, and the remaining 95% of nitrogen and phosphorus were lost. The lost nitrogen and phosphorus caused a problem of eutrophication in the downstreams of a reservoir. The best management practices of the tea farm is to reduce 20% dosage of the fertilizer. Also, the reduction of the 20% can still ensure not to damage the good quality of the tea production.

Select this Article		Optimal Best Management Practices (BMPs) Placement Strategies—Application to Fei‐Tsui Reservoir Watershed in Taiwan J. T. Kuo, C. D. Hsieh, S. K. Chiu, and P. H. Hsieh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)45 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The nonpoint source pollution control is in the beginning stage in Taiwan. Currently, the soil and water conservation law provides regulations that the land developer should retain the exceeding stormwater runoff and sediment due to any significant development in the watershed. Most of stormwater controls have been designed at the local, or on‐site level, but not at the regional or watershed level in a comprehensive and systematic manner. The purpose of this study is to establish an optimization model for the optimal placement of structural Best Management Practices (BMPs) at the watershed scale. The complete model consists of two interacting components, i.e. an optimization model base on dynamic programming (DP) and a zero‐dimensional reservoir water quality model. To search for the optimal placement strategy of BMPs system, a preliminary procedure is needed to find suitable sites for various BMPs construction in Fei‐Tsui Reservoir watershed in northern Taiwan. The landuse type, terrain and land ownership are taken into consideration by using a geographic information system (GIS). In the optimization model, the objective function is to minimize the total construction cost of BMPs and constraints consider water quality standards for total phosphorus and suspended solid concentrations in the reservoir. Also, the zero‐dimensional reservoir water quality model of Vollenweider type is embedded in the whole optimization framework to estimate the average pollutant concentrations after pollutants from nonpoint source pollution flow into Fei‐Tsui Reservoir. Due to the advantages of DP, the most cost‐effective BMPs placement strategies can be found in this study. The trade‐off curves between the resulting optimal cost and benefit of water quality improvement can be found which provide the decision makers with clear and useful information for nonpoint pollution control and management at the watershed scale.

Select this Article		A BMP System for a Clay Mining Facility in Taiwan Jen‐Yang Lin, Shen Huang, Shi‐Huang Chen, Wen‐Chun Chen, and Shaw L. Yu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)46 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The present paper describes the planning and implementation of a best management practice (BMP) system for a clay mining facility in Northern Taiwan. The mining factory is a 32‐hectare operation located next to the Masu River, whose watershed is still relatively undeveloped except for the clay mine and some chicken and hog farms. Processed water and stormwater runoff from the mining areas have been found to cause sediment and acidity problems for the Masu River. The Water and Environment Research Center (WERC), working with Taiwan Normal University, initiated a study in 2002 on using BMPs for mitigating the impact of the clay mining operation on the Masu River water quality. The long‐term BMP plan includes the use of coral rock ditches, swales, dry and wet ponds and constructed wetlands. The first phase BMP plan called for the use of three existing ponds in series, modified to include coral rocks, wetland vegetation and swales, to form a BMP treatment train. Field sampling results show that the ponds are very efficient in removing suspended sediment (more than 90%), but not as efficient in raising the pH level in the effluent water. Further tests are continuing at the present time.

Select this Article		Best Management Practices (BMPs) for Lakes in Yunnan of China Zhen‐Ren Guo and Jining Chen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)47 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Environment protection or restoration of the endangered or polluted plateau lakes in Yunnan, China, has brought intentions of mass activities that raise a great need for best management practices (BMPs). By relating algal bloom and nutrient status in the lakes plus cost‐effective and sustainability analysis, it is recommended that phosphorous should be intentionally cut first to control algal bloom, pollutant source reduction should start from the source on water surface and ecological modules should be promoted to guarantee sustainability of environmental protection measures. Part of above strategy has been implemented and led positive results.

Select this Article		Nonpoint Pollution Control for the Xili Reservoir in Shenzhen, China X. H. Zhang, T. H. Wang, W. Q. Yuan, H. L. Duan, W. H. Zhang, and C. X. Li ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)48 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Xili reservoir is one of the major water sources for Shenzhen City, China. The reservoir has long been impacted by pollutions from a number of sources including fruit garden runoff which surrounds the reservoir and the reservoir bottom deposits. To identify the pollution source specifically, the qualities of bottom deposit and overlying waters were investigated through a year‐long period. A number of pollution sources were investigated including fruit garden, flower garden, vegetable land, fish pond, villages, express roads, river water and a long‐distance diversion channel. More than 27 thousand data were collected. It is concluded that the water qualities were mainly influenced by the bottom deposits through pollutant releasing under anoxic conditions, while the bottom deposits accumulated through deposition of nonpoint pollution sources. About 1.8 millions kg of SS were poured into the Xili reservoir through runoff. It is found that the accumulation of phosphorous in bottom deposit has been brought to control, however the accumulation of organic nitrogen is becoming even more serious. A newly finished diversion project can improve the water qualities of Xili reservoir by renewing the water every 15 days. However, it is also found that the diversion project may bring 3.8 millions kg of suspended materials a year into the Xili reservoir which will influence the Xili reservoir significantly in many aspects. Finally five control strategies are suggested to further improve the Xili reservoir.

Select this Article		To Improve the Quality of Urban Water Environment in China: Technology and Demonstration Projects Gang Yu, Jiuhui Qu, and Bing Ke ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)49 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract With the rapid economic development in the last two decades many Chinese cities are facing serious urban water pollution problems, such as uncontrolled point source and non‐point source (NPS) pollution, polluted urban lakes, rivers as well as the damaged urban aquatic ecosystems. In order to develop and demonstrate the urban water environment quality improvement technology which is suitable to most Chinese cities, the Ministry of Science and Technology of China launched a key research project, “to improve the quality of urban water environment: technology and demonstrations” in 2002. Eleven cities across the country, including Shenzhen, Guilin, Suzhou, Dalian, Wuhan, Beijing, Shanghai, Tianjin, Daqing, Zhenjiang and Zibo were selected as demonstration cities. More than twenty research institutes and universities are involved in this effort to develop technologies and processes to control NPS pollution, to treat and reuse the wastewater, to restore impacted aquatic ecosystems and others. This paper will describe the main urban water environmental problems in China and report on the research progress of the ongoing key project.

Select this Article		Trading Allowances for Stormwater Control: Hydrology and Opportunity Costs Hale W. Thurston, Michael A. Taylor, and William D. Shuster ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)50 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Excess stormwater runoff is a serious problem in a large number of urban areas, causing flooding, water pollution, groundwater recharge deficits and ecological damage to urban streams. It has been posited that to mitigate the effects of excess stormwater runoff, policy makers could use economic incentives to reward those who install detention technologies. This paper builds on research investigating the use of a tradable allowance system to promote placement of dispersed, smaller‐scale best management practices (BMP) for water detention to control excess runoff. Using continuous hydrologic modeling and cost information on BMP that include opportunity costs of land dedicated to the BMP, we investigate the outcome of scenarios that include diverse price and spatial constraints on BMP placement.

Select this Article		Land Use and Seasonal Effects on Urban Stormwater Runoff Microorganism Concentrations Ariamalar Selvakumar and Michael Borst ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)51 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Stormwater samples collected from storm sewers draining small municipal separate storm sewer systems shown to be free of cross connections within an urban watershed dominated by a single land use were analyzed for pathogens (Pseudomonas aeruginosa and Staphylococcus aureus) and indicator organisms (total coliforms, fecal coliforms, fecal streptococci, enterococci, and E. coli). The samples were collected from three land‐use designations (high‐density residential, low‐density residential, and landscaped commercial) in all four seasons. Flow‐weighted samples were collected using automatic samplers connected to flow meters. Rain gauges in the drainage basin recorded the event while the flow meter recorded flow velocity, water level, pH, dissolved oxygen, conductivity, and temperature of the runoff. The concentrations of microorganisms in the stormwater runoff were found to be similar to, but less variable than, those reported in the National Pollutant Discharge Elimination System (NPDES) database. Organism concentrations from high‐density residential areas were higher than those associated with low‐density residential and landscaped commercial areas. Concentrations of organisms were significantly affected by the season during which the samples were collected. The lowest concentrations were observed during winter. The results will help watershed managers target BMPs or treatments to land uses having higher runoff loads having greater impact on lowering the total load to a receiving water.

Select this Article		Managing Microbial Contamination in Urban Watersheds M. K. Stinson and J. M. Perdek ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)52 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point or diffuse sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction of microbial concentration is usually achieved. Diffuse sources of pathogens are commonly managed with the use of structural and nonstructural best management practices (BMPs). The primary function of BMPs is reduction of flow volume, sediment, and/or nutrients, while reduction of pathogens is a secondary function and not always quantified.

Select this Article		Life Cycle Analysis Factors for Construction Phase BMPs in Residential Subdivisions Shawn R. Loew, S.M.ASCE, Liv M. Haselbach, M.ASCE, and Michael E. Meadows, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)53 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Best management practices (BMPs) are used to mitigate the impacts of development on the environment. A life cycle analysis (LCA) is a systematic method for identifying and quantifying the effects of various factors upon BMP field efficiencies. Two life‐cycle factors for 2 different LCAs are studied. The first factor is the installation probability for designed and approved silt fences during the construction phase of individual lots in a residential subdivision. Ownership change of the lots during construction is also investigated to determine its effects on this factor. The second factor is the probability a permanent residential detention facility will receive uncontrolled sediment loads from individual lots during the construction phase. The study focused on 14 residential subdivisions from which 184 construction phase lots were field visited and the files of 330 lots were researched on land records. Designed and approved silt fencing was only installed at 27% of the field visited lots. Of the 330 records researched, 76% of the lots underwent a construction phase ownership change. In the 14 subdivisions, 47.4% of the permanent detention facilities were receiving uncontrolled sediment loads from 1 or more individual lots. Typical damages to the facilities included partial or full clogging of basin inlet and outlet structures, loss of reservoir volume, side‐wall erosion, and vegetation damage.

Select this Article		A Comparison of Best Management Practices: International, National and Regional Les K. Lampe, P.E., Dr., Howard O. Andrews, P.E., and Donald W. Baker, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)54 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Although the objectives of urban stormwater management practices are generally the same internationally, domestically within the United States (U.S.), and regionally for a given area of the U.S., the best management practices (BMPs) used to accomplish those objectives can vary substantially. The purpose of this paper is to compare and contrast those best management practices. Although the authors have reviewed literature on practices throughout the world, the primary basis for commentary on international practices has been obtained through the primary author's service as principal investigator on a project to evaluate performance and costs of BMPs and sustainable urban drainage systems in the U.S. and the United Kingdom (U.K.). This project is jointly funded by research foundations in both countries. Commentary on national practices has been derived from Black & Veatch BMP projects carried out in states throughout the country, including Oregon, California, Nevada, Arizona, Colorado, Texas, Oklahoma, Kansas, Nebraska, Iowa, Missouri, Louisiana, Illinois, Michigan, Ohio, Tennessee, Florida, North Carolina, Virginia, Maryland, New Jersey, and Massachusetts. The area of the U.S. used to demonstrate a regional perspective on BMPs in the Kansas City metropolitan area, where Black & Veatch has performed numerous watershed studies and stormwater facilities master plans, and recently prepared a regional BMP guidance manual.

Select this Article		Herding Cats: BMP Manual Development in a Bi‐State Metropolitan Region Tom Jacobs and Jeffrey Henson, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)55 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Kansas City metropolitan region includes two states, eight counties and over 100 municipalities with populations ranging from less than 1,000 to over 400,000. Each entity has its own vision, priorities, and needs. Not surprisingly, the region possesses significant variability in terms of local policies, codes and standards. The textured geographic, economic and political terrain limits the ability of communities to work together to address regional issues such as stormwater management. Despite the many hurdles, the community has developed shared resources to manage public works projects through the local chapter of American Public Works Association (APWA). The chapter was formed in 1963. In 1981, it produced a set of design criteria and specifications for storm drainage projects that were adopted by ordinance in many communities. They were updated in 1990 to incorporate lessons learned during their use in the 1980s. While these standards functioned well, evolving local priorities led the community to revisit how stormwater was being managed. As a result of severe flooding in October 1998, a strong regional consensus reframed the practice of stormwater management to address water and environmental quality, in addition to flood control and public safety. The rationale underlying the new approach includes substantial long‐term savings in the development and maintenance of public infrastructure, better protection of natural resources, and compliance with new federal water quality regulations. A regional “Water Resources Action Plan” developed in 2001 by area public works and planning directors from communities throughout the metro area called for more regional cooperation on watershed management through an institutionalized Water Resources Policy, Planning and Practices (WRP3) committee structure. A key short‐term objective of the committee was to revise local stormwater engineering standards and planning guidelines.

Select this Article		Herding More Cats: Developing Vision, Principles, and Priorities for an Integrated Stormwater Management Program M. Ali Almai, P.E. and Michael A. Ports, P.E., F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)56 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Kansas City, Missouri traces its genesis back to the year 1821, when the Missouri Territory was admitted to the Union as a state. That same year, a Frenchman named Francois Chouteau traveled up the Missouri River from St. Louis and established a trading post on the south bank of the river. Other French families gradually joined him. From the beginning, the fledging settlement suffered from flooding. In 1826, M. Chouteau rebuilt his trading post on higher ground after a large, destructive flood. 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 seventeen incorporated municipalities. By far the largest municipality is Kansas City, Missouri with a population of approximately 450,000. Spread out over approximately 320 square miles, the City now includes parts of four counties and continues to grow in both population and area as new territory is annexed. Roughly half of the City lies north of the Missouri River and half south of it. The area south of the river generally is older and much of it is served by combined sewers. The City 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.

Select this Article		Catchbasins and Inserts for the Control of Gross Solids and Conventional Stormwater Pollutants Robert Pitt and Richard Field ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)57 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract While many types of inlet devices may capture some stormwater debris, care must be taken in their design. Catchbasins with sumps may remove up to about 30% of suspended loads that enter the intet, but much of this material is relatively coarse and in many cases would not have moved to the outfall. The sumps do minimize sediment accumulation in the sewerage and reduce maintenance. These should probably be considered as grit traps, more than pollutant trapping devices. Some devices can also trap floatables. However, if not frequently maintained, clogging and ponding may occur. In addition, if water is forced through the trapped debris (especially leaves), degradation of the organic material may occur, actually causing the production of some pollutants. Some new inlet devices have been recently designed and are undergoing testing that promise more effective control of stormwater pollutants, along with better retention of bed load material and floatables.

Select this Article		The Role of Street Cleaning in Stormwater Management Robert Pitt, Roger Bannerman, and Roger Sutherland ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)58 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The authors have been involved in numerous street cleaning research projects for over 30 years. This paper will give us a unique opportunity to highlight the historical use of street cleaning as a method for reducing stormwater pollutants, and will examine newly emerging street cleaning technologies. There have been many misconceptions concerning this potential stormwater management control. This paper will examine the limitations of street cleaning, and describe how it can be more effective. Street cleaning plays an important role in most public works departments as an aesthetic and safety control measure. Street cleaning is also important to reduce massive dirt and debris buildups present in the spring in the northern regions. Leaf cleanup by street cleaning is also necessary in most areas in the fall.

Select this Article		Broadway Outfall Stormwater Retrofit Incorporating a CDS Unit Betty Rushton, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)59 \| Cited 1 time Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A major storm sewer outfall was retrofitted with a Continuous Deflective Separation (CDS) unit and a linear marsh to help treat stormwater discharged from an urban drainage basin in Tampa, Florida. The CDS unit was very effective for removing the gross solids including litter, trash, debris, leaves and sediments larger than 64 microns. These pollutants have not usually been evaluated in stormwater studies that use automated water quality sampler. Most of the gross solids were deposited between February and August 2003. During the first year of this ongoing study, about 300,000 cubic meter of flow passed through the system including both storm and base flow. The CDS unit removed 11.69 m³ (413 ft³) of gross solids from the flow stream including toxic levels of Polycyclic Aromatic Hydrocarbons (PAHs).

Select this Article		Evaluation of Monitoring and Analysis Methods Yielding Significant Differences in BMP Efficiency Gary Lippner, P.E., Amardeep Singh, P.E., and Roger James, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)60 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The California Department of Transportation (Caltrans) as part of the Best Management Practice (BMP) Retrofit Pilot Program evaluated the performance of a BMP installed at 2 sites on I‐210 in Los Angeles County to capture and retain floatables, trash, debris, fine sand and larger particles of sediment. Runoff and rainfall data were collected during the 2000–01 and 2001–02 seasons at each of the sites and gross pollutant and trace element data were collected during a total of 10 events at one site and 17 events at the other site. Floatables were characterized during each season while all solids captured by the BMPs where quantified and characterized in 2001–02. The efficiency of the BMPs was determined using a Caltrans Scoping Study Methodology adapted from a Federal Highway Administration 1989 study and a Mass Balance Approach that considers the mass of material captured by the BMP. These two methodologies produced significantly different results in the BMP efficiency. These material differences were attributed to limitations of the Scoping Study Method when small data sets are used, incorrect use of sediment data, use of calculated rather than actual measured data and limitations of automatic samplers to collect representative samples of solids in storm water runoff. The Mass Balance Approach produces a better method of characterizing BMPs when there are solids in the storm water runoff.

Select this Article		Street Surface Storage for Control of Combined Sewer Surcharge Stuart G. Walesh, P.E. and Carolyn Esposito ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)61 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract One type of Best Management Practice (BMP) available is the use of street storage systems to prevent combined sewer surcharging and to mitigate basement flooding. A case study approach, based primarily on two largely implemented street storage systems, will be used to explain the concept through construction and operation aspects of street storage systems. Street storage refers to the technology of temporarily storing stormwater in densely developed urban areas on the surface (off‐street and on‐street) and, as needed, below the surface close to the source. Close to the source means where the water falls as precipitation and prior to its entry into the combined, sanitary, or storm sewer system. The idea is to accept the full volume of stormwater runoff into the sewer system but greatly reduce the peak rate of entry of stormwater into the system. System components include street berms, flow regulators, and surface and subsurface stormwater storage facilities. By eliminating surcharging in combined sewer systems, street storage has the potential to cost effectively and simultaneously mitigate basement flooding and combined sewer overflows (CSO). Other possible benefits of street storage are mitigating sanitary sewer overflows (SSO), eliminating surface flooding, reducing peak flows at wastewater treatment plants (WWTP) and controlling non‐point source pollution. This technology, in the two case studies discussed here, has proven to eliminate surcharing, complied with regulations, proved to be cost effective and earned public support.

Select this Article		Risk‐Based Optimal CSOs Curve Designs for Stormwater Quality Control D. J. Jo, J. H. Lee, J. H. Kim, and M. J. Park ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)62 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a systematic approach for the economical design of rain‐water quality control systems. For the design of runoff quality control system (RQCS), the rainfall‐runoff process requires the local rainfall data recorded continuously. In this study the rainfall probability distribution is assumed to follow an exponential decay function. Applying the exponential decay function, the normalized curves are derived to explain the non‐exceedance probability distributions. The optimal curves for the determination of the RQCS size are derived based on the overflow risk. Comparison of the optimal capture volume and peak runoff rate to those computed by an urban rainfall‐runoff model (ILLUDAS) demonstrates that the optimal curves derived in this study can be utilized for the design of rain‐water quality control systems in Korea avoiding an excessive computational effort by the rainfall‐runoff model.

Select this Article		Ceramic Membrane Filtration: An Alternative Wet Weather Management Technology Ronald D. Neufeld, Ph.D., P.E., DEE, John Bendick, Betty J. Kindle, Charles Miller, and Radisav D. Vidic, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)63 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A pilot scale investigation was undertaken at the Allegheny County Sanitary Authority (ALCOSAN) for approximately 14 months to evaluate the feasibility of cross‐flow ceramic membrane microfiltration for the treatment of primary sewage effluent simulating combined and sanitary sewer overflows. Ceramic membranes of various pores sizes (0.05 – 1.4 microns) were tested to understand the impact of cross flow velocity, transmembrane pressures, and inlet suspended solids on permeate water quality and flux rate. A 0.2 micron membrane operated with a 1.8 m/s cross flow velocity, a transmembrane pressure less than 2.1 bar and a backpulse frequency of 60 seconds was selected as the preferred operating conditions. Permeate from this membrane had virtually undetectable levels of fecal coliforms, e‐Coli, enterococci, and levels of BOD₅ and SS commensurate with secondary treatment expectations. Elevated membrane‐feed suspended solids concentration reduces steady state flux rates; a quantification of the influence of feed suspended solids is for the design of multi‐stage membrane systems.

Select this Article		Continuous Deflective Separation (CDS) Use for Treating Sanitary Wet Weather Flows James A. Heist, Alex Davey, Robert Hawkins, John Fitzgerald, and Peter Warren ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)64 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Continuous Deflective Separation (CDS) screens are being used around the world in a number of different ways to treat CSO and SSO wet weather flows. In addition to fine screening (effectively to less than 100 microns) with direct discharge to the environment, CDS units are being used as pretreatment for constructed wetlands. This fine screening has also been demonstrated to provide sufficient removal of solids to allow effective disinfection with UV light. CDS screening has been demonstrated for clarification of chemically flocculated raw sewage, leading to the proposed use in providing a higher level of treatment for wet weather CSO/SSO flows. The regulatory environment in which these applications units are utilized is discussed; performance data for these various applications will be presented, along with design criteria and descriptions of several actual facilities.

Select this Article		Milwaukee's Integrated Approach: A Watershed Moment Kevin Shafer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)65 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Recently, the City of Milwaukee, Wisconsin embarked on a long term planning effort based on the Environmental Protection Agency's watershed approach. The use of this integrated approach was prompted by the understanding that if every sanitary sewer overflow was stopped tomorrow, non‐point pollution would still cause beaches to close and make fish unfit to eat. The Milwaukee Metropolitan Sewerage District (MMSD) launched this effort to develop an approach to reduce non‐point water pollutants. To insure success, MMSD believes it must increase public awareness and public educationof the sources of these pollutants in order to reduce non‐point pollution. The use of good stormwater management principles by the general public is a major component of this effort. For these principles to be effective, the public must be informed about how water becomes polluted and what manmade influences induce flooding. This public education must start with the basic understanding of what happens to a drop of water when it lands on an individual's property. Knowing how that drop of water becomes polluted, how it can cause flooding, and how it can cause sewer overflows is critical to any stormwater management program. Public outreach, public education and public collaboration are the tools to making the leap to less flooding and cleaner waterways; stormwater management cannot be effective without it.

Select this Article		BMP Design Guidelines: Vegetative Biofilters M. L. Clar, P.E., B. Barfield, P.E., and T. O'Connor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)66 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Urban Watersheds Management Branch of US Environmental Protection Agency Edison, NJ, Laboratory is in the process of developing design guidelines for a number of BMP techniques. This paper provides a summary of the design guidelines that are being developed for a group of onsite BMP control practices that are referred to as vegetative biofilters and includes the following BMP control practices: grass swale, grass swale with filter media (dry swale), wet (wetland swale), filter and buffer strip, bioretention cell.

Select this Article		General Considerations in BMP Design Thomas P. O'Connor, Michael Clar, and Bill Barfield ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)67 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Today, many municipalities are implementing best management practices (BMPs). The most commonly used structural treatment BMPs that will be discussed in the presentation are ponds (detention/retention) and vegetated biofilters (swales and filter/buffer strips). Historically, structural BMPs were employed to capture peak flows, assist in local drainage, and manage the quantity of runoff produced during wet‐weather flow (WWF), i.e., flood control. Current design typically still focuses on rainfall events that range from 2 to 10 inches of daily rainfall and occur at much longer return periods ranging from 2‐ to 100‐year storm. These storms may contain significant pollutant loads, but their contribution to the annual average pollutant load is really quite small due to the infrequency of their occurrence. In addition, longer periods of recovery are available to receiving waters between larger storm events allowing receiving water systems to flush themselves and the aquatic environment to recover. Water quality control of urban runoff is still a relatively new and developing area of engineering and science. The addition of water quality considerations in the design of BMPs has introduced a new dimension to the traditional hydrologic considerations for BMP design. Water quality considerations have created a shift from flood events to a continuous long‐term rainfall‐runoff BMP design volume approach and the pollutant loads associated with these volumes. To treat the bulk of the pollutant loads from stormwater runoff, many states and municipalities specify a treatment volume that is designed to capture the initial component of the stormwater runoff. In practice this is achieved by specifying a rainfall amount (e.g., the first ½‐inch or 1‐inch) or the capture of a stormwater runoff volume that correlates to a design storm (e.g., 6‐month, 1‐year, or 2‐year frequency storm). BMPs that encompass both peak discharge hydrology and small storm hydrology would optimally use a system that incorporates on‐site treatment and storage of stormwater for the smaller storms while protecting downstream from floods. By including supplemental measures using either distributed and/or centralized controls, the peak discharge control strategies can be upgraded to perform water quality control.

Select this Article		Constructed Wetlands vs. Retention Pond BMPs: Mesocosm Studies for Improved Pollutant Management in Urban Stormwater Treatment S. Struck, C. Nietch, and M. Borst ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)68 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Increased urbanization has increased the amount of impervious area resulting in larger quantities of stormwater runoff. This runoff can contribute significant amounts of debris and pollutants to receiving waters. Urban watershed managers often incorporate best management practices (BMPs) to treat these pollutants. Although many studies have evaluated the capabilities of two popular treatment methods — retention ponds and constructed wetlands — to reduce pollutant concentration and load in stormwater, few have focused on the internal mechanisms controlling the efficacy of these stormwater BMPs. Experimental mesocosms were constructed in Edison, NJ to simulate retention pond and wetland BMPs and to evaluate, describe, and model key processes that occur within these treatment systems. Understanding the hydrologic character of the mesocosms, and BMPs in general, is necessary to model the performance of these systems. Preliminary data suggest constructed wetland mesocosms outperformed retention pond mesocosms for removal of total suspended solids and total Kjeldahl nitrogen. However, retention pond mesocosms were the most effective at treating dissolved nitrates. Complete data that includes hydraulic modeling, multiple nutrient parameters, microbial indicators and metals will provide more information on the mechanisms controlling BMP effectiveness. A primary goal is developing models for constructed wetland and retention pond BMPs that will allow for better stormwater BMP design leading to overall improvements in receiving water quality to meet state and federal water quality standards.

Select this Article		On and Off Site Sediment Control Using Silt Fence Ellen Stevens, Bill J. Barfield, Khaled Gasem, and Marty Matlock ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)69 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Greater public awareness and the enactment of increasingly stringent regulations have made reliable and cost‐effective erosion control methods or best management practices (BMPs), particularly on construction sites, a national priority. At present, silt fence is the most widely used BMP, but unfortunately, the instances of failure are widespread. We believe that with proper assessment, following recommended installation methods, and conducting routine maintenance, better erosion control can be achieved with current silt fence technology. The current phase of our research is to investigate the current technology and develop design tools to assist users to get better results through avoiding structural failures and also provide a means of assessing performance in terms of trapping efficiency or effluent concentration. The next phase of our research will be to develop and evaluate several structural, material, and chemical enhancements to the current technology. This paper describes the progress made to date in investigation of current technology and development and application of the design tool.

Select this Article		National Benefits of Erosion and Sediment Control Regulations J. W. Pritts, P.E., M.ASCE, J. E. Swanson, P.E., J. Collins, and A. Miles ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)70 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract EPA is developing national effluent guidelines for discharges of stormwater from construction sites to augment the existing Phase I and II NPDES stormwater regulations. As part of this effort, EPA is required to evaluate the environmental benefits of the rulemaking. In evaluating the benefits of regulations, EPA attempts to both quantify the degree of reduction of a range of pollutants or indicators, as well as monetize the expected environmental improvements that result. Due to the national scope of this evaluation and limited data available on both the quality of discharges from construction sites and the locations of those discharges, as well as the limited range of methodologies available to quantify and monetize in‐stream improvements, EPA relied on a modeled approach in lieu of using actual field‐sampled data. For this evaluation, EPA estimated sediment export from construction sites using the Revised Universal Soil Loss Equation (RUSLE) and modeled sediment reductions using SEDCAD. EPA then developed a methodology for determining the geographic distribution of construction sites and modeled in‐stream water quality improvements and monetized benefits of several regulatory scenarios using EPA's National Water Pollution Control Assessment Model (NWPCAM).

Select this Article		The Effect of Stormwater Controls on Sediment Transport in Urban Streams Christine A. Rohrer, P.E., Larry A. Roesner, PhD, P.E., F.ASCE, and Brian P. Bledsoe, PhD, P.E. M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)71 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This study evaluates the potential impact of watershed development on sediment transport in a prototype headwater stream subjected to typical residential development. Event based and continuous simulations, using 50 years of hourly rainfall records were performed for two climatically different locales. The first is the semiarid climate of Fort Collins, Colorado and the other a typical southeastern climate, Atlanta, Georgia. Five scenarios were evaluated for the study watershed, including: current (undeveloped) conditions, fully developed conditions, without stormwater controls, and fully developed conditions with stormwater controlled using (a) the City of Fort Collins flood control standard, (b) the City of Fort Collins flood control standard and water quality capture volume (WQCV) criteria, and, (c) using common standards of practice in the United States: control of the 100‐ and 2‐year storms to historic peak discharge rates and control of the WQCV. For each scenario examined, sediment transport potential is evaluated for two noncohesive soil types: medium gravel and medium sand.

Select this Article		Study on the Surface Infiltration Rate of Permeable Pavements E. Z. Bean, W. F. Hunt, and D. A. Bidelspach ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)72 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Asphalt surfaces have greatly increased the amount of pollutant‐carrying runoff entering surface waters. To counteract this, permeable pavement can be installed to allow water to infiltrate, thus reducing runoff and acting as a filter. This study tested the surface infiltration rate of 27 permeable pavement sites in North Carolina, Maryland and Delaware. One of these sites in North Carolina was monitored to compare pollutant loads of asphalt runoff to those in infiltrate. Concrete grid pavers (CGP) and permeable interlocking concrete pavers (PICP) were tested with pavement ages ranging from six months to 20 years. Two infiltration tests were run on 14 CGP lots filled with sand. The initial test was on the existing condition of the surface and second test was run after the removal of the top layer of residue (1.3 – 1.9 cm) to simulate maintenance. Maintenance improved the infiltration rate on 13 of 14 sites. Analysis of the data showed that maintenance improves surface permeability at a confidence level of 99.8%. The median average infiltration rate increased from 5.0 cm/hr., for existing conditions, to 8.0 cm/hr after maintenance. Eleven PICP sites were also tested. Sites built in close proximity to loose fine particles had infiltration rates significantly less than sites free of loose fines. Averages of each condition are 60 cm/hr and 2000 cm/hr respectively. Even the minimum existing infiltration rates were comparable to those of a grassed sandy loam soil. Water quality data included in this study shows the results of six storms from June to October, 2003. With only a few storms to compare, only Zinc has been identified as having a statistically significant difference between infiltrate and runoff.

Select this Article		Water Quality Friendly Field Operations Yard Construction Christopher Bowles, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)73 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Clean Water Services (District), formerly Unified Sewerage Agency, is a County Special Service District operating in the urban area of Washington County, Oregon. The District is in charge of the public storm water and sanitary sewer systems, and we administer the erosion control and water quality programs in the urban areas. There are 12 member cities and a large unincorporated area within our boundary. In 2002, the Field Operations Division started the construction of a permanent field yard. The site is 2 hectares (5 acres) in size with a 1,672 m² (18,000 sq. ft.) administration office, 1,394 m² (15,000 sq. ft.) of indoor vehicle parking, and 1,208 m² (13,000 sq. ft.) of outdoor carport parking. The $9 million facility houses 58 employees and more than 70 pieces of equipment including street sweepers, dump trucks, crew vehicles, sewer cleaning equipment, excavators, and more. The Field Operations crews maintain 1,156 km (718 miles) of sanitary sewer lines, 591 km (367 miles) of storm lines, sweep public streets monthly, clean storm drains and catch basins, maintain more than 300 stormwater detention and water quality facilities, and provide 24‐hour emergency response to sewer overflows and flooding within our 316 km² (122 square‐mile) service area. It was essential that the construction be done to the highest standards relative to erosion control and water quality. One of the project goals was to incorporate innovative erosion control and water quality treatment aspects, both during construction and that would be in place in the long term. The project goals called for the site to be a demonstration project so contractors, engineers, plan review staff, and the public could see these techniques in action.

Select this Article		Optimization of Detention Basins for Highway Runoff Control Derek N. Rapp, James P. Heaney, and Joong G. Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)74 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Site specific characterization data are very important in estimating the effectiveness of wet‐weather controls (WWCs) in removing pollutants from highway and urban runoff. An analysis of urban runoff sedimentation data is used to develop first order reaction rate constants using linear regression techniques. The reaction rate constants and associated initial concentrations are used to evaluate the dependency of detention basin designs on removal rates. A continuous simulation spreadsheet model is used to evaluate the pollutant removal performance of a detention basin as a function of storage volume and release rate for a one year period. The design is optimized by minimizing the total cost of the detention basin while maintaining a specified level of pollutant load removal. Simulations were run with different reaction rate constants and results from the optimized solutions indicate that storage‐release strategies are heavily dependent on the assumed reaction rate constant. Different performance levels were also evaluated and the results indicate that attempts to achieve pollutant load reductions above 80% are much less cost effective.

Select this Article		Performance and Design of Vegetated BMPs in the Highway Environment Michael E. Barrett ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)75 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The objectives of this paper are to document the pollutant removal of existing vegetated areas adjacent to highways and to identify the minimum design requirements needed to obtain substantial pollutant reduction. The pollutant removal performance of highway shoulders (buffer strips) is based primarily on eight test sites located on highway rights‐of‐way in California that were not designed for stormwater treatment. At each location, multiple stormwater collection systems (over 30 systems total) were installed and equipped with automated samplers to collect highway runoff after passing through vegetated buffer strips of varying widths. The vegetated buffers at each of the eight sites differed in characteristics such as slope (up to 50 percent), width, vegetation type and coverage, soil, and hydraulic loading. The data collected between 2001 and 2003 indicate that concentration reductions consistently occur for TSS and total metals and frequently for dissolved metals. Conversely, concentration increases were observed for dissolved solids and occasionally for organic carbon. Nutrient concentrations were generally unchanged by the buffer strips. The pollutant removal and design of roadside swales is based primarily on the performance of two sites located in Austin, Texas, and which were constructed solely for stormwater conveyance. The data collected between 1994 and 1997 indicate that the majority of the pollutant removal occurs on the side slopes of the swales rather than along the length. Minimum discharge concentrations observed at these sites were similar to those observed from buffer strips in California. The greatest pollutant removal occurs when the geometry of the swale maximizes the length of the side slope; consequently, the optimum cross‐section geometry for highway medians is V‐shaped rather than the trapezoidal geometry normally illustrated in guidance manuals. In addition, the relatively constant side slopes facilitates mowing and is safer for the traveling public than channels with abrupt changes in side slopes. Swales along highways are normally sized to convey large, infrequent events, which when combined with the low side slopes implemented for safety reasons results in a broad bottom that reduces the concentration of runoff constituents. Consequently, a flat bottom is not required for effective operation.

Select this Article		Optimization of Roadside Infiltration for Highway Runoff Control Chelisa A. Pack, James P. Heaney, and Joong G. Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)76 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Stormwater runoff from highways can be detrimental in terms of the water quality and quantity of runoff produced. The roadside area can be improved to filter more suspended pollutants from the runoff and also to infiltrate more of the annual stormwater volume through the use of controls such as biofilters. A simple continuous simulation example was developed to illustrate the process of setting up a spreadsheet‐based design optimization problem. Accurate site‐specific infiltration estimates are critical for the continuous simulation. Optimization procedures generated the least‐cost combination of storage to infiltrate 80% of the annual runon volume of stormwater. The model shows the conceptual framework for integrating continuous simulation, optimization, and cost estimation into the design process.

Select this Article		Evaluating Bioretention Areas from Two Field Sites in North Carolina W. F. Hunt and A. R. Jarrett ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)77 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Due to recent fish kills along the Mid‐Atlantic coast, new regulations require all future land disturbing activities — including the urbanization or development of land — to be environmentally friendly. Consequently, stormwater management practices are being designed to remove nutrients, particularly nitrogen and phosphorus, before runoff reaches streams. One stormwater practice, bioretention, is gaining popularity in commercial development because it can easily be sited in the required natural areas of parking lot medians; however, the current design criteria used for bioretention have not been tested extensively. Pollutant removal, especially for species of nitrogen, has not been tested under various conditions. Currently used bioretention monitoring protocol assumes bioretention devices retain little water. Current designs do not reduce nitrate‐nitrogen levels sufficiently, as bioretention is constructed without any zone designed to be saturated. For nitrate‐nitrogen to be converted to nitrogen gas, thus enhancing total nitrogen (TN) removal, an anaerobic zone may be necessary. This research determined the effect of an anaerobic layer within bioretention devices on the concentrations and loadings of TN, nitrate‐nitrogen (NO₃‐N), and other nutrient and pollutant species in stormwater runoff including ammonia‐nitrogen (NH₃‐N), total kjeldahl nitrogen (TKN), total phosphorus (TP), ortho‐phosphate (Ortho‐P), zinc (Zn), iron (Fe), copper (Cu), lead (Pb), and total suspended solids (TSS). Four field bioretention areas were installed and monitored in two North Carolina cities. The field sites were used to test the pollutant removal abilities and hydraulic retention of bioretention devices that ranged in depth from 0.6 m (2 ft) to 1.2 m (4 ft) and were designed with or without an anaerobic layer. The field studies in North Carolina confirmed high annual TN mass removal rates at two conventionally drained bioretention cells (40% reduction). NO₃‐N mass removal rates varied between 75% and 13%. The presence of an anaerobic zone was tested at the Greensboro field site and significantly (p<0.10) reduced TP and Fe outflow concentrations. Annual metal mass removal rates at the Greensboro site were over 98% for both Zn and Cu and 81% for Pb. A very large mass of Fe (nearly 17 Kg from a 0.20‐ha (0.5‐acre) watershed was added to the storm sewer network by the bioretention cell. TP and TSS removal rates were highly variable from cell to cell.

Select this Article		BMP Model for Low‐Impact Development Mow‐Soung Cheng, Larry S. Coffman, Yanping Zhang, John Riverson, and Jenny Zhen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)78 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Low‐impact development (LID) techniques can be used for controlling stormwater impacts from new development and redevelopment / urban retrofit. Prince George's County has developed a Best Management Practices (BMPs) evaluation module to assist in assessing the effectiveness of LID technologies. This module uses process‐based algorithms to simulate BMP function and removal efficiency and accepts flow and water quality time series either from observation or generated by runoff models such as the Hydrologic Simulation Program, FORTRAN (HSPF) as input data. Process‐bases algorithms include weir and orifice control structures, storm swale characteristics, flow and pollutant transport, flow routing and networking, infiltration and saturation, evapotranspiration, and a general loss/decay representation for a pollutant. The module offers the user the flexibility to design retention style or open‐channel BMPs, define flow routing through a BMP network, and compares BMP controls against pre‐development conditions. BMP effectiveness can be evaluated and estimated over a wide range of storm conditions, site designs, and flow routing configuration approaches. The simulation processes of the model have been validated using available monitoring data and literature values. The BMP Module has been applied to several real land development projects using actual long‐term meteorological data recorded at Washington National Airport. These development projects were designed based on the State stormwater management requirements and regulations. The simulation results indicate that LID can actually minimize water quantity and quality impacts of the developments. For all cases, the results indicate that post‐development condition with LID BMPs exceeds existing condition (assumed to be completely forested) in terms of hydrologic attenuation benefit and pollutant control benefit. This paper provides an overview of the model and demonstrate the simulation results. The results also raise an interesting question: Is using the Natural Resources Conservation Services (NRCS) Rainfall Type II Distribution appropriate for the design of stormwater BMPs? With the U. S. Environmental Protection Agency's support, the model is currently being enhanced to include the following: linkage to the CSO model, development of an optimization module, and integrating with GIS platforms.

Select this Article		The Selection of Appropriate Satellite Sources of Impervious Surface Information for Urban Hydrology Aderbal C. Correa and Janggam Adhityawarma ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)79 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Impervious surface is a basic parameter used in hydrologic studies, particularly in urban watersheds. The availability of a new generation satellite image collection systems providing data with a high spatial resolution, in digital format, comparable to what is obtained from aerial photographs, creates a new source of data available to civil engineers involved in hydrologic or stormwater projects. Aerial photography provides a spatial resolution (less than 0.5 m for a large scale photo) that is higher than what can be obtained from civilian satellites (i.e., 0.6 to 4.0 m range), however, there are a number satellite image characteristics that make them a preferred source of impervious data for some applications. The major advantages of satellite images over aerial photographs are the capability (1) to provide up‐to‐date information for an area of interest, (2) to allow for digital data processing and integration with other digital datasets and (3) to produce color displays. This paper presents results of the use of medium and high spatial resolution satellite image data to estimate the impervious surface areas in Springfield, Columbia and Ashland, Missouri and Overland Park, Kansas urban watersheds. The results provide an important overview of quality of the results that can be expected for urban watersheds characterized by different development patterns, building densities and varying amounts of vegetation (trees and grass). The results provide guidance on the use of satellite image data to produce impervious surface estimates required by most hydrologic studies. The results of this study are valuable to the profession because existing regulatory programs such as the Federal Emergency Management Agency's (FEMA) National Flood Insurance Program and the Environmental Protection Agency's (EPA's) Phase I and Phase II storm water regulations require proactive actions to measure the impact of land use/land cover and storm water runoff on water quantity and quality. The results presented in this paper are a contribution to the state‐of‐the‐art methodology applicable to urban hydrology projects by formulating guidelines to determine what satellite data sources are appropriate for a given application or modeling effort.

Select this Article		A Planning Tool for Watershed LID‐BMP Implementation Jenny X. Zhen, Shaw L. Yu, M.ASCE, and Yanyun Zhai ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)80 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The paper describes the development of a planning tool for comparing different LID‐type BMP implementation scenarios in a watershed and selecting the optimal spatial placement strategy for the BMPs. The framework of the planning tool includes the following components: A watershed model, which simulates nonpoint pollutant loads from all parts of the watershed under given wet‐weather conditions; A sub‐program that performs computations of the water quality impact of the implementation of LID‐type BMPs such as bioreention cells in a watershed; An “optimization” tool, which will search for the optimal scenario for BMP placement in the watershed. In the present study, a watershed model developed at the University of Virginia, called WINVAST, was used. WINVAST is a comprehensive, event‐based stormwater model, which simulates pollutant loads generated from a given storm event and has interfacing capability with GIS databases. A sub‐program to the WINVAST model was developed to simulate certain BMP processes (currently wet detention ponds and grassed swales) in a watershed. The optimization tool used in the present study was the “Scattered Search” methodology. A tributary watershed to the Swift Creek Reservoir near Richmond, Virginia was used as a case study. Several BMP implementation scenarios were tested, namely, on‐site or micro‐scale such as LID‐types, sub‐regional and regional placement of BMPs. The results show that the on‐site placement scheme would cause a larger reduction of watershed runoff peaks, but the water quality results were mixed. On the other hand, when watershed water quality requirement is higher, the placement of BMPs tends to favor locations closer to the watershed outlet over upstream locations on a cost‐effectiveness basis. The results also show that when the maintenance cost was tied with the amount of sediment accumulation in a pond BMP, the overall system cost would be lower.

Select this Article		Evaluating the Effectiveness of Stormwater Reduction Practices Using Continuous Simulation Eric D. Loucks, Nicole Garrett, and Kimberly A. Oriel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)81 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Stormwater reduction practices (SWRPs) such as rain barrels, rain gardens, porous pavement or roof gardens have become popular approaches to reducing the volume and peak rate of stormwater runoff. The effectiveness of such measures is an important factor in decisions concerning investment of public funds in such practices. There are two issues in the assessment of SWRP effectiveness: (1) how well do specific SWRP implementations work in the field and (2) what are the long term “end of pipe” benefits of a broad implementation program. The analyses presented in this paper seek to answer the second question. Continuous hydrologic simulation is employed to determine the benefits of various SWRPs in the combined sewer service area (CSSA). The effectiveness of individual SWRPs are assumed based on various papers and websites.

Select this Article		Filterra by Americast: Advanced Bioretention System Discussion of the Pollutant Removal Mechanisms and Design Strategies Larry S. Coffman and Terry Siviter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)82 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Filterra represents the latest advancement in Bioretention technology for treatment of contaminated urban stormwater runoff. Americast, a Division of VALLEY BLOX, Inc., working with the University of Virginia's Civil Engineering Department has developed a best management practice (BMP) that optimizes the physical, chemical and biological pollutant removal mechanisms found in the plant / soil / microbe complex of the Bioretention BMP. It was the objective of Americast to standardize the application of Bioretention technology taking it out of the realm of experimental devices by developing a much more reliable, dependable and adaptable urban BMP. In working towards this goal, Americast has developed a patented specially engineered high flow rate treatment media in a structurally sound container or simply “Bioretention in a box” system. Laboratory data demonstrates that Filterra can treat 90 to 95 % (higher if desired) of the total annual rainfall volume with maximum pollutant removal rates of 95% for total suspended solids, 82% total phosphorous, 76% total nitrogen and 91% heavy metals (measured as Cu). Filterra's excellent pollutant removal efficiency is primarily due the multiple treatment systems inherent in Bioretention's plant / soil / microbe treatment complex. The actual total annual pollutant removal for an application will vary depending on site conditions, rainfall intensity and the annual volume of runoff treated. Americast has also devised a simple and unique design /sizing strategy that is adaptable to the unique rainfall distribution / intensity of any hydrologic regime. This unique approach is based on developing a rainfall intensity probability distribution from actual rainfall information taken over many years from local weather stations (e.g. 50 years or more of airport rainfall data). From an area's intensity distribution a simple surface area to drainage area ratio and curve can be developed to size the device to treat the desired annual volume. By multiplying the annual volume treated by the pollutant removal efficiency of Filterra, the total annual pollutant removal rate can be calculated. This paper will outline the wide array of pollutant removal mechanisms and the unique design sizing strategy for Filterra.

Select this Article		Infiltration Strategies for LID Robert G. Traver ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)83 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of Low Impact Development (LID) is to minimize the effect of changes in land use on the post construction site hydrology. Specifically this encompasses minimizing increased stormwater volumes, peak flows and non‐point source pollutants generally associated with land development. Infiltration is a key component of LID in accomplishing these goals. The author discusses the relationship between goals and capture volume, placement, and general usage of infiltration Best Management Practices (BMP) incorporated within the LID Framework.

Select this Article		Properties, Mechanisms and Application of Porous Pavement as an Environmentally‐Conscious Construction Material for the Built Environment J. Sansalone, PhD, P.E., M.ASCE, L. Wang, PhD, P.E. M.ASCE, J. Teng, PhD, and X. Kuang, M.S., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)84 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract As we move into the new century approximately 50% of the world population lives in the built environment and these demographics will increase to 60% of the population by the year 2025. With this growth is a commensurate increase in impervious surfaces, in particular pavement, associated with modern society's dependence on personal and commercial vehicular transportation. Well‐established consequences of this increase in imperviousness in our modern built environments are deleterious impacts to water quantity (local flooding as well as local scarcity), water quality (specifically metals and particles) and local climate. In addition, impervious surface impacts to quantity and quality are related. Impervious surfaces alter the local hydrologic cycle (increased flow rates, increased volume and decreased lag time) and promote increased conveyance of anthropogenic constituents. Even with such understanding, conventional transportation and urban infrastructure engineering design philosophy and construction practices utilize impervious pavement almost exclusively. Conventional practice and current regulatory developments are at odds, resulting in a significant environmental and economic dilemma in our built environments. Permitting requirements for NPDES Phase II stormwater regulations have been in place as of March 2003. In large part, this significant cost associated with these regulations, is due to the spatial extent of impervious surfaces, alteration of the rainfall‐runoff relationship and generation of anthropogenic constituents from activities on these impervious surfaces. While no one solution is the single answer to this complex problem, the development and application of multifunctional engineered porous pavement materials can fulfill modern built environment requirements for relatively smooth load‐transmitting surfaces while serving as a more environmentally‐conscious infrastructure material for in‐situ rainfall‐runoff quantity and quality control.

Select this Article		Particle Separation by In‐Situ Partial Exfiltration of Rainfall‐Runoff Z. Teng, PhD, M.ASCE and J. Sansalone, PhD, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)85 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Urban rainfall‐runoff is capable of entraining and transporting a wide gradation of particulate matter and constituents such as metal elements and organics. Under conditions where rainfall‐runoff pH is relatively high (> 7) combined with higher alkalinity (> 50 mg/L as CaCO₃), long residence times and high particulate loadings, cationic metal elements transported in urban land use rainfall‐runoff are often adsorbed on or incorporated with entrained particles that are ubiquitous in such runoff. Infiltration‐exfiltration can be an effective structural in‐situ particle separation and quantity control unit operation and process (UOP) that also will allow runoff to return to soil after passive physical‐chemical treatment. The in situ partial exfiltration reactor (PER), which combines the surficial straining of a porous pavement (CPP) layer with filtration of oxide coated sand (OCS) media beneath, provides control of water quantity and quality. In this study, particle analyses were carried out for both influent and effluent to examine filter efficiency as a function of particle size and hydrology. Influent d_m/d_p ratios suggest that the dominant PER particle separation mechanisms were physical‐chemical filtration with the CPP layer functioning as a straining surface. Particle size distributions were modeled based on a 2‐parameter cumulative power‐law function. PER filter performance was shown to be a function of unsteady hydrology and for all events examined the PER functioned as a variably saturated system. Temporal variation in the filter coefficient and the volumetric particle fraction remaining were directly related to the unsteady influent loading rate. Particle removal efficiency by the PER based on concentration ranged from 71 to 96% on a mass‐based concentration and 92 to 99% on a number based concentration. Results suggest that a properly designed PER can provide effective in‐situ control for particles and could be combined with or function separately from source control (i.e. pavement cleaning or a mass trading framework).

Select this Article		Modeling Stormwater Quantity Attenuation by a Partial Exfiltration System Z. Teng, PhD, M.ASCE and J. Sansalone, PhD, P.E. M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)86 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The processes involved in the relationship between rainfall and runoff are directly impacted by urban and transportation infrastructure and anthropogenic activities. Consequently, the results of such interactions impact the quantity and quality of receiving waters and the surrounding environment. Systems that combine both infiltration and exfiltration such as an in‐situ partial exfiltration reactor (PER) loaded by transient sheet flow, have the potential to attenuate the impact of both the quantity and quality of urban runoff. These in‐situ systems are subject to highly variable water quality and quantity and generally function under variably saturated flow conditions. To improve the understanding of the hydrologic response of a field‐scale PER that has been monitored for water quality and quantity control, a two‐dimensional numerical model was used to simulate the effluent hydrograph and water content profiles under transient hydraulic loadings for the PER. Richard's equation was applied in the model using parameters estimated from laboratory and field experiments; as well as event‐based hydrographs measured in situ for the PER. The dynamics of the water content with time illustrated the function of PER to lower peak flow, capture and redistribute runoff volume, and attenuate temporal aspects of the inflow hydrograph despite surrounding clayey soils of low hydraulic conductivity. Simulation of the same historical loadings for different surrounding soils demonstrated the effect of the surrounding soil hydraulic conductivity on the hydraulic performance of the PER. Simulations for a series of design storm events showed that the exfiltration capacity of the surrounding clayeysoil was limiting for peak flows during the 5 year return storm. Depending on the climate, evaporation could be the dominant mechanism for the drying process in the top layer of the PER. During the summer climate in Cincinnati, Ohio approximately 2 days was required to evaporate all but residual moisture from the upper layer of the PER.

Select this Article		Management of Stormwater Heavy Metals Using Media Filtration Shirley E. Clark, M.ASCE, Pauline D. Johnson, M.ASCE, Sarah Gill, and Mukesh Pratap, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)87 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This 3‐year study was funded by the Water Environment Research Foundation (WERF) to investigate innovative heavy metal removal from stormwater. This research focused on two major areas of heavy metal control: media filters and swales. This presentation will focus on the filter tests. The test stormwater used for most of the laboratory tests was collected from a campus parking lot at the University of Alabama during many storm events. The characteristics of the stormwater indicated that the most prevalent metals detected in the runoff were iron, zinc, copper and small amounts of particulate bound lead. Ranges of the metals were within national ranges reported by other studies. Twelve media were chosen for initial evaluation. Equilibrium and kinetic studies were formed on these media to assess their performance in capturing metals from urban runoff. The three best performing media: peat‐sand mix, compost, and zeolite were then selected for in‐depth study. The results of this investigation emphasize the importance of characterizing the stormwater before selecting a treatment media since the type and quantity of metals, pH, and other runoff characteristics can vary a great deal between sites. Upflow columns proved more effective than downflow columns in the control of detention time and reduction in clogging of the media by solids and associated head loss in the column.

Select this Article		Stormwater Characteristics as Contained in the Nationwide MS4 Stormwater Phase 1 Database Robert Pitt, Alex Maestre, and Renee Morquecho ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)88 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The University of Alabama and the Center for Watershed Protection were awarded an EPA Office of Water 104(b)3 grant in 2001 to collect and evaluate stormwater data from a representative number of NPDES (National Pollutant Discharge Elimination System) MS4 (municipal separate storm sewer system) stormwater permit holders. The monitoring data collected over nearly a ten‐year period from more than 200 municipalities throughout the country have a great potential in characterizing the quality of stormwater runoff and comparing it against historical benchmarks. This project is creating a national database of stormwater monitoring data collected as part of the existing stormwater permit program, providing a scientific analysis of the data, and providing recommendations for improving the quality and management value of future NPDES monitoring efforts. Each data set is receiving a quality assurance/quality control review based on reasonableness of data, extreme values, relationships among parameters, sampling methods, and a review of the analytical methods. The statistical analyses are being conducted at several levels. Probability plots are used to identify range, randomness and normality. Clustering and principal component analyses are utilized to characterize significant factors affecting the data patterns.

Select this Article		High Level Treatment of Stormwater Heavy Metals R. Pitt, S. Clark, P. D. Johnson, R. Morquecho, S. Gill, and M. Pratap ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)89 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This presentation reviews the results of several recent and related stormwater research projects that focused on the treatability of stormwater heavy metals.

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GROUND WATER ISSUES SYMPOSIUM

Select this Article		Conjunctive Use of Surface and Groundwater Resources: Application of Genetic Algorithms and Neural Networks M. Karamouz, F.ASCE, M. Mohammad Rezapour Tabari, and R. Kerachian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)90 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a methodology for conjunctive use of surface and groundwater resources is developed using the combination of the Genetic Algorithms (GAs) and the Artificial Neural Networks (ANNs). Water supply, 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 the PM 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. 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.

Select this Article		Spatially Distributed Model of Interacting Surface and Groundwater Storages Thomas E. Croley, II ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)91 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract NOAA's Great Lakes Environmental Research Laboratory (GLERL) developed their Large Basin Runoff Model (LBRM) as a serial and parallel cascade of linear reservoirs representing moisture storages within a watershed. Each reservoir represents a moisture storage: surface, upper soil zone, lower soil zone, and groundwater zone. GLERL adapted the LBRM from its lumped‐parameter definition for an entire watershed to a two dimensional representation of the flow cells comprising the watershed. This involved changes to the model structure to apply it to the micro scale as well as organization of watershed cells and an implementation of spatial flow routing. GLERL modified the LBRM continuity equations to allow upstream inflow when the model is applied to a single cell within a watershed and found the modifications in terms of corrector equations to be applied to the original solution. They began by considering flows between adjacent cells' surface storages while keeping the upper soil zone, lower soil zone, and groundwater zones in each cell independent. Thus each cell's upper soil zone, lower soil zone, and groundwater zone connected only to that cell's surface zone and not to any other cell, but the surface zones connected between adjacent cells. GLERL further modified the model to allow subsurface routing between cells of surface runoff (from the upper soil zone), interflow (from the lower soil zone), and groundwater flows (from the groundwater zone). Now surface and subsurface flows interact both with each other and with adjacent‐cell surface and subsurface storages. This involved adding additional flows out of the various subsurface storages in a watershed cell and additional flows (from upstream watershed cells' subsurface storages) into the storages. The continuity equations are again modified in terms of corrector equations applied to the original solution and are derived handily. GLERL then organized LBRM applications to constituent watershed cells into a flow network by identifying the network flow cascade and automatically arranging the cell computations accordingly. They identified required characteristics of any flow network map and designed system checks to guarantee them. They devised a scheme for ordering computations and routing surface flows throughout the watershed.

Select this Article		Mathematically Optimizing Water Management Richard Peralta and Ineke M. Kalwij ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)92 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Software for formally optimizing groundwater and conjunctive water management has improved dramatically in recent years. Historically utilized have been a range of classical and heuristic optimization methods, and of simulator and surrogate simulator techniques. Different combinations of optimizers and simulators are best for different types of optimization problems—groundwater supply, groundwater plume management, and conjunctive use. Methods for speeding the optimization process include linking a heuristic optimizer to Tabu Search or artificial neural networks.

Select this Article		Assessing Ground Water and Surface Water Interaction through Tracer Observation Randall W. Gentry, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)93 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In many cases the ability to determine and quantify groundwater and surface water interaction based upon hydraulic observations is an arduous task. The task is further complicated by possible transient interactions that can obscure chemical leakage signals observed in the groundwater system. The impetus of this paper is to provide an introduction to two studies where groundwater is being recharged from surface water sources on a relatively fast time of travel. The two test cases demonstrate the research plan for identifying groundwater‐surface water interaction in an unconsolidated semi‐confined aquifer and a karst setting. The study identifies emerging techniques and hypothesis testing for determination of groundwater under the direct influence of surface water and the potential role of these techniques in possible quantification of the flux. The tracer techniques used in the research include geochemical testing, tritium/3‐helium, and microbiological molecular techniques. These inter‐disciplinary studies are currently underway and this paper will provide a summary of the methodology, preliminary data and interpretation of the variant signals observable in a groundwater system from surface water interaction.

Select this Article		Sustainable Groundwater Management: The Theory of a Game Hugo A. Loáiciga ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)94 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Principles of sustainable groundwater exploitation are presented in this article. The renewable and inappropriable nature of groundwater is examined in light of the process of recharge. An example illustrates the interplay among groundwater extraction, recharge, natural recharge, and storage. It demonstrates the aquifer‐specific characteristics of overdraft and replenishment, which are driven by climatic variability and the rate of groundwater mining. A second example uses game theoretic methodology to quantify the roles of cooperation and non‐cooperation on groundwater extraction. The economic and environmental advantages of cooperative groundwater extraction are demonstrated with data from a coastal aquifer.

Select this Article		Robust Optimal Groundwater Remediation Design and Reuse Options Bin Zhang and Teresa B. Culver ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)95 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract To cost‐effectively restore contaminated sites to productive use requires integrated planning of cleanup and reuse. Ultimate reuse objectives should guide remediation decisions, instead of being dictated by pre‐described remediation plans. This study links a robust groundwater remediation approach with reuse planning. A genetic algorithm optimizer that is integrated with a subsurface contaminant transport model (The Modular Groundwater Optimizer) is modified to allow for a robust search. A robust approach is used to increase the likelihood of successful remediation in the context of the uncertainties in the system. The genetic algorithm objective is to find a low cost and reliable remediation plan. The remediation costs are then reduced by the expected reuse benefits. Reuse benefits are dependent on the time required for the remediation stage and on the endpoint of remediation. As more complete remediation is reached additional reuse options may become feasible. An analysis approach is developed and will be demonstrated to explore the trade‐offs between increasing costs for more complete, faster, and more reliable remediation versus the potential reuse benefits gained from implementing more profitable reuse options and from beginning reuse sooner. The case study shown is based on the Emmell's septic landfill on the National Priorities List.

Select this Article		Uncertainty Based Multi‐Objective Optimization of Groundwater Remediation at the Umatilla Chemical Depot Abhishek Singh and Barbara Minsker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)96 \| Cited 1 time Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Management of groundwater contamination often involves conflicting objectives and substantial uncertainty. A critical source of this uncertainty in groundwater problems often stems from uncertainty in the hydraulic conductivity values for the aquifer. For a remediation solution to be reliable in practice it is important that it is robust over such potential errors. This paper presents the application of a robust multi‐objective optimization method on a field‐scale pump‐and‐treat design problem at the Umatilla Chemical Depot site at Hermiston, Oregon. A simple methodology is used to establish plausible realizations of hydraulic conductivity that are then efficiently sampled within the optimization framework using Latin Hypercube sampling. A noisy multi‐objective genetic algorithm, developed and tested earlier on a hypothetical aquifer, is then applied to this field‐scale case to come up with a set of robust and Pareto‐dominant design solutions for the clean up of contaminants (RDX and TNT) in the groundwater. Interactions between the various trade‐offs and the inherent uncertainty at the site are analyzed. Finally it is demonstrated that by using such robust multi‐objective optimization schemes, it is possible to increase robustness of the optimal solutions without significant increases in costs.

Select this Article		Multi‐Objective Design of Natural Attenuation with Active Remediation Systems Under Uncertainty Using Genetic Algorithms Amy B. Chan‐Hilton and Satyajeet K. Iyer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)97 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this study to analyze the effects of parameter uncertainty on the optimal design of cost‐effective and reliable remediation plans that use natural attenuation with active remediation. An optimization framework is used identify appropriate remediation strategies that are inexpensive and effective under several scenarios of parameter uncertainty, thus assessing the potential of natural attenuation with active remediation. The overall simulation‐optimization framework combines a contaminant fate and transport simulation model and spatially‐correlated random field generator with the enhanced multi‐objective robust genetic algorithm (EMRGA) optimization approach. The optimization problem minimizes the expected cost of the natural attenuation‐active remediation system while minimizing the expected dissolved contaminant concentration, given uncertainty and heterogeneity in system parameters. Decision variables are the extraction well locations and rates of the active remediation system. The EMRGA evolves a set of Pareto‐optimal solutions that represent the best designs that identify the trade‐off between the expected cost and clean‐up level. The optimization model is applied to a problem based on a field site located in Eglin Air Force Base, Florida, contaminated with benzene. The optimization model is subjected to a series of cases, which vary the model parameters and degree of uncertainty associated with these parameters. The uncertain parameters examined in this study are the heterogeneous hydraulic conductivity, hydraulic gradient, and first‐order benzene degradation rate. The results indicate that hydraulic conductivity is the most sensitive parameter, increasing the difficulty in achieving lower cleanup levels and higher remediation reliabilities.

Select this Article		Using WASH123D to Design Spreader Canals for Water Management in Watersheds Hwai‐Ping Cheng, Hsin‐chi Jerry Lin, Gour‐Tsyh Yeh, Earl Edris, and Mitch Granat ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)98 Online Publication Date: 7 October 2004 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. Many competing entities have an interest in the restoration process which will probably include physical changes to the land surface and adjustments to water deliveries. The Biscayne Bay Coastal Wetlands (BBCW) Project is one component of more than 60 restoration plans and has a goal to restore or enhance freshwater wetlands, tidal wetlands, and near shore bay habitat. In an effort to restore wetlands, several structures, and management plans and scenarios are considered. One of the plans is to deliver fresh water from the existing canals through a shallow spreader canal system that is to distribute fresh water through wetlands into the Biscayne Bay. To achieve this, a tool is needed to design this complicated shallow spreader canal system. This paper presents how a spreader canal system, which includes 1D canal network routing, 2D overland flow, 3D subsurface flow, and flow through the interface of any two sub‐domains of the spreader canal system, is simulated with the WASH123D computer code. A brief description of the model will be given. A hypothetical example that includes two cases and uses topographic data and a high‐resolution computational mesh for one project area will be considered to demonstrate how WASH123D can help design a spreader canal system. A couple of issues concerning run time and numerical convergence of the coupled flow model will also be discussed in this paper.

Select this Article		Using the Parallel WASH123D Code to Simulate Overland‐Subsurface Interactions Hsin‐chi Jerry Lin, Jing‐Ru (Ruth) Cheng, Hwai‐Ping (Pearce) Cheng, Earl Edris, David Richards, and George Yeh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)99 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract WASH123D model is a first‐principle, physics‐based model, where water flow and/or contaminant and sediment transport within a watershed system are computed. In the WASH123D model, a watershed is conceptualized as a coupled system of 1‐D canal/stream network, 2‐D overland regime, and 3‐D subsurface media. It is designed to answer the environmental issues concerning both water quantity and quality. To reach numerical solutions with reasonable and tolerable computer time for a regional scale watershed simulation, numerical algorithm improvement and code parallelization are two essential tasks when a distributed numerical model, WASH123D, is used. This paper presents the code parallelization approach, followed by demonstrating its scalability performance. The test problem of a large mesh uses the topographic data in the C‐111 Spreader Canal Project.

Select this Article		Groundwater Policy and Regulation at the Former Fort Ord: Regulatory Redundancies at the State and Local Levels Derek S. Lieberman, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)100 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This case study of groundwater policy regulation and documentation analyzes the roles of state and local agencies in the protection of public health and water resources at the former Fort Ord, California. State requirements for documents restricting land use represent a possible redundancy to a local ordnance that establishes a “Special Groundwater Protection Zone” at the former Fort Ord. Is this redundancy necessary to ensure the protection of public health and the environment?

Select this Article		Evaluation of Everglades Agricultural Area Storage Reservoirs Using Regional Modeling A. A. Prymas, P.E., L. M. Brion, and L. I. Hornung ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)101 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Everglades Agricultural Area (EAA) Storage Reservoir is a critical element of the Comprehensive Everglades Restoration Plan (CERP) being jointly implemented by the United States Corps of Engineers (USACE) and the South Florida Water Management District (SFWMD). The project purposes are to improve environmental conditions in Lake Okeechobee by reducing harmful high and low water levels; reduce the frequency of damaging flood releases from Lake Okeechobee to the estuaries; provide agricultural flood protection and water supply in the EAA; improve the performance of the large constructed wetland treatment systems (stormwater treatment areas) by attenuating inflows; and improve the timing of environmental water deliveries to the Everglades. Because the EAA is centrally located within the massive south Florida water management system and the EAA Project is addressing multiple goals, comprehensive computer modeling is needed. The South Florida Water Management Model is being utilized to simulate major hydrologic/hydraulic processes, including overland, canal, and groundwater flows, water control structure operations, and evapotranspiration. The model will help evaluate alternative plans using evaluation criteria that address benefits/impacts to Lake Okeechobee, the estuaries, agricultural and environmental water deliveries, and performance of stormwater treatment areas. The results of the hydrologic modeling will be applied to evaluation criteria and interpreted using Criterium Decision Plus, a multiple criteria decision support model. The paper will present a summary of alternative descriptions, evaluation criteria, and the approach used to compare alternatives and select the preferred plan.

Select this Article		Improving Numerical Model Efficiency of an in ‐House Simulation Model L. Guan and G. M. Shook ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)102 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In the past fifteen years, the numerical model, TETRAD, has become a standard numerical tool at Idaho National Engineering and Environmental Laboratory (INEEL). TETRAD is a multi‐phase, multi‐component numerical model used extensively in reservoir engineering and environmental modeling studies at the INEEL. Typical environmental studies take about 10‐CPU weeks to run and there are approximately 120 studies at INEEL each year. So, the time involved to complete environmental studies is significant. The applications of TETRAD involve iterative solution to the conservation equations, with convergence realized when all equation residuals are less than some user‐selected convergence tolerance. Because of the vast differences in mole fractions in many applications (order 10⁻⁸ for tracers or pollutants), this can lead to numerical difficulties including round off in the solution of the larger mole fractions (e.g., water, air). We implemented and tested revisions to TETRAD that include species‐dependent convergence criteria, such that all conservation equations are solved to similar accuracy. Various test cases are discussed, whose run times are much faster than the original version of TETRAD, with excellent comparison in species distribution.

Select this Article		A Generic Format for Multi‐Dimensional Models N. L. Jones, R. D. Jones, C. D. Butler, and R. M. Wallace ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)103 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Environmental Modeling Research Laboratory (EMRL) at Brigham Young University in partnership with the U.S. Army Engineer Research and Development Center (ERDC) is currently developing a generic data format for multi‐dimensional models. The goal of this exercise is to develop, promote, and deploy a common modeling format that facilitates data storage, exchange, access, analysis, and discovery of scientific and engineering data. The project encompasses one‐, two‐, and three‐dimensional models including river cross‐sections, scatter points, unstructured (finite element) grids, and structured grids. The objective of the project is to define a standard file format for all computational models developed at ERDC. The new model format is called XMDF (for Generic Model Data Format) and consists of a file format and an object code library (Application Programming Interface (API)). The API consists of a series of subroutines in both C/C++ and FORTRAN that can be used to read and write model geometry and data sets to the XMDF format. Model developers within ERDC will be encouraged to adopt the format for all existing and future models. Numerous benefits will be derived from the standardized model format including highly compact and efficient file i/o. Using a common format makes it possible to easily share data between models, link models, and gain access to powerful visualization tools.

Select this Article		Optimal Groundwater Contamination Monitoring Using Pumping Wells S. Shlomi, A. Ostfeld, H. Rubin, and C. A. Shoemaker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)104 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the concept, methodology, and application of a groundwater contamination monitoring plan using measurements at pumping wells. The monitoring strategy relies on the best accumulated engineering knowledge data and judgment of the contaminant concentrations on site, annual well‐pumping locations and flows, and pumping radii of influence. The monitoring objective is to accurately and quickly locate the contaminant sources and plumes, subject to a maximum annual number of samples. The decision variables are the wells to be sampled at each sampling round. The methodology suggested is a heuristic adaptive algorithm, which is limited at this stage to a single organic compound. The methodology was tested on a synthetic computer‐generated aquifer, and on real data of the Coastal Plain Aquifer in Israel. Comparisons made to previously developed monitoring algorithms indicated a much better convergence of the description of the contaminant distribution in the aquifer to its real image.

Select this Article		Multiobjective Long‐Term Groundwater Monitoring Design: The Benefits of Biasing Search Towards Key Tradeoffs Patrick M. Reed and Venkat Devireddy ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)105 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Growing interest in long‐term groundwater monitoring stems from the significant challenges that stakeholders and regulators face while negotiating sampling strategies. This study presents a new optimization tool developed to aid this negotiation process by enabling decision makers to rapidly assess tradeoffs between their conflicting objectives (e.g., minimizing sampling costs and minimizing uncertainty). This paper demonstrates how the Nondominated Sorted Genetic Algorithm‐II (NSGA‐II) and ε‐dominance archiving can be combined so that stakeholders can bias multiobjective search towards key tradeoffs. The archiving strategy for the NSGA‐II serves three purposes: (1) it ensures that high quality solutions are not lost, (2) it allows stakeholders to bias search towards important design tradeoffs, and (3) it reduces the NSGA‐II's computational demands. In this study, results are presented for a previously published groundwater monitoring case study in which ε‐dominance archiving helped to reduce the NSGA‐II's computational demands by more than 80‐percent relative to prior results. The techniques presented in this study will aid practitioners in incorporating their preferences into multiobjective search while also reducing the computational demands associated with quantifying long‐term monitoring tradeoffs.

Select this Article		Evaluation of Geostatistics for Combined Hydrochemistry and Microbial Community Fingerprinting at a Waste Disposal Site Paula J. Mouser and Donna M. Rizzo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)106 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Traditional multivariate statistics and geostatistics were used to analyze groundwater hydrochemistry (alkalinity, Mn, Fe, Si, Al, Mg, NH₄, Ca, K, Na, Cl, SO₄, H₂S, NO₂, NO₃, CH₄, pH, DO, EC, and DOC) and microbial data (16S rDNA DGGE community profiles of Bacteria and Archaea) previously collected from a landfill leachate contaminated aquifer. Variograms and cross‐variograms developed for principal components formed from hydrochemistry and rDNA correlation matrices showed spatial correlation between 30m–55m. Kriged principal components indicate the combination of hydrochemistry and Bacteria data may provide better estimates for unknown locations, particularly along the boundary of the plume. The principal components between these two types of data appear to complement each other, as hydrochemistry PC1 appears to separate sample locations vertically and Bacteria PC1 separates sample locations horizontally. These combined data with a multivariate‐geostatistical approach may be useful for delineating leachate contaminated zones at waste disposal sites and provide managers with better estimates of risk at unknown locations.

Select this Article		Development of Ant Colony Optimization for Long‐Term Groundwater Monitoring Yuanhai Li, Amy B. Chan Hilton, and Liang Tong ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)107 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Groundwater remediation projects require long‐term monitoring (LTM) to assess compliance of active remedial systems and post‐closure sites where groundwater contamination is still present. LTM can be costly given the large number of sampling locations, frequency of monitoring, and number of constituents monitored at a given site. This work presents the development of a methodology to optimize a groundwater‐monitoring network in order to maximize cost‐effectiveness without compromising program and data quality. We propose method that combines ant colony optimization (ACO) with a genetic algorithm (GA). The ACO method is inspired by the fact that ants are able to find the shortest route between their nest and a food source. This is accomplished by using pheromone trails as a form of indirect communication. Ant colony simulation techniques are adapted to minimize the number of monitoring locations in the sampling network without significant loss of information.

Select this Article		Aquifer Characterization and Parameter Heterogeneity Estimation with a Coupled Zonation‐Geostatistical Method and Natural Neighbors Frank T.‐C. Tsai, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)108 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This research develops a generalized parameterization method that couples zonation and geostatistics for characterization and identification of a stochastic field. The coupled zonation‐geostatistical method honors distinct pointwise measurements in a field to create a zonation structure, a kriging field, or a mixed distribution. In this study, a Voronoi tessellation (VT) is adopted to create a zonation structure of Voronoi cells over a set of sample points. VT determines the boundary, shape, and distribution of zones completely and uniquely for a given set of sample points. Other than zonation approach, this study develops a natural neighbor kriging (NNK.) method that honors natural neighboring sample points for estimation. The natural neighbors of an estimation site are determined by VT. Specifically, we combine VT and NNK together as a coupled VT‐NNK method by introducing a set of binary weighting coefficients to the sample points. The coupled VT‐NNK method possesses greater flexibility to characterize the randomness of parameter heterogeneity and makes the best linear unbiased estimation (BLUE) over a set of binary weighting coefficients. In the numerical example, we identify transmissivity heterogeneity with coupled VT‐NNK by seeking the optimal binary value of weighting coefficients such that the fitting residual of observed groundwater heads is minimized. The nonlinear binary integer minimization problem is accomplished by a genetic algorithm (GA) to obtain a near‐global optimal solution. Results show that coupled VT‐NNK. is able to capture the non‐smoothness of true heterogeneity and gives small groundwater head fitting residual.

Select this Article		Optimizing LTM Networks: A Comparison of Approaches at Three Sites (Extended Abstract) Kirk Cameron and Philip Hunter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)109 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Air Force spends millions of dollars annually on groundwater Long‐Term Monitoring (LTM) networks at installations around the country. Because LTM is costly and its well networks so extensive, the Air Force is actively pursuing testing and implementation of optimization strategies for its LTM networks at a number of sites. One such strategy developed in coordination with AFCEE is a decision‐logic statistical optimization scheme named the Geostatistical Temporal‐Spatial algorithm or GTS. GTS uses known statistical and geostatistical techniques in a novel manner to answer two questions: given an existing LTM network, 1) what is the optimum number and placement of wells in that network (i.e., is there spatial redundancy and/or is there ‘undercoverage’ within the spatial network)?, and 2) what is the optimal sampling frequency for wells in the network (i.e., is there temporal redundancy)? Optimized networks in typical applications of GTS have resulted in an estimated cost savings off the total LTM budget of over 30%. To measure spatial redundancy, GTS has heretofore applied kriging and robust spatial modeling techniques in an iterative fashion in order to identify optimal subsets of the existing monitoring network. Optimality is measured by balancing the costs of sampling, analyzing, and maintaining the ‘optimal’ network against 1) deterioration in estimated site maps compared to the baseline, 2) increases in global uncertainty associated with map estimates, and 3) increases in localized areas of uncertainty. To maximize the algorithm's flexibility, numerous changes and improvements to GTS have been tested. Some of these changes have been applied at LTM networks on three different Air Force bases in California, New Hampshire, and Maine. More specifically, comparisons have been made between the iterative mapping approach — where increasingly optimal well location subsets are identified via changes in the global estimation weights — and a newer approach based on the use of genetic algorithms. The specific genetic algorithms developed for GTS are designed to perform the overall spatial optimization more efficiently and in fewer analysis steps.

Select this Article		Predicting the Probability of Occurrence of Heavy Metals in Ground Water Using Ordinal Logistic Regression Navin Kumar C. Twarakavi and Jagath J. Kaluarachchi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)110 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Ground water is an important natural resource that provides drinking water to more than half the population in the United States. Unfortunately, this important natural resource is vulnerable to variety of contaminants. Some of these contaminants are nitrates, pesticides and heavy metals. Heavy metals like arsenic, mercury, lead, cadmium and chromium contaminate ground water from natural and anthropogenic sources. Few studies have been done to characterize heavy metal contamination on a regional scale. A new ordinal logistic regression (LR) model was used to predict the probability of heavy metal contamination with respect to two thresholds‐ natural background concentration and maximum contaminant level (MCL). Sumas‐Blaine Aquifer, located in Washington State, was used as the study area for the model. The model considered variables representing soil, land uses, permeability, depth, clay content and surface elevation. Ordinal LR model was applied to relate the probability of contamination by individual heavy metals to the independent variables. The model showed a good fit. The model results are in agreement with observed data. Spatial analysis was performed using GIS technology to better understand the spatial distribution of probabilities of heavy metal contamination with respect to thresholds. Ordinal LR model was applied to predict the probability of heavy metal contamination, in general. The model results are close to the observed probabilities (r² = 0.90). Estimating the probabilities of occurrence of concentration with respect to background concentration and MCL for heavy metals individually and in general, help in managerial decisions as well as understanding the geochemistry of heavy metals.

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INTERNATIONAL ISSUES

Select this Article		Evaluation of Impacts on the Lower Indus River Basin Due to Upstream Water Storage and Diversion Altaf A. Memon, Ph.D., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)111 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The River Indus system comprises of seven rivers. Due to upstream storage and diversion activities in the upper basin, there has been a steady decline of the water outflow to the lower basin, the Indus delta, and to the Arabian Sea. This has created a huge water shortage problem in the lower basin, resulting in devastating economic, social, and ecological losses. This paper evaluates some of these impacts and offers some recommendations.

Select this Article		Integrated Environmental and Economic Development Planning: A Methodology with Case Study in North East Thailand D. Gunaratnam, H. Ludwig, J. Foerster, and Kumar Mohit ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)112 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Integrated environmental and economic planning that considers both regional economic development and the environmental impacts of such development has rarely been used by governments to plan regional growth largely because of the absence of a methodology that would allow future environmental impacts of proposed development plans to be quantified in monetary terms and used by Economists (E1) in their overall cost‐benefit analysis of projects/sectors targeted for investment. This paper discusses a new approach for achieving integrated economic‐cum‐environmental planning (IEEDP). This paper involves use of “unit load curves” (ULCs) for major pollutants, such as BOD, SS, and Toxics, expressed in terms of pollutant load (tons)/unit Gross Regional Product (GRP ‐ $) to determine current and projected loads of pollutants and their cost to the economy. ULCs are also used to determine the costs of all other known environmental impairments including reduction in dry season river flows due to deforestation, peak flow changes and flooding, additional health costs, river water quality deterioration costs, and lost fisheries, These are considered to be the main threats to sustainable development in Northeast Thailand which was used for a case study. The development of the IEEDP method is based on work undertaken as part of an Asian Development Bank (ADB) project in the Mekong River Basin. The results show that conventional or “business‐asusual” planning for Northeast Thailand would cost some 28.1 billion baht between 2000–2030 in water related damages due to economic growth. An integrated economic‐cum‐environmental plan is developed to assess and cost environmental damages (EDs) of conventional development planning to prepare and cost a correction program for these damages, and to modify the investment plan to include only projects will favourable cost/benefit resulting in a sustainable development plan both economically and environmentally. The results show that IEEDP would lower water related damages in Northeast Thailand to some 12.6 billion baht between 2000–2030. The investment in the correction program would have an approximate not present value of 6.8 billion baht with an IRR of 104%.

Select this Article		Recovery of a Water Supply System as a Means to River Restoration I. Jose Ochoa‐Iturbe ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)113 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract During the 1960s the Tuy river supplied 4 cubic meters per second to the water supply system of Caracas, Venezuela. Forty years later, the river is so highly polluted that water is only extracted during emergencies (droughts mostly) and other rivers have been tapped to replace the Tuy and to balance demand from a growing population. The paper resumes years of data collection for the basin, its main polluters and degrees of pollution along the river. It analyzes costs of recovery and the benefits to be obtained, specially from the reuse of the river as a water supply source. Costs are compared with the building of yet another dam in a river about 200 miles from the city and at a lower elevation, increasing pumping costs. The paper demonstrates that the renewal of 4 cubic meters per second of potable water to the city justifies , from the economic viewpoint the restoration of the upstream basin from the intake, and delays in time the building of the new dam.

Select this Article		Integrated Water Resource Management in Chile: To Be or Not to Be Matthew D. Davis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)114 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Development and impediments to integrated water resource management in Chile are presented. Sustainable water use supports social objectives into the indefinite future without undermining environmental and hydrological integrity. International consensus exists that integrated water management and watershed management form a sound basis for sustainable water use. Increased water user conflicts, water quality degradation, recognition of economic inefficiencies, acknowledgment of ecological flows requirements, and public good issues are leading toward a more integrated and watershed based approach to water management in Chile. Despite these issues and concerted effort since the early 1990s, however, integrated water resource management and watershed management has not yet materialized and progress remains slow. Impediments in Chile to integrated water resource management include opposition due to political dogma and special interest groups, as well as lack of stakeholder participation and enabling legislation.

Select this Article		Community‐Based Urban Safe Water Management in Semarang Indonesia Wijanto Hadipuro ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)115 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Some conflicts on water resources management in Indonesia are escalating nowadays ‐ conflicts between privatization and heavy state intervention in managing water resources among NGOs and also among government institutions such as conflicts between State Ministry of Environment and Ministry of Settlements and Regional Infrastructure. Whether the best way in managing water resources is by inviting private sector or through heavy state intervention, the fact is that the victim of the two conflicting ways in managing water resources is community‐based water resources management. Actually in urban areas such as in Semarang, the capital of Central Java Province in Indonesia, there are many community‐based management in providing safe water for a community in certain area. Sinar Waluyo Estate, Tanah Mas Estate, Bukit Semarang Baru Estate, and Jangli Permai housing area are some of them. Sinar Waluyo Estate and Tanah Mas Real Estate for example have supplied safe water for their residents for more than twenty years. Because of the bad services of Semarang City Regional Public Water Utility Company, the residents of Jangli Permai and the developer of Bukit Semarang Baru have also managed to provide safe water by themselves. As one of the alternatives in managing water resources, specifically in providing safe water for household activities, it is interesting to do a thorough research on how they manage safe water by themselves: how they practice participatory management for the urban safe water, the efficiency that is the attempt to maximize the economic and social welfare, the equity in the allocation of scarce water resources and services to different economic and social groups, and the environmental sustainability of the three actors in water management, the government as regulator, the management of urban safe water as policy maker, and the behavior of the community. Many people forget that community‐based management in providing safe water has longer history than both private and heavy state intervention. The result of the research could give picture of community‐based urban safe water management model in developing countries.

Select this Article		Indigenous Rights and Modern Water Management in Chile Matthew D. Davis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)116 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract An overview of indigenous rights and modern water management in Chile are presented. Fundamental cultural and spiritual differences exist between the dominant and indigenous cultures. The prevailing European or Western societal view of natural resource management embodied in current legislation is of ownership and use. Indigenous communities in Chile traditionally viewed themselves as part of nature and often treated water as a communal good. Historic interaction of indigenous communities and European immigrants in Chile followed a similar world pattern: spread of disease, armed conflict, subjugation to the dominant culture, and usurpation of indigenous land and water rights. Many indigenous communities were further marginalized during the military regime (1973–90), perhaps due to their communal society being associated with communism. Increased water conflict has occurred during the last 30 years due to socio‐economic government policies and rapid economic growth that has stressed the resource. Insufficient protection of indigenous rights and lack of targeted policies to enable indigenous communities to sustain themselves have occurred. Important national steps have been taken recently to redress and reconcile a multi‐ethnic society. It remains to be seen whether this process continues and produces tangible results.

Select this Article		Brief Introduction of South‐to‐North Water Transfer Benqing Ruan, Lianxiang Wang, and Lintao Chen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)117 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In order to mitigate water crisis in northern and north‐western China, a huge project of South‐to‐North Water Transfer is going to be built, which will divert water from upper, middle, and lower reaches of Changjiang River to the north part and northwest parts of the country. The project consists of 3 water diversion route projects, i.e. Western Route Project (WRP), Middle Route Project (MRP) and Eastern Route Project (ERP). The 3 routes will come across with 4 major rivers, i.e., Changjiang River, Huaihe River, Huanghe River and Haihe River. They will jointly form a general frame called as “Four‐plus‐Three”. By the target year of 2050, the total water volume to be diverted will be 45 billion m³. The whole project will be executed in 3 stages depending on real situation of the project development.

Select this Article		Water Resources Development and Management in Taiwan Jan‐Tai Kuo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)118 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Annual average precipitation in Taiwan is 2,500 mm which is about three times the world average. However, because of its high population density (23 million), the average annual precipitation per capita is 4,500 m³ which is only sixth of the world average. Due to other natural factors, such as uneven temporal and spatial distribution of precipitation and steep slope of rivers, which make water resources management in Taiwan more difficult. Taiwan also is facing other problems, such as people's opposition of building new large dams. This paper reports the stages of water resources development in Taiwan, discusses the important issues of water resources management and suggests some solutions.

Select this Article		Application of Remote Sensing to Water Resources Management in Arid Regions of China Jiren Li ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)119 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract China is lack of water resources, especially in its arid regions. So the management of water resources in these areas is very important. Remote sensing technology has its special advantage in this aspect. The paper introduces the application of remote sensing, including GIS, in this field, such as surface water resources investigation, groundwater exploration, dynamic monitoring of ecology, salinisation, water environment and deserfication, drought monitoring, planing of water diversion projects and so on. It shows that remote sensing technology can play important role for economy development in West China, especially in Northwest China.

Select this Article		Utilization of Water Resources and Water Right Management in Yellow River Huian Li and Wenge Zhang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)120 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Yellow River Basin is characterized with ‘different sources of water and sediment, less water and much sediment, mismatching of flow and sediment and uneven distribution of precipitation both in a year and in years’. With the development of economy and society, the contradiction between water supply and water requirement in Yellow River basin has become sharp increasingly and water resources conflicts among different water users occur frequently. Especially in 1990s, the problem of zero‐flow in its lower reaches became seriously year after year. This paper introduced the basin water features, analysed the present situation of water utilization and water problems in the Yellow River basin. Then, as for as existing problems presently of water shortage and water pollution, the authors analysed the importance of developing water right management, studies the legal base and problems to implement water right management. At last, the basic thinking of water right management was proposed.

Select this Article		Situation of Water Resources Quality and Its Progress of Research in China Guibao Li and Huaidong Zhou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)121 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The authors analyzed the situation of water resources quality in China. Results showed that the major rivers are generally confronted with organic pollution and non‐point source pollution, which is getting serious. Dianchi Lake, Taihu Lake and Chaohu Lake have seen a rising trend of eutrophication. The ground water in most cities has suffered with point‐sources and non‐point sources pollution and the contents of some elements in some places exceeded the limitation. A summary of the progress of studies was made mainly in 4 aspects: water purification and treatment technology; water resources quality and safety; water resources quality planning and assessment; and water resources quality simulation and calculation.

Select this Article		Development and Utilization of Water Resources in Northern China Zhang Xiangming and Wang Jiancheng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)122 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The north part of China is the most serious area of water shortage in China. The total amount of water use was increased from 243.7 billion m³ in 1994 to 254.2 billion m³ in 2002. The annual increase rate of water use was much lower than the growth rate of the population. The water use per capita was also decreased. The over‐development of water resources has caused severe eco‐environmental problems so it is very difficult to further augment the capability of water supply. Therefore optimizing the distribution of water resources, improving the efficiency of water use, enhancing the saving of water use as well as protection and rehabilitation of eco‐environment have become the key factors for the sustainable development and utilization of water resources in the northern China.

Select this Article		Discussion on Compensation for Water Resources Restoration Ben‐qing Ruan, Chun‐ling Zhang, and Jia‐bao Huang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)123 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The compensation for water resources restoration aims at promoting the natural water system. The authors analyzed water resources decline problems and discussed the compensation mechanism for water resources restoration, for the purpose of solving problems, such as water shortage, water environment degeneration, and ecology destroy. The connotation of water restoration and compensation was discussed. Four types of compensation and two scopes of compensation as well as between generations were also discussed.

Select this Article		Study of Aeration in the Water Flow over Stepped Spillway Xiang‐ju Cheng, Lin Luo, and Wen‐qian Zhao ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)124 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Stepped spillway is one of the idea forms to increase oxygen content in water body for hydraulic and environmental engineering. The effect factors on aeration rate in the water flow is closely related with the height, slope of step and water depth of the flow over stepped spillway. The relation between aeration rate and the effect factors mentioned above is developed. The aeration rates of 35 working conditions in the water flows over stepped spillways are simulated using numerical model. The simulated results are compared with experimental data by Chanson. It has shown that the simulated results are fairly coincident with experimental data. The study provides solid theoretical fundament on optimum design of spillways to increase oxygen content in water body.

Select this Article		Pollution and Water Quality Evaluation for Tseng‐Wen Reservoir Chih Hua Chang, Ching Gung Wen, Su‐Maan Chuang, Chih Sheng Lee, Shui Ping Chang, Jonq‐Lin Wu, and Pao‐Wen Liu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)125 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Tseng‐Wen Reservoir is the largest reservoir in Taiwan. It is also the most important water resource of Taiwan's largest plain ‐ Chianan Plain. Due to the development of recreation and agriculture applications in the drainage area, the water quality was achieving a eutrophic state. The concentration average of the total nitrogen (TN) was 0.92 mg/L. The concentration average of the total phosphorus (TP) was 40 (μ/L, and the concentration average of chlorophyll‐a was 5.84 μg/L. The nutrient released to the reservoir primarily came from non‐point pollution sources. Regardless of the forecast which occupied 77% of the drainage area, agriculture lands contributed 16.4% of the TN and 11.3% of the TP to this reservoir. Fishing also contributed 7.6% of the TP. Therefore, regulating inappropriate forest applications, promoting best management practices (BMP) in agricultures, and forbidding the fishing activities are recommended to improve the water quality in this reservoir.

Select this Article		The Application of Middleware Technology in Design of Flood Control Decision Support System Jian‐cang Xie, Min‐cong Huang, and Ni Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)126 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Considering the actuality and problem faced the Flood Control Decision Support System, an integrated design about a flood control system based on middleware technology is introduced in this paper to realize the reuse of the existing results. A simple instance based on the design is also implemented so as to advance a new thought on improving software reusability and on accelerating the industrialization of software produce.

Select this Article		Spatial Variability of Water Levels in River Network of the Pearl River Delta Xiaohong Chen, Yongqin David Chen, Jinghan Zhou, and Lei Zhang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)127 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Based on the theory of regionalized variables, the spatial variability of water level in river network of the Pearl River Delta (PRD) was analyzed. The semi‐variagram revealing the spatial structure of water level in river network of the PRD was given. The directionality and the range of correlation for water level in the river net were worked out. With the analysis of spatial distribution of water levels, an example for optimized interpolation for water levels in river net of the PRD with ordinary kriging was given. Comparison between kriged and measured stages at 15 stations in the PRD river net showed that the maximum relative error is less than 1%.

Select this Article		Primary Ecological Effect Analysis of Emergent Water Transportation in the Lower Reaches of Tarim River Based on Remote Sensing Technology Shi‐Feng Huang, Mei Xu, and Jia‐Bao Huang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)128 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Tarim River is the biggest inland river in China. Its problem of eco‐environment is worsening in the lower reach. For keeping this trend within limits, emergent water diversion to the lower reach was carried out. In this paper, the remote sensing technology was applied to the analysis of eco‐environment effect after water diversion. The result show that the vegetation index and cover ratio increased but not markedly, the eco‐environment situation can not been improved obviously up to now. Its effectiveness was temporary. The continuity, quality and quality of water source for the Tarim River must be ensured.

Select this Article		Transboundary Water Resources of the West Bank Loay J. Froukh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)129 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The political boundaries between the Palestinian and Israelis make the water issues critical and sensitive, Groundwater is the primary source for the Palestinian in the West Bank. Although, there are many studies on the shared surface resources (Jordan River Basin), there are few studies on the groundwater shared resources between the Palestinians and Israelis. There are three primary groundwater basins underlying the West Bank (Eastern, Northeastern and Western Basins) as shown in Figure 1, Both the Northeastern and Western basins are shared between Israelis and Palestinians. The Palestinians have a limited access to the Northeastern Basin and strictly limited access to the Western Basin. In addition to the quantity of available water resources, the quality of water is emerging as a critical issue. Threats to ground water quality include disposal of untreated wastewater, increasing salinity due to agricultural activities and intrusion of native groundwater of poor quality. Widespread use of herbicides and pesticides also represent a threat to drinking water supplies. The Declaration of Principles signed in Washington D.C in 1993 was a major step toward resolution of the political conflict between the Israelis and Palestinians. However, the water issue is part of the final status negotiations, which still unresolved. As resolution to political conflict is pursued, it is clear that water resources management issues remain at the forefront because of the transboundary nature of the hydrologic regime. Cooperative management on the technical level appears to be the only alternative to further conflict and degradation of the region's scare water resources. This paper will study the impact of the transboundary resources on both sides and explore some of the most significant groundwater management issues facing both the Palestinians and Israelis.

Select this Article		Will Palestinian Water Development be Possible? Mac McKee, Anan Jayyousi, Ammar Jarrar, and Jagath Kaluarachchi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)130 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper examines the history that lead to the present‐day allocation of the waters that are jointly claimed by Palestinians and Israelis. It describes the status of the water sector in Israel at the time the Oslo II Peace Accords were signed, and contrasts these Israeli conditions with the development of water resources in the Occupied Palestinian Territories under the auspices of the Oslo II accords. The paper reports on the impacts that have been sustained by the Palestinian water infrastructure during the current Intifada, and speculates on the conditions that will have to prevail before Palestinian‐Israeli water issues can be resolved. The paper is based in part on personal experiences of its authors in working in the Palestinian water sector since 1996. It documents a sampling of problematical situations and conditions related to water management in the region that are not frequently reported in the western media, that do not command the attention of academic researchers, but that provide a glimpse into reasons why the joint management of the waters shared by Palestinians and Israelis was not possible under the framework of Oslo II. In particular, conditions “on the ground” that are peculiar to the water sector and that continue to prevent an integrated approach to the management of transboundary water in the Occupied Palestinian Territories are discussed.

Select this Article		An Overview of the Two Seas Canal and Its Implication Ammar Jarrar, Anan Jayyousi, Hafez Shaheen, Mac McKee, and Jagath Kaluarachchi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)131 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Jordan River is a relatively small watercourse with many historic, cultural, hydrologic, ecologic and political significance. It is shared by five independent countries, Lebanon, Syria, Jordan, Israel and Palestine. During the last thirty years, most of the Jordan River was diverted for different uses which leave less than 10% of the long‐term average flow into the Dead Sea. As a result, the Dead Sea surface area reduced from 1,700 km² to less than 500 km² and the level dropped more than 25 meters. To save the Dead Sea from disappearing and to produce more water available, a canal among many other solutions has been proposed to transfer water to Dead Sea from adjacent water bodies using the difference in elevation between the Dead Sea and Red Sea or the Mediterranean. This paper discusses the concept of intersea transfer and the feasibility of this approach.

Select this Article		Development of Water Supply and Demand in Palestine Anan Jayyousi, Ammar Jarrar, Mac McKee, and Jagath Kaluarachchi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)132 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Palestine is among the countries with the scarcest renewable water resources due to both natural and artificial constraints, amounting to only 100 cubic meters per capita per annum. This amount is far below the available water in other countries in the Middle East and the World. At present, the water demand exceeds the available water supply. The available supply is constrained mainly due to artificial non‐economic factors. The gap between the water supply and water demand is growing due to the population growth, improving standard of living standard, and the need to expand irrigated agriculture and industrialization. This paper will give an estimate of the projected Palestinian water demand in light of the proposed national targets and will assess all potential water sources both conventional and non‐conventional.

Select this Article		Hydro‐Ecological Situation in the Basin of the River Zaravshan in Uzbekistan D. Kh. Fayzieva ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)133 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Zaravshan River Basin is one of the most densely populated areas in Central Asia. The length of Zaravshan River is 877 km, the watershed area is 17.7 thousand km², and the population is more than 5 million. The current social and economic situation in this region requires a significant increase of water supply to communal and household needs, developing industry, irrigated agriculture and other fields of the national economy. Although the Zaravshan River is the sole source of potable water supply, it receives communal, household, industrial and agricultural sewage in Leninabad province of Tajikistan, and the Samarkand and Navoi provinces of Uzbekistan. All along, the river is characterized by intensive pollution by agricultural, stock‐breeding, industrial and sewage waste flow. Consequently, it is one of the most polluted rivers in Central Asia. Impoverishment of water resources in this area has been caused by significant consumption of water for irrigation and drainage of agricultural lands. Drainage water brings herbicides, pesticides and defoliants. Salinity of water increases 6–8 times from the river head to the river outlet ‐ from 0.27–0.30 g/l to 2–2.4 g/l. Particularly in its lower part it becomes unusable for drinking purposes due to chemical contamination. Since there are no water and sewage systems in rural areas, population of the region receives water that does not meet any health related requirements. At the same time, a tense situation with water utilization and ecology is developing in the region which no doubt manifests itself in the health situation of the region. The situation is also worsening because a number of residents in rural areas use water from open reservoirs and canals for household needs and drinking. According to the report of the Central hydro‐meteorology service of Uzbekistan, the quality of water in the Zaravshan River is of class IV by the Surface Water Pollution Index, which means polluted and heavily polluted water. The most contaminated water is in the area below the Navoi city. The maximum concentration of pollutants, which are the major indicators of contamination of water reservoirs with organic and biogenic substances in this area is: phenol ‐ 0.005 mg/L (5 times higher than the maximum allowable concentration (MAC)), petroleum products ‐ 0.64 mg/L (12.8 MAC), nitrates ‐ 0.202 mg/L (10.1 MAC). Such concentrations of these substances are mostly due to the existing anthropogenic pressures on the water resource.

Select this Article		Cost/Benefit Analysis of Oily Water Discharge Regulations in Egypt Amir A. M. Gerges and Edward Smith, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)134 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Current Egyptian regulations for discharging oily water from production operations to the sea allow a maximum of 15 ppm oil‐in‐water. International standards call for a maximum of 40 ppm, which will eventually decrease to 25 ppm by 2006. The rationale behind setting up the limit to a maximum of 15 ppm has not been evaluated previously. The intention of this research was to verify the need for such a highly restrictive limit. The study has been confined to the Gulf of Suez, being a major oil exploratory zone as well as a worldwide tourist attraction. Its rich marine life ranks it as one of the most sensitive environmental habitats in the world. Findings were based on their direct impact upon Gulf of Suez oil and gas production operations and categorized as ‘political’, ‘technical’ and ‘commercial’. Although extensive research in this field has taken place, there is no globally recognized set of standards to govern the process of produced water disposal. Environmentally sensitive areas within the Red Sea have been least affected by oil and gas produced water discharges. The main threat to the ecology of the Red Sea is oil lost by ships, from construction and dredging, and from wastes produced by activities in the coastal zone. Moreover, emphasis on the overall monthly or yearly loadings rather than daily concentration of oil‐in‐water discharges is considered the best approach in managing discharges to a marine body. Fate and transport modeling confirmed that adopting a discharge requirement of 25 ppm (maximum) will have negligible impact on environmentally sensitive areas in the Gulf of Suez. Although a sizable fraction of the oil‐to‐sea will be deposited in the sediments, a considerable portion will exit the ecosystem altogether, with a resulting negligible effect on water quality. From a commercial perspective, treatment of produced water to 15 ppm or lower would cost operators between 5 to 6 times over the normal industry practice for 40 ppm, rendering any associated environmental gains unjustifiable. In summary, relaxing the discharge criteria to 25 ppm (which is the current global industry aspiration) for new fields will have a negligible impact on the environmental conditions and almost no negative impact on the biological or marine life in the Gulf of Suez, while at the same time promoting conditions for sustainable development in Egypt.

Select this Article		Flux and Bioavailability of Phosphorus in the Solute and Sediment Loads of the Brahmaputra River: Sustainable Management of a Key Resource C. Mahanta, R. K. Goswami, and U. Dutta ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)135 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Large gaps exist in the understanding of how P forms, in what quantities, to what depths, with what mobility and availability in the Brahmaputra river basin. Almost 90% of the suspended load in the Brahmaputra is carried during monsoon as medium and fine sands. Concentrations of suspended sediments were found to vary from 500mg/l to 1800mg/l over a midstream stretch of 700 km. Suspended sediments ranged in size up to 600 μm. 70–80% of the monsoon load was coarser than 40 μm. The total P in suspended load varied between 950 μg/g to 1330 μg/g with net increase in down‐river concentration. Sequential extraction revealed about 80% P to be extractable. Grain size differentiation in sediments, particularly in case of detrital‐P was a major cause of decrease of organic‐P and total‐P after deposition. Apatite‐P formed significant part of sediment associated P during high flow except at locations where agricultural, industrial and municipal loads were large. Demographic and socio‐economic factors indicated that the factors driving environmental changes in the Brahmaputra watershed are likely to continue, and problems for sustainable management of key nutrients like P would also prevail. Considering that the Brahmaputra watershed is only next to the Yellow river in terms of average sediment yield, this would subsequently contribute significantly to the modification of the global cycles of P. The total flux of P from the Brahmaputra (8.4 × 10⁴ tons/year) constituted nearly 5% of the global flux and was about three times greater than that carried in dissolved form. However, low P bioavailability in the suspended load suggested that curtailing sediment input to the Brahmaputra might not be critical compared to other rivers, as minimizing sediment input to the river would produce little reduction in bioavailability of P.

Select this Article		A Strategy for Protection Drinking Water Resources and a R&D Project to Evaluate Threshold Values for the Oligotrophication Process of Lakes I. Chorus, B. Heinzmann, and I. Schauser ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)136 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract After reduction of the external phosphorus load by phosphorus elimination plants, Lake Tegel and Schlachtensee in Berlin underwent a significant trophic improvement. The phosphorus elimination plants work by precipitation/coagulation/flocculation — sedimentation — post precipitation — filtration. The external load was reduced by one to two orders of magnitude down to 10 – 20 μg P L⁻¹. The inlake phosphorus concentration followed. Below a threshold value of about 50 μg P L⁻¹ the development of algae and cyanobacteria was clearly phosphorus‐limited. In Lake Tegel, the external load reduction was counteracted by internal load, related to the nitrate concentrations above the sediment. A current R&D project aims at determining patterns of the oligotrophication process, including thresholds for reactions, using mass balance calculations and numerical models.

Select this Article		NAFTA Ten Years Later — The Environmental Side Agreements Mark W. Killgore, P.E. and David Eaton, Dr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)137 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract On January 1, 1994, Mexico, Canada, and the United States implemented the North American Free Trade Agreement (NAFTA). As part of that process, the three nations also began to operate under NAFTA's Environmental Side Agreements. Ten years have elapsed and it is worthwhile to examine issues associated with the decade's efforts to improve environmental conditions in North America and enhance environmental health along the Mexico‐U.S. border. This paper is an initial product of the Environmental and Water Resources Institute's (EWRI) Task Committee on Trans‐boundary Environmental Management in Canada, Mexico and USA after NAFTA (NAFTA Task Committee), which was set up in 2002 to monitor developments under NAFTA. It is beyond the scope of this paper to address the environmental consequences under NAFTA. This paper does describe the activities in three trans‐boundary environmental institutions established under the NAFTA environmental side agreements: the North American Commission on Environmental Cooperation (CEC), the Border Environmental Cooperation Commission (BECC), and the North American Development Bank (NADBank). These comments are based in part upon visits by the co‐authors to Washington, D.C. to discuss NAFTA with officials of the U.S. State Department and the U.S. Environmental Protection Agency in February 2003 and their participation as EWRI representatives at the Tenth CEC Joint Public Advisory Committee (JPAC) Meeting in Washington DC, held June 23 through 25, 2003.

Select this Article		Is the Irrigated Subsector of the Developing World Ready for the Shock Waves of Coming Globalization? L. Humberto Yap‐Salinas ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)138 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Irrigation has been considered the hope for economic recovery in many agriculturally‐based developing countries. However, irrigation has not satisfied the economic and social needs of these countries. Why hasn’t irrigation, despite many development projects and its status as a priority in these societies, been able to significantly improve living conditions and decrease poverty? There are external reasons, internal reasons, and the element of human capital involved in each. In order to make irrigation a true key to development and reduction of poverty in the Third World, an understanding of underlying factors, with corresponding substantial changes, is necessary. An integrated approach to the situation should address both internal and external problems that impede the benefits that irrigation should bring. External factors are related to the market. Are developed nations really sincere in their desire to help the developing world? Two suggestions—reduction of tariffs and reduction of farm subsidies in developed nations seem to be the main avenues to open markets to farmers in the developing world. In fact, these possible solutions have been discussed in WTO meetings in Doha and were on the decision‐making agenda for the WTO meeting in Cancün, where agricultural trade was discussed. Indications were that globalization would be implemented as of 2005. Globalization will come as an economic shock to the developing world. However, the next question is: Is the developing world ready and flexible to meet the demands of and rapid response required by globalization, when and if it happens? The answer is that it generally is not. In this article, strategies to prepare the agricultural sector in the developing world for this coming shock wave are discussed. Structural and nonstructural alternatives are prioritized.

Select this Article		The World's Poverty, Climate, Water Supply, Energy, and Risks George H. Hargreaves, F.ASCE and Mark R. Hargreaves, J.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)139 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract There is an urgent need to improve the quality of life for the 2.5 – 3 billion people now living in poverty. More than 1.1 billion are undernourished. Many are water poor and/or energy poor. It is urgent that efforts be increased to improve the knowledge of renewable, sustainable, and environmentally friendly resources that can be used to provide a better quality of life for the present population and for the probable doubling of the population within this century. Water is available as precipitation, surface water, and groundwater. Knowledge of the adequacy of these sources of water is based on estimates. These estimates are based on available data that is usually incomplete, fragmentary, or of poor quality. The international agencies should make a strong effort to improve the quantity and quality of the available information on how much, when, and where water is available. Some estimates of the availability of water are included in this paper. A moisture adequacy index (MAI) and some of its uses are described. The World Water and Climate Atlas and its use in determining water availability are described. The World Commission on Dams and the United Nations (UNESCO) have provided guidelines on how to meet the needs for increased electrical energy and for water used for other purposes. A small increase in the use of electrical energy can produce a large reduction in poverty, reduce malnutrition, improve health, and decrease population growth. This paper strongly supports the recommendations of the World Commission on Dams and The United Nations (UNESCO). The world wide potential for green energy is enormous. Laws that decrease the use of non‐renewable energy and encourage the use of renewable resource energy should be strengthened. A brief overview of some of the legal issues is included.

Select this Article		Community Perceptions and Priorities for Managing Water and Environmental Resources in the River Njoro Watershed in Kenya M. W. Jenkins, F. K. Lelo, L. W. Chiuri, W. A. Shivoga, and S. N. Miller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)140 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Njoro Watershed, typical of the semi‐arid basins in the Rift Valley of Kenya, is undergoing a new phase of rapid land use change in the uplands portion of the watershed, and on‐going significant growth in both rural and urban populations. Considerable negative environmental impacts are occurring, in particular to the quantity and quality of river water. Domestic, livestock, commercial, industrial, and institutional water users in the basin are affected, as well as important downstream habitat in Lake Nakuru, a large shallow saline lake designated a Ramsar wetlands site of international importance. In response to these concerns, ajoint US‐Kenyan multidisciplinary applied research project called Sustainable Management of Watersheds Collaborative Research Support Program (SUMAWA‐CRSP) was established. SUMAWA aims, over the next 3–5 years, to demonstrate improved and integrated management of water and environmental resources in the Njoro Watershed through local stakeholder participation and action supported by scientific information and analyses. Preliminary results from elements of the SUMAWA planned process for stakeholder participation in management of the Njoro Watershed are presented. A mixture of participatory methods, discussion forums, awareness‐raising activities, and local capacity building are being undertaken to address some of the challenges involved in engaging local stakeholders and communities in watershed action planning. The first phase of activities adapts Participatory Rural Appraisal methods to assess local residents' interests in and perceptions of the current condition of river water quality and quantity, of problems and their causes, and opportunities for local action in six different communities along the length of the watershed.

Select this Article		Water Resources Management Policy Evaluation in the Brantas Basin, East Java, Indonesia Charles Rodgers and Ximing Cai ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)141 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract We describe the application of an integrated economic‐agronomic‐hydrologic river basin policy simulation model, intended to assist water managers in designing and evaluating strategies for improving the physical and economic productivity of water. The model is specified for the Brantas Basin in East Java, Indonesia, a densely populated catchment of 12,000 km² containing extensive irrigated agriculture. The Brantas is seasonally water constrained, and municipal and industrial users compete with irrigated agriculture, and with environmental quality demands, for increasingly scarce water. As options for supply augmentation in the Brantas are limited, water managers will depend increasingly on demand management strategies, particularly those effective in limiting irrigation abstraction. We describe the results of three simulation scenarios, including the introduction of volumetric water charges, the reduction of paddy and sugarcane price supports, and the introduction of formal water use rights in combination with market instruments. The effectiveness of these policies is evaluated on the basis of two criteria: the extent to which net irrigation withdrawals are reduced, particularly during the dry season, and the financial impact on the irrigation sector. We discuss key policy findings based on the results of these scenarios.

Select this Article		Metrics for Sustainable Water Use David W. Watkins, Jr., Jennifer R. McConville, and Brian D. Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)142 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In order to advance water resources research and practice that addresses sustainability concerns, this paper identifies and explores the use of a few metrics for water use sustainability. Examples include the ratio of water withdrawal to total supply, the percentage of income spent on water and sanitation, the incidence of waterborne disease, and indices related to a managed system's ability to cope with extreme events. The spatial and temporal, scales over which these metrics can be calculated using available data are assessed, and additional data requirements are identified. Some of the challenges faced in predicting future values of these sustainability metrics are also discussed, along with research needs to improve predictability and adaptability.

Select this Article		Ecohydrologic Indicators for Rivers of Northern Taiwan Jian‐Ping Suen, Edwin E. Herricks, and J. Wayland Eheart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)143 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, water resources planning and management activities have expanded from narrowly focusing on flood defense, water quantity improvement and quality control to the better integration of ecosystem needs in management protocols. Because ecosystem needs are still subject to discussion, a reasonable surrogate is the use of the natural flow regime. The natural flow regime integrates ecological, geomorphic, and hydrologic functions in a watershed and provides a flow‐based approach to protecting ecosystems (ecohydrology). This paper identifies a suite of ecohydrologic indicators, called the Taiwan Ecohydrology Indicator System (TEIS). This system of indicators considers seasonal change, typhoons, and ecological requirements of resident species in hydrologic indicator selection. The final set of 60 TEIS hydrologic indicators captures the magnitude, frequency, and duration characteristics of natural flow regimes. To facilitate use in policy analysis, a reduced set of indicators was selected. This set includes six parameters that can be used to minimize the complexity of optimization procedures and still reflect ecological considerations in decision making and planning.

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CLIMATE AND METEOROLOGY

Select this Article		Event‐Based Comparison between General Circulation Model Precipitation Results and Point Observations Y. Guo and M. J. Senior ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)144 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Coupled atmosphere‐ocean general circulation models (GCMs) are widely used to study the current climate system as well as its possible changes in the future. The precipitation output from these models has been compared to observations in order to verify the reliability and accuracy of GCMs in simulating the precipitation process. Depending on the specific interest and emphasis, different yearly, seasonal, and extreme condition statistics derived from modeled and observed precipitation time series have been compared. So far, however, there is no report of comparison between modeled and observed rainfall events for any specific locations. In this paper, rainfall events as observed at a individual site are defined first. Event‐related statistics are then calculated using modeled and observed precipitation time series. Comparison of these event‐based statistics shows that while GCMs cannot model the rainfall process at the two selected locations on a year‐by‐year, or event‐by‐event basis, they do model fairly well the long‐term average number of rainfall events and event volume distributions. Results presented in this paper may render more confidence in the use of certain information derived from GCM precipitation output, and at the same time assist in identifying directions for further improvement in the modeling of precipitation processes.

Select this Article		Effect of Cities on Rainfall and the Implications for Drainage Design Steven Burian, Parastou Hooshialsadat, Shannon Reynolds, and J. Marshall Shepherd ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)145 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A study of the effect of Houston on rainfall patterns at multiple spatial and temporal scales is being performed. Rainfall data from a variety of sources, from the precipitation radar on the TRMM satellite to rain gauges in the Houston Flood Alert System, have been collected and are being analyzed. The combined rainfall data set covers a range of spatial scales, from tens of kilometers to thousands of kilometers, and temporal scales, from minutes to months. The insight gained from studying data sources with this range of scales is unique for analysis of rainfall modification in Houston. This paper summarizes previously completed Houston rainfall data analyses, introduces new results from the long‐term trend analysis of Houston‐area rain gauge records, and presents a sensitivity study of drainage design that indicates the potential impact of urban‐induced rainfall modification on drainage system components for Houston. The results from the trend analysis suggest a weak increasing trend of warm season rainfall totals in the urban area and urban‐affected area, while no trend was noted for an upwind control region. The results from the drainage design sensitivity analysis indicated that changes in design rainfall intensity similar in magnitude to changes attributable to urban‐induced rainfall modification would be sufficient to modify some design sizes of pipes in simple drainage systems.

Select this Article		Seasonal Precipitation Prediction Using Large Scale Climate Signals Banafsheh Zahraie and Mohammad Karamouz, F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)146 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a method for seasonal precipitation prediction is presented, which consists of three steps. In the first step, the effects of large scale climate signals on the low and high precipitation spells in the Southwest of Iran are investigated. The long‐term records of Southern Oscillation Index (SOI) and North Atlantic Oscillation (NAO) as well as variations in Sea Surface Temperature (SST), Precipitation, and Sea Level Pressure (SLP) in the Middle‐East and Europe are investigated. In order to quantify the effects of climate signals on the wet and dry spells, specific thresholds are defined for very high, high, normal, low, and very low precipitation periods jointly based on long‐term records of average areal precipitation and cumulative streamflows in Winter and Spring. The variations of average SLP and SST during the period of June through November are considered in a number of characteristic locations in Persian Golf, Red Sea, Indian Ocean at north of Australia, Arabian Sea, Mediterranean Sea, Black Sea, Caspian Sea, and some parts of Atlantic Ocean. In the second step, the fuzzy regions and the membership functions for the SLP gradient in the selected locations are developed. Finally, the fuzzy rules are developed to incorporate the SLP variations in precipitation prediction. The fuzzy rules are used to predict the range of total precipitation in the period of 1990 to 2002. The results have shown that the actual precipitation have been within the forecasted range of precipitation in 68 percent of the years and therefore, the developed rules can effectively be used in predicting high, normal, and low ranges of precipitation in winter and spring in the Karoon River basin.

Select this Article		Near‐Term Forecasting of Surface Water Supplies for a Regional Water Utility Janice Lantrip, Mitchell Griffin, and Alaa Aly ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)147 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Tampa Bay Water, Florida's largest wholesale water supplier, is required to cut back groundwater pumping from 158 million gallons per day (mgd) to 121 mgd in 2003, with further reductions to 90 mgd by 2008. To meet the new groundwater pumping limits it was necessary for Tampa Bay Water to develop alternative supply sources including surface waters. Tampa Bay Water utilizes an integrated hydrologic simulation model and an optimization model to manage pumpage from groundwater and surface water facilities. Weekly streamflow forecasting is required for estimating treated surface water availability for input into the optimization model. This paper describes the development of a suite of computer modeling tools that forecast daily flows and levels for a one‐week period at key locations along the Hillsborough River and Tampa Bypass Canal system (HRTBC).

Select this Article		Climate Warming Adaptation for Urbanizing Floodplains: Economic‐Engineering Analysis Tingju Zhu, Jay R. Lund, Marion W. Jenkins, Guilherme Marques, and Randall S. Ritzema ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)148 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper examines flood management for an urbanizing floodplain with increasing flood risk due to climate warming. The lower American River floodplain in the Sacramento, California metropolitan area, is used as a preliminary example. A stochastic dynamic programming model suggests economically promising adaptations to flooding problems given simultaneous changes in climate and urban land values. Economic‐engineering optimizations were done for several climate warming and urbanization scenarios. Methodological and policy conclusions are drawn, based on the results, for floodplain planning considering interaction of climate, costs, and regional economic growth.

Select this Article		Scenario‐Tree Framework for Streamflow Forecasting and Water Resources Decision Support David W. Watkins, Jr. and Wenge Wei ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)149 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Procedures are described for assembling ensemble streamflow forecasts into a tree structure for use in a multi‐stage stochastic linear programming model. Such an optimization model is the basis for a decision support system that has been developed for the Lower Colorado River Authority in Central Texas. In prior work, streamflow ensembles suitable for direct use in a two‐stage model have been generated, and procedures were derived for conditioning the ensemble members on observable climate indicators. Additional work is needed to develop scenario trees that properly represent forecast uncertainty in a multi‐stage model. Verification methods for scenario trees are also discussed.

Select this Article		Regional Performance of NOAA/CPC Seasonal Climate Temperature Forecasts J. M. Schneider and J. D. Garbrecht ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)150 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Operational climate forecasts for 3‐month mean temperature are issued monthly by the NOAA Climate Prediction Center, for lead times from 0.5 to 12.5 months. Among these forecasts, the Probability of Exceedance forecasts present information on expected shifts in the probability distribution of mean temperature relative to climatological distributions. The forecasts appear to support a wide range of applications in water resource management and agriculture, especially in regions where growing season length, snow pack, and lake or river ice processes are important. These temperature forecasts have been reported to have modest skill when skill is assessed across the entire United States. However, the adoption and use of the forecasts has been limited, partly due to a lack of user‐oriented measures of forecast utility on a regional basis. In this presentation, we will examine forecast performance over the years 1997 – 2002, for all forecast divisions in the contiguous U.S. at the shortest lead time (0.5 months). Performance is assessed using two measures of forecast utility: usefulness (degree and frequency of forecast departures from climatological distributions), and dependability (correspondence between the direction of forecast departures and actual occurrences). A similar analysis on seasonal precipitation forecasts showed large variations in utility with region, ENSO state, and season. This analysis shows that the mean temperature forecast performance does not vary as much with region and ESNO state. Forecasts for warmer than average conditions have been very dependable for much of the contiguous United States, especially in the northern Great Plains and Rocky Mountains. This success appears to be the result of persistently warmer than average conditions during this period. There were relatively few forecasts offered predicting cooler than average conditions, and most of those were not dependable.

Select this Article		Utility of Streamflow Forecasts Derived from Seasonal Precipitation Forecasts Jurgen D. Garbrecht, Jeanne M. Schneider, Michael W. Van Liew, and Upmanu Lall ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)151 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this study, the magnitude of streamflow response to a precipitation forecast is examined to establish the conditions under which a probabilistic precipitation forecast, if skillful, is likely to translate into useful streamflow information. The hydrologic model SWAT was used to simulate streamflow response to several hypothetical precipitation forecasts and antecedent hydrologic conditions. The test watershed was a 32.9 km² subwatershed in the Little Washita River watershed in central Oklahoma. The streamflow characteristics were expressed in terms of runoff volume, change in runoff volume, odds of exceeding a specified threshold volume, and probability of exceedance curves of volume. While the numerical findings of this study are specific to the climatic and physiographic conditions of the watershed, the findings suggest that combinations of antecedent hydrologic and precipitation forecast conditions produce a broad range of streamflow responses that are suitable for decision making. It was also found that strong wet/dry antecedent hydrologic conditions can dominate over the impact of typically modest precipitation forecasts. In addition, dry antecedent hydrologic conditions tend to limit the utility of wet/dry forecasts, because any forecasted precipitation is mostly absorbed in the soil and produces little immediate impact on streamflow, though it may influence the antecedent conditions for subsequent precipitation‐runoff events (delayed impact). Finally, streamflow response to a forecast is best expressed in probabilistic terms, and decisions framed in terms of change in odds of success or failure for key indicators. Recommendations are also given for further research.

Select this Article		Effects of Climate Change on Irrigation Decisions and Low Flow Frequency for a Typical Agricultural River Basin of the Midwestern US Hua Xie and J. Wayland Eheart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)152 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Midwest is the largest agricultural area of the United States. Historically, the climate, characterized by moderate temperatures and ample rainfall, has been suitable for un‐irrigated agriculture. However, the specter of climate change has created concerns about the future of Midwestern agriculture, regional fresh water resources and the relationship between the two. Implications of climate change for the Midwest are revealed at the river basin scale in a recent study on the Mackinaw River Basin, a typical agricultural Midwestern watershed of central Illinois, through modeling exercises. Generally in this study a future climate with more frequent droughts is envisioned based on the outcome of one of the major General Circulation Models (GCMs), the Canadian Climate Centre model. Climate change in and of itself will affect the vulnerability of regional fresh water resources, by altering the low flow frequencies of stream at reference gauging stations. Moreover, the threats of droughts may motivate farmers to introduce irrigation in this traditionally rain‐fed area to maintain high and stable yields. Such irrigations, if any, could exacerbate the effects of the changes in climatic factors. This study shows that the changes in climatic factors of temperature and precipitation will reduce the agricultural productivity, trigger irrigation and increase the low flow frequencies at reference gauging stations. However, the adverse effects of changes in temperature and precipitation may well be counteracted by the effects of elevated CO₂ concentration in atmosphere. Thus, the opposing effects of climate change could very well leave agriculture in central Illinois more or less unchanged.

Select this Article		Generating Historically‐Based Synthetic Distributed Precipitation Data M. L. Anderson, Z. Q. Chen, M. L. Kavvas, and J. Y. Yoon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)153 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water resources and environmental assessment using hydrologic models are difficult tasks in ungaged basins. A methodology for reconstructing distributed rainfall data suitable for use in hydrologic models based on the data stored in atmospheric databases such as the U. S. National Center for Atmospheric Research/National Center for Environmental Prediction (NCAR/NCEP) global reanalysis data has been developed. The NCAR/NCEP global reanalysis data provides gridded atmospheric data at six hour intervals at a scale of approximately 210 km by 210 km that is consistent with global observations of weather related variables such as temperature and pressure. For regional and watershed scale hydrologic problems, detailed information such as orographic enhancement of rainfall at a scale down to several kilometers is required instead of the original 210 km data. In order to test the suitability of atmospheric model at regional scale (IRSHAM) and atmospheric model at watershed scale (MM5) to reconstruct rain fields at a scale suitable for use in hydrologic models, test cases have been run over two regions — the Lake Tahoe Basin in the western United States and the Ara/Tone Basins in Japan. Results of the studies indicate that the methodology shows promise for reconstructing rain fields over ungaged basins for use in hydrologic modeling for water resources and environmental assessment.

Select this Article		Dialogue on Adaptation to Climate Change in the Okanagan Basin, British Columbia, Canada Stacy Langsdale, Stewart Cohen, Rachel Welbourn, and James Tansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)154 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Okanagan Basin in south‐central British Columbia is one of the most arid regions in Canada. Presently, water resources in the area are under stress due to recent population growth, intensification of irrigated agriculture and recreational activities, and extensive logging at higher elevations, leading to increased concerns about water quality and fish habitat. In addition the stressors listed, climate change impacts could alter water supply patterns significantly. A major focus of this research is to encourage the local community to consider climate change in their long‐term water plans. Between November 2003 and February 2004, the research team conducted stakeholder workshops to evaluate water management and adaptation options. Participants investigated the local and regional adaptive capacity, determined preferred adaptive strategies, and identified economic, institutional, social, and political barriers to implementing these strategies. The results of these workshops will be presented.

Select this Article		Characterizing the Spatial Variability of Rainfall Across a Large Metropolitan Area Derek Wride, P.E., Mi Chen, Ph.D., and Ralph Johnstone, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)155 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Rainfall input for urban wastewater collection system modeling is critical. The rainfall accuracy and reliability directly affect the confidence of the model results. In order to characterize the rainfall across a large metropolitan area, a network of ground rain gages is typically installed. Networks of ground rain gages have weaknesses in accurately defining the spatial variability of rainfall events across the entire metropolitan area. The density of the rain gage network often leaves large areas where rainfall is not measured and must be estimated. A number of mathematical methods have typically been used to estimate rainfall at points between ground rain gages. Advances in radar rainfall technology have led to the improved characterization of rainfall across larger study areas. Calibration of radar, even with sparse rain gages, results in aerial rainfall estimates that are better than either system alone. This paper inspected the simulated I/I (inflow/infiltration) responses in the sewer system from using four methods to define the rainfall across a portion of the service area of the Metropolitan Sewer District of Greater Cincinnati (MSDGC). The four methods are, 1) closest ground rain gage, 2) the Thiessen polygon method, 3) the inverse of the square of the distance method (IDS), and 4) radar‐rainfall technology. The calibrated sanitary sewershed models were used as areas to estimate precipitation and to compare the simulated results with the rainfall input defined by the four methods.

Select this Article		A Multiple Approach to Rainwater as a Renewable Resource G. S. Burnham ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)156 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The abstract of this paper states the paper will be about rainwater harvesting and indicates rainwater harvesting is a field that should be accorded serious attention by many disciplines. Within the body of this paper there will be numerous illustrations demonstrating that rainwater harvesting on any major scale is considered “outside the box” by those who could affect the status of this overlooked subject. The first time the term “outside the box” was applied to my efforts was just after I received an invitation to try out for the New York Giants baseball team. It was the bottom of the ninth in an important game for the team and myself. There was one out and we had a runner on third. I was at bat and the coach just called for a suicide bunt. The other pitcher and I had been having a real duel and the score was tied at zero‐zero. They must have picked up the sign because his pitch was very high, something he had not done all game. My teammate was on his way and was definitely dead meat if I did not do something. All I could think of was to go after the ball, so I jumped up and laid down a perfect bunt. The action was so unusual everyone was safe. That other coach went running out to the umpire (a major league umpire) screaming “he was out of the box!” It turned out there was no rule against jumping up in the air and hitting the ball while both feet are off the ground. That umpire ruled that the “box” is three dimensional, not two. By going “outside the box” we were able to win the game.

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ENVIRONMENTAL WATER QUALITY ISSUES

Select this Article		Multiple Regression Approach in Predicting Highway Runoff Pollutants Concentration M. Kayhanian, C. Suverkropp, A. Ruby, and K. Tsay ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)157 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Multiple linear regression (MLR) analysis was performed to develop mathematical relationships to predict highway runoff pollutant concentrations from various site and storm event predictor variables. Partial correlations were used to select the independent variables for the MLR models. The final “optimized” MLR model was used to generate a new fitted variable calculated as the cumulative effects of the significant predictor variables for each constituent. This fitted variable was then included as the single covariate and final MLR models were developed for each constituent. Predictor variables found to have significant impacts on highway runoff pollutant concentration include: total event rainfall (TER), cumulative seasonal rainfall (CSR), antecedent dry period (ADP), contributing drainage area (DA), and annual average daily traffic (AADT). The MLR models then were validated using actual highway runoff measurements that were not included in model development.

Select this Article		De‐Silting Lake Nasser with Slurry Pipelines B. E. Abulnaga and M. S. El‐Sammany ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)158 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Aswan High Dam Reservoir, formally known as Lake Nasser, is one of the largest man‐made lakes in the world. It has played a major role in protecting Egypt against natural disasters due to shortage of rainfalls at the source of the Nile, during extended draughts or due to the hazards of the very high floods. Since 1964, 4.95 billion cubic meters (bcm) of sediments have deposited in Lake Nasser with almost 85% in Sudan and 15% in Egypt. Studies indicate that up to 134 million cubic meters a year end up in the lake, with 130 million sedimenting and 4 million passing through the Aswan High Dam to the valley north of Aswan. This paper proposes to mine these rich sediments using modern lake mining techniques. Current technology for hydraulic dredging using jet and slurry pumps, floating pipelines in High Density Polyethylene (HDPE) would allow such a solution. Sediments would be pumped in a slurry form to engineered mud ponds, similar to tailings dams to throw the foundations for new communities. The de‐silting of the Nasser Lake may be executed at local, national and international levels (between Egypt and Sudan). Small‐scale dredgers should be used for local farming. Preliminary calculations indicate that a 20 Megawatts pumping system would be recommended to convey to shore 10 million cubic meters of sediments. From the shore, a system of dedicated slurry pipelines, booster stations with local ponds for slurry discharge would fertilize lands closer to population centers.

Select this Article		Optimal Site Selection for Military Land Management R. M. Wallace ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)159 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Site selection procedures have improved rapidly with the acceptance of GIS technologies that can quickly evaluate the properties of thousands of potential sites. However, when more than a single parcel of land is required or when the certainty of the decision requires a more deliberate selection procedure, a systematic methodology is needed to analyze multiple scenarios and select an optimal or near‐optimal solution. This need is especially true for military installations where unique land uses require calculated decision making that reflect more than “best judgment” decisions. Examples of these unique land uses include the location of hazardous storage facilities and the location of live‐fire exercises. These distinctive activities are further complicated by the desire to increase the level of readiness by conducting additional training exercises on limited resources. An additional factor influencing the location of activities on military installations is that many of these sites have become prime habitat for threatened and endangered species. This paper describes the use of a site selection model to identify and evaluate and generate optimal regions with specific shape properties. In addition a heuristic algorithm that uses the “greedy” principle is applied to find solution regions with specific shape properties and non‐inferior cost values. A case study using the model will be used to identify least cost areas for training activities on the Fort Hood military reservation.

Select this Article		Clay Surface Imaging — Atomic Force Microscope and Environmental Scanning Electron Microscope Arunkumar Selvam and Brian Barkdoll ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)160 Online Publication Date: 7 October 2004 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 tanks are used commonly to store gasoline and other organic chemicals, both for industry and the commercial market. These materials also called liners are an inexpensive method of preventing seepage of chemicals into the groundwater. The behavior of clay liners for underground storage tanks or landfills is examined here on a microscopic level. Images from an Environmental Scanning Electron Microscope are presented with ramifications for clay modification to reduce seepage of chemicals through the clay liner.

Select this Article		Forecast Simulations of 3‐D Fish Response to Hydraulic Structures R. Andrew Goodwin, Ph.D., M.ASCE, John M. Nestler, Ph.D., James J. Anderson, Ph.D, and Larry J. Weber, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)161 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Utility of a theoretically‐ and computationally‐robust mathematical model for decoding the movement patterns of individual fish in 3‐D space‐time is described. Hydrodynamic stimuli queried from a 3‐D CFD model (U²RANS) are used to elicit spatially‐explicit virtual fish behavior. The modeling scheme, coupled Eulerian‐Lagrangian agent individual‐based modeling (CEL Agent IBM), is intuitive and based on well‐established principles in computer science, fluid and water quality dynamics, computational fluid dynamics (CFD) modeling, and game and foraging theories. We demonstrate the utility of a prototype CEL Agent IBM (the Numerical Fish Surrogate) developed for outmigrating juvenile salmon in the Pacific Northwest. The Numerical Fish Surrogate is used by the US Army Corps of Engineers to decode behavior and then, using results from back‐casting analysis, forecast the response of salmon to virtual designs of proposed alternative bypass structures to aid project selection and design. CEL Agent IBMs and the Numerical Fish Surrogate provide the means to integrate high fidelity CFD and water quality modeling and individual‐ based modeling to improve biological simulation of aquatic wildlife for water resource decision‐support and reduce reliance on the build‐and‐test paradigm.

Select this Article		Role of Spill Prevention and Control in Meeting NPDES Requirements D. Leszczynska and A. Dzurik ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)162 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The 1989 Exxon Valdez oil spill showed that spill prevention and response actions in Prince William Sound and most other seaports were inadequate. Spills have continued to occur, but major improvements have been made in oil spill prevention and response planning. Federal programs have been enacted to deal with emergency spill and response measures including the Oil Pollution Act of 1990. The Act has incentives to prevent spills, with the U.S. EPA as the lead enforcement agency. EPA issued a final rule in 1992 amending the Oil Pollution Prevention regulation under the Clean Water Act setting requirements for Spill Prevention Control and Counter‐measure Plans (SPCC Plans). During the same 15‐year period, stormwater runoff management became a major concern across the country. The National Pollutant Discharge Elimination System (NPDES), put in place under the U.S. Clean Water Act (CWA), addresses discharge of pollutants to the nation's waterways. The 1987 Amendments to the CWA led EPA to develop Phase I of the NPDES Storm Water Program for industrial sources of stormwater runoff. Phase II, added a few years later, requires municipalities to control runoff. This paper deals with the combined issues of spill prevention and response under SPCC Plans and of industrial spills managed under the NPDES program. It identifies pollution prevention and spill control measures that prevent contaminated stormwater and runoff from entering water bodies. Successes in dealing with spills, spill prevention and NPDES compliance efforts are presented. The paper attempts to broaden the scope of spill prevention by looking at the combined efforts of spill response and recovery measures with stormwater runoff management related to potential industrial spills.

Select this Article		Rainfall and Runoff Variation Analysis for Water Resources Management Strategies Sangman Jeong, Joo Heon Lee, Jongho Kim, and Kumyoung Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)163 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract For the long‐term strategic water resources planning, forecasting the future streamflow change is important to meet the demand of a growing society. The streamflow variation to the decade‐long precipitation was investigated for the two major stage gauging stations in Korea. Precipitation and runoff characteristics have been analyzed at Yongwol stream stage in the Han River as well as Sutong stream stage in the Kum River for the future water resources management strategies. Monte Carlo method has been applied to estimate the future precipitation and runoff. Based on the trend line of 10‐year moving average of runoff depth for the historical runoff records, the relation between runoff and the time variation was examined in more detail using regression analysis. This study showed that the surface flows have been significantly decreased while precipitation has been stable in these basins. Decreasing in runoff reflects the regional watershed characteristics such as forest cover changes. The findings of this study could contribute to the planning and development for the efficient water resources utilization.

Select this Article		A Review of Stormwater Quality Data for Salt Lake County, Utah N. D. Stack, T. G. Way, and K. K. Nichols ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)164 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Salt Lake County (SLCo), Salt Lake City (SLC) and Utah department of Transportation (UDOT) have been permitted under the Municipal Phase I National Pollutant Discharge Elimination System (NPDES) program since 1995. Stormwater runoff monitoring and wet and dry weather screenings have been conducted since 1992 on nine outfall locations located throughout Salt Lake County. A total of 13 storm events have been sampled up to 1999. Annual pollutant loads and event mean concentrations (EMC) were calculated for total suspended solids (TSS), trace metals, total phosphorus, and biological oxygen demand for three primary landuse types residential, transportation, and commercial/industrial. Annual pollutant loads for transportation and commercial/industrial landuses were determined to be the greatest contributor to all major pollutants. EMCs for all six major pollutants were found to fall within the range of values reported by several municipalities across the country with a similar climate type. The calculated EMCs also compared reasonably with the National Urban Runoff Program (NURP) data for Salt Lake County.

Select this Article		Optimizing Meter Locations in Sewage Networks for Sanitary Sewer Overflows (SSOs) Detection Dana Z. Abu Sier and Kevin E. Lansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)165 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Sanitary sewer overflows (SSO) are becoming of increasing concern in the sewage system management to utilities and regulators. Many overflows are not easily identifiable. If undetected, they can adversely impact public health and are an environmental hazard. The number and severity of SSOs can be reduced through the proper sewerage maintenance and the detection‐correction of ongoing events. A methodology is presented to locate meters to maximize the likelihood of detecting a system blockage. When a blockage occurs the discharge rates in the system are affected. If the changes are greater than one would expect due to random variability, they can be attributed to a blockage. The proposed method attempts to optimize the monitoring locations to maximize the number of blockages that can be identified by a given number of meters. The problem is solved using a set‐covering approach. The approach allows the tradeoff between the number of detections and cost of gages to be easily assessed. Data from Pima County Wastewater Management's monitoring system is used as a case study. To introduce blockages and analyze system hydraulics a full hydraulic model for the sewer system is applied.

Select this Article		Reaching Multiple Audiences with One Droplet: The Salt Lake County Storm Water Coalition's Media Outreach Campaign Lisa Hartman and Terry Way ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)166 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In 1998, the H.M.G. team was awarded a consultant contract with Salt Lake County Engineering for the NPS Public Education program. We inherited an up and running program looking for a new direction. We mapped out a 5‐step process to fashion a new era in the UPDES Education Program — a process that led us to where we are today. The five steps are: 1 ) evaluation, 2) problem identification, 3) create a brand identity, 4) target a message to an identified audience and 5) select media and methods of delivery of that message to reach the audience.

Select this Article		Development of Pathogen TMDLs within a Stochastic Framework Lindell Ormsbee, S. V. Teegavarapu Ramesh, and Anil Tangirala ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)167 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Section 303(d) of the Clean Water Act and EPA's Water Quality Planning and Management Regulations (40 CFR Part 130) require states to develop total maximum daily loads (TMDLs) for their water bodies which are not meeting designated uses under technology‐based controls for pollution. The TMDL process establishes the allowable loadings of pollutants or other quantifiable parameters for a water body based on the relationship between pollution sources and in‐stream water quality conditions. Currently, most TMDLs are developed using a continuous simulation approach that employs a traditional deterministic rainfall‐runoff model (e.g. HSPF). Use of such an approach in developing pathogen TMDLs can be problematic due to the water mass‐balance errors which normally remain following even the “best” hydrologic calibration effort, and due to the challenge of calibrating the predicted pathogen loads to the erratic pattern of most observed pathogen data. In the current study both flow and pathogen loadings are modeled using probability distributions that are evaluated using a system dynamics modeling environment (e.g. STELLA) and Monte‐Carlo simulation. The proposed approach has the advantage of eliminating mass‐balance errors by using observed stream flow as opposed to rainfall as well as a better way of characterizing the probability of success of associated management strategies.

Select this Article		A Methodology for Robust Total Maximum Daily Load Allocations Yanbing Jia and Teresa B. Culver ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)168 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The determination of how pollutant loads should be distributed among different pollutant sources in the watershed, which is known as pollutant load allocation, is a critical step in Total Maximum Daily Load (TMDL) development. Under current TMDL practices, TMDL allocations are typically determined through a trial‐and‐error approach of reducing pollutant loadings until the watershed simulation model predicts that water quality standards will be met given a Margin of Safety. Unfortunately, because there may be many feasible combinations of load reductions and/or significant uncertainties, it is difficult and time‐consuming to compare different allocation scenarios using a trial‐and‐error approach. A robust optimization model is developed in this study to incorporate the uncertainty of water quality predictions and to minimize pollutant load reductions given various levels of reliability with respect to the water quality standards. The Generalized Likelihood Uncertainty Estimation is used to explicitly address the uncertainty of a watershed simulation model, Hydrological Simulation Program — Fortran. The uncertainty is integrated into TMDL allocations using a robust genetic algorithm model linked with a response matrix approach. The developed robust optimization model is demonstrated on a case study based on. the Moore's Creek fecal coliform TMDL study. The trade‐offs between reliability levels and total load reductions of allocation scenarios are evaluated, and the optimized load reduction scenarios are compared with the scenario generated by a trial‐and‐error approach and approved by the USEPA. The results show that the optimized load reduction scenario requires 30% less load reductions than the scenario approved by the USEPA at the same reliability level.

Select this Article		An Approach to Establishing Risk Based Margins of Safety for Total Maximum Daily Loads for Phosphorus in Lakes David Langseth and Natalie Brown ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)169 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A TMDL under §303(d) of the Clean Water Act (CWA) is the maximum amount of a pollutant that a water body can assimilate without violating water quality standards (WQSs) and the allocation of that amount to contributing sources of the pollutant (anthropogenic and natural) plus a margin of safety.

Select this Article		Biologic Indicators to Assess Impairment and Correlation to Total Suspended Solids, Belle Fourche River, South Dakota Dan Hoyer, Scott Kenner, and Aaron Larson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)170 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Belle Fourche River has been identified by the 2002 South Dakota 303(d) Waterbody List as impaired due to total suspended solids (TSS). The river has been designated as a warm‐water permanent fishery. Based on this designated beneficial use, the criteria states that the TSS should not exceed the 30‐day maximum of 90 mg/l or a daily maximum of 158 mg/l. A 3‐year study was completed to determine and document sources of impairments to the Belle Fourche River Watershed (2.1 million acres) and to develop feasible recommendations for rehabilitation. The flow in the Belle Fourche River is heavily influenced by the Belle Fourche Irrigation District (BFID) project servicing approximately 51,000 acres. The primary cause of the elevated TSS concentrations is stream incising from alteration of the hydrologic regime due to nonused irrigation water discharging to the surrounding waterways Biologic indicators can be used to indicate long‐term quality of a water body, reflecting overall ecological integrity. Macroinvertebrate biological samples were collected at 16 sites to support the water quality sampling and analysis. A good reference site was not available for this watershed. Thus the Environmental Protection Agency's (EPAs) methodology documented in the Rapid Bioassessment Protocols for Use in Wadeable Streams and Rivers was applied with modifications to develop a measure of impairment. Nonparametric statistical analyses (Kruskal‐Wallis) were used to compare the sites and to determine the relative level of impairment. A robust regression equation was also developed relating TSS and seven biologic indicators.

Select this Article		Development of Flow‐Based TMDLs for Fecal Coliform Qizhong Guo, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)171 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The stormwater runoff is a primary carrier of non‐point source pollutants to surface waters such as streams and reservoirs. Therefore, water quality varies highly with flow rate in the non‐point source dominated surface waters. The existing water quality criteria have commonly been developed for the flow condition under which point source pollutants are dominant but not for the flow condition under which non‐point sources are dominant. This study took Whippany River watershed, NJ as an example to demonstrate how the fecal coliform count varied greatly with the stream flow rate, and how the required reduction level for fecal coliform load would vary greatly depending on the flow condition chosen to meet the numerical water quality criteria. A calibrated watershed model was used to calculate the required load reduction levels for given flow conditions. A statistical method used to develop fecal coliform TMDLs was reviewed and its application results were compared with the watershed modeling results. It is recommended that the flow condition under which a TMDL is developed be quantified, using a calibrated watershed model, in order to achieve a better consistency in the required pollutant load reduction and to better educate the stakeholders.

Select this Article		Stormwater Treatment Areas: Constructed Wetlands for Phosphorus Removal in South Florida Surface Waters Wossenu Abtew, Gary Goforth, and Guy Germain ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)172 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Stormwater Treatment Areas (STAs) in South Florida are large‐scale constructed wetlands operated as flow‐through treatment systems to reduce phosphorus levels entering the Everglades in order to promote ecological restoration. The removal mechanism is through vegetation and periphyton uptake and sediment accretion. As part of the Everglades Construction Project, 16,800 hectares (ha) of constructed wetlands are being built to reduce phosphorus load from stormwater runoff and Lake Okeechobee discharges into the Everglades Protection Area in South Florida. At this time, four constructed wetlands with a total area 7,930 ha are operating, while construction is nearing completion in the remaining two totaling 8,864 ha. This study presents the performance of STA‐1 West from May 1, 1999 through April 30, 2003, corresponding to the fifth through eighth year of operation. The 2,700 ha constructed wetland has five cells with three parallel treatment systems. Surface vegetation cover consists mainly of cattails, submerged aquatic vegetation, open water and other mixed vegetation.

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HYDRAULICS

Select this Article		Rehabilitation for Exist Fishway of Jaeezan Diversion Dam and Find a Possibility for Installing a Fishway at Exist Behbahan Diversion Dam in Iran S. M. Kurdistani, A.M.ASCE and M. S. Bajestan, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)174 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Maroun River in Khouzestan province in south of Iran is one of the most important Iran water resources and it enters to international Shadegan Wetland (Biggest Iranian Wetland). It is very important that we have Fishways with high efficiency for each obstruction across the river such as Diversion Dams and Regulator Dams. The dominant family of fishes, which live in Shadegan wetland, is Cyprinidae family, which is resident at this wetland and Maroun River. On this river, there is one Reservoir Dam and four Diversion Dams that have been constructed by Khouzestan Water & Power Authority (K.W.P.A.). The Reservoir Maroun Dam has no facilities for fish migration and here is some efforts for finding a possibility for installing a suitable fish facility for this dam. Fishway of Jaeezan diversion dam on Maroun River constructed about 6 years ago and dose not have good efficiency and it is not functioning properly. During the migration season, fishes are trapped downstream of the dam. The first part of this paper belongs to results of study on finding rehabilitation for this Orifice‐Weir type Fishway. Behbahan diversion dam on Maroun River, which has been constructed in 20 years ago, has no Fishway and the second part of this paper includes the results of study on finding a possibility for installing a Fishway at this dam.

Select this Article		Fish Passage for Warm Water Fish Species David Admiraal and Steve Schainost ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)175 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In 2002, netting surveys in the Cedar River upstream of Spalding, Nebraska revealed very low numbers of native fish such as channel catfish. At Spalding, a low‐head (∼3.6 m) dam blocks the Cedar River, and the species that exhibited low numbers usually migrate upstream to breed. The low fish counts are not atypical of streams in Nebraska that are straddled by low‐head dams. In 2003, because of necessary repair work, the Spalding reservoir was drained, and the Cedar River ran freely through the reservoir. A brief netting survey in the river revealed a dramatic increase in channel catfish and other migratory species. While the reservoir was empty, small fish were observed migrating up the tailraces. Velocities in the tailraces were measured and will be used, along with other information, to design a low‐velocity bypass for the dam. Critical velocities determined for the fish in the study and the resulting low‐velocity bypass design will provide a practical solution for fish migration problems throughout Nebraska.

Select this Article		Grenup Lock Filling and Emptying System Study Mario J. Sanchez ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)176 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The United States waterway system finds itself facing increasing commercial traffic while the system's infrastructure has essentially reached its design life. The result is an increased demand on the nation's navigation locks. Financial constraints require innovative design concepts on infrastructure improvements. The overall savings estimated from the use of these innovative construction concepts for the US Army Corps of Engineer's top 11 high‐priority navigation projects (lock replacements) are between 1.4 and 1.8 billion dollars. The Greenup Lock in the Ohio River is one of these projects. One of the innovative designs being considered for this site is extending the lock walls of the existing 204.2 m auxiliary lock and converting it into a 408.4 m long lock. Two alternatives have been proposed within this lock extension project. A cost effective design alternative being considered for the filling and emptying system is the use of the existing 204.2 m lock system to fill the 408.4 m lock. This type of system is hydraulically unbalanced and could be prone to extremely slow filling and emptying times, and higher hawser forces. If the filling and emptying times are slow enough to adversely affect the total transit time, significant economic losses could occur. Also, if the hydraulic performance of the system is poor, the risk of accidents increases due to excessive hawser forces and surface disturbances. Another alternative is to build a separate filling and emptying system for the extended portion of the lock. This will provide a more balanced environment within the chamber during the filling and emptying cycles. While being a more costly alternative, it can significantly reduce operation times. Research on these systems has determined minimum filling and emptying times, with acceptable hawser forces, minimal surface drift, and disturbance. Design guidance is developed from a combination of laboratory flume data supplemented with computational modeling results. This paper presents the modeling methods used to establish design criteria. This criterion is necessary for design engineers investigating the 204.2 m extension of the Greenup Auxiliary Lock.

Select this Article		Hydro‐Induction Sediment Discharge Technique for Preventing Sedimentation in Hydropower Dams Jerry Chi Wang, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)177 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Hydro‐induction sediment discharge technique (HSDT) aims to prevent reservoir sedimentation by withdrawing the discharge water from the reservoir bottom to suck up and discharge sediments, and by inducing vertical vortexes and undercurrents in the reservoir bay to keep sediments agitated and moving. The technique is facilitated with an innovative discharge conduit system having bottom intakes that are engineered and configured to suit individual dam situation for maximum process efficacy. Analyses of the hydraulics and operating principles of the bottom intake discharge system are presented. Guidance for designing and configuring the discharge conduit system is provided. Several key issues concerning the practical application of the technique are discussed briefly. The process feasibility and functionality of the bottom intake discharge system have been demonstrated with a small test setup. Testing with large scale models and field tests are needed to develop design data for big dam application.

Select this Article		Red River CWMS Watershed Modeling Dragoslav L. Stefanovic, Ph.D. and Leonardo R. Kreymborg, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)178 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Red River watershed modeling study was conducted by WEST Consultants, Inc. for the U.S. Army Corps of Engineers, St. Paul District. The primary purpose of the study was to develop hydrologic, water control, and hydraulic models for the Red River of the North above Fargo, North Dakota / Breckenridge, Minnesota. The modeling work included development, calibration and verification of the HEC‐ResSim (reservoir simulation) model, unsteady HEC‐RAS (flood routing) model, and a hydrologic model that provides local inflows from all the contributing areas in the watershed. The models will be incorporated into the Corps Water Management System (CWMS), a nationwide integrated framework of hardware, software, and other resources that acquires, analyzes, and stores data; develops decision support information; and allows user access to any data and information on the system. This paper presents individual model components of that integrated system for the Red River watershed.

Select this Article		Re‐Channelization of Stream Channels Affected by an Extreme Flood Due to the 2002 Typhoon Rusa in Korea Chang Wan Kim, Hyoseop Woo, Won Kim, Du Han Lee, and Kwang Seok Yoon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)179 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract One of the strongest typhoons ever struck the Korean Peninsula, Typhoon Rusa, from the 31st of August to the 1st September 2002, caused the historical precipitation and floods on some parts of Korea. In a region, a historical rainfall amount of 880 mm for 24 hours exceeding the PMP (840 mm within 25 km²) was recorded. The resulting floods left 213 dead and another 33 missing in the whole country. Damages caused by the typhoon were as much as $4.5 billion. During the floods, morphologies of many streams flowing especially to the East Coast from the mountainous regions were dramatically changed by the high‐speed and highly concentrated flows. Channel response to such extreme flood clearly shows the inertia‐dominant behavior of channel straitening, widening, and steepening. Re‐channelization is to restore the stream channel with new channel forms and new floodplain management practices after a stream channel and surrounding floodplain are completely or near‐completely altered by the extreme flood. It would usually follow, in case that the channel and socio‐economic conditions allow, the channel forms newly shaped by the extreme flood.

Select this Article		Two‐Dimensional Modeling of Time‐Varying Hydrodynamics and Juvenile Chinook Salmon Habitat in the Hanford Reach of the Columbia River William A. Perkins, Marshall C. Richmond, and Geoffrey A. McMichael ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)180 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Hanford Reach is the only remaining unimpounded reach of the Columbia River in the United States above Bonneville Dam. Discharge in the Hanford Reach is regulated by several dams and is often subject to rapid changes. Sharp flow reductions have led to the stranding or entrapment, and subsequent mortality, of juvenile Chinook salmon (Oncorynchus tshawytscha) and other important fish species within the Hanford Reach. A multi‐block two‐dimensional depth‐averaged hydrodynamic model was used to simulate time‐varying river velocity and stage in a 37 km portion of the Hanford Reach. Simulation results were used to estimate time‐varying juvenile Chinook salmon habitat area, and the part of that habitat affected by discharge fluctuations. Affected habitat area estimates were made for the Chinook salmon rearing period of four years. These estimates were used, along with other important factors, to establish a statistical relationship between discharge fluctuation and impacts on juvenile Chinook salmon.

Select this Article		Modeling Channel‐Floodplain Co‐Evolution in Sand‐Bed Streams J. W. Lauer and G. Parker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)181 \| Cited 2 times Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The importance of including floodplain effects in one‐dimensional river channel hydraulic computations is well known. However, in morphodynamic modeling, these are often partially ignored by using a single effective discharge to drive bed elevation changes. This neglects both changes in the flow and sediment transport fields at overbank discharges and long term change in channel capacity (and thus effective discharge) caused by deposition on or erosion from either the channel bed or the floodplain. This paper presents a model for reach‐averaged channel bed and bank top elevation evolution that specifically accounts for changes in channel depth over time. The model considers two grain sizes: one for sand, which interacts primarily with the bed, and one for mud, which interacts only with the floodplain. The model also describes the evolution of the proportion sand and mud in the floodplain deposits. Sediment transport and floodplain deposition are driven by a simple gradually varied flow solution. Erosion from the floodplain is represented as a net loss associated with channel migration. Because overbank deposition is strongly affected by flow, effective floodplain deposition and in‐channel sediment transport are obtained by integrating results from an entire flow duration curve. In the absence of bed elevation changes, the channel and floodplain co‐evolve toward a stable bankfull geometry where overbank deposition just equals floodplain erosion.

Select this Article		Comparison of HEC‐RAS and MIKE11 Unsteady Flow Modeling for the Tillamook Valley Todd H. Bennett, P.E., Raymond Walton, P.E., Ph.D., Peter D. Dickerson, P.E., and John W. Howard, E.I.T. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)182 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Numerous flood events have historically devastated the Tillamook Valley in Tillamook County, Oregon. The City of Tillamook and both the commercial and agricultural activities in the Tillamook Valley are highly susceptible to flooding events, as the local topography is flat and broad before rising abruptly to the steep mountains of the Pacific Coast Range. As a result of the February 1996 flood, Congress authorized a request from Tillamook County to investigate water resource problems in the region. Under a contract with the U.S. Army Corps of Engineers, Portland District (District), WEST Consultants Inc. (WEST) developed one‐dimensional unsteady flow hydraulic models of the system, originally applying the Danish Hydraulic Institute (DHI) MIKE 11 model and then later converting the model to the U.S. Army Corps of Engineers Hydrologic Engineering Center River Analysis System (HEC‐RAS). These two hydraulic computer simulation models are commonly utilized for unsteady flow application in the both the public and private sectors in the United States; however, it is in error to assume that the construction of these models should always be developed in the same manner and with the same modeling assumptions. WEST recognized the differences between these two models, as part of the study, and compared specific aspects between HEC‐RAS and MIKE11 including the model equations and variables, approaches for model construction and development, and the effects of these variations on computation results as they relate to the Tillamook Valley. This paper discusses specifically the differences in computation of the channel roughness.

Select this Article		Characterization of Turbulent Open Channel Flow in a Full‐Scale Spiral Corrugated Culvert Gregory R. Guensch, Marshall C. Richmond, Hans Tritico, and Walter H. Pearson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)183 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract As part of a larger study of juvenile fish passage, a micro‐Acoustic Doppler Velocimeter (ADV) was used to characterize the three‐dimensional velocity and turbulence characteristics in a full‐scale culvert with spiral corrugations. The culvert was set up in a test bed constructed to examine upstream passage success of juvenile salmon under various culvert conditions. The test culvert was 12.2 m long and 1.83 m in diameter, and set at a 1.14% slope. The corrugations were 2.54 cm deep by 7.62 cm peak to peak with a 5° right‐handed pitch. Tailwater elevation was adjustable with a stop‐log system and was set slightly above the water surface level at the culvert exit. Cross‐sectional grids of ADV measurements were taken at discharges of 28, 57, 113, 227, and 453 lps at nine locations within the culvert barrel and just inside the headwater and tailwater tanks. Results revealed asymmetries in the velocity and turbulence distributions. These asymmetries caused a Reduced Velocity Zone (RVZ) on the right side of the culvert as seen looking upstream. Velocity and turbulence levels in the RVZ were found to be less than in mid channel or on the left side of the culvert, and the difference became greater as flow rates increased. Lateral and vertical velocity components were very small relative to the axial component, while lateral and vertical turbulence intensities were comparable to the axial component. Inlet loss coefficients were calculated as well and ranged from 0.32 to 0.42. Relationships between the average velocity and the velocity and turbulence intensity in the RVZ were developed, which may be useful for evaluating whether the barrel of a culvert is passable for juvenile fish. The RVZ could be beneficial to juvenile salmon during upstream passage.

Select this Article		Application of Suction Scoops to Improve Pump‐Approach Flow Distributions in Three‐Pump Intake Bays Tatsuaki Nakato ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)184 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Two geometrically undistorted models of St. Louis Water Company's Meramec Plant Intakes 1 and 2 were constructed at a scale of 1:5 in order to solve chronic pump‐vibration problems. Because of the unconventional layouts of small, deep, rectangular pump pits with three pumps each, vertical‐pump inverted drafttubes (VPIDs) were developed. Each intake chamber was divided into three individual bays using two vertical partition walls. Each VPID included a two‐segment straight‐line suction scoop, a floor splitter, a backwall splitter, two sidewall floor‐corner fillets, two vertical backwall corner fillets, flow‐turning vanes, and a vertical guidewall at the VPID entrance. In this paper only modeling efforts on Intake 1 are described. This is the second VPID model designed by IIHR — Hydroscience and Engineering (IIHR), The University of Iowa.

Select this Article		High Yield Riverbank Filtration Systems for Public Water Supply: Measuring the Impact of Riverbed Plugging S. A. Hubbs ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)185 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Louisville Water Company (LWC) has investigated the alluvial aquifer upstream of the Falls of the Ohio River since the late 1940s with an interest in securing an adequate volume of high quality water from this resource. A high‐yield horizontal bank filtration collection well was put into operation at the B.E.Payne Water Treatment Plant in 1999 (Ohio River Mile 592), with a design capacity of 15 million gallons per day (MGD) and an initial maximum capacity estimated at 27 MGD. In the first 3 years of operation, the yield has decreased to an apparently stable safe yield of 18 MGD. This paper seeks to better define the stochastic relationship between riverbed plugging and riverbed scouring for the nearly 4‐year operating history of the riverbank filtration system at Louisville, and to project the performance of this system through a 20 year forecast. If successful, the technique used to determine this model will be applied to several other bank filtration systems in the US and Europe to gain a better understanding of the influence of riverbed scouring in bank filtration systems.

Select this Article		Monitoring and Simulating 3‐D Density Currents at the Confluence of the Snake and Clearwater Rivers Christopher B. Cook and Marshall C. Richmond ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)186 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Summer temperatures in the Lower Snake River can be altered by releasing cold waters that originate from deep depths within Dworshak Reservoir. These cold releases are used to lower temperatures in the Clearwater River, a major tributary to the Lower Snake River, and to improve hydrodynamic and water quality conditions for migrating salmon. This project monitored the complex three‐dimensional density currents at the Clearwater and Snake River confluence and the processes that led to stratification of Lower Granite Reservoir (LGR) during the late spring, summer, and fall of 2002. In addition to monitoring the LGR environment, a three‐dimensional hydrodynamic and water quality model was also applied. By utilizing both field data and a numerical model, a more holistic view of the 3‐D density currents was discovered than by using either method alone. During this process, it was discovered that several predictable stratification patterns would develop depending upon the discharge ratio and the thermal gradient between the two rivers. These results illustrate the complex hydrodynamic structure at the confluence of the Clearwater and Snake Rivers, which has previously been shown by fish biologists to be a difficult passage zone for migrating salmonids of various life stages.

Select this Article		Modeling Entrainment of Air at Turbulent Free Surfaces David T. Souders and C. W. Hirt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)187 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In free‐surface flows the turbulence in a liquid may be sufficient enough to disturb its surface to the point of entraining air into the flow. The process of entraining air can be important in many applications including hydraulics and other areas. For example, in water treatment air is needed to sustain microorganisms for water purification and in rivers and streams to sustain a healthy fish population. Air entrainment is typically engineered into spillways downstream of hydropower plants to reduce the possibility of cavitation damage at the base of the spillway. There are also situations where air entrainment is undesirable such as in the sprue and runner systems used by metal casters, and in the filling of liquid containers used for consumer products. CFD can be used as an alternative to modeling such processes or as a compliment to experimental processes because it can quickly provide a large amount of information about flow. What makes it even more attractive is when conditions are difficult to reproduce experimentally or data is difficult to obtain (for example, regions that cannot be seen or are inaccessible to measurement). Unlike physical experiments, it is easy to measure quantities throughout the computational domain because all regions within that domain are accessible.

Select this Article		Methods for Determining Manning's Coefficients for Illinois Streams David T. Soong, M.ASCE, Teresa M. Halfar, Megan A. Jupin, and Loren A. Wobig, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)188 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Determination of Manning's coefficient, n, for natural streams remains a challenge in practices. One source for determining the n‐values that has received practitioners' attention is presenting the n‐values determined from field data (measured discharge and water‐surface slope) in combination of photographs and site descriptions (ancillary information). Further improvements in the visual approach can be made in presenting site characteristics and describing site ancillary information. In this manner, users can use the presented information for sites of interest with similar features. This approach in a current project on the subject for Illinois streams is discussed.

Select this Article		Energy Dissipation through Screens Bozkus Zafer, Cakir Pinar, Ger Metin, and Ozeren Yavuz ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)189 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Screens may be utilized efficiently for dissipating energy of water. In this study, water flowing beneath a gate is used to simulate the flow downstream of a hydraulic structure and screens are used as an alternative tool for energy dissipation. Investigations are done conducting a series of experiments. The porosity, thickness, and the location of the screens are the major parameters together with the Froude number of the upstream flow. The experiments covered a range of Froude numbers between 5 and 18, porosities between 20% and 60%, and location of the screen up to 100 times of the undisturbed upstream flow depth. The thicknesses of the screens used are in the order of the undisturbed upstream flow depth. The results show the importance of each parameter on the energy dissipating performance of the screens and the system. It is observed that screens dissipate more energy than a jump within the Froude number range covered in the present study.

Select this Article		Predicting Depth‐Averaged Velocities in Trapezoidal Channels G. V. Wilkerson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)190 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Using dimensional analysis and experimental data from three previous studies, two relationships for predicting depth‐averaged velocity distributions in straight trapezoidal channels were developed. The data had a range of discharges (8.0 to 4,248 l/s), velocities (0.10 to 1.03 m/s), bottom widths (0.30 to 3.6 m), flow depths (5.2 to 80.5 cm), and sideslopes (1.0 to 3.0, horiz./vert.). The first relationship is general and requires measured velocity data for calibration. When measured data are not available, the second model, for which specific coefficients are prescribed, must be used. The first model is more accurate and should be used when possible. The second model also yields acceptable results. Among other things, the models can be employed in stable channel designs, streambank stability analyses, and to evaluate streambank stabilization designs including riprap and bioengineering designs. Brief reviews of the models are presented along with a demonstration application.

Select this Article		Determination of Critical and Normal Depths Using Excel Tommy S. W. Wong, F.ASCE and M. C. Zhou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)191 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract By means of the software “Excel”, the critical and normal flow depths can be determined through the use of analytical solutions and procedure presented in this paper. Four channel shapes are included: they are triangular, trapezoidal, parabolic and circular. For the triangular and trapezoidal channels, the critical and normal depths can be determined for channels with unequal side slopes.

Select this Article		Comparing Techniques to Estimate Roughness Due to Vegetation M. L. Alkis and D. E. Werth, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)192 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Natural or introduced vegetation often comprises the largest component of composite channel roughness in flood plains, flood control channels, and naturally occurring rivers and streams. Recent research has yielded numerous techniques for predicting Manning's “n” for flexible vegetation. This paper presents a comparison of several of these techniques. New data obtained from recent laboratory studies involving actual vegetation is used to independently validate and compare the various techniques.

Select this Article		Flow Resistance of Emergent Vegetation Brian D. Barkdoll, Sandeep Vittilam, Sean J. Bennett, and Carlos V. Alonso ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)193 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract River restoration and bioengineering programs commonly use vegetation to stabilize banks. For this, it is important to know the forces that the flowing river water exerts on the vegetation. To this end, a laboratory study was performed at the USDA‐ARS National Sedimentation Laboratory. Dowels were used to simulate emergent rigid vegetation. Dowels were systematically placed in the laboratory flume, beginning with a single dowel connected to a load cell to measure the drag force and then placing dowels around the single dowel to determine any shielding effect. It was found that the drag coefficient of a single dowel ranged from 4.5 to 6.5, which is higher than that published for a 2‐D cylinder of infinite length. A momentum balance analysis shows that (1) for the single dowel case, the momentum balance approach determines C_D>>1 contrary to the low values for a cylinder and (2) the C_D for the measured dowel is about two times higher than the momentum formulation. This difference is attributed to the presence of large standing waves upstream of the dowel and the breaking of these waves. When additional vegetation elements were added to form a matrix, it was found that as vegetation elements were added, the drag forced increased initially due to the vegetation concentrating the flow towards the instrumented dowel, and then decreased due to dowels being directly upstream of the instrumented dowel and thereby blocking the flow. These results have implications for managed planting arrangements in stream corridor rehabilitation programs.

Select this Article		3D Numerical Simulation of Compound Open Channel Flows with Vegetated Floodplains by Reynolds Stress Model Hyeongsik Kang and Sung‐Uk Choi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)194 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a Reynolds stress modeling of compound open‐channel flows with vegetation on the floodplain. In the Reynolds stress model, we use the SSG model by Speziale et al. for pressure‐strain correlation term, Mellor and Herring's model for the turbulent diffusion term, and Hanjalic and Launder's model for the dissipation term. In order to take into account the anisotropy of turbulence due to the free surface, the combination of Shir's model and Gibson and Launder's model is included in the pressure‐strain correlation model. Model validations are carried out for the compound open‐channel flows without vegetation. Then, the model is applied to the compound open‐channel flows with vegetated floodplains. The mean flow and turbulence structures are simulated and the impact of vegetation on the floodplains is investigated.

Select this Article		Techniques and Measurements for Flows and Water Levels in a Large Northern Delta Peter Ward, Hassen Yassien, and Stephen J. Burges ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)195 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Field work on the Athabasca part of the Peace Athabasca Delta, in Northern Canada, has shown the usefulness of employing new equipment to understand channel hydraulics in remote areas. A differential GPS system was used for accurate surveying work, and an Acoustic Doppler Profiler (ADP) was used to determine flow rates. Channel bank heights for an 81km distance upstream from Lake Athabasca were determined, as were river surface levels at medium discharge in the Athabasca River and its distributary channels. As many as 15 channel sections were surveyed per day with a boat‐mounted ADP. For the same daily discharge value, cross‐sectional average velocities in the main channel were found to be preserved at about the same value for a remarkably long distance in the final part of the delta, all the way to the lake. Comparison with old data shows a remarkably rapid rate of channel building. Flood magnitudes that cause bankfull flow conditions were found to change by a large factor from the head of the delta to the lake.

Select this Article		Automated Incremental Loading of Numerical Hydrodynamic Engines Alan K. Zundel and Thomas Moreland ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)196 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Environmental Modeling Research Laboratory (EMRL) at Brigham Young University in partnership with the U.S. Army Engineer Research and Development Center (ERDC) and the Federal Highway Administration (FHWA) has developed a tool for automating the process of incrementally loading boundary conditions into numerical hydrodynamic engines. The process of incrementally loading includes making revisions of model parameters from unrealistic but numerically stable values to realistic values that require similar initial conditions in order to be numerically stable. Variables that are traditionally used for incremental loading include water surface elevation, flowrates and eddy viscosity. This study involves extensive model runs with two different numerical models, TABS‐RMA2 and FESWMS‐FLO2DH. The effectiveness of incrementally loading each variable individually and various combinations of loadings are compared. Results include guidelines for efficiently applying incremental loading strategies to numerical modeling applications.

Select this Article		Depth‐Averaged 2‐D Model of Tidal Flow in Estuaries Weiming Wu, Honghai Qi, and Sam S. Y. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)197 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A depth‐averaged 2‐D numerical model for unsteady tidal flow in estuaries is established using the finite volume method on non‐staggered, curvilinear grid. The 2‐D shallow water equations are solved by the SIMPLEC algorithm with the Rhie and Chow's momentum interpolation technique. The convection terms are discretized by one of the hybrid upwind/central difference scheme, exponential difference scheme, QUICK scheme and HLPA scheme. The algebraic equations are solved using the strongly implicit procedure (SIP). The model is capable of handling the drying and wetting problem due to the variation of water surface elevation. The model has been tested in Tokyo Bay and San Francisco Bay. The tests show that the present model is very stable and efficient. The simulated water elevation and flow velocity are in good agreement with the measured data.

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HYDROLOGIC PROCESSES

Select this Article		The Joint Probability of Rainfall and Runoff Deficits in the Netherlands Jules J. Beersma and T. Adri Buishand ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)198 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Netherlands are situated at the downstream end of the Rhine River. A large part of the country can be supplied with water from the river in the case of precipitation deficits. For the assessment of the economical damage due to drought it is necessary to consider the rainfall and river inflow simultaneously. Transformed normal distributions as well as Gumbel distributions have been fitted to the observed precipitation and discharge deficits. The sensitivity of joint probabilities to the choice of the marginal distributions, the dependence structure and the ‘failure region’ is investigated. It is found that the bivariate normal distribution underestimates the probability that both the rainfall and runoff deficit are extreme due to its asymptotic independence.

Select this Article		Probabilistic Modeling of Activated Sludge Systems: Strategies for Reducing Process Uncertainty Benjamin S. Magbanua, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)199 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Probabilistic modeling of activated sludge wastewater treatment systems was performed to compare the uncertainty, with respect to attaining pollutant removal targets, associated with specific reactor configurations (conventional, completely mixed, and step feed activated sludge systems) and operating variables (solids residence time, hydraulic residence time, recycle ratio, and influent distribution). Stochastic simulation results showed that different reactor configurations inherently had different levels of uncertainty associated with them. Whether a specific operating parameter had an effect on uncertainty, and the extent of that effect, was dependent on the process configuration. In allof the configurations considered, process uncertainty could be reduced by increasing the solids residence time. Treatment uncertainty was also reduced when the hydraulic regime of the reactor was closer in character to plug flow rather than to completely mixed. Hence, the treatment uncertainty for the conventional activated sludge system was lower than that for the completely mixed activated sludge system. Furthermore, operational changes that enhanced mixing, such as increasing the recycle ratio in a conventional activated sludge system, or distributing the influent along the length of the reactor basin in a step feed activated sludge system, also tended to increase process uncertainty. In every case, system response could be traced to the effect of the imposed configuration and parameter changes on the hydraulic regime and reaction kinetics within the treatment system.

Select this Article		A Hydrologic Functional Assessment Model for Depressional Wetlands A. J. Hill and V. S. Neary ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)200 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes development of a hydrologic functional assessment model for depressional wetlands. Model output is a normalized metric that ranges from 0 to 1 and indicates the level of alteration to the wetland hydrologic regime relative to the unaltered condition. The metric selected to characterize the hydrologic regime is the number of days (0–365) with standing surface water. The model includes four variables, each corresponding to an alteration type common in the study area. One variable reflects alterations to wetland morphology that increase or decrease storage capacity. Two variables reflect alterations to the wetland watershed that result in increased surface runoff. The remaining variable reflects changes in evapotranspiration losses resulting from a timber harvest. Model variable sensitivity and interaction are examined by simulating 47 years of hydrology for a depressional wetland site. Simulation results are used to develop simple relationships between model variables and the normalized metric.

Select this Article		Verification of Wetland Restoration Using Mathematical Models Roger S. Copp and Ananta K. Nath, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)201 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract An integrated surface water/groundwater model of the western Big Cypress Basin in southwest Florida was developed using the MIKE SHE/MIKE 11 modeling system to evaluate the effectiveness of structural measures for restoration of the wetlands in Southern Golden Gate Estates (SGGE). The terrestrial and the estuarine ecology of the SGGE its receiving estuaries have been severely damaged by ill‐planned development of roads and drainage canals. The hydro‐geologic system of the basin is characterized by a high water table, low topographic relief, and a vast network of man‐made canals that were excavated to lower the water table Restoration of over 135,850 hectare (55,000 acres) within the area is planned as one of the priority projects of the Comprehensive Everglades Restoration Plan. The restoration plan includes plugging of canals and introduction of water into previously drained wetlands. An initial study was conducted that evaluated the benefits of one scenario. In this study, the model was updated with more accurate canal information and ground water demands, and the re‐calibrated model was superior to the original MIKE SHE model. Twenty‐five alternative restoration strategies were evaluated to identify a strategy that maximized wetland restoration and minimized construction cost and flooding to rural residential areas. The model results indicate that a number of the alternative restoration strategies will significantly improve wetland hydrology. Model results will be presented to demonstrate the expected changes in hydrology in the proposed wetland system.

Select this Article		Development of a GIS‐Based Stormwater Quality Management Planning Tool Hong Qin, Steven J. Burian, and Findlay G. Edwards ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)202 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Increased federal regulation of stormwater runoff in recent years has concomitantly increased the interest of engineers, planners, and municipal officials towards the effective planning and design of stormwater management programs. Given the increased attention to stormwater management, the demand for technical tools to solve problems efficiently has arisen. To meet the demand for planning tools that can take advantage of spatial data, a Visual Basic for Applications tool for use within the ArcGIS 8.x geographic information system (GIS) software package has been created. The GIS tool offers a construction site erosion and sediment control module and a post‐construction stormwater management module to aid the development of best management practice (BMP) plans. Within the GIS environment, BMPs can be placed on a site map and the automatic processing can be activated to determine the cost and pollutant removal performance of the BMP plan given spatial data describing site topography, land use/cover, and soil type. Site specific BMP performance and cost information can be input or a database of national cost and performance data can be used by default. BMP plans can be revised and the relative cost and performance of alternative plans determined and compared. The construction site erosion and sediment control module implements an erosion prediction algorithm based on the Revised Universal Soil Loss Equation (RUSLE). The post‐construction stormwater management module implements Curve Number hydrology for long‐term runoff volume prediction, as well as Event Mean Concentration associated with land use for pollutant load prediction. Monte Carlo water quality simulation and a BMP optimization routine are also being developed for later implementation.

Select this Article		ArcGIS‐SWAT: A GIS Interface for the Soil and Water Assessment Tool (SWAT) Francisco Olivera, Milver Valenzuela, and Raghavan Srinivasan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)203 \| Cited 1 time Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract ArcGIS‐SWAT, a GIS interface for the Soil and Water Assessment Tool SWAT has been developed. It is an ArcView 8.x extension that uses objects defined according to the ArcObjects standard, which conform to the Component Object Model (COM) protocol; and its code has been written entirely in Visual Basic (VB). It consists of a data model in geodatabase format specifically designed for SWAT, and the necessary tools to populate it, prepare the SWAT input files and write the SWAT simulation results back to it. The data model approach has the advantage of being the repository of all the data (including the geographic data) of a SWAT simulation.

Select this Article		Digital Terrain Model Processing for Integrated Hydraulic Analysis and Floodplain Mapping M. G. Shapiro and E. J. Nelson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)204 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract An important data requirement for a typical one‐dimensional hydraulic flood model is accurate cross section data describing both channel bathymetry and the floodplain at multiple locations along a river reach. Sources of obtaining these data include traditional surveying, light detection and ranging (LIDAR) datasets, and digital elevation models (DEM) produced from remotely sensed elevation datasets. Required cross section data can then be extracted from a digital terrain model (DTM), which is created using data from one or more of these sources. High density datasets can be merged with datasets of a lower resolution to create a DTM. Sparse data in a DTM may exclude important terrain features such as accurate river bathymetry and levees while data that is too dense may present challenges because of computer processing times. Many rivers have existing levees, either built for flood control or formed by structures like roads, which affect water levels during a flood event, but are often not well represented in a DTM. It is possible to manually edit each cross section to represent a levee or another topographic feature, but it would be a tedious task. Faulty or unnecessary data points should be edited or removed from high resolution DTMs in order to obtain optimum input cross section data. Some rivers do not include levees presently, but it is desirable to analyze and compare the results of flood events with and without proposed levees or roads. Editing terrain data to accurately include river bathymetry, or structures such as levees is a process that will improve the quality of flood event analysis from a digital terrain model as well as open the door to analyzing multiple scenarios with ease.

Select this Article		GIS: An Effective and Efficient Tool for Prioritization of Floodplain Mapping Studies M. Radaideh, Ph.D., C.F.M., H. Fehlman, P.E., D. Ruark, P.E., and L. Murray, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)205 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Floods cause loss of life, property, and economic activity. In January 1997, California experienced one of the most geographically extensive and costly floods in the State's history. Of the State's 58 counties, 48 were declared disaster areas. Nine people were killed, 120,000 people were evacuated from their homes, and 300 square miles were flooded. Damages approached $2 billion, and floods impacted over 23,000 homes as well as numerous businesses, agricultural lands, bridges, roads, and floodwater management infrastructures. Estimated indirect costs associated with the disruption of the State's economy exceeded $5 billion. California is expected to witness an increase in its population by an estimated 40 to 50 percent over the next 25 years, leading to development pressures on floodplains that have not been mapped (United States Census Bureau). In 2001, the California Department of Water Resources (DWR) focused its attention on these flood‐prone areas by initiating the statewide Awareness Floodplain Mapping Program (AFMP) where floodplains were analyzed using approximate methods supplemented with field verification. DWR noted that mapping all floodplains to Federal Emergency Management Agency (FEMA) standards would be a formidable task as well as cost prohibitive. DWR's priority is to identify potential flood hazard areas by producing quality maps that maximize the extent of coverage and makes the most efficient use of funding. A goal of the State's AFMP is to compliment FEMA's mapping program and not supersede it. The AFMP will only study streams located outside existing FEMA floodplains. The State's intent is to map potential flood hazard areas for these floodplains within the next 10 years. This will enable California communities to better protect its citizens and their properties.

Select this Article		Estimation of Uncertainties in Hydrometric Measurements R. W. Herschy ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)206 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract All measurements of physical quantities are subject to uncertainties. These may be due to bias errors in the equipment used for the measurement or to random scatter caused by a lack of sensitivity of the equipment. Every day throughout the world numerous hydrometric measurements are made of components of the water cycle without any explicit report on the uncertainty of the measurement. The uses made of these measurements in civil engineering design and operation of river works and in water resources management generally requires an assessment of the reliability of the measurements. The result of a measurement is only an estimate of the value of the measurand and only complete when accompanied by a statement of the uncertainty. The arithmetic mean value of the observations is the basic statistic and starting point, but a measure of the scatter, or dispersion, about the mean is required. To determine this dispersion in measurable terms is the object of uncertainty analysis of hydrometric data. The “true value” of a measurand is unknown, but an estimate can be made by the use of simple uncertainty techniques, uncertainty being defined as the range in which the true value is expected to lie within specified limits. In this respect a confidence limit, or level, of 95% is normally adopted for hydrometric data which infers that 95% of the observations should, on average, lie within the specified limit of two standard deviations from the mean. It should be noted, however, that no uncertainty value can be assigned to the remaining 5%. Examples will be presented of uncertainty analysis of river flow measurements that follow the procedure adopted in the International Standards Organization's “Guide to the Expression of Uncertainty in Measurement”

Select this Article		Applicability of Various Clustering Techniques for Regional Frequency Analysis Kyung‐Duk Kim, Jun‐Haeng Heo, Woo‐Sung Nam, and Eun‐Woo Shin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)207 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Regional analysis of annual maximum precipitation data was conducted by using index‐flood method based on L‐moments. Annual maximum rainfall series for the durations of 1, 2, 6, and 24 hours were collected at 337 gauging stations in Korea. The identification of homogeneous regions was performed based on cluster analysis such as hierarchical and nonhierarchical techniques. As the results, various cluster analyses can be used to group appropriate sites into a region for regional analysis and to estimate more reliable quantiles.

Select this Article		Hydrologic Modeling of a Large Agricultural Watershed in Illinois Using BASINS‐HSPF Jaswinder Singh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)208 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Illinois State Water Survey is developing detailed hydrologic and water quality simulation models of the entire Illinois River basin. Under this plan, a hydrological simulation model was developed for the Vermilion River watershed (one of the major tributaries of the Illinois River) using 1970–1995 observed streamflow data from two U.S. Geological Survey gaging stations in the watershed and weather data from six representative stations. The model was developed using the Hydrological Simulation Program ‐ FORTRAN. The watershed was subdivided into 25 smaller hydrologically connected sub‐watersheds and their stream reaches. Hydrologic response units were created within each sub‐watershed based on land use and hydrologic soil groups. The model was calibrated using 1987–1995 streamflow data from the gage at Pontiac, IL, and then verified using 1972–1986 data from the same gage and using 1972–1995 data from the streamflow gage at Leonore, IL. The model simulated the mean monthly streamflows with correlation coefficients and Nash‐Sutcliffe Efficiency near or greater than 0.8 during calibration and verification periods. Flow‐duration curves of the daily observed and simulated streamflow data indicated good simulation for all flow conditions except for some very low flow periods. The model underestimated the flood year of 1993, but generally overestimated some very low‐flow years.

Select this Article		Modeling the Complex Hydrology and Hydraulics of the Lower Cache River Misganaw Demissie, H. Vernon Knapp, and Paminder S. Parmar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)209 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Cache River is located in the extreme southern part of Illinois, just north of the confluence of the Ohio and Mississippi Rivers. In 1915, a cutoff to the Ohio River was constructed east of Karnak that resulted in sub‐dividing the Cache River watershed into the Upper and Lower Cache River watersheds. The Upper Cache River watershed consists of the eastern part of the watershed draining directly to the Ohio River through the Post Creek Cutoff. The Lower Cache River watershed consists of the western part of the watershed draining to the Mississippi River through a diversion channel at the outlet. The Cache River levee was built in 1952 along the west bank of the Post Creek Cutoff to prevent runoff from the Upper Cache River watershed from entering into the Lower Cache River. Because of these and other alterations in the watershed, the hydraulics of the Lower Cache River are very complex. Smaller, local tributaries provide the source of water for the upper portion of the Lower Cache River. Once water from tributaries enters the upper part of the Lower Cache River, it can flow in an easterly direction towards the Cache River levee or flow in a westerly direction towards the Mississippi River. A combination of several factors determines the direction of flow in the upper part of the Lower Cache River. Hydrologic and hydraulic models were developed to simulate the hydraulics of the Lower Cache River and to evaluate different alternative measures that can be implemented to reduce or eliminate the unnatural reverse flow in the upper portion of the Lower Cache River.

Select this Article		A Bayesian Hierarchical Nonhomogeneous Regional Flood Model for New South Wales, Australia Tom Micevski, George Kuczera, and Stewart W. Franks ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)210 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Long‐term climate variability has been shown to affect flood frequency in New South Wales, Australia. This study extends this work by developing a Bayesian hierarchical model for predicting floods at ungauged locations. Flood records were stratified using a threshold value of the Interdecadal Pacific Oscillation (IPO), which characterises the low frequency component of sea surface temperature anomalies in the Southern Pacific Ocean. It is shown that the stratified flood distributions differ significantly with ratios of flood magnitudes being approximately 1.6 times greater during the IPO negative years. Moreover, the evidence suggests that the log‐normal distribution fits the stratified flood records satisfactorily. The stratified flood records were then subjected to regional flood analysis using a Bayesian hierarchical approach. The regional model considers at‐site floods to be spatially correlated via an intersite distance correlation function. The hierarchical model proposes that the parameters of the flood frequency distribution for any site are random samples from a regional probability model. This allows the inclusion of catchment characteristics, while also explicitly allowing for intersite variability. Model calibration was performed using Markov chain Monte Carlo methods. An important outcome is the quantification of predictive uncertainty at an ungauged catchment.

Select this Article		Performance Evaluation of Physically Based Distributed Hydrologic Models and Lumped Hydrologic Models E. A. Meselhe, E. Habib, O. C. Oche, and S. Gautam ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)211 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Accurate predictions of rainfall‐runoff relationship have been the goal of numerous hydrologic studies. Despite the availability of data, the usefulness of physically based, distributed parameter hydrologic models over lumped models remains uncertain. The purpose of this study is to evaluate the performance of a physically based, distributed model and a lumped model, and shed some light on their capabilities and limitations for a mid‐size catchment. The watershed selected for this study is the Goodwin Creek Experimental Watershed, located in northern Mississippi. The drainage area of Goodwin Creek is 21.2 km². The hydrologic modeling system HEC‐HMS developed by US Army Corps of Engineers, and MIKE SHE developed by the Danish Hydraulic Institute were used as the lumped and disturbed hydrologic models, respectively. The evaluation criterion of model performance is the ability of each model to predict time and magnitude of peak discharges, and runoff volume.

Select this Article		Development of Non‐Homogeneous and Hierarchical Hidden Markov Models for Modelling Monthly Rainfall and Streamflow Time Series Julian Whiting, Martin Lambert, Andrew Metcalfe, and George Kuczera ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)212 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Hidden Markov models (HMMs) offer a plausible representation of long‐term hydroclimatic persistence in rainfall and streamflow observations. Persistent climate processes influence hydrological observations at various time scales. This paper develops the stochastic framework of two‐state HMMs to better represent climate‐rainfall interactions at both monthly and annual levels. Two new models, a hierarchical HMM and a non‐homogeneous HMM are introduced, and fitted to monthly rainfall and streamflow observations from Australia. The value of these models to identify two‐state persistence is compared to that of existing two‐state HMMs.

Select this Article		Quantifying the Influence of Spatial Variability on the Run‐On Process: A Numerical Study N. Nahar and R. S. Govindaraju ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)213 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This study presents a numerical examination of surface and subsurface solute transport processes over spatially heterogeneous hillslopes with special focus on investigation of role of spatial heterogeneity on the run‐on process. The high degree of heterogeneity exhibited by the soil parameters that govern the mechanisms of infiltration on hillslopes necessitates a stochastic approach. In this study, numerical techniques are used to generate error maps that serve as guidelines as to when spatial variability has to be explicitly considered because run‐on is substantial, versus those cases where the nature of spatial variability is such that run‐on can be essentially ignored. When run‐on is not significant, mathematical analysis can be utilized to determine field‐scale infiltration, runoff, sediment transport, and surface and subsurface solute transport.

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INTERNATIONAL ISSUES

Select this Article		Water Loss in the Potomac River Basin during Droughts Erik R. Hagen, Julie E. Kiang, and Jonathan J. A. Dillow ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)214 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Washington D.C. metropolitan area's (WMA's) PotomacRiver water supply intakes are located downstream of the Potomac's Point of Rocks gage and upstream of the Little Falls gage. In early July of 2002, it was noted that there was an apparent water loss between these two gages. Little Falls flow was estimated based on Point of Rocks gaged flow, with adjustments for intervening withdrawals and inflows. The estimated Little Falls flow was as much as 150 million gallons per day (MGD) higher than the recorded flow at the Little Falls gage. This discrepancy implied that water was being lost between the Point of Rocks and Little Falls gages. Management of streamflow in the Potomac River is critical during drought conditions to ensure an adequate water supply in the WMA, which is the main source of water to 3.6 million people and to ensure recommended environmental in‐stream flow. Water is released from several key reservoirs to maintain minimum flows and to supply water for the WMA during times of drought. These releases are managed carefully in order to maintain sufficient reservoir storage; therefore, water loss is a major concern. Gage error, permitted withdrawals, evaporation, and transpiration by trees along the river were investigated to account for the loss. The Interstate Commission on the Potomac River Basin (ICPRB) calculated potential gage error and examined permits to determine permitted levels of consumptive withdrawals from the Potomac. Gage error may account for some loss but was thought unlikely to explain a significant portion of the loss In total, about 24 ‐MGD of the loss could be attributed to permitted withdrawals during the summer.

Select this Article		Establishing a Drought Warning System Based on Long‐Lead Climate Forecasting T. M. Liu, C. P. Tung, C. J. Chen, and S. W. Chen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)215 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This study proposes a drought warning system based on long‐lead climate forecasting data to provide information for risk management of water resources. The proposed method was applied to the Taipei areas in Taiwan. The system consists of a water resources system dynamic model, a streamflow model, and an irrigational water demand model. The GSM climate forecasts were downscaled by the RSM model in another study with a lead time of three months. Then the downscaled climate forecasts were entered into the streamflow and water demand models. The water resources system dynamics model predicts deficits in water supply after entry of forecasted streamflow and water demands. Drought warnings will be issued when cumulative water deficits reach an optimized threshold. The water supply and demand from 1978 to 1999 were simulated and used as input to test the system. Drought warning based on long‐lead climate forecasting can provide decision makers more information in advance to determine water resources management strategies.

Select this Article		Software for Optimizing International Water Resources Management R. C. Peralta and S. Wu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)216 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Simulation/Optimization MOdeling System (SOMOS) has modules adapted for a range of international water resource management needs. The SOMOA module is best for field groundwater and conjunctive water management situations. It employs several analytical simulation models and several optimization methods to give appropriate optimal guidance for situations having sparse data. SOMOA requires understanding of the limitations of common analytical equations. It does not require experience in finite difference or element numerical modeling. SOMOS also has modules ideal for situations in which there is sufficient data for numerical modeling or aquifer and stream‐aquifer systems. Emphasized here are SOMOA and its applications for common field‐level water management problems. Sample situations include optimizing: minimizing required surface reservoir size for a period of low surface flows in a stream‐aquifer system; conjunctive use for blending irrigation waters of different qualities; and artificial injection.

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IRRIGATION AND DRAINAGE

Select this Article		Evaluating the Transport of Pesticides in Tropical Soils in Hawaii M. Sanda, C. Ray, J. Dusek, B. Loo, and R. Green ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)217 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Three new herbicides, a fungicide, and an insecticide were tested for their ability to leach in various tropical soils in Hawaii. In addition, atrazine and bromide ions were used as two reference chemicals in the study. Label rates of these chemicals for agriculture or insecticidal use were applied to tilled soils. Five test sites at differing topographic, climatic and soil conditions were selected in the 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. Disturbed 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 content of the chemicals, yielding concentration profiles for elapsed times of 1 day to 16 weeks. Prior to pesticide application, soil profiles have been also characterized for pH, ΔpH, organic carbon content and basic nutrients: P, K, Mg, Ca. Undisturbed soil core samples have been taken and sets of water‐retention curves have been determined in the laboratory. Field tests for unsaturated and saturated hydraulic conductivity using tension disc infiltrometers have been carried out at all sites. In addition, laboratory tests on the sorption and degradation of the chemical compounds are being carried out.

Select this Article		Methodology for Estimating Specific Yield in Shallow Water Environment Using Continuous Soil Moisture Data Ahmed Said, Mahmood Nachabe, Mark Ross, and Jeff Vomacka ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)218 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Ground water hydrologists use specific yield to estimate the total volume of recoverable ground water in storage in an aquifer and measure pumped or drained water from water bearing material dewatered. Specific yield is defined as the volume of water that a saturated rock or soil will yield by gravity per unit area of soil per unit change in water table elevation. Accurate estimates of specific yield and other hydrogeological parameters are critical for management of water resources and can be used to control well yields and resulting water level depths and rates of water level declines. The study area is in Lithia, near the planned Tampa Bay Regional Reservoir in the southeastern portion of Hillsborough County, Florida. Data from four soil probes were studied. The objective of this paper is to obtain precise estimates of the specific yield by methodological fitting procedure and determine functional relationships between measured soil and site characteristics. A methodology for estimating specific yield in shallow water environment using continuous soil moisture data is introduced. The ultimate specific yield values estimated varied from 0.23 to 0.37 within the sensors and varied with depth in the profile of shallow water vadose zone. The results will be incorporated into the large‐scale integrated surface and ground water models that have been used successfully in west central Florida.

Select this Article		Another Look at Wetted Perimeter along Irrigated Furrows — Modeling Implications Wynn R. Walker and Babukannan Kasilingam ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)219 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In modeling furrow irrigation, it is often assumed in furrow irrigation modeling that roughness and cross‐section are constant along the furrow length; and as a result, wetted perimeter decreases as the flow decreases. Several researchers have attempted to determine the relationship between infiltration in furrow irrigation and wetted perimeter. Fangmeier and Ramsey, Strelkoff and Souza, Blair and Smerdon, Izadi and Wallender, Schwankl and Wallender, and Oyonarte et al., have concluded that infiltration varies, either linearly or non‐linearly, with wetted perimeter. However, Trout has argued that such a relation exists only in the case of stagnant tests, not in tests conducted under real conditions. The basis of Trout's argument is that field measurements clearly show that cross‐section and roughness change along the furrow. Infiltration is a function of wetted perimeter and is typically modeled through compensations for wetted perimeter. A problem arises between field analyses attempting to measure infiltration and the subsequent use of the results in simulation and design models. Field studies typically give either very limited point measurements or an average of the entire furrow length. Point measurements using various infiltrometers usually lack sufficient coverage to identify spatial variability. Tests which deduce infiltration from advance, runoff, and/or tailwater provide a single value in which all field variations are consolidated, and if they include the adjustments for wetted perimeter, they do so with a formulated relationship and assumptions regarding the cross‐section and roughness.

Select this Article		Development of Procedures for Estimating Infiltration Model Parameters Sarah Herman, Bob Mittlestadt, Marshall English, and Clint Shock ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)220 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Oregon State University in collaboration with the ASCE/EWRI task committee on Soil and Crop Hydraulic Properties for surface irrigation has begun conducting a comprehensive evaluation of various algorithms proposed for the determination of infiltration parameters from surface irrigation measurements. The procedures under development will include the following elements: (1) Establish specifications and guidelines for assembling and formatting data sets used by the various infiltration parameter estimation models to be tested. These input specifications will include different types of field data commonly collected, the units to be used, formatting of field data to be consistent with the units used, and any constants and other prior assumptions to be employed; (2) Formulate procedures for assessing input data quality and for determining whether the functional forms of infiltration models that are assumed either explicitly or implicitly in the various algorithms of interest are in fact consistent with input data patterns; (3) Establish criteria for characterizing the performance of algorithms as analytical tools when used specifically for decision making in surface irrigation; and (4) Conduct prototype evaluations of two algorithms for determining infiltration parameters; specifically, the one‐point and two point methods.

Select this Article		Modified Two‐Point Method for Closed‐End Level‐Bed Furrows D. Zerihun, C. A. Sanchez, and K. L. Farrell‐Poe ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)221 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The two‐point method is a simple, compact, and relatively accurate inverse solution technique widely used to estimate the parameters of the Kostiakov‐Lewis infiltration function. However, the applicability of the method is limited to sloping free‐draining furrows. In this paper, the two‐point method is modified to extend its application to close‐end level‐bed furrows. The modifications deal with the calculation of the basic intake rate and the inlet flow cross‐sectional area during the advance phase. With the modified method, basic intake rate is calculated as the quotient of the change in volumetric surface storage between two selected time lines during the steady state period and the product of the furrow length and related time interval. In addition, the inlet flow cross‐sectional area can be calculated as a function of flow depth at the inlet or using the Manning equation and an assumed linear flow depth gradient. The proposed approach was tested by comparing advance trajectories computed by SRFR, on the basis of infiltration parameter estimates by the modified two‐point method, with field observed advance. A satisfactory agreement was obtained between SRFR predicted and field observed advance.

Select this Article		Correcting the Volume Balance Equation for Shape Factors during Advance Wynn R. Walker and Babukannan Kasilingam ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)222 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The volume balance model has been an important tool in the evaluation and design of surface irrigation systems. Perhaps it's most useful application has been in evaluating the intake parameters of a sloping border or furrow during the advance phase of irrigation. Unfortunately, these volume balance estimates of intake parameters may not provide a unique enough solution to allow accurate simulation of runoff and recession. There are three important problems with a volume balance approach. First, the inflow during the advance phase must be steady. This is often difficult to achieve in the field. Second, if an intake equation with steady‐state or cracking terms is used, the related parameters must be determined outside of the volume balance analysis and then input. These values are difficult to measure accurately in the field. And third, unless the analysis specifically ignores the surface volume during advance, these models use a uniform flow equation, like Manning, to describe the cross‐sectional area of flow at the field inlet and then an assumption regarding the shape of the flow profile downstream — generally assuming the cross‐sectional area is constant. The assumption of a constant cross‐sectional area is known to introduce substantial errors.

Select this Article		Optimal Control of Irrigation Canals Using Recurrent Dynamic Neural Network (RDNN) Omer F. Durdu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)223 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A recurrent dynamic neural network (RDNN) based on Hopfield model was applied to linear quadratic regulator controller of an irrigation canal. The Saint‐Venant equations of open‐channel flow were linearized using the Taylor series and a finite difference approximation of the original nonlinear, partial differential equations. Using the linear optimal control theory, a Linear Quadratic Regulator (LQR) controller was developed for an irrigation canal with a single pool and results were observed. And then LQR controller was redesigned with applying Hopfield recurrent dynamic neural network (RDNN) to solution of Riccati equation for calculating the LQR control gains. The main advantage of Hopfield neural network model is its robustness and flexibility when dealing with unknown perturbations and parameters. The results of this study shows that an RDNN based LQR controller (RDNN/LQR) for irrigation canals offers an alternative to traditional LQR controller when dealing with the disturbances in the irrigation canals.

Select this Article		Rubber Dams in Bangladesh Harness Surface Water for Farmers to Irrigate at Lesser Cost M. S. Khan, M. Eklimur Reza, M.ASCE, and Md. M. Rahman, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)224 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Farmers in Bangladesh have significantly extended agricultural activities into the dry winter‐summer season over the past 2 decades to produce more through double and triple cropping and also to remain safe from damages due to floods. Agriculture in winter‐summer season is fully irrigated. Ground water is now meeting the lion's share of this irrigation need. However, limit of abstraction of ground water within the capacity of technical and financial management by individual farmers, as it is now, will soon be reached at. It is, therefore, necessary that available surface water be harnessed, as far as possible, to support irrigation need in the dry season. Further to that, detection of arsenic contamination of ground water in some parts of the country in the recent past has made conservation of surface water all the more important. Also, surface water is cheaper and of better quality and so farmers have definite priority of choice of surface water over ground water for irrigation. There is no scope to develop reservoirs for storage of water in this flat country. With this background, Bangladesh has adopted Rubber Dams for conservation of water in the channels of its small and medium rivers to support winter‐summer irrigation. Since introduction of the technology in 1995, Rubber Dams have been recognized as a successful method of water conservation under the conditions in Bangladesh. The Paper presents the technology of Rubber Dams in some details together with last 7 years' experience of Bangladesh with Rubber Dams. References have been made of the impact of Rubber Dam Projects on rural poverty reduction through the impact on agriculture of small and marginal farmers and through the scope of certain other economic activities for the local poor. Reference has also been made on the potential of application of Rubber Dams in regional countries — India and Sri Lanka together with interests indicated by some concerned agencies.

Select this Article		Determination of Residential Irrigation Water Use in Florida Michael D. Dukes, Melissa C. Baum, and Grady L. Miller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)225 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Residential irrigation water use is a large component of total water use in Florida. With one of the largest state populations in the U.S. that is rapidly growing, competition between urban, agricultural, and other water users is increasing. This project measured residential irrigation water use and irrigation system uniformities in central Florida. Three treatments were established as follows: typical irrigation practices (T1), irrigation based on historical evapotranspiration (T2), and water wise landscape plus irrigation designed to minimize water use (T3). T1 homes averaged 143 mm of irrigation per month in 2003 while T2 and T3 averaged 103 and 74 mm, respectively. This corresponds to a 28 and 48% reduction in irrigation water use compared to the typical practices, respectively. Distribution uniformity (DU_1q) of homes tested averaged 0.40–0.50 which was statistically lower than irrigation heads tested under controlled conditions and also lower than industry standards. The preliminary results indicate that design for uniform application of water is difficult in small non‐uniform areas of residential yards with current commercially available equipment and that irrigation water use can be reduced by proper scheduling and with landscapes that are designed to minimize irrigation.

Select this Article		Hydraulic Model Study of Tehama‐Colusa Canal Raymond Walton, Daniel Eggers, Mark Jonas, and Alan Stroppini ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)226 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The California Department of Water Resources (DWR) conducted feasibility‐level engineering and environmental studies under the Integrated Storage Investigations Program. The U.S. Bureau of Reclamation (USBR) was the lead federal agency for the EIS/R. As part of the investigation, DWR and USBR evaluated alternatives using the Tehama‐Colusa canal to provide up to 5,000 cubic‐feet‐per‐second (cfs) of conveyance capacity to deliver water to the proposed Sites Reservoir. To evaluate the existing canal's capacity, and to assist in the design of alternatives to increase the capacity, a hydraulic model was developed. HEC‐RAS was applied between Mile Posts (MP) 0.51 and 66.07, and included 16 check structures, 20 inverted siphons, 33 bridges, and numerous other crossings. The canal was designed and built in reaches using standard cross sections for each reach. A spreadsheet was developed to automatically create the HEC‐RAS geometry file from these standard sections and individual station invert elevations, obtained from construction plan/profile drawings. After the various structures were added, the model was calibrated to recent moderately‐high flows, and then applied to evaluate a range of alternatives. The alternatives included raising the canal's lining and structures, and widening the canal to achieve new design flow capacities.

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MODELS AND ADVANCED COMPUTING

Select this Article		A Calibration Model for CE‐QUAL‐W2 Shani Salomons and Avi Ostfeld, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)227 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract An instance‐based heuristic evolutionary algorithm for the parameterization of the 2D surface water quantity and quality model CE‐QUAL‐W2 is presented. The methodology developed is a hybrid genetic algorithm (GA) ‐ k‐nearest neighbor algorithm (GA‐kNN). To reduce computational efforts, a “hurdle race” approach was developed, with a “hurdle” being a predefined value of the parameterization objective function computed at different points during a simulation run. The “hurdle race” is formulated for accepting/rejecting a proposed set of parameters during a CE‐QUAL‐W2 simulation; the k‐nearest neighbor algorithm (kNN) for approximating the objective function response surface; and the genetic algorithm (GA) for a mutual linking. The proposed methodology overcomes the high non‐applicable, computational effort required if a conventional parameterization search technique is used, while retaining the quality of the final solution.

Select this Article		Performance of Automated Calibration for Water Distribution Systems Thomas Walski, Zheng Wu, and Wayne Hartell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)228 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Use of optimization to calibrate a water distribution model has been the subject of considerable research. Such models have not been systematically studied on realistic sized systems to any great extent. This paper presents an evaluation of Darwin Calibrator, a genetic algorithm approach to achieving optimal calibration. It shows that the Calibrator works well when given a sufficient amount of good quality data and examines the relationship between the quality of the data and the quality of results.

Select this Article		Calibration and Validation of Long‐Term Streamflow Forecasting Models Mohammad Karamouz, F.ASCE, Shahab Araghinejad, and Amin Haghnegahdar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)229 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Long‐lead streamflow forecasts are very important for the operation of water resources systems. Calibration and validation of long‐term forecasting models are needed to increase the accuracy of forecasted values, especially in the regions with limited observed data. This study discuses the procedure of model calibration and validation in two conceptual and statistical models. The forecasting techniques applied in this study are artificial neural networks (ANN), and non‐parametric K‐Nearest Neighbor (K‐NN) method. The procedure of calibration and validation of these models is also discussed. The processes of model selection, calibration, and cross validation are combined through an optimization procedure. The best architecture and the number of training epochs in ANN, and the best weights of independent variables beside the number of neighbors in the K‐NN method are determined by this optimization procedure. The models are applied to the Zayandeh‐rud reservoir basin in Iran to forecast the monthly streamflows of Zayandeh‐rud River, one of the greatest rivers in the central part of Iran. Hydroclimatic data, such as observed soil moisture, snow budget, rainfall, air temperature, and streamflow data in the previous month are considered as the predictors of streamflow in the models. The results of forecasting using the calibrated models indicates that the presented procedure for the time series analyses techniques provides significant improvements in the accuracy of streamflow forecasting.

Select this Article		Automatic Calibration and Uncertainty Analysis of a Watershed Model Christine Shoemaker, Bryan Tolson, and Fernando Mendez ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)230 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper will discuss the application of a range of algorithms to optimization of calibration. The application is to the Cannonsville Reservoir, which has an area of 1200 square kilometers. The Cannonsville supplies water to NY City. There is a danger of excessive phosphorous over the watershed causing euthrophication of the reservoir and the water supply. The model predicts flow and the transport of sediment and phosphorous. For this problem, a modified simulated annealing algorithm and a global greedy search were the best algorithms.

Select this Article		Impact of Data Collection and Calibration of Water Distribution Models on Model‐Based Decisions Derya Yalcin Sumer, Dana Abu Sier, Jesse Roach, Scott Schladweiler, Umur Yenal, and Kevin Lansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)231 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In practice, water distribution model calibration has been based on modeler judgment. Recent research has examined model parameter and predictive uncertainties and how those uncertainties can guide future data collection experiments. This paper presents a methodology that extends previous work by considering the impact of uncertainty on the final goal of the model of system design.

Select this Article		CFD Prediction and Validation of Butterfly Valve Hydrodynamic Forces Fangbiao Lin, Ph.D. and Gerald A. Schohl, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)232 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a computational fluid dynamics (CFD) model developed using the commercial software FLUENT, and presents predicted hydrodynamic force coefficients for a disc‐shaped butterfly valve at different valve operating angles. The predicted force coefficients were used to provide estimates of hydrodynamic loads on the butterfly valve during closure against flow. The results of this study expand the knowledge base of butterfly valve hydrodynamic forces. The use of FLUENT for estimating force coefficients was validated by comparing CFD predictions to experimental results for the drag coefficient of a coin‐shaped disc placed perpendicular to flow in an infinite flow field. The sensitivity of the results to turbulence model selection, accuracy of discretization schemes, grid quality, and grid dependence was studied as part of the validation. CFD models of the butterfly valve were used to compute drag coefficients, lift coefficients, moment coefficients, and discharge coefficients for the valve at seven different opening positions. The computed discharge coefficients compared very well with experimental discharge coefficients available in the literature, which provided confidence in the accuracy of the predicted force and moment coefficients as well, and suggests that CFD analysis can be a useful tool for predicting drag forces and lift forces on similar hydraulic structures.

Select this Article		Fast‐Track Design Efforts Using CFD: Bonneville Second Powerhouse Cynthia L. Rakowski, Laurie L. Ebner, and Marshall C. Richmond ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)233 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A set of three‐dimensional, computational fluid dynamics (CFD) models were developed and used for the Bonneville Project tailrace to study the impact of a proposed outfall structures on the tailrace hydraulics; these structures were designed to improve the survival of (juvenile) salmon migrating downstream. Flows were simulated by solving the Reynolds‐Averaged Navier‐Stokes equations together with the k‐ϵ turbulence model in a commercial CFD code. The numerical model was validated using field‐measured velocity data. The model results identified undesirable combinations of outfall location and operational scenario, which aided in selecting where the outfall structure was built. The numerical model provided an effective tool to rapidly simulate and visualize the flow field for multiple proposed outfall locations over a large number of operational scenarios. The visualizations of the results from the CFD model provided insights to hydraulic engineers and fisheries biologists working on the design and placement of the outfall structure.

Select this Article		Multi‐Objective Conjunctive Use Optimization H. C. Fayad and R. C. Peralta ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)234 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a simulation/optimization model based on artificial neural networks and genetic algorithms for solving multi‐objective conjunctive water use problems. The model simulates and optimizes water flows in a hydraulically connected reservoir‐stream‐aquifer system. It is a powerful tool to help water managers and authorities in developing conjunctive water management strategies and evaluating tradeoffs between conflicting goals.

Select this Article		Multi‐Objective Evolutionary Algorithms for Cost‐Effective Management of Ecosystem Services in a Watershed E. G. Bekele and J. W. Nicklow, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)235 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Ecosystem services such as sediment and nutrient load reductions, flood control, nutrient cycling, regulation of atmospheric gases, and expansion of wildlife habitat and biodiversity are increasingly recognized as society essentials and as having significant economic value. With the considerable successes that have been achieved in controlling industrial point source pollution, the target for improving ecosystem services in the United States and elsewhere is increasingly centered on landscapes. Control of non‐point source water pollution, for example, is an issue that must be addressed by better managing land use patterns. This study aims to identify multi‐seasonal land uses and tillage practices that most cost‐effectively produce improved ecosystem services within a watershed and ultimately enable examination of the tradeoffs between commodity production and generation of those services. It focuses on three particular ecosystem service related objectives, namely reduction of sediment, phosphorous, and nitrogen loads to improve water quality in rivers and streams. To solve this multi‐objective problem, an optimal control computational model is developed by interfacing a widely‐used distributed watershed model, the U.S. Department of Agriculture's Soil and Water Assessment Tool, with a Pareto‐based multi‐objective evolutionary algorithm known as the Strength Pareto Evolutionary Algorithm (SPEA). The model is applied to the Big Creek watershed in southern Illinois. The results demonstrate that the SPEA is capable of handling the complexities posed by the multi‐objective watershed management problem. Furthermore, the overall integrative methodology is effective in identifying a set of optimal solutions and gives the user access to important information regarding the tradeoffs among competing objectives. In addition, the model could be used to determine the most cost‐effective means for meeting Total Maximum Daily Load (TMDL) criteria. Future work will emphasize the inclusion of additional ecosystem services and further investigation and comparison of alternative multi‐objective search methods.

Select this Article		Interactive Genetic Algorithm Framework for Long Term Groundwater Monitoring Design Meghna Babbar, Barbara Minsker, and Hideyuki Takagi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)236 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In standard optimization approaches for water resources management problems, the designer is responsible for correctly formulating mathematical equations to describe the system objectives and constraints. The search for optimal or near‐optimal solutions is made under the assumption that these formulated objectives and constraints completely describe the system. However, in real systems that is often not true. Many qualitative criteria can be integral parts of the design analysis that numerically based algorithms cannot capture. For such problems, designer interaction with the search algorithm can help the search be more creative and inclusive. Genetic algorithms are ideally suited for incorporating such interaction in their usual search process, and can successfully evolve solutions that are optimal with respect to both qualitative and quantitative objectives. Under an interactive approach, the genetic algorithm performs the usual operations of selection, crossover, and mutation, but the user evaluates the suitability (‘fitness’) of candidate solutions, enabling objectives that cannot be quantified to be included in the search process. In multi‐objective problems, where quantitative objectives can be as important as qualitative fitness of designs, analysis of designs is done based on tradeoff fronts made from both quantitative and qualitative information. In this paper, we demonstrate the use of interactive genetic algorithms for long term groundwater monitoring problems, which have multiple numerical and subjective objectives. We also analyze the effects on the optimal monitoring designs of using an interactive optimization approach instead of more traditional numerical optimization approaches.

Select this Article		Comparing Formulations for Multi‐Objective Groundwater Remediation Design under Uncertainty Omar Beckford and Amy B. Chan‐Hilton ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)237 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This work compares alternative genetic algorithm (GA) methods and applies the enhanced multi‐objective robust genetic algorithm (EMRGA) for groundwater remediation design under uncertainty. The research presented in this study investigates modifications to the EMRGA and optimization problem. In the EMRGA, the overall fitness of a string is based on its performance over multiple generations. This work is significant due to the multi‐objective nature of groundwater management problems and the inherent uncertainty involved in obtaining aquifer parameter values. The overall EMRGA simulation‐optimization approach unites a GA with a contaminant fate and transport simulation model and a spatially correlated random field generator for hydraulic conductivity values to determine tradeoffs between expected remediation design cost and reliability. One advantage of the EMRGA over other GA optimization approaches is its ability to efficiently solve optimization problems that are both multi‐objective and include parameter uncertainty. The EMRGA is evaluated on a pump‐and‐treat remediation design problem with the goal of identifying the optimal locations and pumping rates of extraction wells given uncertainty in hydraulic conductivity. The EMRGA evolves Pareto‐optimal sets, which identify trade‐offs between the conflicting objectives: minimizing both cost and contaminant concentration. Future plans for the EMRGA include evaluating its performance on a real field site, comparing the EMRGA with other hybrid methods, and using GIS to present and analyze the results.

Select this Article		Optimal Operation of Multi‐Reservoir River Systems Using an Artificial Life Algorithm T. Dessalegne and J. W. Nicklow, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)238 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract An optimization algorithm derived from the artificial life paradigm is introduced. The algorithm was first tested on standard optimization test functions and subsequently applied to determine the optimal dam operations in a multi‐reservoir river system. The optimal dam operation scheme is that which indirectly minimizes environmental impacts caused by short‐term water level fluctuations, while maintaining desired stages within the river network, desired storage levels in the reservoirs, bounds on releases from dams/gate openings, and minimum pool levels behind locks and dams. The dam operation problem is solved using a discrete‐time optimal control methodology in which an artificial life algorithm is interfaced with NWS‐FLDWAV, an unsteady, one‐dimensional, hydraulic simulation model. The hydraulic simulation model is used to solve governing hydraulic constraints, while the artificial life algorithm is employed to solve the overall control problem. Constraints on water surface and storage levels are handled using an additive penalty method. The developed model is applied to a portion of the Illinois River, for which the hydraulic simulation model was calibrated and verified. The model may prove to be a useful tool that assists engineers and managers in establishing coordinated reservoir operation rules.

Select this Article		Constraint‐Handling Techniques for Evolutionary Algorithm‐Based Management of Water Supply and Irrigation Canal Networks Talaat El Gamel and Laura J. Harrell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)239 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Strategies for water supply and irrigation canal systems management must be established to meet water demands throughout the network over time while preventing problems such as water shortage or flooding of sensitive areas. A previous study demonstrated that by incorporating an unsteady flow model into an evolutionary algorithm‐ (EA‐) based framework, efficient strategies for scheduling gate operations and allocating crops can be determined to address the various objectives and constraints over a period of time. However, as implemented previously and applied to a case study in Egypt, this method did not find solutions that satisfied all system constraints. Therefore, other constraint handling techniques are investigated to improve the EA performance for this problem. The most common technique for handling constraints in an EA is the use of penalty functions that are incorporated into the fitness criterion to degrade the fitness of solutions that violate one or more constraints. Alternative techniques have also been reported in the literature, including a multiobjective optimization technique that treats the constraints in single objective problems as additional objectives and a stochastic ranking procedure, both of which have been shown to perform efficiently for other engineering applications. In the previous study, a static penalty function was used to handle constraints in the EA. This paper investigates the performance of six constraint‐handling techniques (five techniques from the literature, and a new proposed technique) for a water supply and irrigation canal network operation problem.

Select this Article		Evaluation of Constraint‐Handling Techniques for Evolutionary Algorithm‐Based Watershed Management Kwisun Park Yu and Laura J. Harrell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)240 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Nonpoint source management using wet detention ponds to reduce pollutant loading into receiving water bodies is a common practice. Design of these ponds is typically carried out individually to meet a target total suspended solids (TSS) removal level. An improvement to this approach is to generate cost‐effective pond configurations that meet system‐wide targets for removal of pollutant loadings, corresponding to a specific build‐out land use plan. The amount of pollutant loading can be managed better through appropriate land use allocation planning conducted simultaneously with the design of detention ponds. Harrell and Ranjithan presented a modeling approach to address this problem and its solution using a evolutionary algorithm‐ (EA‐) based search procedure. The model includes constraints on the system‐wide land use distribution, which were handled using penalty functions. Most penalty function implementations, which are incorporated into the fitness criterion to degrade the fitness of solutions that violate constraints, require the user to specify and fine‐tune penalty factors that determine the amount of penalty assigned as a function of the level of constraint violation. Alternative techniques have also been reported in the literature, including a multiobjective optimization technique that treats the constraints in single objective problems as additional objectives and the stochastic ranking procedure, which have been shown to perform efficiently for other engineering applications. This paper investigates the performance of three penalty function implementations and two alternative techniques for constraint handling in a watershed management problem.

Select this Article		Generating Urban Watershed Management Alternatives Using Evolutionary Algorithms J. L. Dorn and S. Ranjithan, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)241 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The design of urban drainage networks is complicated by the need to consider a number of issues that conflict and compete with the goal of managing flood impacts. These issues primarily include environmental considerations, but may also include issues such as developable land impacts, system reliability, wetland impacts, aesthetics, etc., some of which may not be modeled explicitly. Modeling to generate alternatives (MGA) is a formal optimization‐based technique to find near optimal alternatives that are maximally different from one another with respect to their decision attributes. This paper presents a new evolutionary algorithm (EA)‐based technique, the Solution Set Algorithm (SSA), for performing MGA and its application to design problem involving the design a least‐cost drainage network using the EPA's Storm Water Management Model (SWMM).

Select this Article		Development of Discharge‐Water Level Relationship for Low‐Slope Tidal Streams Using Non‐Parametric Data‐Driven Models E. Habib, E. A. Meselhe, and S. Kalikivaya ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)242 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Development of stage‐discharge relationships for coastal low‐gradient streams is a challenging task. Such relationships are highly nonlinear, nonunique, and often exhibit multiple loops. Traditional methods, such as parametric regression, usually fail to model these relationships. Instead, this study takes advantage of advanced computation‐intensive techniques, such as neural networks and local nonparametric regression, to model such complex stage‐discharge relationships. Results indicate that both neural network and local regression models are able to reproduce the multiple loops that are observed at the outlet of a low‐gradient stream in southwestern Louisiana. The models have higher prediction accuracy with high flows than with low flows. The study discusses the effect of issues such as sample size and data division on the performance of the developed models.

Select this Article		Design of Water Quality Monitoring Network for River Systems M. Karamouz, F.ASCE, M. Karimi, and R. Kerachian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)243 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Design of water quality monitoring network could be a fairly complicated problem, where some questions such as number of gages required, frequencies of sampling, and benefits over cost ratio of monitoring should be determined. These issues are in case of sampling river water quality variables, as they are more error‐prone, costly, and time consuming. The basic difficulty underlying the design and evaluation of monitoring systems is the lack of an objective criterion to assess the efficiency and the cost effectiveness of the monitoring network. In this paper, a combination of the Genetic Algorithm (GA) optimization model and a one‐dimensional water quality simulation model is proposed for design of river water quality monitoring network considering the economic constraints. First, the locations of sampling stations are determined so that the water quality data can provide the best fit to the historical spatial distribution of different water variables considering their relative weights. Then the efficiency of the proposed model is evaluated using the water quality data of Karoon River in Iran. The results show that the model can be used as an effective tool for optimal design of water quality monitoring networks. This study also shows the capability of the GAs to overcome dimensionality problems, which can not be easily solved by other optimization methods such as dynamic or non‐linear programming.

Select this Article		Multireservoir System Optimization Using Multi‐Objective Genetic Algorithms Taesoon Kim and Jun‐Haeng Heo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)244 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Multireservoir system consists of several reservoirs which are connected serially or parallel in the same basin. To optimize such a complex multireservoir system, the dynamic programming (DP), linear programming (LP) and non‐linear programming (NLP) have been widely applied to real problems. However, when DP is applied to multireservoir system it has a major problem, so called ‘the curse of dimensionality’ and LP and NLP have essential approximation problems dealing with discontinuous, nondifferentiable, non‐convex, or multi‐modal objective functions. Recently, there has been an increasing interest in a biologically motivated adaptive system for solving optimization problems. The genetic algorithms (GAs) are one of the most promising techniques in natural adaptive system field and receiving many attentions because of their flexibility and effectiveness for optimizing complex systems. Optimization of multireservoir system is to solve multi‐dimensional and multi‐objective problems and GAs are appropriate optimization methods to multireservoir system. GAs are not restricted by a number of dimensions because computer memory increases by dimensions linearly, not exponentially. Thus, there is no ‘curse of dimensionality’. Especially classical optimization methods such as DP, LP, and NLP are not proper to multi‐objective optimization because these methods use a point‐by‐point approach, in which the outcome of classical optimization methods is a single optimal solution. However, GAs use a population of solutions in each iteration instead of a single solution, so they are called as population‐based approaches. This is one of the most striking differences between classical optimization methods and GAs.

Select this Article		Bump Elimination Method of Training an Artificial Neural Network Arcadio Pacquiao Sincero ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)245 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Given a set of data patterns; the objective is to determine which of these patterns should be used to train a back propagation neural network (BANN or ANN). To determine these training patterns, in this study, two types of data sets were investigated: a data set on turbine power and a data set on water quality data. As applied to each of the type of pattern set, the following procedure was applied. The set was arranged from the lowest to the highest, in terms of the target values. The first (lowest value) and the last (highest value) patterns were then used to train the network; this produced the first set of weights. These weights were then tested to see if they could predict the rest of pattern set, which served as the target values. The predicted values were then plotted against the actual values. These predicted values produced bumps on the plot. The pattern that produced the biggest bump was then chosen as the third pattern in the training set; this, in turn, produced the second set of weights. These weights were again tested if they could give a good prediction of the target data, which, of course, again produced bumps on the plot. The pattern that produced the biggest bump was again chosen and added as the fourth pattern to the training set, producing the third set of weights. The process was repeated for the fourth set of weights, the fifth and so on, until the plot of the predicted and the actual data produced a straight line. The patterns that finally produced the straight‐line plot are selected as the training patterns.

Select this Article		Simplifying the Parameterization of Real‐Coded Evolutionary Algorithms Patrick M. Reed and Satoshi Yamaguchi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)246 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper demonstrates how existing parameterization techniques for binary coded genetic algorithms can be extended to real‐coded evolutionary algorithms. An easy‐to‐implement framework for automating parameter setting for real‐coded evolutionary algorithms is demonstrated in this study using Differential Evolution (DE), a real‐coded evolutionary algorithm. DE was selected because the algorithm has been successfully demonstrated on a wide range of applications as a result of its inclusion in both the Mathematica and MATLAB optimization toolboxes. Preliminary results show that the framework successfully eliminates trial‐and‐error parameter analysis, minimizes the algorithms' computational demands, and ensures that DE reliably attains high quality solutions. The parameterization framework is not application specific and can be easily implemented on other real‐coded evolutionary algorithms.

Select this Article		Multiscale Island Injection Genetic Algorithm for Ground Water Remediation Eva Sinha, Barbara Minsker, and Meghna Babbar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)247 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Genetic algorithms have been shown to be powerful tools for solving a wide variety of water resources optimization problems. Applying these approaches to complex, large‐scale applications, which is usually where these methods are most needed, can be difficult due to computational limitations. Large grid sizes are often needed for solving field‐scale groundwater remediation design problems. Fine grids usually improve the accuracy of the solutions, but they are also computationally expensive. Multiscale parallel genetic algorithms have been shown to improve the performance of engineering design problems that use spatial grids. In this paper we present multiscale island injection genetic algorithms (IIGAs), in which the optimization algorithm has different multiscale populations working on different islands (group of processors). Each island has a fraction of its population on the coarse grid and a fraction on the fine grid. Different islands exchange the best individuals, at the same scale, after a fixed number of generations and thus drive the GA towards better and more accurate solutions faster. The performance of this approach is compared to a single population multiscale approach developed previously, using a field‐scale pump‐and‐treat design problem at the Umatilla Army Depot.

Select this Article		Artificial Intelligence Methods Applicability on Water Distribution Networks Calibration Juan Saldarriaga, Rafael Gómez, and Daniel Salas ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)248 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water distribution network calibration is mathematically unsolvable. Then, trial and error, optimization and artificial intelligence methods have been used to solve it. Artificial intelligence has given some effectiveness. However, some artificial intelligence methods are too slow, static or hard to adapt to changes in problem, etc. Therefore, some experiments are proposed to determine advantages and disadvantages of each AI method used to calibrate water distribution networks.

Select this Article		Water Distribution Network Calibration with Fuzzy Logic Daniel Salas, Rafael Gómez, and Juan Saldarriaga ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)249 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The calibration of water distribution networks is a problem with no mathematical solution. Fuzzy logic is used in this research to capture knowledge from people who manually calibrate those networks. This way, process could become automatic. Fuzzy logic is used to calibrate simple pipes, pipes series and paths inside networks. Several initial configurations are needed in the calibration process. Fuzzy system defines and calculates the changes that should be making to topological variables, in order to improve calibration. This procedure is repeated until fuzzy system establishes that no more changes must be made. A satisfactory calibration is obtained. Finally, fuzzy sets configuration is refined to improve the system accuracy.

Select this Article		A Dynamic Meta‐Model Approach to Genetic Algorithm Solution of a Risk‐Based Groundwater Remediation Design Model Shengquan Yan and Barbara Minsker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)250 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Approximation (“meta”) models have been used in coupled water resources optimization and simulation models to improve computational efficiency. In most instances, multiple simulation runs have been done before the optimization, which are then used to fit an approximate model that is used for the optimization. In this study, we propose a dynamic meta‐modeling approach, in which artificial neural networks (ANN) is embedded into a genetic algorithm (GA) optimization framework to replace time‐consuming flow and contaminant transport models. Data produced from early generations of the GA are sampled to train the ANN. We propose a dynamic learning approach that periodically re‐samples new solutions both to update the ANN and correct the GA's converging route. This allows the meta model to adapt to the area in which the GA is searching and provide more accuracy. The results show that a proper sampling strategy can benefit both GA's searching and ANN'S retraining. In our test case, more than 90 percent of the numerical model calls were saved with no loss in accuracy of the optimal solution.

Select this Article		Optimal Cost Potable Water Network Distribution Design with Genetic Algorithms Santiago Lopez‐Giraldo and Juan Saldarriaga ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)251 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A potable water supply network design methodology was implemented using a Genetic Algorithm (GA). Information about location and network connectivity, pipe materials and minor losses coefficients is required. The GA searches for designs (diameter combinations) optimal from the point of view of cost of the networks' pipes while satisfying supply for demanded volumes and minimum pressures in the network junctions. Adjustment of GAs to this problem is shown: functions of adaptation (construction cost), recombination (crossover) and mutation are modified to suit it. A scheme (Cost‐Restriction function) is introduced to induce the algorithm to generate designs that fulfill the required hydraulic restrictions. The variation of the cost of resulting design based on probability of mutation, generation size, and coefficients specific to the adaptation function are studied. Special attention is given to the influence of the factors that vary the diversity within each generation of the algorithm (represented by the probability of mutation and one of the variables of the reproduction function). Finally the designs obtained through the algorithm are compared with the designs obtained according to Featherstone criterion.

Select this Article		Application of Genetic Algorithms for Calibration and Verification of QUAL2E Model R. K. Goktas and A. Aksoy, A.M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)252 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Traditional trial‐and‐error methods make the calibration and verification of a model considerably time consuming. In addition, it is doubtful whether the best results will be achieved. However, by use of optimization techniques in calibration and verification, the best kinetic parameter estimates can be obtained in a shorter time period. In this study, a genetic algorithm (GA) is used to determine the reaeration coefficients for QUAL2E. An objective function, defined by sum‐of‐least‐squares, is used in order to describe the difference between the observed and simulated dissolved oxygen concentrations. Simultaneous calibration and verification is carried out by treating the verification of the calibrated parameters as a constraint. The efficacy of GAs in predicting the model parameters is evaluated for perfect and biased measurements. The results show that GAs can successfully carry out simultaneous calibration and verification, and estimate the best set of reaeration coefficients to be used in stream water quality modeling with QUAL2E, especially for the accurate observation data.

Select this Article		Semi‐Automatic Parameter Calibration of a Lagrangian Transport Model for NAPL Remediation by Means of a Hybrid Genetic Algorithm Felipe P. Espinoza ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)253 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Numerical models are a useful tool to evaluate and design NAPL remediation systems. Traditional models are complex and expensive on its application. For this reason this paper presents the application of a simplified Lagrangian transport model. For the application of this model, the hydraulic and NAPL structure is defined by means of probabilistic models. The parameters of these models are evaluated by means of a hybrid genetic algorithm, the SAHGA algorithm developed previously for the design of pump‐and‐treat remediation systems. The paper also includes one example of the application of this model to analyze tracer movement at a PCE contaminated aquifer.

Select this Article		An Intensity Scale for Riverine Flooding Janice M. Fulford ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)254 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Recent advances in the availability and accuracy of multi‐dimensional flow models, the advent of precise elevation data for floodplains (LIDAR), and geographical GIS allow the creation of hazard maps that more correctly reflect the varying levels of flood‐damage risk across a floodplain when inundated by floodwaters. Using intensity scales for wind damages, an equivalent water‐damage flow intensity scale has been developed that ranges from 1 (minimal effects) to 10 (major damages to most structures). This flow intensity scale, FIS, is portrayed on a map as color‐coded areas of increasing flow intensity. This should prove to be a valuable tool to assess relative risk to people and property in known flood‐hazard areas.

Select this Article		Monitoring Hydraulic Roughness during Flow Process in Unstable Channels Morris Sade, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)255 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A systematic review of the literatures, stream flow and sediment data pertinent to the Yazoo Basin tributaries in theDemonstration Erosion Control (DEC) project was conducted to identify the hydraulic roughness during flow process in the unstable channels. The stream flow process was identified by the temporal variation of stage and discharge parameters. The 15‐minute stage‐discharge data and the field survey information were used to analyze the stage‐discharge and the hydraulic roughness parameters. Several functional relationships in the forms of normal rating curve (stage vs. discharge) and roughness impacted rating curve (stage vs. roughness*discharge) were conceptualized to identify these parameters during a channel flow process. Regression analysis was performed to identify the best parametric relationships. By this method two types of parametric relationships, in the forms of polynomial and power were identified for each site. The polynomial relationships exhibit the highest correlation coefficient, followed by the power relationships among the other parametric relationships. The simultaneous application of normal rating curve (H vs. Q) and the roughness impacted rating curve (H vs. nQ) can provide an effective monitoring tool for the temporal changes of n during a channel flow process.

Select this Article		Muskingum‐Cunge Revisited William J. Heatherman, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)256 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A physically intuitive derivation of the Muskingum‐Cunge method is presented, based on work by Cunge, Perumal and others. Common misunderstandings related to “prism and wedge” storage and negative values of X are clarified. A connection is made between the Modified Puls method of channel routing and Muskingum‐Cunge, and guidance is given for evaluating the hypothetical number of reservoirs to use in Modified Puls for both prismatic sections and complex natural stream reaches.

Select this Article		2‐D Numerical Model for the Analysis of Mixing in the Meandering Stream Myung Eun Lee and Il Won Seo ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)257 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Two‐dimensional model solving advection‐dispersion equation was constructed with modified governing equation using finite element method. This model was testified by the comparison with the experimental results of the mixing in the laboratory S‐curved channel and also RMA4 was run at the same condition and compared. These results show the improved simulation result for the meandering channel.

Select this Article		Conceptual and Mathematical Model for Evolution of Meandering Rivers in Naturalization Processes Jorge D. Abad and Marcelo H. García ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)258 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract River planform, restoration, and naturalization processes have attracted many research efforts in the last decades. Meandering rivers are defined by a sinuous characteristic, and they are considered the most common type of natural streams and their studies are governed by the complexity of the physical processes that are involved in these natural environments. This complex system covers phenomena such as secondary flows, turbulence flows and sediment transport. Additional complexity is introduced by the irregularity of the boundaries presented in rivers, and by the continuous planform migration due to erosion and sedimentation processes, which makes even more difficult to obtain accurate results. Several rivers have been channelized in the past causing environmental and ecological problems, where restoration techniques evolve as natural solutions to channelization. These restoration techniques require the knowledge of the complex phenomena of rivers described before, in which the analysis of sedimentation and erosion, bank erosion, vegetation and of course flow field behavior in the river is required. Then, a methodology to analyze the evolution of meandering rivers is needed for the prediction of planform migration. This prediction is indispensable for economic and social reasons such as development of urban areas close to rivers, for prevention of damages in civil structures (bridges, harbors, etc), for prevention of agricultural land losses, and for the maintenance of biological diversity in the river. The most significant finding of this study is to present a conceptual and mathematical model for evolution of meandering rivers that can be used in restoration and naturalization processes. Based on the conceptual and mathematical model for meandering evolution, a methodology for river restoration process is also presented. In this methodology, main criteria for designing stream restoration are presented.

Select this Article		Simulation of Meandering Channel Evolution with an Analytical Model D. Chen and J. G. Duan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)259 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Bank retreat rate, the receding rate of bank top‐lines through basal erosion and bank failure, was calculated based on the analysis of bank stability and sediment mass conservation near banks. This study indicated that the gradient of sediment transport rate in the longitudinal direction and the strength of secondary flow determined the rate of bank retreat. An analytical model was developed based on this result and applied to simulating the evolution of sine‐generated meandering channels. Not like the conventional methods which assumed that the rate of bank retreat was proportional to the magnitude of excessive near‐bank velocity or shear stress, this approach in simulating bank retreat and meandering channel evolution has advantages by taking into account the gradient of longitudinal velocity and the strength of secondary flow, and will avoid the estimation of the erodibility coefficient in traditional bank erosion models.

Select this Article		Evaluation of Scouring Reliability at Bridge Abutments A. Melih Yanmaz and Tugsan Celebi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)260 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Serious scouring may take place around bridge abutments during floods, which can lead to considerable damage or structural collapse. Design of abutment footings must, therefore, rely on the estimation of maximum possible depth of scour through the bridge opening. Deterministic scour‐prediction equations are based on simplified assumptions and they do not account for randomness of the scouring variables, which leads to an unavoidable risk in footing design. This study is concerned with the development of a new reliability model for scouring around bridge abutments using the resistance‐loading methodology. The validity of the proposed model is tested using the Advanced First Order Second Moment (AFOSM) and the Monte Carlo simulations. In an example, it is shown that the results of the proposed model are in good agreement with these simulations. It is also observed that the execution of this model is less time‐consuming than the latter approaches. A sensitivity analysis is carried out to examine the effects of coefficients of variation and probability distributions.

Select this Article		Drought Frequency Analysis with a Hidden State Markov Model Peter F. Rasmussen and Bertug Akintug ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)261 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract As an alternative to the more conventional ARMA models, we explore the potential of hidden state Markov models for simulating hydrologic droughts. In the simplest case, the hidden (unobserved) Markov process has two states, wet and dry, representing the general climate regime prevailing at the time. Each state has a particular distribution of streamflow associated with it. Conditional upon the value of the state variable at time t, the distribution of flow at time t is independent of previous flows. Autocovariance is provided for through the Markov process. A brief discussion of model properties and parameter estimation is given. The results of an application of the hidden state Markov model to drought frequency analysis are presented along with a comparison with more conventional models.

Select this Article		Risk Analysis Using Spatial Data in Flood Damage Reduction Studies Christopher Smemoe, Jim Nelson, and Alan Zundel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)262 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The traditional approach for determining the safety of a levee has been to find the flood depth for a storm with a design flood and to add three feet of freeboard as a factor of safety. In recent years, however, risk analysis has been used to size levees and other flood control structures in a floodplain. These risk analysis procedures, defined by the US Army Corps of Engineers (USACE), use a series of curves to determine the expected annual damage (EAD) for a computation unit called a “damage reach”. The process of using risk analysis for determining the return period for a flood is not a new concept, but the procedures for evaluating the engineering and economic performance of flood control structures are still new and are under evaluation. The National Research Council (NRC) has published a report on how the current procedures for risk analysis can be improved. One recommendation for improvement to the current methods of evaluating the performance of flood control structures involves the need to consider spatial variability. A technique involving a Monte Carlo‐style stochastic simulation can be run using an integrated hydrologic (HEC‐1), hydraulic (HEC‐RAS) and digital terrain model to evaluate the annual exceedance probability (AEP) in a floodplain using spatially‐defined data. This paper will introduce methods used in floodplain delineation studies and will describe new procedures that can be used for risk analysis in floodplain delineation studies. A case study will demonstrate how these procedures can be used to evaluate the uncertainty of the floodplain boundary.

Select this Article		Application of Point Estimate Methods to the Modeling of Toxic Concentrations in the Niagara River Samuela Franceschini and Christina Tsai ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)263 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Introduction of the Point Estimate Methods (PEMs) has recently attracted some attention in the field of environmental engineering. Differently from other uncertainty analysis methods, the PEM requires a substantially smaller computational effort for a comparable degree of accuracy in the estimation of the first few statistical moments of a model output. The application of PEMs such as the Rosenblueth method or the Tsai and Franceschini method to the modeling of toxic concentrations in the Niagara River can provide significant insights into stochastic mechanisms of the transport process of selected contaminants. This paper presents the result of the uncertainty analysis on the concentrations of Chrysene and PCBs in the Niagara River. It also proposes a potential application of the uncertainty analysis to quantifying the effective risk associated with exceeding established water quality standards for contaminants of concern.

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MONITORING AND MEASURING WATER RESOURCES

Select this Article		New Methodology to Subtract Noise Effects from Turbulence Parameters Computed from ADV Velocity Signals Carlos M. García, Mariano I. Cantero, Chris R. Rehmann, and Marcelo H. García ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)264 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Acoustic Doppler Velocimeter (ADV) signals are affected by Doppler noise which is intrinsic to the Doppler measurement technique. It has the characteristics of white noise and its integral effects must be subtracted from some turbulence parameters. New tools are introduced in this paper to evaluate the relative importance of the noise energy on the total energy as well as to define the characteristic frequency in the measured energy spectrum where noise energy is more important than turbulent energy (flat plateau). To develop these tools a model for the power spectrum is adopted which allows the analysis of a range of flow conditions. Results show that noise energy can have an important contribution on the total measured energy, mainly in low energy flows. However in those cases, the noise energy level can be defined from the spectrum because the characteristic frequency is smaller than the Nyquist frequency. After the noise energy level is defined, corrections to the rest of the turbulent parameters (length and time scale, convective velocity, etc) must be performed.

Select this Article		Estimates of the Dissipation of Turbulent Kinetic Energy from Temperature Microstructure Chris R. Rehmann, Danielle J. Wain, and Cheeta L. M. Soga ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)265 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract We discuss issues in computing the dissipation of turbulent kinetic energy from temperature microstructure measurements. In the temperature microstructure method, the dissipation is obtained by fitting a theoretical form of the temperature gradient spectrum to measured spectra. Issues requiring consideration include the resolution of temperature sensors, the speed of the water past the sensors, dividing a temperature gradient profile into segments, anisotropy, fitting the theoretical spectrum, and confidence intervals. We use data from an experiment on air bubble plumes in a 7‐m deep tank and laboratory comparisons of dissipation measured with the temperature microstructure method and a velocimetry technique to illustrate the various issues involved in dissipation estimates.

Select this Article		Experimental Evidence for Scaling Laws in Bubble Plumes L. E. Rincón, F. A. Bombardelli, and M. H. García ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)266 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents experimental evidence regarding the behavior of bubble plumes in two tanks of different size, under non‐stratified conditions. The smaller vessel has been geometrically scaled down from the larger one with a relation 1:10. Velocity measurements were performed in both tanks with acoustic sensors (ADVs) and time‐averaged velocity profiles obtained at both scales were compared. This comparison was used to support a methodology to scale vertical and horizontal (radial) distances in bubble plumes, while allowing for the simulation of portions of the reservoirs. The bubble‐slip velocity and a length scale D were determined as the relevant scales in the analysis. Previous scaling of bubble plumes, based on the preservation of the number M_H and the use of the ratio diffuser depth/airflow rate, appear as a special case of this more general theory.

Select this Article		Exploratory Study of the Influence of the Wake Produced by Acoustic Doppler Velocimeter Probes on the Water Velocities within Measurement Volume Jorge D. Abad, Rodrigo A. Musalem, Carlos M. García, Mariano I. Cantero, and Marcelo H. García ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)267 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Acoustic doppler technique is widely used in both fields and laboratory facilities to compute the mean water velocity and to characterize the turbulence of a flow. In general they provide the three dimensional components of flow velocity in a measurement volume in the water body with fairly good spatial and temporal resolution for engineering applications. The most sophisticated devices can even gauge a velocity profile measuring the water velocity in several measurement volumes along a line. However, these devices are semi intrusive which might have, depending on the experimental setup, substantial consequences in the measurements obtained due the flow perturbation created by the probe. The goal of this paper is to explore experimentally and numerically the wake effect of the probe on the measurement volume in order to validate the measurements provided by this kind of instruments or incorporate some corrections if needed. A computational fluid dynamic (CFD) model is used to simulate an open channel flow where the model was validated with previous experimental results. In the other hand, the laboratory measurements were conducted in an open channel flume located in the Ven Te Chow Hydrosystems Laboratory of the University of Illinois. The measurements were done using particle image velocimetry technique (PIV) producing two dimensional velocity fields around the acoustic probe measurement volume with and without the presence of the probe. The numerical and experimental ranges of Reynolds numbers (Re) tested were 3×10⁶ to 1×10⁷ and 1×10⁴ to 5×10⁴ respectively. Non dimensional contour plots showing the difference between the flow velocity and turbulent quantities with and without the probe are built. Both results show that the errors are less than 10 percent around the probe. This methodology is still under development, however it provides more insight for experimental setups and it could be applied to other acoustic doppler instruments such as the ADV (Acoustic Doppler Velocimeter) and ADCP (Acoustic Doppler Current Profiler) among others.

Select this Article		Methodology for Estimating ADCP Measurement Uncertainty in Open‐Channel Flows M. Muste, K. Yu, J. A. Gonzalez‐Castro, M. Ansar, and R. Startzman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)268 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Acoustic Current Doppler Profilers (ADCPs) are most often used for measuring discharge in channels and rivers. Recently, ADCPs have become increasingly used for measuring the cross‐sectional distribution of the long‐term average streamwise velocity and for estimating turbulence characteristics for studies that range from calibration of hydraulic structure ratings to verification and validation of hydrodynamic models for ecological restoration. In spite of the ADCP expanding applications, the rigorous assessment of ADCP measurement uncertainty is not yet available. In this paper, we present a methodology for the assessment of uncertainty of ADCP discharge and mean velocity measurements recommended by authoritative guides and standards. The method includes identification and assessment of the elemental error sources involved in the ADCP measurement process and a first‐order Taylor approximation‐based algorithm for propagating elemental uncertainties to final results. The paper describes the framework and the practical implementation of the method for estimating the total uncertainty of the ADCP discharge and mean velocity measurements in riverine environments.

Select this Article		Implementing Advanced Early Warning Systems to Safe Guard Public Drinking Water David O. Pitcher, P.E., D. Gerard Yates, and Monica B. Hoyt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)269 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Utah Valley Water Treatment (UVWTP), which is operated by Central Utah Water Conservancy District (the District), receives its raw water from a river intake and a 5‐mile long aqueduct system. The river has a major highway paralleling it through a winding narrow mountain canyon. Because of this, vehicles, including large freight trucks, have ended up in the river resulting in a potential spill event. Historically the early warning for such an event consisted of an uncertain reliance upon a phone call from the local emergency response agencies informing the UVWTP of a spill into the river. This system has been fairly reliable, but had the potential for failure if no call was made. In addition, natural changes in source water quality can have an adverse effect on the treatment plant processes. With both of these objectives in mind, the District concluded that a multiple barrier approach to early warning systems would be a prudent course of action to accomplish what the District estimates would reasonably be expected from the public to safeguard the production of finished water. The District then actively pursued an opportunity to participate in American Water Works Research Foundation (AWWARF) Project #2527 “Design of Early Warning and Predictive Source Water Monitoring Systems” in order to evaluate best available technology in early warning systems. As a result a District staff member was invited and became a Project Advisory Committee (PAC) member of this project. This project provided valuable information, allowing the District to make a well‐informed decision on what types of early warnings systems would best meet the District's needs.

Select this Article		Development of a Consortium for Water Security and Safety: Planning for an Early Warning System Robert M. Clark, M.ASCE, Nabil R. Adam, Vijay Atluri, Milton Halem, and Eric F. Vowinkel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)270 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The events of September 11, 2001 have raised concerns over the safety and security of the Nation's critical infrastructure including water and waste water systems. In June 2002, the U.S. EPA's Region II Office (New York City), in response to concerns over water security, in collaboration with Rutgers University agreed to establish a Regional Drinking Water Security and Safety Consortium (RDWSSC). Members of the consortium include: Rutgers University's Center for Information Management, Integration and Connectivity (CIMIC), American Water (AW), the Passaic Valley Water Commission (PVWC), the North Jersey District Water Supply Commission (NJDWSC), the N.J. Department of Environmental Protection, the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agencies, Region II Office. In December of 2002 the consortium members signed a memorandum of understanding (MOU) to pursue activities to enhance regional water security. Development of an early warning system for source and distributed water was identified as being of primary importance by the consortium.

Select this Article		NEXRAD Radar Rainfall: Meeting User Requirements for Design and Real‐Time Hydrologic Applications J. E. Vieux and B. E. Vieux ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)271 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Radar rainfall is a source of high‐resolution rainfall that is representative over areas ranging from small urban catchments to large river basins. The NEXRAD radar system deployed coast‐to‐coast in the United States is an important source of rainfall information for a variety of users. A common requirement among users is the need to know where, when, and how much rainfall fell, or is falling in real‐time. Customization and post‐processing of specific NEXRAD products takes into account precision, accuracy, spatial resolution, and beam altitude requirements. Spatial resolution, temporal updates, and beam altitude can impose limitations on the suitability of the radar data in specific applications. Achievable accuracy standards are affected by the data precision of measured reflectivity. To quantify potential differences between two products, with high and low precision, rainfall rates are compared during Tropical Storm Allison, which caused extensive flooding in Houston, Texas, June 5–9, 2001. Even when radar bias is corrected using rain gauges, low‐precision data can introduce significant truncation errors over specific watersheds. This paper examines these key radar rainfall characteristics that affect applicability and suitability for specific uses.

Select this Article		Large River Real‐Time Flood Forecasting System Based on Neural Network Model Hyun‐Suk Shin, Bong‐Chul Seo, and Kang‐Hoon Yoon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)272 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of this study is to develop a real‐time flood forecasting model in order to predict the flood runoff having nature of non‐linearity and to verify applicability of neural network model for large river basin. Developed model in this study, NRDFM (Neural River Discharge‐stage Forecasting Model) was applied to predict the flood discharge on Waekwan station in Nakdong river of Korea. As a result of flood forecasting on Waekwan, it can be concluded that NRDFM‐ II is the best predictive model for real‐time operation. In addition, the forecasting results of NRDFM‐ I and NRDFM‐III show sufficient probability for real‐time forecasting. Consequently, it is expected that NRDFM will be available in real‐time flood warning system.

Select this Article		Hydrologic Prediction Accuracy Assessment Using Radar Rainfall B. E. Vieux and P. B. Bedient ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)273 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Capturing the spatial and temporal distribution of rainfall is important for accurate hydrologic prediction. One of the most important sources of spatially distributed rainfall data is radar. Beginning in the early 1990's, the WSR‐88D (popularly known as NEXRAD) radar network was deployed by the US National Weather Service (NWS) for surveillance and detection of severe weather. Producing accurate rainfall estimates from this system requires post processing within a statistical framework that recognizes systematic and random errors as components of uncertainty. Statistical control of this input data is shown to have important consequences on distributed hydrologic modeling. Hydrologic evaluation of radar rainfall using archived radar rainfall provides the opportunity to evaluate the predictability of a fully distributed physics‐based model through event reconstruction.

Select this Article		Application of Point‐Estimation Method to Calculate Uncertainties in Discharges from Stage‐Discharge Ratings Arthur R. Schmidt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)274 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Most discharge records are developed using stage‐discharge relations (ratings) to estimate the discharge based on measured water stages, permitting a fast and relatively inexpensive means to determine the discharge. However, for all but the simplest stage‐discharge ratings, uncertainties in the resulting discharges have either been ignored or were based on a statistical estimate of the fit between the rating and calibration measurements. Recent research has demonstrated the feasibility of developing stage‐discharge ratings theoretically, rather than empirically, providing unprecedented opportunity to examine the uncertainties in the rating and in discharges determined from the rating. Reliability‐analysis methods, particularly, the point estimation method, can be applied to estimate the uncertainty in discharges determined from theoretically developed ratings and appropriately addresses complicating factors such as correlation among independent variables. This paper presents an overview of the application of reliability‐analysis methods to determine the uncertainty in theoretical developed ratings. An example for an existing gauging station shows the uncertainties in discharges determined from the theoretical rating and the stage record from the site.

Select this Article		Uncertainties in Discharges from Stations Where Rating Shifts are Utilized Arthur R. Schmidt ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)275 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, stage‐discharge ratings and rating shifts are described from the viewpoint of the fundamental hydrodynamics of unsteady, non‐uniform flow. Ratings and shift adjustments from an existing U.S. Geological Survey gauging station are compared with results obtained from a theoretically derived rating. Furthermore, the uncertainties in the discharge records from the shift‐adjusted, empirical rating and the theoretical rating are compared, illustrating the problems with attempting to quantify the uncertainty in discharge records from an empirical rating to which shift adjustments are applied. An alternative, theoretically based approach to adjust existing ratings while allowing more reasonable calculation of uncertainties in the discharge records is suggested.

Select this Article		Avoiding Submergence Transition Zone for Radial Gates in Parallel A. J. Clemmens ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)276 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The calibration of partially submerged radial and vertical‐sluice gates has proven difficult to determine under field conditions. In a recent paper, the author and colleagues developed a method for determining the calibration of radial gates from free flow to submerged flow, continuously through the transition. The method uses the energy equation on the upstream side of the vena contracta and the momentum equation on the downstream side, and thus has been named the energy‐momentum or EM method. Because of the nature of the partially submerged jet, an empirical energy correction is needed during partial submergence. One advantage of the method is the ability to account for a wide variety of downstream conditions, including channels that are significantly wider than the gates. It was anticipated that the method would allow estimation of discharge based only on gate openings and upstream and downstream water levels, even for multiple gates with different openings. However, if one gate is free‐flowing and another in the transition zone, estimation of discharge is complicated by lateral flow, and may become intractable. One solution is to measure the downstream pressure in the vena contracta. With the energy correction term, this measurement avoids the need for use of the momentum equation downstream. However, such measurements are difficult in the field. Another solution is to move all gates to the same position, so that the EM‐method can be used in the transition. This option is not suitable where operators prefer to move only one of several gates to obtain finer resolution. An alternative is to determine the position of the gates such that each is either free‐flowing or fully submerged. The purpose of this paper is to explore the feasibility of options for avoiding the transition zone for multiple radial gates in parallel while still allowing the operator to adjust one gate to vary discharge. The approach is demonstrated on the Salt River Project's Arizona Canal.

Select this Article		Issues and Problems with Calibration of Canal Gates Tony L. Wahl ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)277 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Accurate flow measurement at irrigation canal check gates, bifurcations, and turnouts makes it possible for water managers to better match supply and demand, thereby reducing administrative spills and enabling delivery of the optimum amount of water to crops. Recent developments have improved our ability to accurately measure discharge at canal gates, and further improvements are possible. An ASCE Task Committee active since late 2002 has been working to focus research efforts in this area. This paper reviews recent developments, highlights areas in which research is now being performed, and discusses issues and difficulties yet to be overcome.

Select this Article		Submerged Radial Gate Calibration Using Historical Data to Improve Canal Automation Performance Patrick Dent ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)278 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Radial (Tainter) gates are the most widely used flow control structures on large, open‐channel conveyance systems. Despite their widespread use for many years, this type of gate is arguably the most difficult to consistently and accurately calibrate for flow measurement. This paper discusses the ongoing research and development of methods for predicting volumetric flow through a radial gate. Included is a new method to accurately calibrate discharge coefficients, along with an algorithm that determines the amount of discharge per unit of gate opening as a function of the differential head. This new algorithm was developed using telemetered field data collected over a 3‐year period from 39 check structures on the Central Arizona Project aqueduct system. This method is currently implemented in the Central Arizona Project canal automation software.

Select this Article		Effects of Uncertainties in Field‐Measured Parameters on Discharge Rating at Gated Spillways Matahel Ansar, Juan A. Gonzalez‐Castro, and Robb Startzman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)279 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, we study the uncertainty of discharge ratings for gated spillways typical of South Florida, developed from field measurements at prototype structures. The study accounts for the uncertainties of flow and water stage measurements, gate openings, as well as for the uncertainties of the physical characteristics of the structure such as the width and sill elevation. The study focuses on the ratings for the most prevalent flow conditions at gated spillways in the region, namely, submerged orifice flow. The uncertainty of each of the variables and parameters in the rating are assessed first, then the uncertainties are combined to estimate the total uncertainty based on the first‐order Taylor series expansion method for propagation of errors. The relative contributions of uncertainty from each source are also studied. The sources of uncertainty with the largest relative contribution to the total uncertainty of the discharge ratings at gated spillway are the measured discharges, and the measured head differential between upstream and downstream stages. In particular, we found that under deeply submerged conditions, the uncertainty in the head differential has the largest contribution to the total uncertainty in the rated discharge.

Select this Article		Real‐Time Flow Monitoring in a Large Scale Water Management System Muluneh Imru and Emile Damisse ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)280 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents the linkages between three essential components of real time flow monitoring in south Florida: the supervisory control and data acquisition (SCADA) system, the hydrodynamic model used to estimate discharge (FLOW), and the corporate database for archiving hydrologic data (DBHYDRO). Water resource assessment in South Florida involves flow computation at more than 400 major water control structures consisting of spillways, weirs, pumps, culverts and combination structures. The water control structures are spread over an area of about 46,600 square kilometers (18,000 square miles) in 16 counties, extending from south of Orlando to the Florida Keys. A network of canals and levees, with a total length of about 2,896 kilometers (1,800 miles), control surface water flow that is characterized by reversals of hydraulic gradient and direction due to low and flat relief. FLOW determines magnitude and direction of discharge through control structures and open channels, incorporating real time hydrodynamic data from remote sites and static parameters extracted from DBHYDRO. Daily flows, archived in DBHYDRO, provide historical records for decision making on flood control, water quality enhancement, water supply planning, and ecosystem restoration. Flow values in one‐ to fifteen‐minute intervals provide vital information for real‐time operation of major control structures and the regional water storage system. Instantaneous data are also used for real‐time, automatic flow‐proportional water quality sampling. A data quality improvement process is in place, involving discharge‐rating evaluation, field data collection, and calibration of flow equations. The reliability of flow data has improved significantly as a result of the process.

Select this Article		A Real‐Time Control Strategy for Operating the Milwaukee Metropolitan Sewerage District (MMSD) Conveyance and Storage System Eric D. Loucks, Elizabeth F. Locke, Steven R. Heinz, and Z. Cello Vitasovic ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)281 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the development of a revised wet weather operating strategy for the Milwaukee Metropolitan Sewerage District (MMSD) conveyance and storage system. The MMSD provides for the conveyance, storage and treatment of wastewater in a service area covering approximately 425 square miles in southeastern Wisconsin. The MMSD collects sewage generated in 28 municipalities and agencies and conveys it for treatment at one of its two treatment plants. Most of the municipal sewers in the service area are separate sanitary sewers. However, approximately 25 square miles of service area in the City of Milwaukee and the Village of Shorewood are served by combined sanitary and storm sewers. Under most circumstances, all collected sewage is conveyed directly to one of the treatment plants. During extreme wet weather, excess flows generated in both the combined and separate sewer areas can exceed the conveyance and treatment capacities of the existing facilities. Excess flows can be stored in the District's inline storage system (ISS) or discharged through overflow outfalls in the system. Wet weather conditions can include heavy rainfall, snowmelt, and rain during snowmelt or moderate rain with saturated soil conditions. Wet weather generates stormwater runoff in the combined sewer area and rainfall derived infiltration and inflow (RDII) in the separate sewer area.

Select this Article		Real‐Time Forecasting of River Flow for Water Supply Operation Nisai Wanakule and Alaa Aly ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)282 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Tampa Bay Water, a wholesale water supplier, provides about 200 MGD of groundwater to assist in meeting potable water needs of nearly 2 million people in the Tampa Bay area of Florida. Under the current Consolidated Permit, Tampa Bay Water is required to cut back groundwater pumpage from 11 regional wellfields in phases. The reduction amount will be compensated by the enhanced surface water system withdrawing from three sources including the Tampa Bypass Canal (TBC), Alafia River and Hillsborough River. Artificial Neural Networks (ANNs) have been developed to forecast daily river flows at key points at selected flow gages in the upper and middle basins of the Hillsborough river. The multilayer backpropagation ANNs are designed to mimic the governing physical equations (e.g. continuity equation and energy balance), which use initial and boundary conditions to predict future system states. Furthermore, the ANNs inputs include terms that reflect the autocorrelation properties of the underlying time series. About 13 years of daily data were used to train and test the ANN models. The fitted networks utilized about 70% of the data for training while the rest was reserved for testing and validation. Testing results indicated that the trained ANNs provide highly accurate predictions for daily flows over the next seven days.

Select this Article		Statistics of Recent Updates to NOAA/NWS Rainfall Frequency Atlases Geoffrey M. Bonnin, Deborah Todd, Bingzhang Lin, Tye Parzybok, Michael Yekta, and David Riley ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)283 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The rainfall frequency atlases and technical papers published by the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) serve as de‐facto national standards for rainfall intensity at specified frequencies and durations in the United States. The NWS has updated the standards for the semiarid southwest,and is planning updates for the Ohio River basin and surrounding states, Hawaii, Puerto Rico, and the Virgin Islands. The Hydrometeorological Design Studies Center located within the NWS Office of Hydrologic Development is responsible for the updates and its work is funded by contributions from other Federal, State and local agencies. This paper provides an overview of the updates as well as selected statistics obtained in determining and parameterizing the probability distribution functions underlying the published estimates.

Select this Article		Operational Bayesian GLS Regression for Regional Hydrologic Analyses D. S. Reis, Jr., J. R. Stedinger, and E. S. Martins ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)284 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This study develops the quasi‐analytic Bayesian regression model described by Reis et al. into a practical Generalized Least Squares (GLS) regional hydrologic regression methodology able to address estimation of flood quantiles, regional shape parameters, and other statistics. New GLS regression diagnostics statistics include a goodness‐of‐fit pseudo R² and analysis of variance table. Leverage and influence are extended to identify rogue observations, address lack of fit and to support gauge network design. These statistics are illustrated with two examples. Results provide a comparison between ordinary, weighted, and generalized least squares procedures, and also illustrate the advantages of the Bayesian estimators over the Stedinger‐Tasker method‐of‐moment framework.

Select this Article		LP3 Quantile Estimators Using At‐Site and Regional Information V. W. Griffis and J. R. Stedinger ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)285 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The methodology currently recommended for flood‐frequency analyses by U.S. federal agencies is presented in Bulletin 17B. To improve the accuracy of skewness estimators, the Bulletin recommends combining the station skew with a regional skew using the inverse of the mean square errors as weights. While these weights can yield the minimum MSE skewness estimator, they need not provide the minimum MSE quantile estimators. Optimal weights which provide minimum MSE quantile estimators are derived. A Monte Carlo experiment demonstrates the value of different weighting schemes, and the value of using an informative regional skew. For reasonable values of the regional skew, the MSE of quantile estimates is reduced when the sample skew is combined with an informative regional skew, and use of the correct variance for the regional skew provides some improvement in performance. Modest reductions in the MSE of quantile estimates are obtained using optimal quantile‐weights rather than the MSE‐skew weights, especially for ∣γ∣ ≥ 0.5. However, when the regional skew is actually very informative, there is a large loss of efficiency for positively skewed distributions when the optimal quantile‐weights are incorrectly employed with a regional skew variance of 0.302 as recommended by Bulletin 17B.

Select this Article		Joint Seasonal/Annual Hydrologic Frequency Analysis S. Rocky Durrans ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)286 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Hydrologic frequency analysis, as commonly practiced, focuses on estimation of return periods associated with annual maxima or minima of streamflow magnitudes, precipitation depths, etc. However, in some applications, it is desirable to perform joint (i.e., simultaneous) frequency analyses for seasonal as well as annual events. This paper presents arguments for performing joint seasonal/annual frequency analyses and highlights problems that are encountered in such analyses. Methods for coping with the estimation problems that are encountered in such analyses are also proposed.

Select this Article		Reflections on Some Methods Used to Fit Statistical Distributions to Hydrological Data F. Ashkar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)287 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Among the methods used to fit statistical distributions to extreme hydrological data are the methods of maximum likelihood (ML), of moments (MM), and of probability weighted moments (PWM), in addition to two classes of relatively recent methods, which are the methods of generalized moments (GM) and of generalized probability weighted moments (GPWM). We review some previously published results and share some recently obtained ones pertaining to the relative performance of these fitting methods. Particular attention is given to the capacity of these methods to estimate shape parameters of populations and distribution quantiles. Reflections are made on the effect of sample and population characteristics on the performance of the various fitting methods. The Pareto, log‐logistic and Weibull distributions are used to aid in the discussion.

Select this Article		Comparison of Estimates of Uncertainty of Discharge at US Geological Survey Index‐Velocity Gages on the Chicago Sanitary and Ship Canal, Illinois Thomas M. Over, James J. Duncker, and Juan A. Gonzalez‐Castro ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)288 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Estimates of uncertainty of discharge at time scales from 5 minutes to 1 year were obtained for two index‐velocity gages on the Chicago Sanitary and Ship Canal (CSSC), Ill., instrumented with acoustic velocity meters (AVMs). The velocity measurements obtained from the AVMs are corrected to a mean channel velocity by use of an index velocity rating (IVR). The IVR is a regression‐derived relation between the AVM velocity estimates and those obtained using acoustic Doppler current profilers (ADCPs). The uncertainty estimation method is based on the first‐order variance method, but the AVM velocity error is estimated from an empirical perspective, using the statistics of the IVR regression. Some uncertainty exists regarding whether to include the standard error of the IVR regression (σε2) in the discharge uncertainty. At the 5‐minute time scale when σε2 is included, it has the dominant contribution to the discharge uncertainty, and the discharge uncertainty (expressed as the standard deviation of the discharge estimate) is about 5 m³/s at one gage and 8 m³/s at the other, independent of discharge. When σε2 is not included, the discharge uncertainty at the 5‐minute time scale is much smaller (about 0.5 m³/s) and depends more strongly on discharge. For time scales one day or greater and when σε2 is not included, the uncertainty of the IVR parameters dominates the discharge uncertainty. The value of the discharge uncertainty is about 0.4 m³/s for one gage and 0.5 m³/s for the other gage at long time scales.

Select this Article		Uncertainty and Sensitivity Analysis of Activated Sludge Model No.1 by Monte Carlo Simulation for Single CSTR with Universal Distribution Parameters JinSheng Huo, R. Bruce Robinson, and Chris D. Cox ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)289 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Uncertainty in activated sludge design parameters can result in unacceptable levels of uncertainty in plant performance. We conducted Monte Carlo simulations of the Activated Sludge Model No. 1 (ASM1) to quantify the extent to which uncertainty in the model parameters, as determined from a survey of the literature, leads to uncertainty in plant performance. The results demonstrate that the levels of uncertainty may, depending on the effluent permit, be unacceptably high. We use Spearman rank correlation analysis of the Monte Carlo results to identify the model parameters to which the model is most sensitive as an aid in selecting model parameters to be measured as part of the design process. As a result, engineers and regulators can have a high degree of confidence that the plant will perform as required, without resorting to overly conservative assumptions or large safety factors.

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Select this Article		A Digital Image CD‐ROM and Website for Environmental and Water Resources Engineering Curricula and K‐12 Education J. W. Nicklow, L. R. Chevalier, B. T. Ray, and L. A. Boruszkowski ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)290 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Integration of engineering related photos and videos into classroom lectures gives students the added benefit of witnessing virtual on‐site projects and phenomena. The images enable students to better conceptualize and understand topics they are being taught. Unfortunately, previous image collections did not have a strong focus on environmental and water resources related topics and did not provide images in sufficient resolution for classroom projection. This paper describes the development of a digital image database dedicated to environmental and water resources education. Funded by the National Science foundation, this project involved development of a CD‐ROM and website (http://civil.engr.siu.edu/NSF_DI) that contains a database of photographs and video clips. The images illustrate concepts related to hydraulic structures, open channel flow, sedimentation, water and wastewater treatment, and other specializations, and there is no cost associated with image access and use. The database was constructed by filming an array of existing engineering operations, facility renovations, and construction projects, as well as naturally occurring phenomena. The majority of images are available in three alternative resolutions, each suited towards a particular viewing medium (e.g., printing, LCD projection, on‐screen viewing). The image collection is ideal for use by instructors who prefer stand‐alone images that supplement classroom lectures or by those who prefer to rely on computerized lecture media. Images can also be accessed by students outside of the classroom or as part of distance learning courses. In addition to the images, a portion of the website is dedicated to recruitment and education of K‐12 students. A short video is highlighted and aims to answer various questions about engineering education and training, as well as broader questions about the careers in environmental and water resources engineering.

Select this Article		Activated Sludge Treatment and Anaerobic Digestion of Opium Alkaloid Factory Y. Kaçar Kunukcu and U. Wiesmann ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)291 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The degradation of organic pollutants present in opium alkaloid factory wastewater was carried out by a single aerobic biological degradation and by a single anaerobic digestion. The evolution of the pollutant organic load was followed measuring the dissolved oxygen demand (DOC). In both processes, the kinetic study was performed using the Monod model applied to the experimental data. A comparison of the results with data obtained from WAO (wet air oxidation) pretreatment of the same wastewater is also made. The implications for complete removal organic pollutants by aerobic biological degradation followed by chemical oxidation (WAO, ozonation, UV irradiation, etc.) step are discussed.

Select this Article		Misconceptions about Unstirred SVI R. O. Mines, Jr. and C. R. Horn ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)292 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Settling characteristics of mixed liquor from a completely‐mixed activated sludge process were evaluated in 1‐L stirred and unstirred, plastic settling columns in addition to performing the same analyses in 5‐L stirred and unstirred settling columns. All analyses were performed in accordance with 1992 Standard Methods. Mixed liquor suspended solids concentrations ranged from approximately 1,200 to 9,400 mg/L. Two‐tailed, paired comparison, statistical analyses at the 5% level of significance indicated there was a significant difference between the SVIs obtained from the stirred and unstirred 1‐L and 5‐L settling columns. Two‐tailed, paired comparison, statistical analyses performed at the 5% level of significance indicated there was a significant difference between the zone settling velocities observed in the stirred and unstirred 1‐L and 5‐L settling columns. Surface areas based on stirred settling column analyses may result in areas that are 33% to 238% smaller then those predicted from unstirred settling column analyses. In the design of full‐scale, secondary clarifiers, it is recommended that a scaling factor of 1.5 – 2.0 be applied to the limiting solids flux values obtained from stirred settling column analyses in order for them to handle peak solid loading rates.

Select this Article		Frequency Analysis of Low Streamflow Characteristics Using Statistical Distributions F. Ashkar, J. Bayentin, N. Savoie, and N. El‐Jabi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)293 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Deficit Below Threshold method was applied to characterize low flows in terms of volume, duration and intensity for 31 hydrometric stations in New Brunswick, Canada. The volume, duration and intensity data series were fitted to seven distributions which are the Pareto (PAR), gamma (GAM), Weibull (WEI), log‐logistic (LLOG), log‐normal (LN), Kappa (KAP) and exponential (EXP) distributions. The goodness of fit was assessed using the Anderson‐Darling statistic. For volume, the KAP, LN, LLOG, PAR and WEI distributions gave the best fit. LN, LOG and KAP distributions were best fitted to the duration while the WEI, GAM, LLOG and the LN distributions provide the best fit for intensity. The skew coefficients (C_s) were also calculated for the data series for V, D and I and can provide insight to which distributions may be adequate to fit the low flow characteristics.

Select this Article		Acoustic Doppler Velocimeters (ADV) Performance Curves (APCs) Sampling the Flow Turbulence Carlos Marcelo García, Mariano I. Cantero, Yarko Niño, and Marcelo H. García ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)294 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The capability of Acoustic Doppler Velocimeters (ADV) to resolve flow turbulence is analyzed by mean of a new tool denoted ADV Perfomance Curves (APCs). These curves can be used to define optimal flow and sampling conditions for turbulence measurements using an ADV. To generate these curves, a conceptual model is developed which simulates both, different flow conditions (flow component) and the instrument operation (instrument component). Different scenarios (ranges of flow conditions and sampling frequencies) are simulated using the conceptual model to generate several synthetic time series of water velocity and corresponding sampled signals. For the sake of comparison, the main turbulence statistics parameters of the synthetically generated sampled and non‐sampled time series are plotted in dimensionless form; these plots are called APCs. The performance of the developed tools is validated using experimental results. Using the APCs a new criterion is proposed to perform ADV measurements with good resolution of the flow turbulence. In cases where this criterion can not be satisfied these curves can be used to make the corrections.

Select this Article		Storm Event Monitoring in the Great Smoky Mountains National Park R. B. Robinson, M.ASCE, J. C. Roby, J. R. Buchanan, T. W. Barnett, and S. E. Moore ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)295 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Four YSI sondes, three autosamplers, two recording rain gauges, and one sequential precipitation sampler were installed in a stream in the Great Smoky Mountains National Park in order to collect data before, during, and after a road reconstruction project. The equipment has been installed since September 2003 and has shown routine significant pH drops from 1 to 1.5 pH units along with turbidity spikes up to 1200 NTU's during storm events. The significant drops in pH are attributed to the poor buffering capacity of the watershed, acid precipitation and possibly flushing of dry deposition and natural organic materials during storm events. Precipitation pH averaged 4.1 and 5.1 at two sites in the watershed. Clear diel variations in pH were also observed at the two downstream sites and are consistent with biological action. Regression models to predict pH as a function of stream stage and time of day were constructed for each site with r‐square values ranging from 0.61 to 0.76.

Select this Article		Performance Appraisal of Water Utilities Using DEA Approach Mukul Kulshrestha and Atul K. Mittal ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)296 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents an introduction to the use of Data Envelopment Analysis (DEA) technique for assessing the relative performances of water supply utilities. The DEA is a non‐parametric, linear programming technique that generates an efficiency frontier for the sample utilities and measures performances relative to the frontier. The paper details the technique and its applications, and discusses some of the input and output variables that can be employed for evaluating performances of the water utilities. The paper notes that some of the important variables often need omission, as relevant data is often not available with most utilities in the developing countries. This highlights the need for evolving mechanisms to collect, and make public, the data pertaining to significant indicators of performance; and to evolve standardized definitions of various performance indicators for reliable appraisal of water supply utilities.

Select this Article		Neural Networks Model for Analysis of Input Information Uncertainty in the Small Catchment Sungwon Kim ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)297 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Elman Discrete Recurrent Neural Networks Model(EDRNNM) was used to be a highly suitable flood stage forecasting tool yielding a very high degree of flood stage forecasting accuracy at Musung station(No.1) of Wi‐stream, one of IHP representative basins in South Korea. A relative new approach, EDRNNM, has recurrent feedback nodes and virtual small memory in the structure. EDRNNM was trained by using two algorithms, namely, LMBP and RBP. The model parameters, optimal connection weights and biases, were estimated during training procedure. They were applied to evaluate model validation. Sensitivity analysis test was also performed to account for the uncertainty of input nodes information. The sensitivity analysis approach could suggest a reduction of one from five initially chosen input nodes. Because the uncertainty of input nodes information always result in uncertainty in model results, sensitivity analysis can help to reduce the uncertainty of EDRNNM application and management in the small catchment.

Select this Article		Several Configurations and Aggregation Levels in Neural Networks for Water Distribution Networks Calibration Rafael Gómez, Daniel Salas, and Juan Saldarriaga ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)298 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Neural networks are used in this research intending to perform the hydraulic modeling process in an reverse direction. That is, obtaining pipe's roughness from pressures and flow rates. At the beginning, system's training is done with previously calculated input — output pairs. The training is done on neural networks, which are specially designed for each water distribution network. Opened, closed and of different sizes water distribution networks are used. Several neural architectural configurations are tested. Some aggregation levels are tested too.

Select this Article		Two‐Dimensional Flood Modeling of the Santa Cruz River in Tucson, Arizona Using RMA2 G. Chung, K. E. Lansey, T. W. Kim, and J. H. Kim ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)299 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Two‐dimensional depth‐averaged schemes are able to represent variations in the velocity distribution in a channel. This paper deals with the application of two‐dimensional depth‐averaged model (RMA2) to the Santa Cruz river, an ephemeral channel that is overgrown with vegetation. Vegetation has taken hold in the near dry river bed causing widely varying conditions across the channel. A two‐dimensional simulation may improve the representation of a river. To examine this hypothesis, steady flow simulations from RMA2 are compared with results from HEC‐RAS under the one‐dimensional steady water profile simulation option. Maximum flooding depths, floodplain widths, and velocities are compared and show a significant difference in flow velocities across the section.

Select this Article		Maintaining Natural Conditions in Urban Arroyos: Is it Possible? R. A. Mussetter and M. D. Harvey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)300 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The desire to preserve and restore habitat in urban channels leads to a potential conflict with the need to protect public safety. Traditional engineering approaches to flood and erosion control that provide high factors of safety are often incompatible with good habitat characteristics. Bioengineering and other soft treatments, such as the Prudent Line concept that has been implemented in Albuquerque, New Mexico, and other municipalities, provide opportunities for achieving both safety and environmental objectives, but their factor of safety is often much lower than can be achieved with the traditional, hard‐engineering approach. The Prudent Line concept is based on the idea that a corridor can be defined along an arroyo within which it would not be “prudent” to construct property improvements due to the potential for damage associated with erosion, flooding, or a combination of the two. The undeveloped corridor has the added benefit of maintaining open space and a naturalistic environment while providing the required level of public safety. In many cases, however, the width of the safe buffer zone creates political and economic conflict between planning and resource agencies and property owners. In addition, advocates for increased open space and environmental protection often have a mistaken view of the ultimate stability and appearance of the drainageway after it responds to the effects of urbanization. Arroyos that drain through urbanized areas in the arid southwestern U.S. present a particularly challenging problem in this regard because they tend to be very sensitive to changes in water and sediment supply, and they generally require some form of grade control and bank stabilization. In this paper, some of the technical challenges of implementing the Prudent Line concept in urban channels and the potential benefits that accrue from meeting those challenges are discussed. Examples of some successful and unsuccessful applications of the concept are presented.

Select this Article		Reconnecting the Eugene Delta Ponds to the Willamette River K. H. Price, P.E. and M. Martz ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)301 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Eugene Delta Ponds are located within the City of Eugene, Oregon, adjacent to the Willamette River and surrounded by urban development. The ponds occupy a historic side channel of the Willamette River, separated from the river by a levee. As part of a proposed habitat restoration project, a regulated structure will reconnect the Delta Ponds to the river to simulate the natural pulsation of flows that historically occurred in this reach. The project improves fish and wildlife habitat through restoration of emergent wetland, forested riparian and other indigenous habitats, and control and management of non‐native weedy vegetation and fish species. The hydrologic connection improves water quality in the ponds that were previously isolated from the system. The ponds are transected by a major highway and bounded by a large mall, auto dealers, and school parking lots. As part of the project design, a riparian buffer zone isolates the area from the surrounding development. This paper presents some of the lessons learned during project design and during the three‐year feasibility phase process, with a particular emphasis on the affected hydrologic and hydraulic systems. The design phase included hydraulic modeling of numerous connection scenarios, and the final project design represents an optimal balance between undisturbed conditions and the constraints imposed by an urban system. The project is funded under the U.S. Army Corps of Engineers Section 206 Restoration Authority, with the City of Eugene as the local sponsor. The project utilizes the altered condition of a historical gravel mine for a positive environmental benefit while working within the framework of existing development and the corresponding need to avoid flood impacts. Construction of the project is anticipated in Summer 2005, and the project path thus far serves as an example of the balancing act required to implement river restoration in urban settings.

Select this Article		Flash Flood Guidance and Sediment Yield by a Typhoon, Korea Hung Soo Kim, Byung Sik Kim, Byung Ha Seoh, and Myung Pil Shim ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)302 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The severe flood disaster by a typoon Rusa was occurred in the last year in Korea. The Rusa brought the rainfall of 870.5mm per a day in the city of Kangnung, Kangwon‐do, Korea and this rainfall amount is 62% of the annual mean rainfall in this area. Our focus is to investigate the flash flood guidance and the sediment yield for the basins of small streams of Yangyang town in Kangnung area. Say, the flash flood guidance and the sediment yield by the Rusa are estimated and compared with the given informations obtained from the past flood events. As the results, the flash flood guidance and sediment yield in the study area showed much bigger values than the given informations and so we could know that the Rusa influenced the severe flood of the study area.

Select this Article		A Framework of Water Quality Management to Maintain Sustainability and Simplify EIA Yun‐Ru Chen, Ching‐Pin Tun, Tsun‐Kuo Chang, Guey‐Shin Shyu, and Min‐yu Wei ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)303 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A framework of water quality management is proposed in this study to maintain the sustainability of watershed and simplify project environmental impact assessment (EIA). Continuously mining natural resources and discharging pollutant to environment result in degradation of water quality in Taiwan. Although EIA is required for new developing projects, stream still keeps degrading due to lack of considering cumulative impacts. To maintain sustainability, cumulative impacts should not exceed environmental carrying capacity. In this study, carrying capacity is evaluated and allocated to land units, and thus cumulated pollutant discharge from all land units will not exceed carrying capacity. Then, a developing project only needs to check whether it meets the requirement that designed pollutant discharge divided by developing area does not exceed unit pollutant load. A case study has been done for the TouChien Creek watershed, which carrying capacity of BOD is estimated by QUAL2E and allocated by an optimization model, respectively. The proposed framework not only simplifies the process of EIA but also guarantees that cumulative impacts will not exceed carrying capacity to maintain sustainability.

Select this Article		Application to Reservoir Operation Rule‐Curves S. Y. Hsu, C. P. Tung, C. J. Chen, and C. F. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)304 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Researches in reservoir operation rules had already been studied more than half a century but much still remains to be done. Besides, as a result of global climate change and many nature or human causes, make the frequency and intensity of a lot of hydrological events such as drought and flood change, the existing reservoir operation rules need to change. This paper aims at reservoir operation rule‐curves in detail, and applies to the newly rising evolution algorithms to optimize reservoir operation systematically. Furthermore, the study detects the drought events by the prediction data and water resource system model, optimizes the double‐group rule‐curves and makes the water resources more effectively. The LiYuTan reservoir in Taiwan, for example, establish, the up‐to‐date operation rule.

Select this Article		Reservoir Water Quality Modeling in the Huntington District Raymond Walton, Vincent J. Marchese, and George P. Kincaid ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)305 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract CE‐QUAL‐W2 was used to study and evaluate eutrophication kinetics in two systems in the Corps of Engineers, Huntington District area. In both cases the code was modified to enable simulations of features not available in the current release version. In the first application to the Winfield Pool of the Kanawha River in West Virginia, the code was modified to permit operator‐controlled headwater water surface elevations based on allowing a constant water surface during non‐flood periods for navigation and the passage of river floods. The model was developed as part of a larger project to model water quality transport and fate through the multiple‐controlled Kanawha River system. The second application to Tappan Lake in Ohio was to simulate the addition of one or two new intakes higher in the lake to manage the hydrogen sulphide releases. The summer release of anoxic water from deep in the reservoir contained high concentrations of hydrogen sulphide that was causing problems in the concrete‐lined outflow tunnel. The code was modified to simulate the release of the same flow rates, but through multiple intakes selected by following temperature and dissolved oxygen rule curves. The modified model was used to select two additional intakes set at elevations to minimize temperature excursions and the release of anoxic water.

Select this Article		Optimizing Complex Plume Pump and Treat Systems for Blaine Naval Ammunition Depot, Nebraska Richard C. Peralta, Ineke M. Kalwij, and Bassel Timani ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)306 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract We employed simulation / optimization (S/O) modeling to design optimal pumping strategies for trichloroethylene (TCE) and trinitrotoluene (TNT) contamination at Blaine Naval Ammunition Depot (NAD). Formulation 1 minimizes present value of cost of remediating TCE and TNT contamination within 30 years. Formulation 2 is like Formulation 1, except that 2400 gpm of pumped flow does not require treatment. Formulation 3 minimizes the maximum total pumping rate of any period. We optimized using genetic algorithms (GA), simulated annealing (SA), tabu search (TS) and artificial neural networks (ANNs). We developed the same least‐cost strategy for Formulations 1 and 2, costing $40.82M for Formulation 1 and less for Formulation 2. Our optimal Formulation 3 strategy requires 2139 gpm. Our S/O modeling yielded 19, 34 and 26 percent improvements for Formulations 1, 2 and 3, respectively compared to trial‐and‐error method using simulation models alone. S/O modeling is a powerful tool to develop efficiently optimal pumping strategies for real‐world complex groundwater management problems.

Select this Article		Reuse Experience Indicates a Modification in Golf Course Practices F. Bloetscher, D. E. Meeroff, and C. K. Jones ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)307 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Golf courses are major users of reclaimed water in Florida. In 2001, a total of 185 wastewater treatment plants discharged reclaimed wastewater for irrigation purposes on one or more of Florida's estimated 1450 golf course. The quantity of water used at any given golf course is dependent upon climate, season, and management practices. In Florida, the total amount of water used for irrigation on golf courses in 1995 was estimated to be 297 MGD, for an average of 315,000 gallons per day supplied to each golf course. The wastewater plants provide a large year‐round supply of nutrient‐rich irrigation in proximity to urban areas, which reduces fertilizer requirements on the courses and potentially lowers nutrient loading to natural waters. In terms of water conservation, the use of reclaimed wastewater as an alternative to consumptive use of ground water or surface water supplies is also advantageous from the perspective of the water resource managers.

Select this Article		Developing a Water Quality Control System for Material Circulation T. Kato, H. Kuroda, and H. Nakasone ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)308 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Material circulation like compost recycling is one of the main methods of the watershed management to reduce the pollutant load. The authors developed a water quality management system to evaluate scenarios to improve water quality in the Kasumigaura basin, Japan. The watershed is divided into six sub‐watersheds and the nitrogen effluent load of each is computed from the statistical database. Outflow load from the Kasumigaura basin was calculated using a water quality tank model classified by land use. Two scenarios of compost recycling were simulated, and outflow load from Kasumigaura basin was predicted for the long term. The results showed that the nitrogen load could be reduced about 0.1g⋅m⁻² in the sub‐watershed of high animal waste by the sharing compost within watershed. The model quantitatively evaluated the scenarios.

Select this Article		Wastewater Treatment Using Constructed Wetlands at Highway Rest Areas: A Demonstration Project at I‐70 Near Greenfield, IN T. P. Chan, V. Jain, T. J. Cooper, J. E. Alleman, and R. S. Govindaraju ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)309 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Wastewater management at highway rest areas often presents unique challenges because of the rural locale, high variability in wastewater flow rate and strength, and lack of knowledgeable personnel. Subsurface constructed wetlands are considered in this study as an alternative to conventional treatment technologies in handling wastewater generated at rest areas. This study involves the construction of a subsurface flow constructed wetland treatment and biofield disposal system at interstate highway I‐70 rest area station near Greenfield, Indiana. As the effluent wastewater is highly concentrated due to the use of low‐flow restrictors at the restrooms, a different hydraulic scheme is called for in designing this wetland system in order to increase oxygen transfer and hence treatment efficiency of the system. Two parallel wetland cells are devised for a cyclic operation to allow filling of one cell while draining the other. Such configuration is combined with recirculation and followed by a third conventional plug‐flow wetland cell to further enhance treatment ability. A biofield is also designed for subsurface discharge of a small portion of the effluent while the rest of the effluent is returned to the local sewer. Extensive instrumentation is installed to monitor flow rates and collect water samples at various strategic points in the system. This paper presents an overview of the project, details the design of the system and the instrumentation for flow measurement and sampling. Preliminary assessment of the wetland performance is presented along with the data from the first few months of operation. Future study goals are also identified in the paper.

Select this Article		Prediction of the Total Dissolved Gas Downstream of Spillways Using a Two‐Phase Flow Model M. Politano, P. Carrica, C. Turan, and L. Weber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)310 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract One of the possible negative environmental effects of hydropower installations is the supersaturation of gas in the stilling basin, responsible for the bubble disease in fish. Large amount of bubbles are entrained when the plunging jet impacts the pool of water. These bubbles might travel deep into the water pool transferring mass to the liquid and causing an increment of the concentration of total dissolved gas (TDG). Some numerical studies have been conducted in the past to predict TDG downstream of spillways, most of them based on experimental correlations for the gas volume fraction. A better approach to predict the TDG is possible using a two‐phase flow model. This method is based on the two‐fluid model to calculate the gas volume fraction and velocity of the bubbles. A transport equation for the TDG is solved considering the mass exchange with the bubbles. We assume one variable bubble size, which may change due to local mass transfer and pressure. The simultaneous solution of a bubble number density equation allows the prediction of the bubble size. The two‐phase equations were implemented CFDShip‐Iowa, a parallel, multiblock RANS solver developed at IIHR. Results of TDG, gas volume fraction, bubble number density are discussed. The numerical results of TDG are compared with available field data in the stilling basin of Wanapum Dam on Columbia River.

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QUENTIN MARTIN MEMORIAL TRACK ON RIVER BASIN MANAGEMENT

Select this Article		Drought Definitions and Forecasts for Water Resources Management Jaehyun Ryu, Richard N. Palmer, Sangman Jeong, and Jooheon Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)311 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Interest in the potential impacts of climate variability on existing and planned water resource projects is commonplace. Climate impact investigations have focused primarily on evaluating extreme events with large potential impacts, like floods and droughts. Droughts, in particular, are difficult to analyze because of their slow onset, spatial variability, heterogeneous impacts, and uncertain management actions. Recent studies have attempted to define drought characteristics as a function of precipitation, streamflow, soil moisture, and storage level (for developed systems). This paper extends these other studies by focusing on drought in the Geum River basin of Korea with three primary goals: 1) generating an operational definition of drought, 2) creating mid‐term forecasts of climate variability, and 3) developing a decision support system for drought management that incorporates these other two features. The drought definition is derived from a series of computer simulations that use past precipitation, past and current streamflow, and reservoir storage to anticipate the onset and continuation of a drought event. Next, ensemble climate forecasts (developed from NCEP forecasts) are used to generate predictions of streamflows for the basin. These forecasts are mid‐range in length (up to six month) and are derived from global spectral models (GSMs). These monthly meteorological forecasts are then interpolated to the finer hydrologic model scale. Finally, a decision support system is created to integrate the current degree of drought intensity and streamflow forecasts into a management plan. The decision support system indicates the likelihood of inadequate supplies and proposes management actions.

Select this Article		Optimal Fuzzy Decision Strategies for Reservoir Management A. Cavallo, A. Di Nardo, and M. Di Natale ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)312 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper different decision strategies for the management of an artificial reservoir are considered and compared. In particular, a Standard Operation Policy, a completely heuristic Fuzzy Operation Policy and a new Optimized Fuzzy Operation Policy are analyzed. In order to test the different strategies, a software simulator for the reservoir is employed by using MATLAB/Simulink. An innovative aspect of the proposed method is the use of dynamic hybrid system modeling for the description of the different operation phases of the reservoir. This approach is implemented by using the Stateflow toolbox, thus obtaining a completely integrated software environment.

Select this Article		Preparing for Extreme Droughts: Moving Beyond the Historical Planning Event in the Potomac Basin Julie E. Kiang and Erik R. Hagen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)313 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Drought planning for the Washington, D.C. metropolitan area has traditionally relied on a planning event based on the worst drought experienced in the 73 year historical streamflow record. However, the severity of future droughts is not limited to what has been observed in the historical record. As drought conditions unfolded from fall 2001 to summer 2002, observations of below normal precipitation, record low groundwater levels, and record low streamflows raised the spectre of drought conditions worsening into something more severe than had yet been observed in the historical record.

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SEDIMENTS AND SEDIMENT TRANSPORT

Select this Article		Analysis of Flow Characteristics in an Annular Flume: Implications for Erosion and Deposition of Cohesive Sediments Mariano Cantero, Silvina Mangini, Francisco Pedocchi, Yarko Niño, and Marcelo García ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)314 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Criteria for developing operating curves for annular flumes and defining appropriate values for shear stress for erosion and deposition experiments are proposed. The work of several authors is reviewed and new large eddy simulations (LES) are presented for the annular flume in the Ven Te Chow Hydrosystems Laboratory at the University of Illinois at Urbana‐Champaign (VTCHL), USA. The CFD simulation methodology is validated with experimental data by Petersen and Krishnappan. Then, the code is used to address the flow characteristics in the VTCHL annular flume. Two different pairs of operating curve and shear stress definitions are proposed based in this study: one for erosion experiments and one for deposition experiments.

Select this Article		Application of RMA‐2 Modeling for the Construction of Artificial Islands with Dredged Sediments to Enhance Aquatic and Terrestrial Habitats Nani G. Bhowmik, Misganaw Demissie, and Paminder S. Parmar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)315 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Many rivers and lakes have been filling up with sediments, reducing the useful capacities of these bodies of water. This has been quite true in the Midwest where row crops have replaced cover crops over the last 100 years or so. These dramatic changes in land‐use patterns have been associated with increased soil erosion and sediment yields to the receiving bodies of water. This has been the case for many lakes, streams, and rivers in Illinois. The Illinois River, which drains more than 40 percent of the State of Illinois, has a drainage area of about 75,000 square kilometers (sq km). The Illinois River is a commercially navigable waterway in which a 2.74 meter (m) deep navigation channel is maintained with the assistance of locks and dams.On the average, about 12 million tons of sediments are delivered annually to the river, with about 7 million tons of the total being deposited within the floodplains and main body of the river.

Select this Article		Impacts of Boundary Condition on Unsteady Flow Modeling in Using the UNET Model Yanqing Lian, M.ASCE and Misganaw Demissie, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)316 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Since 1995, the Illinois State Water Survey (ISWS) has conducted a series of studies on unsteady flow modeling of the lower Illinois River using the one‐dimensional unsteady state flow (UNET) model with a primary focus on the management options of Levee and Drainage Districts (LDDs) for flood peak reduction should overtopping or levee failure occur. The same model also is being used as a tool for evaluating impacts of proposed or ongoing restoration efforts in the Illinois River basin. The Illinois River is one of the major tributaries of the Mississippi River. Most of its floodplains from Peoria to Grafton have been leveed for agricultural purposes through the establishment of LDDs. A total of 24 LDDs were established between 1879 and 1916. The UNET model uses either stage or flow hydrographs as boundary conditions. The Hydraulic Engineering Center's storage database (HEC DSS) is used in the UNET model for input and output hydrographs and hydrograph ordinates, which enables easily adapting the model for large river systems and various scenarios. For the lower Illinois River, the UNET model was used to evaluate the impact of using a single LDD or combinations of selected LDDs to reduce peak stages. Spillways of certain sizes were assumed to be placed for floods through the levees. The UNET model also is being used to evaluate the possible reduction of flood stage fluctuations during the growing season by opening selected LDDs or by removing the levees to open a portion or all floodplain areas to the river. It is generally assumed that a well‐calibrated and verified hydraulic model will be sufficient for evaluating management and restoration alternatives that involve possible modifications of model geometries. Application of the UNET model for the lower Illinois River showed that the stage and flow relations can be changed drastically by modifying the channel geometries, however. Boundary conditions for the UNET model have to be adjusted accordingly to maintain mass balance for the system. This study presents comparisons of stage and flow relations altered by possible restoration efforts under assumed scenarios, and the problems caused when appropriate boundary conditions were not used in the UNET model for the Illinois River system.

Select this Article		A Watershed Classification System Using Hierarchical Artificial Neural Networks for Diagnosing Watershed Impairment at Multiple Scales Jeffrey J. Doris, Kristen L. Underwood, P.G., and Donna M. Rizzo, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)317 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A hierarchical system of simple, geostatistical‐based, artificial neural networks (ANNs) have been developed to enhance existing geographic information system (GIS)‐based watershed management tools for diagnosing geomorphic instability at a variety of sub‐basin and watershed scales. Two ANNs originally developed for the classification of reach‐scale vulnerability and geomorphic condition have been tested (in concert with best judgment by experts) using existing data for two Vermont watersheds. These ANNs will support future development of modules to enhance land use management at the watershed scale to better predict geomorphic instability and sediment transport in response to natural and anthropogenic stresses.

Select this Article		Depth‐Averaged Modeling of Flows and Sediment Transport in Open‐Channel with Submerged Vegetation Sung‐Uk Choi and Hyeongsik Kang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)318 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a depth‐averaged model for the numerical simulations of flow and sediment transport in open‐channel flows with submerged vegetation. Since the flow structure and the concentration profile in the open‐channel with submerged vegetation are different from those in the plain open‐channel, the conventional methods of estimating the friction coefficient and sediment load should be modified. The vertical structure model with k‐ε turbulence closure is used to adjust the relevant parameters in the depth‐averaged model. The impacts of model modifications are provided and discussed. Using the developed model, flow and suspended sediment transport through submerged vegetation are simulated, and predicted results are compared with experimental data.

Select this Article		Development and Validation of GSTARS‐1D: A General Sediment Transport Model for Alluvial River Simulation—One Dimensional Jianchun Huang, Blair P. Greimann, and Chih Ted Yang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)319 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract GSTARS‐1D, Generalized Sediment Transport model for Alluvial River Simulation — One Dimensional, is the latest development in the GSTARS series. GSTARS‐1D is a hydraulic and sediment transport numerical model developed to simulate flows in rivers and channels with or without movable boundaries. It is able to compute water surface profiles in single channels, simple channel networks, and complex channel networks. It has both steady and unsteady flow models, many sediment transport equations, floodplain simulation, and computation of width changes using a minimization theory. Lateral inflows can be simulated along with internal boundary conditions, such as time‐stage tables, rating curves, weirs, bridges, and radial gates. Two examples are presented in this paper. The first example shows the capability of the network channel simulation with sediment transport. The second example illustrates the use of the unsteady flow and unsteady sediment transport features of GSTARS‐1D in real engineering problems with hydraulic structures.

Select this Article		Three‐Dimensional Numerical Simulation of Flow and Mass Transport in a Shallow Oxbow Lake Xiaobo Chao, Yafei Jia, and F. Douglas Shields, Jr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)320 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A three‐dimensional numerical model was developed for simulating the flow field and mass concentration distribution in a shallow oxbow lake, Deep Hollow Lake, Mississippi. Flow within the lake was primarily wind‐induced, and the simulated dynamics of wind‐driven flow and mass transport in the lake were validated using field measurements. Two data sets from Deep Hollow Lake were used for model test. The first data set resulted from slug injection of a tracer dye, with measurements of dye concentration distribution within the lake at selected intervals over two days. The simulated and measured dye concentration distributions agreed quite well. The second test involved long‐term simulation of phytoplankton production, expressed as concentration of chlorophyll. Trends of total chlorophyll concentration obtained from the numerical model were in general agreement with the field measurements.

Select this Article		Calculation of Flow and Sediment Transport in the Lower Yellow River Using CCHE2Dfvm Model Enhui Jiang, Weiming Wu, and Sam S. Y. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)321 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this study the depth‐averaged 2‐D model, CCHE2Dfvm, is applied to calculate the flood routing and sediment transport in the 100km‐long reach between Huayuankou and Jiahetan gauging stations in the lower Yellow River. The model solves the two‐dimensional shallow water equations by using the finite volume method with the SIMPLE(C) algorithms and Rhie and Chow's momentum interpolation technique on a curvilinear, non‐staggered grid. The sediment transport equations are also solved by the finite volume method. A semi‐coupled procedure is used, in which the flow and sediment are calculated in a decoupled way but the three components of the sediment module: sediment transport, bed changes and bed material sorting are computed in a coupled fashion. The computations of the 1982 and 1996 floods show that the model is capable of efficiently simulating flow and transport of sediment with low and middle concentrations (<200 kg/m³) in the widely wandering Yellow River with very complex topography and abruptly wetting and drying processes. The simulated flow discharges, water elevations and sediment discharges are in reasonably good agreement with the measured data.

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SHARED VISION PLANNING/SYSTEMS DYNAMICS MODELING

Select this Article		Collaborative Models for Planning in the Mississippi Headwaters Hal Cardwell, Beth Faber, and Kenton Spading ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)322 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water resources planning today requires both complex models and the involvement of various interest groups with differing levels of technical sophistication. This paper highlights a case study of the shared vision planning process for determining the re‐operation of nine reservoirs in the headwaters of the Mississippi River. One of the unique aspects of this planning process is the Corps of Engineers is using the Hydrologic Engineering Center's (HEC) Prescriptive Reservoir Model for optimization in conjunction with a simulation model developed using systems dynamics software. The paper covers both the joint use of the simulation and optimization models and the interaction with working groups composed of various agencies, interested groups and members of the public (the other unique aspect of this planning process). This application differs from earlier shared vision planning efforts because of the combined use of simulation and optimization, and because leadership of the shared vision process rests with local planners who have intimate knowledge, both of the water resource system, and, of the local issues in their region.

Select this Article		Collaborative Water Supply Planning: A Shared Vision Approach for the Rappahannock Basin in Virginia Jeffrey Connor, Lauren Cartwright, and Kurt Stephenson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)323 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water supply planning involves a complex mixture of technical analysis and value judgments. Technical analysis is needed to determine current and future water availability, risks, and water use patterns. Value judgments are required to determine how water will be allocated and shared between localities, identify acceptable water shortage risks, and agree on acceptable water uses. Conflict in water supply planning arises when there are fundamental conflicts in the underlying values held by participants. These conflicts are often obscured and persist because participants argue as if technical analysis alone will resolve the problems. This paper will review recent efforts of the Rappahannock River Basin Commission's alternative approach to water supply planning, called “Shared Vision Planning” (SVP). By design, SVP integrates technical analysis into a collaborative planning and negotiation process. At the center of the SVP process is a shared vision model (SVM) which relies on stakeholders representing a wide range of interests to help construct a computer simulation of the river basin system. The process of constructing a simulation model of the system collaboratively facilitates stakeholder cooperation and aids in identifying tradeoffs. Stakeholders are able to help construct the river basin system model because the model is produced using a user friendly, graphical interface software platform. Transparent, user‐friendly models allow stakeholders to understand and develop trust in the model. As a result, the stakeholders trust the technical analysis provided by the model, and can focus discussions on addressing underlying value judgments.

Select this Article		Role of Hydro‐Morphological System Dynamics in Watershed Malay Mukhopadhyay, Dr., Shri. Sumit Roy, and Manisha Deb Sarkar, Dr. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)324 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract With the present rate of development, water resources for various needs are already showing scarcity trend. This is due to their inequitable distribution to vagaries of monsoon and highly varied hydro‐morphological and basic geological setup at micro level. In India nearly 65% of the land is occupied by hard rocks with their residual soil formation, whose receptiveness to absorb precipitation is limited so also their capacity to store and transmit water. As a result, even in high rainfall areas, water scarcity is felt in summer months. Majority of the areas in India has a rainfall less than 1000 mm. and hard rocks occupy most of the drought prone area. This has a low storage volume and the monthly fluctuation of water level is greater and showing steep declining trends. Though there is a very little change in the morphological character within a short distance, there is a wide variation in the dynamic aquifer parameters, which ultimately retards the recharging of the static deep aquifer reserve. Thus, it is essential to adopt proper methods and approaches for increasing the recharging capacity for reviving the depleted dynamic and static aquifers. The approach to study the hydro‐morphological system dynamics must be user friendly and must reach to the community as well as to the farmer's level.

Select this Article		Evaluation of Conservation Measures in the Upper San Pedro Basin Derya Yalcin Sumer and Kevin Lansey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)325 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water resources management in Arizona is critical to the development and sustainability of local communities. Several regions in the state are facing immediate challenges to meet water demands. However, tools to assist the wide range of water interests understand the impact of decisions are lacking. This paper describes the development of a dynamic simulation based decision support system for the Upper San Pedro Partnership.

Select this Article		Reallocation of Federal Multipurpose Reservoirs: Principles, Policy and Practice George F. McMahon, M.ASCE and Michael C. Farmer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)326 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Most federal reservoirs in operation throughout the United States serve multiple purposes, typically flood control, hydropower, navigation, recreation, water quality, irrigation and municipal water supply. In the decades since many of these projects were first constructed, social preferences for how they should be operated and the purposes they should serve have changed, in some cases substantially. Changes in demand, expressed as society's willingness to pay for services provided, may prompt reallocation, ordinarily defined as a change in reservoir operating rules and operational priorities. Reservoir storage is a convenient measure of operational priorities and project costs carried by the various purposes served. Assuming project storage to be in most cases fixed by original design, significant questions of fairness and economic efficiency arise with respect to the redistribution of benefits and costs after reallocation. Fairness questions center on distribution of costs and benefits, while efficiency considerations center on net economic surplus or net benefits aggregated across project uses. A case study in reallocation of a multipurpose federal reservoir reveals substantial discrepancies between benefits and costs evaluated in accordance with the full set of federal planning principles and abbreviated procedures historically used when the scope and scale of reallocation become large.

Select this Article		Institutional Innovations for Coping with Severe and Sustained Drought in an International Basin Frank A. Ward, J. F. Booker, and Ari M. Michelsen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)327 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Rio Grande is the fifth longest river in North America, forming a nearly 2,000 kilometer international border between Texas and Mexico on its way to the Gulf of Mexico. The basin faces the same problems confronted by many arid regions where water is over allocated, there are growing competing international demands, and river flows and uses are vulnerable to drought and climate change. Currently in the third year of severe drought, irrigation and municipal water diversions have been severely curtailed, extensive river channel diversions threaten endangered species, and reservoir storage has been virtually depleted. A central challenge in these settings is development of policies which efficiently and equitably allocate Basin water resources between the multitude of competing uses across political and institutional jurisdictions. We have developed an integrated hydrologic‐economic model for the upper half of the Basin to test whether innovative policy adjustments in water management and allocation could substantially reduce these damages. Compared to existing institutions, we find that future drought damages could be reduced by $7.4 to $11.8 million per year through intra‐Compact and interstate water markets, respectively, that would extend across current water management jurisdictions. Benefits of market transfers are primarily concentrated in municipal sectors by reducing costly pumping of depletable, low quality groundwater, while costs excluding transfer compensation payments are concentrated in agricultural sectors. Many of the benefits of these alternative water management policies are not limited to drought but also apply to other hydrologic conditions.

Select this Article		Modeling Transboundary Systems Gerald Sehlke and Jacob Jacobson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)328 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The battles are once again brewing in the west over water. Historically, water has always been in the midst of many regional and local battles. Department of Interior Secretary Gale Norton says fights over precious Western water have become much nastier in recent years, thanks in part to booming population growth (May 2003). That trend will only get worse as urban centers grow and need for water increases. The fundamental thesis is: Is there enough water for everyone if we do a better job of allocating it or do we have to decide who and what to sacrifice for the good of others. How do we decide? We can't use trial and error. There is too much at stake. We must understand the system and the repercussions of our actions. The water law of each western state is different and complex. When water crosses state lines management of those waters passes to that state. Management plans exist for each state and each state has their own models. Their models only include the sections of the river system that are within their bounds. There are rarely models available that include the entire river system regardless of the state boundaries.

Select this Article		System Dynamics Modeling and Valuation of Ecosystem Services Daniel D. Heagerty, Kevin R. O'Hara, Gillian C. Ockner, and Ed Whitelaw ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)329 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Ecosystems provide society with a range of natural services and functions collectively known as ecosystem services. Some of the services provided by ecosystems include water supply, fish habitat, air purification, erosion control, and nutrient cycling. Ecosystem economics is the quantification and valuation of the ecological and economic benefits of these services. Ecosystem economics provides a method to quantify changes to ecosystem services resulting from implementing selected projects and to assign economic values to those changes. The results of the analysis aid decision‐makers in setting priorities and evaluating project alternatives. By understanding the economic value of ecosystem services, project managers and decision makers will be better prepared to accurately weigh the benefits and costs of programs and projects designed to meet regulatory mandates and agency and stakeholder objectives.

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WATER AND WASTE WATER ISSUES

Select this Article		Can the Results of Modeling ASR Systems Answer Long‐Term Viability Issues? Frederick Bloetscher, Ph.D., P.E. and Albert Muniz, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)330 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A recent AWWWA survey indicated that there are over 60 aquifer storage and recovery (ASR) projects nation‐wide, albeit many of those are in the test phase and not currently operational. Most of the systems are in areas where freshwater is injected into aquifer zones of relatively fresh native water. The limitations for such systems are mostly related to geo‐chemical concerns. However, where the freshwater is injected into brackish water, ASR technology is not as well understood as some believe. Questions about the effects of buoyancy on the migration of the water, how well the system will operate over large injection horizons and the effects of the aquifer formation are all issues of concern. The current groundwater modeling software base (MODFLOW) is not sufficient to model ASR systems in brackish environments. As a result the authors have used SEAWAT, a USGS density driven model to look at these effects on some specific ASR systems: Collier County and Ft. Lauderdale in south Florida. Modeling ASR systems successfully can provide a tool for engineers and policy‐makers for answering more extensive questions on non‐potable ASR systems that might use surface waters or wastewater effluent. These ASR systems will need to answer concerns about nutrients, pathogens and potentially more exotic public health concerns such as endocrine disruptors. Using current Congressional directives to US EPA, may pose serious concerns in the near future despite the current analytical techniques not being available to detect the pharmaceuticals and viruses. The results of the modeling will shed light on limitations identified by the authors over the past several years, and provide some guidance as to their solutions.

Select this Article		Evaluation of Process Alternatives for City of Temple Terrace Design‐Build Water Reclamation Facility Viraj de Silva, Ph.D., P.E., DEE, Joseph J. Motta, P.E., Woody Garcia, and Steve Schaefer, P.E., DEE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)332 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents conceptual evaluation and life cycle cost analysis for the four liquid process alternatives for the city of Temple Terrace Water Reclamation Facility (TTWRF). The preliminary design for TTWRF is based upon 2.5 MGD annual average, 3.3 MGD max month, to be procured under a design build project delivery process. The hourly peaking factor for the design is 2.75. The Biological Nutrient Removal (BNR) and disinfection processes are the core of the treatment process, with several additional peripheral processes and facilities.

Select this Article		A Generic Approach to Benchmarking of Water and Sanitation Utilities Mukul Kulshrestha, Umesh Bharadwaj, and Atul K. Mittal ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)333 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper details out a simple methodology evolved to benchmark water and sanitation utilities in terms of a single numerical performance score. The work involved identifying key indicators and assigning weights and mutual integration of these weights with a carefully devised scale over a spreadsheet to obtain performance scores. The weights were decided by employing a 3‐tier DELPHI study, while the scale was devised using the mean indicators values available in the literature. This simple approach can reveal not just the relative rankings for partner utilities, but can also help utilities to figure out shortcomings in identified areas so that corrective measures can be adopted. The methodology has been exemplified by benchmarking four water supply utilities in Haryana, India.

Select this Article		Fluidized Bed Incinerator Replacement at Lynn Regional Wastewater Treatment Facility Grant E. Davies, P.E., Clifford L. Green, P.E., Louis T. Barry, P.E., and Robert J. Tina ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)334 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A capital improvements program is underway at the Lynn Regional Wastewater Treatment Facility located in Lynn, Massachusetts, to upgrade aging preliminary treatment and biosolids handling facilities. As part of this program, new dewatering and fluidized bed incinerator (FBI) systems are replacing the existingsystems for incineration of dewatered primary and secondary treatment biosolids with ultimate disposal at an on‐site ash landfill. This program is being administered under a design/build/operate project delivery format. The design and construction period for the capital improvements program is 34 months and the operating term is 20‐years. The project began in the fall of 2001 with new dewatering systems completed in mid 2003, and incinerator and ash handling systems scheduled to be operational in mid 2004. This paper focuses on the residuals and biosolids management facility improvements, beginning with a brief background on the Lynn Regional Wastewater Treatment Facility, followed by a description of the design criteria for the new dewatering and FBI systems, a discussion of the project challenges associated with design, construction, and regulatory approval, and a summary of the major FBI system components.

Select this Article		Resolving World Water Crises through Virtual Waterless Manufacturing Ashok Sharma, B.Sc., B.E. (Mech.), M.A. (Ec.), Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)335 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract As the world rapidly heads towards an imminent ‘hydrocide’ caused by irresponsible human activity and billions cry for safe drinking water, enterprises are mass producing effluents as if wastewater was their main produce. No sane process could aim at avoidable effluent generation as an outcome of production. It is certainly the inadequate practices and insensitivity towards a seemingly abundant bounty of nature that led to the current scenario. The author spent about two decades evolving Cleantech as an innovative environment management approach towards source reduction of effluents in manufacturing industries now successfully demonstrated in over hundreds of industries. In all cases, significant emission cuts including zero emission in many cases have been achieved beyond compliance management with assured profits. Over the recent years, he made attempts to widen the scope of Cleantech from mere zero emission to include zero consumption of freshwater. By applying innovative process modifications and introducing improved set of manufacturing practices he has been able to demonstrate a new approach of virtual waterless manufacturing incorporating zero intake of freshwater and zero emission of wastewater. The concept has been successfully tested in a host of process industries including sugar, fruit processing, dairy and textile processing. In the current paper, the author has outlined the salient features of virtual waterless manufacturing as a scientific response to the oncoming global water crisis presenting exhaustive case studies of select process industries to establish a replicable general methodology and an inventory of replicable clean technology capsules universally applicable for similar manufacturing situations. With possible extension over a wider canvass of industrial activity and the visible multiplier effect, the concept holds a demonstrable potential to address the adverse impact of process industry on global water resources, saving the valuable resource and eliminating the cause of conflict between often competing water users like industry and communities.

Select this Article		Weekend Water Releases for Downstream Recreation Werner C. Loehlein, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)336 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Conemaugh Valley Conservancy (CVC) and a representative of Congressman John P. Murtha originally contacted the Pittsburgh District of the U.S. Army Corps of Engineers in 2000 with questions about the possibility of controlled water releases from Conemaugh River Lake for improving conditions for canoeing downstream of the dam. Subsequently, in May 2001, the Borough of Saltsburg, in partnership with the CVC, made a formal request for an initial appraisal (IA). The primary purpose of the IA was to perform a very preliminary and general investigation into the effects and impacts of changing the water control procedures at Conemaugh River Lake and near‐by Loyalhanna Lake on summer weekends to improve recreational opportunities downstream of the dams. The IA completed in 2002 determined that the proposal merited further investigation and analysis in the form of a more detailed reconnaissance study. In order to analyze the impacts of a change in procedures over a range of hydrologic scenarios, the reconnaissance study is being conducted over a three‐year period, i.e. 2003–2005.

Select this Article		Amphiphilic Polyelectrolytes as Primary Flocculants/Coagulants in Water Treatment: Dynamic Light Scattering Study R. Alnaizy, M. Sayem Mozumder, and B. F. Abu‐Sharkh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)337 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract It is vital to reduce the concentration of natural organic matters (NOM) in groundwaters. Polymer‐based coagulants such as amphiphilic polyelectrolytes are used in water treatment in two distinct ways, as coagulant aids and as primary coagulants. In the latter role, polymers have a number of advantages over inorganic coagulants, notably the smaller volume of sludge produced and reduced sludge management costs. This study examines the impact of molecular structure of novel amphiphilic polyelectrolytes on floc size and size distribution determined by dynamic light scattering. These parameters are related to hydrophobe contents and charge of the polyelectrolyte. These characteristics are also related to the removal efficiency of NOM. The results showed a much lower amount of polymer is needed when amphiphilic polyelectrolytes were used as primary coagulants/flocculants in treating groundwater contaminated with natural organic matters. This substantially lower polymer amount would result in a lower treatment cost as well as it would yield a much lower sludge volume. Dynamic light scattering and UV absorbance results confirmed an optimum polymer dose of 0.3 ppm with up to 5% hydrophobe contents. The polymer hydrophobe contents were directly related to the system performance and NOM removal efficiency. The pH of the solution was virtually unaffected.

Select this Article		Coagu‐flocculation Mechanism and Experimental Study Zhan Hanhui, Zhang Xiaoqi, Luo Dingti, and Hu Yuehua ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)338 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Analyzing and discussing the earlier investigation work of the Coagu‐flocculation mechanism, this paper proposed three processes of Coagu‐flocculation and its physical model, and received good verification in experiments.

Select this Article		Purification Performance of a Composite Material with Zeolitic Tuff and Waste Cement Slurry Kazunori Uchida, Yosuke Kawamoto, Masahiro Fujiwara, and Kazuhiro Nishita ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)339 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The preservation of water resources and water purification are very important for zero emission and sustainable development. The purpose of this investigation is to evaluate performance of an appropriate composite material for a purification system of waste irrigation water. This material is consisted of a natural zeolitic tuff and waste cement slurry; the main component of the former is mordenite; the latter is covered over the fragile tuff. It is cured at 170 degree and about 8,100 hPa in autoclave to make them more stiff and porous, and to synthesize calcium silicate hydrate (C‐S‐H). In this study, we experimented water purification test is conducted to reveal the removal performance for ammonium and phosphate. It is found from the experiment that the material had high removal performance for not only ammonium but also phosphoric acid. This result can be interpreted that zeolitic tuff contributes to removal of ammonium, and that C‐S‐H contributes to that of phosphoric acid, respectively.

Select this Article		Ozone Treatment of Acid Yellow 17 Dye L. W. Lackey and R. O. Mines ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)340 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A pilot study was undertaken to evaluate the effect of ozone on the removal of acid yellow 17 dye and the effect of system pH and dye concentration on the ozonation of the dye. A synthetic textile wastewater was prepared by adding acid yellow 17 dye to 8 liters of tap water (City of Macon). A 11.12‐L, clear, Plexiglas column was used in the study. Ozone was supplied to a sparger at the bottom of the column at 3.78 L/min (8 scfh). Acid yellow 17 dye concentration, chemical oxygen demand (COD), and the quantity of ozone utilized was measured as a function of time at initial pH values of 2.7, 7.0, and 9.9. Results indicate that ozonation is very effective at removing acid yellow 17 dye from synthetic textile wastewater. Acid yellow 17 dye removal and COD removal increased as the pH of the initial textile wastewater was increased from 3 to 10. At the optimum pH, the acid yellow dye concentration decreased from 220 mg/L at time zero to 0.08 mg/L at 40 minutes of ozonation. Similarly, the COD concentration decreased from 197 mg/L at time zero to 39 mg/L at 40 minutes. The ozone consumed to apparent dye removal ratio ranged from 2 to 15,000 mg ozone per mg of dye decolorization and was dependent on both ozonation time and apparent dye concentration.

Select this Article		Water Purification by a Combination of Sunlight, Titanium Dioxide and Alum Fadhil M. Salih ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)341 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water purification was attempted using sunlight as the germicidal source, TiO₂ as a photocatalyzing agent, aluminum sulphate (alum) as a coagulant and Escherichia coli as the microbiological indicator. Sunlight possesses a potential water disinfection property but still suffers shortcomings, mainly the length of exposure required. The efficiency of sunlight disinfection was significantly improved by the presence of one g.1⁻¹ powdered TiO₂ to produce an enhancement ratio of 1.64. This enhancement was attributed to the aggregation of TiO₂ particles and bacterial cells, and the generation of hydroxyl free radicals (OH^•, a highly reactive species) by the photoactivation of TiO₂. The presence of powdered TiO₂ in water imposed a serious technical problem, as it was very difficult to remove by conventional means, and even after leaving the sample to settle for a reasonably long time. This turbidity problem was overcome by the addition of alum at 80 mg.1⁻¹. The latter resolved the problem by clarifying the water in about 5 hours. However, when alum was present during light exposure, further aggregation of bacterial cells and TiO₂ particles was detected despite the fact that light exposure gradually decomposes aggregates. This effect augmented the photocatalytic action of TiO₂ to about 1.53 times that seen with TiO₂ alone increasing the total enhancement ratio to a value of 2.51 of that without any added agent. Such aggregation possibly increases the local concentration of OH^• generated thus creating a better chance for the OH^• radicals to produce more cell damage. It is worthwhile noting, however, that the presence of alum alone did not change the solar disinfection capacity.

Select this Article		Disinfection Byproduct Precursor Removal Using Manganese‐Oxide‐Coated Media Jeff Kuo, Sermsak Korprasertsud, and Larry Y. C. Leong ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)342 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract To meet the future regulatory limits of disinfection byproducts (DBP), the Castaic Lake Water Agency (CLWA) in southern California may need to reduce DBP levels by less than 25 percent of current levels. Use of manganese‐oxide‐coated (MOC) filter media, by itself or in an appropriate combination with other technologies, may be able to meet the proposed DBP rule in a cost‐effective manner. Application of using MOC materials for natural organic matter (NOM) removal to field situations is innovative. Batch kinetic and adsorption isotherm studies were successfully completed using MOC‐anthracite, MOC‐sand, raw water, and ozonated water to determine the adsorptive capacity of MOC media and their efficacy in removing DBP precursors. The findings include: (1) the concept of using MOC media to reduce THMFP was demonstrated; (2) the adsorption data have a good fit with the Langmuir isotherm and the Freundlich isotherm models; (3) MOC‐anthracite reduced more of THMFP for both raw and ozonated water than MOC‐sand; (4) there is some selectivity of NOM adsorption onto the MOC‐media; and (5) removal of NOM by MOC‐media did not have significant impacts on fractionation of THMs formed by chlorination.

Select this Article		Fouling of Quartz Surfaces in Potable Water Ultraviolet Disinfection Systems: Effect of Phosphate Addition Isaac W. Wait, Cliff T. Johnston, and Ernest R. Blatchley, III ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)343 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Ultraviolet (UV) irradiation is rapidly gaining acceptance as a broad spectrum, low maintenance, and cost effective method of disinfection. One limit to widespread adoption of UV disinfection systems is the formation of inorganic precipitates on the quartz jackets surrounding UV lamps. Surface fouling is problematic because it absorbs UV irradiation, reducing the dose applied to the water treated, and is most significant in waters with high concentrations of dissolved metals. One suspected precursor to lamp jacket fouling is aqueous phosphate. Phosphates are often added to drinking water to aid in sequestering dissolved metals and prevent distribution network corrosion, but orthophosphate and condensed phosphates may have the potential to speed lamp jacket fouling by combining with dissolved metals and precipitating onto lamp jacket surfaces. A low‐pressure high‐output (LPHO), mercury amalgam UV disinfection system was used in conjunction with water known to have a high fouling potential to better understand the relationship between water chemistry and fouling dynamics. A pilot‐scale UV reactor was operated and fouling was quantified and compared to fouling observed during an experimental run with phosphate‐dosed water. Significant decreases in radiation intensity and greater metal surface accumulation suggest that phosphate treatment of drinking water has the potential to worsen lamp jacket fouling in locations with high levels of hardness, and highlight the need for adequate pilot studies representing the entire spectrum of possible water compositions and treatment conditions prior to UV disinfection system implementation.

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WATER RESOURCES PLANNING AND MANAGEMENT

Select this Article		Ongoing Determinations for Applicability and Compliance for the Oil and Natural Gas MACT Kristin M. Koblis, CHMM ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)344 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Under the 1990 Clean Air Act Amendments, the U.S. Environmental Protection Agency (EPA) was required to develop National Emission Standards for Hazardous Air Pollutants (NESHAPs) for both existing and new major sources. The statute requires the standards to reflect the maximum degree of reduction in hazardous air pollutant (HAP) emissions that is achievable based on control technology in common use (Maximum Achievable Control Technology ‐ MACT). On June 17, 1999 the EPA promulgated the final MACT standards for the Oil and Natural Gas Production (ONG) and Natural Gas Transmission and Storage (T&S) industries. The primary HAPs of concern for both the ONG and T&S industries are benzene, toluene, ethylbenzene, mixed xylenes (collectively referred to as BTEX), n‐hexane and formaldehyde. The ONG MACT rule defines major sources as a source that emits greater than 10 tons per year of any single HAP, or HAPs in aggregate of greater than 25 tons per year. Major and synthetic minor (which use control devices to regulate HAP emissions below major source thresholds) source facilities were registered with State and Federal agencies by June 17, 2000. In addition to the initial registration requirements, some of these sources were subject to the need for additional control devices (such as condensers for glycol dehydration units; or vapor recovery or incineration systems for tankage; or implementation of leak detection and repair programs for fugitives). Existing sources were also subject to additional monitoring and recordkeeping requirements, which were to have been in place by June 17, 2002. The first periodic ONG MACT report covering the period from December 14, 2002 to June 13, 2003 was due August 10, 2003.

Select this Article		Reflections of a One‐Time State Water Administrator Walter A. Lyon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)345 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper will discuss policy and institutional issues that have emerged during the author's half a century experience as a State Water Administrator and senior professional. Issues which will be discussed include: Federal‐State Relationships, Education and Careers, Organization, Public Participation, Toxics Integration, Values and Water Law. Much of my experience came from the field of water quality management‐ drinking water protection and water pollution control primarily in my home state of Pennsylvania from 1957 to 1983 but also in other parts of the country and the world. Water quality management represents only a small part of what we call environmental management. Because chronologically it came first it was a pioneering effort and set a pattern for those that followed, it provided important experience and set a pattern for other endeavors in environmental management. It is therefore not inappropriate for one who has his roots in water quality management to attempt to expand his view and contemplate questions, and decisions that may present themselves in the years to come. This paper is written with an understanding that the world is still in the formative stages of learning how to deal with complex scientific institutional social and economic questions that confront us in trying to maintain the quality of life and beauty of the globe—of our “spaceship earth” as Adelai Stevenson so aptly called it.

Select this Article		The Southwestern U.S. Urban Storm Water Quality Assessment L. Donald Duke, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)346 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This research compared runoff and receiving water quality data for 12 permitted municipalities in 7 states, comprising a total of 54 monitoring locations. Differences between waterbodies were not explained by differences between climate regimes, land use types, urban activities, or other identifiable factors. The results demonstrate the usefulness of trend analyses on individual waterbodies rather than statistical aggregations of watersheds by land uses or other descriptors. This form of analysis is limited by the necessarily smaller number of data points in each statistical sub‐population, but on the other hand is capable of detecting features that do not appear in aggregated statistical studies or are masked in the aggregated data. These features include: the influence of infrequent outliers in comparison to the norm for a given waterbody; identification of sustained, single‐season high concentrations of constituents that can indicate one‐time polluting events in a waterbody that may be targeted for future management decisions; and variations among waterbodies that may otherwise have been thought to be sufficiently similar for statistical aggregation. The analysis also has implications regarding the relative effectiveness of a variety of monitoring program designs implemented by the 12 selected municipalities, and can be used to make recommendations to improve storm water monitoring programs to effectively capture total constituent loading to receiving waters and to attain the consistency necessary to compare storm water quality across multiple U.S. urban permit holders.

Select this Article		New Air Quality Requirements for Facilities with Boilers F. Jason Martin, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)347 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The rule affects any new or existing boiler and process heater located at a facility that is a major source of hazardous air pollutants (HAPs). According to the Clean Air Act, a facility that has the potential to emit 10 tons a year or more of a single HAP, or 25 tons or more of a combination of HAPs is considered a major source. The rule applies to units that combust solid, liquid, and gaseous fuels, with few exemptions. The U.S. Environmental Protection Agency (EPA) has estimated that 58,000 existing boilers and process heaters are subject to this rule. According to the rule language, new boilers and process heaters must be in compliance on the effective date of the final rule or upon start‐up, whichever is later. Existing sources must come into compliance with the rule within three years of its effective date. The rule sets limits on the amount of air pollution that may be released from the boilers, creates performance test requirements, and recordkeeping requirements.

Select this Article		Ammonia Emissions from Poultry Operations in the State of Delaware: A Critical Review, Estimation and Fate S. Rao Chitikela and W. F. Ritter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)348 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Under Delaware's air pollution regulations, ammonia emissions from agriculture are not regulated. Delaware has some of the most concentrated poultry production in the U.S. A total of 257 million broilers were marketed in 2002. Ammonia emissions from broiler houses may vary widely from day to day, but recent monitoring in several areas of the U.S. indicate average ammonia emissions may range from 200–300 g/d/AU (AU‐animal unit). If an ammonia emission factor of 250 g/d/AU is used, the estimated ammonia emissions from the Delaware poultry industry are 8.7×10⁶ kg/yr. This compares to ammonia emissions from permitted industrial sources of 4.9×10⁴ kg/yr.

Select this Article		Relationship between OVA Readings and Air Toxic Emissions from Soil Vapor Extraction Remediation Systems J. H. M. Barringer, P.E., M.ASCE and L. M. Haselbach, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)349 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Soil Vapor Extraction (SVE) is considered an acceptable method for the remediation of petroleum impacted soils by the State of Florida. Typically, SVE involves applying a vacuum to the vadose zone by a mechanical system to collect volatile organic compounds (VOCs) present in the soil pore space. The collected VOCs include air toxics that are Hazardous Air Pollutants (HAPs). In order to comply with the federal air quality regulations, Florida has instituted a number of policies and procedures concerning HAP emissions from SVE systems. One of the policies includes the collection of off‐gas samples for laboratory analysis of HAPs and other compounds. From the laboratory results and estimated air flow rates, an estimate of HAP emissions can be calculated. Unfortunately, as with most laboratory tests, analytical costs are high. They can cost between $125 and $150 per sample. As a result, off‐gas sample collection for laboratory analysis occurs sparingly, usually only a few times over the duration of a site's remedial system operational life.

Select this Article		Air Permitting of Municipal Water and Wastewater Treatment Operations—An Overview S. Rao Chitikela, K. Witt, and S. Chandran ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)350 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Municipal water and wastewater treatment operations cause air contaminant emissions. The air contaminants of water and wastewater treatment are facility‐specific, and are caused by point, area, and volume sources of operation within the facility. The air contaminants need to be properly characterized and quantified since the applicable requirements are based on them. Water and wastewater treatment operations have applicable air regulations as promulgated by the USEPA and implemented by the individual states; therefore, these operations need air permits. Air permits contain several requirements, including emission and operational limitations, monitoring and record keeping, and reporting. Thus, air compliance of water and wastewater treatment operations is necessary.

Select this Article		Coal Mine Impoundment Safety D. E. Stump, Jr., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)351 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Impoundments at coal mines are used to control surface water runoff throughout mined areas, collect water pumped from active mine areas, and treat contaminated water before it leaves the mine permit. The impoundments function to control and reduce peak discharges during precipitation events, provide locations for treating water to meet the required quality standards, allow detention time for sediment removal, and contain fine coal waste. Coal mine impoundments typically have embankments or dams to create water storage areas. The dams are built from earthen materials readily available on or near the coal mine area. The Office of Surface Mining Reclamation and Enforcement (OSM) of the Department of the Interior and the Mine Safety and Health Administration (MSHA) of the Department of Labor establish and enforce federal safety requirements for coal mine impoundments. Both agency evaluate impoundment safety and require permits, hazard classification, engineered designs, safety factor analysis, inspections, monitoring, closure plans, and emergency action responsibilities. Coal mine impoundment failures have provided valuable lessons for future impoundment design, construction, maintenance, and regulation. In February 1972, several coal waste impoundments in West Virginia failed in series and released 130 million gallons of water and coal slurry. The flooding caused by this release left 124 people dead and 4,000 homeless. Property damage was estimated to be $50 million dollars with 546 homes destroyed and 538 homes damaged. After this failure federal and state coal mine impoundment laws and regulations were significantly revised to insure this type of failure would not happen again.

Select this Article		Saluda Dam Remediation Project: Protecting the Community and the Environment Bernie Garrett, P.E. and Jean‐Claude Younan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)352 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Lake Murray, now a natural and recreational resource located just upstream of Columbia, South Carolina, began as a source of energy. The manmade lake is impounded by the Saluda Dam, which was completed in 1930 by the Lexington County power company. The Saluda Dam became the largest waterpower dam in the world, with a hydroelectric plant downstream that has a capability of 206 megawatts. Situated below the Saluda Dam is McMeekin Station, a 252‐megawatt coal‐fired plant that uses Lake Murray as a source of cooling water. The Saluda Dam Remediation Project involves seismic upgrade requirements with the construction of a new back‐up dam — the largest dam construction project underway in the United States. South Carolina Electric & Gas (SCE&G) has undertaken the $250 million upgrade so that the dam will withstand the strongest probable earthquake that could strike the region. The Lake Murray dam must be remediated to meet changes in Federal Energy Regulatory Commission (FERC) earthquake safety criteria with a strict deadline imposed by FERC. Figure 1 provides an illustration of the Saluda Dam and Lake Murray. The Saluda Dam Remediation Project consists of constructing a back‐up dam, or an additional berm at the downstream toe of the dam to add stability. The new berm will involve a 4 million cubic yard rock berm section and a 1.3 million cubic yard roller‐compacted concrete section. The project area also includes an on‐site quarry, which will be used for excavating the rock to be crushed into aggregate and made into roller compacted concrete (RCC).

Select this Article		Development of a Dynamic Stage‐Frequency (DSF) Relationship for Flood Retarding Structure System (FRS) Management Wen Chen, Ph.D., P.E., Burke Lokey, P.E., CFM, and Valerie Swick, R.H. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)353 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Flood Retarding Structures (FRSs) have been widely installed to regulate runoff from the upper portion of a watershed thereby protecting the downstream from inundation. These flood abatement programs were initiated to protect agricultural lands between the 1930s and the 1970s. In the State of Oklahoma alone, over 2,500 FRSs were constructed by the USDA Soil Conservation Services (SCS, now known as National Resources Conservation Services — NRCS) to control runoff from about 22,000 km² through 1990. In Maricopa County, Arizona, 23 FRSs were constructed by the SCS through 1970. Typically the SCS would design and construct the FRS; operations and maintenances are performed by a local flood control district under intergovernmental agreements. The FRSs are regulated by the state Water Resource Department. A FRS usually includes a principal outfall or spillway to convey runoff from more frequent events (i.e. less than 100‐year event), and emergency spillways to safely release runoff from an event greater than the design storm. The SCS has developed FRS design guidelines and criteria dating to the 1950s. Concurrently, the SCS has developed widely‐used rainfall‐runoff and overland flow methodologies based on readily‐obtainable empirical data. These methodologies have come to be known as the SCS Curve Number (SCS‐CN) procedure. A typical FRS hydrology study consisted of runoff calculations for the contributing watershed using the SCS‐CN method and stage‐storage relationships determined with the level pool routing method. Then, the design parameters (i.e., size of conduit, length/elevation of emergency spillway, and height of dam crest) of each FRS component were determined from the hydrology study.

Select this Article		Economic Engineering Modeling of Agricultural and Urban Water Use and Water Transfers with Stochastic Optimization Guilherme F. Marques, Tingju Zhu, and Jay R. Lund ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)354 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Agricultural and urban sectors compete for water and each can make local and coordinated management decisions based on water availability and economic value. Urban decisions include temporary and permanent water conservation measures to maintain supply reliability and minimize conservation costs. Agricultural decisions include allocation of available land and water to annual and permanent crops to maximize farm revenue. The temporal hierarchy of these decisions can be simulated with multi‐stage programming maximizing net expected benefit of water uses. Permanent decisions are made in a first stage, temporary decisions are made in a second stage, based on the probabilities of different hydrologic year types. This paper presents a two‐stage optimization model for integrating urban and agricultural decisions and assessing the potential for water transfers between the two sectors under probabilistic water supply variability.

Select this Article		Calibrating a Holistic Water Resources‐Economic Model Ximing Cai ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)355 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a calibration approach to a holistic water resources‐economic model, which involves essential water resources and economic components in a consistent model. The model is often formulated as an optimization model, with the objective of maximizing economic welfares/profits from water uses. When we apply the model to a baseline scenario against real world conditions, the economic outputs are often expected to match the observations, since a wide divergence between model outcomes under the baseline case and actual results is not appropriate for policy options starting from the baseline. Following the concept of “positive mathematical programming”, which has been widely used in agricultural and applied economics, this paper presents a procedure to convert an existing normative model to a positive one through calibrating the model to the baseline level using both programming constraints and “positive” inferences from base‐level observations. A genetic algorithm is used to implement the calibration process.

Select this Article		Power and Water Supply Development in New York and New Jersey Paul Schorr, P.E. and Asghar Hasan, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)356 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The planning and operation of power and water supplies have been intertwined with growth and stability in the New York‐New Jersey region for the last 125 years. In 1999 American National Power, a utility company, proposed to site an 1100‐megawatt electric generating station in Rockland County in New York State on a tributary of the Ramapo River that flows into New Jersey. From 100,000 to 600,000 gallons per day would be drawn from the Ramapo River watershed to make up for water used in the process. The power generated would have flowed into the electric grid that served the region. The State of New Jersey opposed the application to protect the downstream water supply infrastructure that serves up to 3,000,000 people in northeast New Jersey. From August 2001 to May 2002 a drought struck the region. Rockland County filed to dismiss the application to protect a threatened and endangered species, timber rattlesnake, and water resources limits. In November 2002, the application was withdrawn. Comparison of this process with an engineering and economic analysis performed by the New Jersey Geological Survey in 1894 indicates how technology has transformed the region within the limits of State jurisdiction and water resources. In conclusion, planning and management of water and power supplies for this region would benefit from a bi‐state agreement with common criteria, simulation models and process if the impacts of water and power plants are to be equitably assessed for the future.

Select this Article		Design and Development of ‘Energy Efficient and Cost Effective’ Hybrid Wastewater Treatment System' D. N. Ravi Shankar, K. S. Lokesh, R. Venkataraman, M.ASCE, and T. P. Halappa Gowda, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)357 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In developing countries conventional wastewater treatment processes are being adopted for quite sometime. Though the processes are well established, there are problems associated with wastewater treatment which need to be addressed considering the huge cost of land, sustainability of ‘Operation and Maintenance’ with respect to skilled labor, power and ease of maintenance. Conventional activated sludge process or trickling filter and their modifications, though efficient are power oriented, require skilled maintenance, and are difficult to sustain in developing countries. Increase in population and rapid growth of urban enclaves resulted in the non‐availability of vast areas of required land with huge costs for wastewater treatment facilities. Thus, there is a need to develop a treatment system which is sustainable with respect to dependency on power, energy recovery, skilled labor, minimum moving parts, least plan area, less odour nuisance, reuse potential, etc. This research based on the concepts cited above, aims to design and develop a combo‐hybrid continuous vertical reactor system. A 40‐foot high ‘pilot model’ has been fabricated and erected at Hebbal sewage treatment plant of Bangalore Water Supply and Sewerage Board, Bangalore, India. The plant is operational from past one year with minimal energy use. The rate of flow of wastewater is 5760 –1920 litres per day with a total reactor volume of 650 liters (UASB reactor volume excluding settling chamber volume) & 700 liters of tower filter volume. The studies have shown very encouraging results with a very good and consistent quality effluent and substantial quantity of Methane gas production per cubic meter of wastewater. The effluent solids varied from 15–25 mg/lit and BOD₅ concentrations vary from 12–27 mg/lit respectively. The plant is being run with considerable ease of O & M.

Select this Article		Reserve Funds vs Borrowing: The Effects on Customer Rates Frederick Bloetscher, Ph.D., P.E., William L. Jarocki, and Patricia Varney ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)358 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In established or stable communities, the replacement of existing infrastructure must be pursued where it is no longer economical to operate, deteriorated to a point where replacement is more cost effective than repairs, where the infrastructure no longer serves its intended purpose or no longer meets regulatory standards. Unfortunately available tools to help utilities determine when it is appropriate or cost effective to replace infrastructure are limited, and often site specific. However, it can be shown that utilities that do not make significant, ongoing contributions to the replacement (or reinvestment) in their infrastructure will incur substantial rate impacts to their customers in the future. These rate impacts are often deferred by current elected bodies in an attempt to protect their political careers. The result is the ongoing deferral of maintenance obligations that expose the utility to ever increasing risk of failure.

Select this Article		Incentives and Challenges in Graduate Education in Integrated Water Resources Management (IWRM) Paul H. Kirshen, M.ASCE, Richard M. Vogel, M.ASCE, Jeffrey K. Griffiths, Elena Naumova, Beatrice Lorge Rogers, John Durant, M.ASCE, J. Michael Reed, and David M. Gute ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)359 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Management of water issues requires experts from all disciplines who understand complexity in both natural and human systems, and who can work together to integrate the multidimensional aspects of water resources management. University graduate programs that provide training in integrated water resources management are limited due to many institutional and academic impediments. We present a framework for an interdisciplinary graduate program in integrated water resource management, and discuss approaches to overcome institutional resistance to this type of program.

Select this Article		A Spreadsheet Replacement for Hardy‐Cross Piping System Analysis in Undergraduate Hydraulics David H. Huddleston, P.E., M.ASCE, Vladimir J. Alarcon, and Wei Chen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)360 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The analysis of water distribution networks has been and will continue to be a core component of civil engineering water resources curricula. Since introduction in 1936, the Hardy‐Cross method has been used in virtually every water resources engineering text to introduce students to network analysis. Implementation of the technique has evolved from manual solution, to programming assignments, to spreadsheet implementations but the basic technique has remained invariant. The technique's amenability to manual calculation methods facilitated its integration into engineering curricula. However, the same subtle elegancies that facilitate manual calculations often obscure the primary engineering and physical principles of water distribution systems relative to the nuances of implementation. Herein, the authors illustrate the application of commonly available spreadsheet software (MicroSoft Excel) to more concisely and effectively solve typical undergraduate network distribution problems using linear theory. Application development is much more efficient and straightforward than the corresponding Hardy‐Cross implementation enabling students to concentrate upon the engineering system and relevant design issues. The technique presented utilizes commonly available technology and is presented as a supplement to alternatives discussed in recent literature.

Select this Article		Company Course: An Innovated Way of Preparing Students for the “Real World” James A. Mueller, P.E., Jeanette A. Brown, P.E.,DEE, and William A. Harkins, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)361 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the Company course in the Department of Environmental Engineering at Manhattan College, a course designed to provide undergraduate students practical experience on state of the art problems. In a case study format, the paper highlights the growth of the course since inception and innovations included over the past few years to make the course a professional learning experience for students. It describes the challenges posed to the students with their responses, most of which were positive. The course provides an enlivening experience for all involved and appears to be an ideal teaching/learning tool for future engineers.

Select this Article		Using Moringa Oleifera for Water Treatment in Rural Communities in South East Nigeria Joachim Ibeziako Ezeji ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)362 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, investigations into the possible use of Moringa Oleifera seed suspension for treatment of rural water is presented. Special focus is placed on the softening of hard water, lowering of turbidity, removal of Suspended Solids (SS) and elimination of bacteria (pathogens) etc. Results obtained for each of these impurities were experimentally obtained in the laboratory. Both the household and large‐scale purification processes were also highlighted. One peculiar feature of results obtained in this study was the application of activated carbon as a tertiary treatment for the removal of taste and odour. The result of this study has given credence to the continued use of moringa oleifera seeds (for coagulant properties) in the treatment and purification of water in tropical areas especially South Eastern Nigeria and other parts of Nigeria and Africa.

Select this Article		Why Worry About the Health of Transboundary Water Resources? — Water Quality Management by Another Name S. Puri ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)363 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper considers the management of water quality in transboundary basins, in which 145 countries are riparians to the worlds 261 international river basins — an issue highlighted in the Agenda 21, Chapter 18, but still neglected in some parts of the world. It is based on the precept that over the last decade the focus of international water policy discussion has been directed to quantity and not enough on quality. The 1997 UN Convention on international waters, the ILA rules and the UN ECE Convention largely focus on quantity of water in rivers. Considerable debate has taken place on the fair allocation of water volumes, with the implicit assumption that water quality is assured if volumes are appropriate. This is not necessarily so for the continued sustainable operation of aquatic ecosystems and ensuring livelihoods of the poor. The paper will seek to show that in international policy development the quality of international water resources should receive as much attention as quantity. Thus the discussion here is of the ‘health’ of transboundary water resources, be it river system or aquifers.

Select this Article		Arable Lands Lost to Erosion Near Beijing, China: Restoration with Municipal Waste Mark F. Madison, John Dickey, Brian Burby, and Tom Miller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)364 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Productive agricultural lands within Beijing Municipality continue to be degraded by erosion and desertification. At the same time, Beijing regional landfills are being filled and biosolids stockpiled at an increasing rate. These environmental problems appear to be separate and distinct, but when considered together, their potential solutions are found to be inter‐related. Compost made with biosolids and organic municipal solid waste could be used to increase the nutrition and water‐holding capacity of the soils at risk of desertification, thereby maintaining productivity and soil stability near the edge of the desert.

Select this Article		Water Supply vs. the Environment: Finding the Appropriate Balance William E. Cox ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)365 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Finding the appropriate balance between dependable public water supply and maintenance of natural aquatic environments involves a basic conflict in values that increasingly results in conflict. After a period covering most of U.S. history during which water supplies were expanded with little regard to environmental consequences, the current regulatory framework for environmental protection places substantial restrictions on water supply development. This modified framework is having major impacts on urban water supply management and ultimately on the typical urban water user. This radical shift in balance between the standing of water supply and preservation of natural aquatic environments has occurred through the evolution of federal controls that give federal officials unprecedented authority over water supply development. As water supply managers strive to adjust to the new decision framework, the broader societal judgment of the appropriateness of the current balance must await the passage of time and the experience that demonstrates impacts and consequences.

Select this Article		Water Supply Reliability: A Facilities Master Plan for the San Diego County Water Authority Richard C. Pyle, P.E., M.ASCE, B.S. CE, M.B.A. and Jennifer Nakayama, A.M.ASCE, B.S ENVE, M.S. CE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)366 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The San Diego County Water Authority (Water Authority), San Diego County's regional water wholesaler, was formed in 1944 for the purpose of importing water to the region. At the time of its formation, the Water Authority supplemented local supplies with imported water. Today, the Water Authority imports 75 to 95 percent of the water used in its service area. Throughout its history, the Water Authority has continually added facilities to meet growing water demands. Following a period of large population growth in the 1980s, the Water Authority completed the Water Distribution Study in 1987. This study described the additional facilities that would be needed to meet regional demands until the year 2010. These recommendations became the basis of the Water Authority's $1.2 billion Capital Improvement Program (CIP). Since the initiation of the CIP in 1989, the Water Authority's Board has annually reviewed the CIP and approved needed modifications, which have included adjustments to and the addition or deletion of various projects. The most significant addition to the CIP occurred in 1998 with the inclusion of the Emergency Storage Project (ESP), the purpose of which is to protect the region against the impacts of a catastrophic interruption of imported water supply, a severe drought, or other similar events that would dramatically decrease the amount of water supplied to the region.

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WATER RESOURCES SYSTEMS ANALYSIS

Select this Article		Parameter Estimation in Unconfined Coastal Aquifers Nien‐Sheng Hsu and Chia‐Chang Hsu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)367 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Using field observations of tidal level and piezometric head at an observation well, this research develops a two‐stage parameter estimation approach for estimating the hydraulic conductivity (K), the specific yield (S_y) and the average saturated thickness (b) of a costal unconfined aquifer. In the first stage, fluctuations of the tidal level and piezometric head at the observation well are collected simultaneously without the influence of pumping. The tidal efficiency and time delay can be computed by applying the Fourier spectra analysis on the two sets of observations. The analytical solution of Ferris (1951) along with the well log data are used to compute an approximation of K/S_y and b. An optimization model is then used to find the values of S_y/K and b. The optimization model couples an implicit finite difference model, which fully describes the flow equation, with the BFGS algorithm. In the second stage, the system is stressed with pumping. The same parameter estimation algorithm is applied to the observations of tidal level and piezometric head at the observation well to obtain the optimal values of K and Sy. The developed approach is applied to a hypothetical aquifer to demonstrate the convergence of the approach.

Select this Article		Evaluation of Regulatory Programs that Constrain Water Withdrawals Based on a Regulated Riparian Legal Foundation Hyunhee An and J. Wayland Eheart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)368 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract With water demands increasing in Riparian areas, and rainfall patterns becoming erratic, conflicts over water among riparian water users have increased considerably. This changing situation in traditionally humid areas has forced water agencies to change the way they regulate water use such that significant quantities of water cannot be withdrawn from the stream without a proper form of withdrawal‐constraining permit. In this paper, we evaluate a withdrawal program based on the ASCE Regulated Riparian Model Water Code, which employs the fixed flow based and fractional flow based permit systems. This evaluation is done by exploring allocation parameters at varying minimum flow requirements. Three performance criteria including low flow frequency, user's net benefit, and frequency of withdrawal interruption are considered for evaluation of regulatory water withdrawal programs. It is concluded that the fixed flow based permit system is able to provide high net benefit and relatively tolerable low flow frequency, but causes too much inconvenience in withdrawal control due to its rather simple but liberal withdrawal formula. The fractional flow based permit system is found much more effectively to preserve the general trend of the natural flow regime while guaranteeing an acceptable net benefit.

Select this Article		Using Environmental Tracers to Verify and Investigate Conceptual Models of Highly Localized Aquitard Leakage Randall W. Gentry, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)369 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this research was to use numerical modeling, environmental tracers and other ancillary data to verify conceptual models for highly localized leakage phenomena that are known to occur in the Northern Mississippi Embayment. The impetus of the research is source water protection and understanding the true risk to drinking water supplies that may be recharged from relatively rapid flow paths in otherwise confined hydrogeologic settings. This research will show how preliminary field data and numerical modeling were used to establish a probable conceptual model that was subsequently tested using environmental tracer data at two study sites where leakage is known to occur in Shelby County, Tennessee. These highly localized leakage areas have been termed aquitard ‘windows’ and locating these points of leakage is an arduous task. The nature of ground water monitoring within large ground water basin areas is insular and the impacts of these leakage sites is not well understood. At the select study site areas, a combination of environmental tracers (tritium/helium‐3), major and trace ion geochemistry, hydraulic response testing, measurement of hydraulic gradients, and groundwater flow modeling is being evaluated to quantify recharge of young water from the alluvial aquifer through the window to the Memphis aquifer. The outcomes of this research will demonstrate which data were most useful in determining the most probable physical model based upon system behavior and a preliminary framework for risk assessment.

Select this Article		Model Reliability Analysis and Data Sufficiency Evaluation for Sustainable Groundwater Management in Semi‐Arid Regions James McPhee and William W.‐G. Yeh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)370 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Sustainable groundwater resources management involves meeting today's needs while simultaneously considering the projected needs of future generations. This is inherently a multiobjective problem, and diverse stakeholders and decision‐makers have different views on what current and future needs are. At the same time simulation models, which are key tools used to evaluate future impacts of decisions over water resources, are subject to uncertainty that stems from incomplete knowledge of aquifer hydraulic properties as well as initial and boundary conditions. The main goals of this research are: 1) to quantify how uncertainty is propagated from the model and parameter spaces to the decision space, and 2) to assess the data needs that arise from reliability requirements in model application. Uncertainty propagation from the parameter space to the management space is evaluated using a first‐order analysis and multiobjective optimization. The methodology is demonstrated by a synthetic case study where sustainable basin‐wide optimal groundwater management policies are sought. Sustainability in this case refers to the aquifer's ability to maintain surface base flows that depend on groundwater table levels. In semi‐arid regions groundwater is the main or unique local source of water supply for human and ecological uses, while imported water usually has to be conveyed from a long distance at a high cost. In such conditions there are many stakeholders involved in decision‐making regarding water resources, and therefore ambiguity in the definition of suitable management objectives must be taken into account. The ultimate questions to be answered are: 1) whether it is possible to achieve sustainability within a prescribed planning horizon, 2) what are the actions to be taken, 3) what are the tradeoffs between present and future generations' needs, and 4) whether these conclusions can be significantly affected by the availability of additional hydrological data.

Select this Article		Water Supply Implications of Removing O'Shaughnessy Dam S. Null and J. R. Lund ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)371 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Hetch Hetchy System provides San Francisco with most of its water supply. O'Shaughnessy Dam is one component of this system, providing approximately 25% of water storage for the Hetch Hetchy System and none of its conveyance. Removing O'Shaughnessy Dam has gained interest to restore Hetch Hetchy Valley. Removal would entail reoperating other existing reservoirs for water storage, but could open the valley to restoration, and economic development from recreation and tourism. The water supply feasibility of removing O'Shaughnessy Dam is analyzed by examining alternative water storage and delivery operations for San Francisco using an economic‐engineering optimization model. The economic benefits of O'Shaughnessy Dam and its alternatives are measured in terms of the quantity of water supplied to San Francisco, economic costs, and hydropower generation. Results suggest there would be little water scarcity if O'Shaughnessy Dam were to be removed, although removal would be costly due to lost hydropower generation and additional water treatment costs.

Select this Article		Reducing Water Supply Costs through Regionalized Surface Water Systems and Transferable Groundwater Permits Brian Kirsch and Greg Characklis ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)372 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A growing water supply issue in the United States is the unsustainable pumping of aquifers. Currently, at least 27 states have regulatory mechanisms in place to protect aquifers through groundwater management areas, and at least 23 of those states have designated management areas designed to limit or regulate groundwater. Cost effectively meeting future demand in these areas will require improved management of existing groundwater resources and thoughtful approaches to developing new resources, usually surface water. With respect to groundwater management, the creation of transferable pumping permits, or rights, is likely to improve the efficiency of groundwater use in such management areas. Joint consideration of pumping permits and regionalized strategies for surface water treatment and distribution have the potential to substantially lower regional water supply development costs. A conjunctive, regional planning model has been developed that evaluates the use of regional surface water systems and marketable groundwater permits. Previous regionalization research minimized total regional costs. However, this model assumes that cities are individual actors and will each choose the alternative that provides treated water with the lowest cost increase at the tap for their customers, an approach that involves new complexities. In North Carolina, a region known as the Central Coastal Plain is facing such restrictions. Over 30 cities are facing groundwater restrictions of up to 75% of current withdrawals. The model was applied to this region and estimates that through surface water regionalization and groundwater permit trading a savings of 35% is possible.

Select this Article		Effect of Optimization Problem Constraints on Pump and Treat Designs for Tooele Army Depot Ineke M. Kalwij and Richard C. Peralta ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)373 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Simulation / optimization modeling is applied for developing management strategies for groundwater TCE contamination at Tooele Army Depot, Utah. Formulations are designed to prevent contaminated water from entering previously clean aquifer. This provides strategies likely to be more acceptable to regulators than strategies developed without those constraints. Optimization provided better objective function values than simulation alone. Objective function value can be improved further by allowing individual extraction wells to pump more than in previous scenarios. This highlights the importance of interaction between designers, clients and regulators during the design phase. Such interaction helps assure that developed optimal pumping strategies are also socially and politically acceptable.

Select this Article		Basin‐Specific Feasibility Studies: Overview of the Evaluation of Alternatives for the ECP Basins Stephanie C. Otis, Ph.D., P.E. and Tracey Piccone, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)374 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Florida's 1994 Everglades Forever Act (EFA) established both interim and long‐term water quality goals designed to restore and protect the Everglades Protection Area (EPA). 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) and the construction of over 42,000 acres of Stormwater Treatment Areas (STAs) through the Everglades Construction Project (ECP). 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. One of these activities was the Basin‐Specific Feasibility Studies (BSFS) which evaluated alternative combinations of BMPs, STAs, Advanced Treatment Technologies (ATTs), and/or regulatory programs to achieve the long‐term water quality goals in the Everglades Protection Area.

Select this Article		Data Envelopment Analysis (DEA) for Assessment of Cryptosporidium and Giardia Removal by Membrane Processes Gideon Oron, Amos Bick, Leonid Gillerman, and Yossi Manor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)375 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Field data from several research sites related to effluent quality; surface water and back‐washed membrane filtrate enables to provide performance estimates efficiencies. The estimates are based on the Data Envelopment Analysis (DEA) method. The exploration focused on individual Ultra‐Filtration (UF) and Micro‐Filtration (MF) experiments allowing determining the membrane performance efficiency in terms of Cryptosporidium and Giardia removal by membrane processes. DEA is an empirically based methodology and the research approach has been found to be effective in the depiction and analysis of complex systems efficiency, where a large number of mutual interacting variables are involved.

Select this Article		Hydraulic Surge Control in Pump Stations with Traveling Water Screens Yifan Zheng ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)376 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper deals with hydraulic surge and control of it in a pump station. A hydraulic surge inside the pump station refers to either a water level upsurge in an open surface pump bay or an uplift force to pump deck level due to the compressed air in an unvented pump chamber, as a result of tripping of a pump or pumps. For pump stations equipped with dual flow type traveling waetr screens, tripping of a pump or pumps can cause a highly clogged screen to become buoyant, lift off its base, and cause damage to screens. The paper describes an actual incident of this type at a pump station for once through cooling system of a power plant, and presents hydraulic surge simulation using a numerical program that calculates the maximum differential water level across screens. The results demonstrate that, under certain conditions, the water level differential across a screen can exceed the screen's own weight and cause the screen to lift off its base, and travel upward. The numerical simulation results also demonstrate that providing proper venting in the pump chamber can minimize the water level differential across screens and prevent the same incident from re‐occurrence. The paper also provides recommendations for future pump station installations with similar configuration and requirements.

Select this Article		Practical Use of Computational Fluid Dynamics Models as a Design Tool — Limitations and Assumptions Laurie L. Ebner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)377 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Three‐Dimensional Computational Fluid Dynamics (CFD) numerical models of the Bonneville Forebay, the Bonneville Tailrace and The Dalles Forebay were developed to address specific design questions. In the process of developing the models, simplifying assumptions are made so the model can provide results within a reasonable time frame. As new uses for the models are identified, it is very important that the original simplifying assumptions and model limitations are identified, revisited and articulated. A practical discussion, with examples, about the numerical model assumptions and limitations will be presented.

Select this Article		Innovative Model for Designing Low Impact Developments (LIFE) Avinash S. Patwardhan, Patrick Graham, Jared Thorpe, Daniel Medina, and Thomas Jobes ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)378 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of a Watershed Management Plan is to develop a realistic, implementable framework for watershed protection that includes combining watershed controls like best management practices and land use management. Watershed studies are conducted, however, at such a large scale that the effects of individual source control measures cannot be evaluated. Without this information, it is difficult to strike a balance between watershed protection, economic growth, and quality of life issues. Low Impact Development (LID) is firmly establishing itself as an effective approach for source control in the arena of storm water management. LID relies on distributed runoff management that seek to control volume by minimization, retardation, infiltration, and treatment of runoff. This paper presents an overview LIFE (U.S. Patent Pending) model developed from basic principles of Low Impact Development, i.e., controlling the runoff at the source. LIFE is a continuous‐simulation, model based on physical processes that occur within bio‐retention facilities, vegetated swales, green roofs, and infiltration devices, as well as effects of LID planning approaches such as site fingerprinting and native soil protection.

Select this Article		Creating a Toolbox for Optimizing Basement Flooding Relief Alternatives Laura Dutt and Brian Hemphill ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)379 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A toolbox approach was developed for optimizing the recommended alternatives for the Sullivan, Stark and Holladay Basin Sewer Relief and Reconstruction Predesign project for the City of Portland, Oregon. The three year project consisted of evaluating three basins in the City of Portland's combined sewer and stormwater collection system. The basins have experienced extensive basement flooding problems in the past, associated with sewer capacity constraints and structural deficiencies. The alternatives that were developed were targeted at eliminating the basement flooding in the basins. In addition, the City of Portland has an ongoing combined sewer overflow (CSO) program and the alternatives developed for the basement flooding relief needed to be integrated with cost‐effective CSO reduction and control measures. Creating the toolbox provided a mechanism to iteratively evaluate the multitude of considered alternatives to improve the combined collection system. The alternatives that were developed from this approach included conventional pipeline improvements and conveyance projects, storage facilities, and partial stormwater separation. Also included in the alternatives were inflow control reduction techniques or “green solutions”. The inflow control reduction programs included in the “toolbox” included an aggressive residential downspout disconnection program, commercial on‐site stormwater controls, landscape infiltration, structural infiltration, landscaped storage, and porous pavement systems. Parcel level GIS and hydraulic modeling provided the tools to evaluate the effectiveness of the recommended alternatives on the collection system. In addition to the GIS and hydraulic modeling, extensive field work was performed to assess the feasibility of implementing inflow control techniques, storage facilities and partial stormwater separation projects, and to verify the assumptions that were input into the hydraulic model. The benefits of using a toolbox approach was that is provided a comprehensive method to evaluate alternatives and provide a cost effective final recommendation based on a combination of technologies.

Select this Article		Optimal Operation of Reservoir Systems Considering the Water Quality: Application of Stochastic Sequential Genetic Algorithms M. Karamouz, F.ASCE and R. Kerachian ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)380 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this study, an algorithm combining a water quality simulation model and a stochastic conflict resolution GA‐based optimization technique is developed for determining optimal reservoir operation rules. This new GA‐based stochastic optimization model can easily incorporate the inherent uncertainty of reservoir inflows. The utility functions of the proposed model are developed based on the reliability of water supply to downstream demands, reservoir volume, and water quality in the reservoir and withdrawn water. A water quality simulation model is also developed to simulate the thermal stratification cycle and the reservoir discharge quality through selective withdrawal structure. The proposed model is applied to the 15‐Khordad Reservoir in the central part of Iran. The results show that the proposed model can reduce the salinity of allocated water to different water demands and the salinity build‐up in the reservoir. The developed operating rules can reduce the average salinity of the releases of the reservoir more than 90 mg/L.

Select this Article		Dover Reservoir Probable Maximum Storm Centering Martin J. Teal and Stephen Stout ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)381 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A single event approach has historically been employed by the U.S. Army Corps of Engineers (USACE) to develop the probable maximum rainfall based upon the methodology presented in National Weather Service (NWS) Hydrometeorological reports (HMR) Numbers 51 and 52. This might be a questionable approach for watersheds with a water control reservoir system due to underlying issues with multiple centered rainfall events. The work described herein involved investigation into current probable maximum flood (PMF) procedures and their applicability to controlled watersheds. The paper will briefly outline the basis for the existing USACE/NWS PMS guidance and its applicability to multiple storm events, and report the results of the investigation of single versus multiple storm centerings. The case of the Dover Reservoir, located in Ohio, will be used to illustrate the concepts and results of the investigation. A sensitivity analysis using the results of an hydrologic model will be discussed. The paper will also present the recommendations for the procedure to be followed in the case of the Dover Reservoir.

Select this Article		An Engineering Model for Wind‐Induced Countercurrent Flow Yisong Yang, Anthony G. Straatman, Horia Hangen, and Ernest Yanful ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)382 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract An engineering model for the phase‐averaged velocity field in wind‐induced countercurrent flow is proposed. The influence of waves on the time‐averaged velocity is accounted for by introducing a skewness factor in Tsanis' eddy viscosity model. The skewness factor characterizes the net effect of the wavy surface in the engineering model for velocity. The coherent velocity components are described separately by an orbital velocity obtained from linear wave theory and are added to the time‐averaged components to give a complete model for the phase‐averaged velocity field. The proposed model collapses to Tsanis' model for deep‐water conditions, but is also shown to yield the correct behavior for intermediate conditions. The bed shear stress, derived from the proposed velocity model, is also shown to be in agreement with experiments.

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WATERSHED ANALYSIS AND MANAGEMENT

Select this Article		Lumped Models for Catchment Scale Modeling of Water Quantity and Quality Ibrahim M. Khadam and Jagath J. Kalurachchi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)383 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Despite the advance of research on physically‐based models for nutrient transport, export coefficients approach plays still an important role in regional and watershed scale management studies. The limited data requirements and their sensitivity to temporal changes in land use and management practices make export coefficients models attractive alternatives to complex models. In this paper, we modified export coefficients approach to the erosion‐scaled export coefficients approach, which is able to model and explain the variability in phosphorus loading resulting from hydrological variability in climatic conditions. Sediment discharge was introduced into the export coefficients equation as a surrogate for hydrological variability. Application to phosphorus modeling in Fishtrap creek, showed the superiority of this approach to traditional export coefficients approach.

Select this Article		The Development of Technology for Integrated Water Resources Management in Republic of Korea Sung Kim, Kyu Cheoul Shim, Han Tae Kim, Hak Soo Kim, and Sung Hack Lee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)384 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Sustainable Water Resources Research Center (SWRRC) as part of the 21st frontier research and development program has been launched and affiliated with the ministry of science and technology in order to manage water resources in an integrated manner in Republic of Korea on August 2001. The mission of the SWRRC is to cope with a future water shortage by developing technology of integrated water resources management. Therefore, it implements the welfare of the developed country, which is a goal of the 21st frontier research and development program. To achieve the goal, securing 3 billion cubic meters of water resources per year has been planned by developing technologies forgathering information on water resources and using gathered material, planning and operating water resources, analyzing hydrological cycle simultaneously surface water and groundwater, exploring sustainable methods and alternative water resources‐recycling, leakage declination, rainwater utilization and desalination. The newly developed technologies can be provided with people in charge of national and local institutions and private companies. And also, the project aims to enable the operators to carry out the technologies and pursue 3 billion cubic meter of water by offering necessary training and results of experiment.

Select this Article		A Feasibility Study on Bridge Scour Countermeasures A. Melih Yanmaz and C. Emre Ozdemir ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)385 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Many bridges are destroyed or completely failed during floods due to excessive scouring around bridge piers and abutments. Safe bridge design is based on joint consideration of structural, hydraulic, and geotechnical aspects. This paper concerns the feasibility study of various types of countermeasures against scouring at bridge sites. The design criteria of these countermeasures are reviewed in terms of hydraulic, hydrologic, constructional, and economical requirements. Conditions of applicability of these countermeasures are evaluated in a case study and hydroeconomic analyses are performed for a bridge. Based on evaluation of the results of hydroeconomic analyses, combinations of riprap and grout filled bags are found to be appropriate measures for piers and abutments against scouring, respectively, whereas vegetation is observed to be applicable for bank protection.

Select this Article		The Impact of Flood Retarding Structures and Varying Climatic Conditions on Streamflow and Sediment Response for a Watershed in Southwestern Oklahoma M. W. Van Liew ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)386 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Flood retarding structures (FRSs) represent one of the most effective methods for reducing damages caused by flooding and sedimentation from agricultural land. The impacts of these structures on streamflow and sediment regime and their effectiveness in reducing watershed floods and associated soil losses under dry, average, and wet climatic conditions were investigated in this study. The Soil and Water Assessment Tool (SWAT) was used to determine differences in streamflow and sediment characteristics with and without flood retarding structures under varying climatic conditions on two subwatersheds of the Little Washita River Experimental Watershed (LWREW) in Southwestern Oklahoma. Differences in the reduction of sediment yield between the two subwatersheds were attributed to such factors as the combined sediment storage capacity of the impoundment structures, their distance from the watershed outlet, and the percent of watershed area controlled by the structures. Model simulations from this study confirm the importance of the flood abatement program in reducing flooding and soil losses from agricultural land, but also show that low flow conditions may be exacerbated by the FRSs.

Select this Article		Optimal Number and Location of BMPs for Stormwater Management C. Perez‐Pedini, R. M. Vogel, James Limbrunner, and J. Durant ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)387 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A distributed hydrologic model of an urban watershed in the northeast U.S. is combined with a genetic algorithm (GA) to optimally locate best management practices for stormwater management (BMPs). The goal of the study is to introduce a methodology for describing the tradeoff between reducing the peak streamflow at the basin outlet and the number and location of BMPs required for such a peak flow reduction. The hydrologic model integrates the Soil Conservation Service Curve Number (SCS‐CN) method with a digital hydrologic network model of the watershed. The distributed model represents the watershed as a system of 4,533 hydrologic response units (HRUs). The hydrologic model is an event based distributed model, which includes surface runoff, unsaturated and saturated components linked by the network of HRUs. BMPs are conceptualized as elements that alter the CN of the HRU where they are applied. The results suggest that more than 20 percent of the peak flow reduction can be achieved by installing fewer than 200 BMPs in the watershed. The maximum peak flow reduction achievable is 31 percent.

Select this Article		California Floodplain Management Task Force Sergio Guillen, P.E., M. Radaideh, PhD., CFM, and D. Ruark, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)388 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In 2000, California Governor Gray Davis signed Assembly Bill 1147, which recommended the creation of the California Floodplain Management Task Force (Task Force). The Task Force was comprised of representatives from State and local jurisdictions, agriculture, building and real estate industries, environmental and emergency management organizations, and Native Americans. Their diverse interests included flood protection, ecosystem health, economic development, conservation of agricultural lands, housing, local land‐use authority, public trust, and private property rights. Representatives of federal agencies (e.g., the U.S. Army Corps of Engineers, the Federal Emergency Management Agency [FEMA], the Environmental Protection Agency [EPA], and the U.S. Fish and Wildlife Service) provided insight and advice to the group. From April to December 2002, the Task Force formulated 38 consensus recommendations. These recommendations were delivered in a final report to the then Director of the Department of Water Resources, Mr. Thomas Hannigan. These consensus recommendations reflected the member's commitment to public safety and the State's agricultural, economic, and environmental resources.

Select this Article		Performance Data and Sampling Issues of a Stormwater Management StormFilter® in the State of Washington James H. Lenhart, P.E. and Scott A. de Ridder ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)389 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In 2003, the Washington State Department of Ecology (Ecology) made substantial revisions to its 1992 Stormwater Management Manual for the Puget Sound. The new manual, Stormwater Management for Western Washington (Manual), provides criteria defining a design storm and expected removal performance for various stormwater contaminants. Through the revised Manual, Ecology also established a process for the application and evaluation of new Best Management Practices (BMPs). Ecology also formed a Technical Review Committee (TRC) comprised of water quality program managers from municipalities throughout the State. The TRC was given the task of establishing a protocol for accepting and evaluating BMPs, which became known as the “Technology Acceptance Protocol—Ecology” (TAPE). The TAPE provides for both the treatment and acceptance classification of a BMP. BMP treatment requirements are listed under various treatment categories such as Pre‐Treatment, Basic (TSS), Enhanced (dissolved Cu and Zn), and Phosphorus. BMP acceptance classifications are listed as Pilot Level, Conditional Short Term Use Level, or General Use Level Designation (PLD, CULD, and GULD). Pilot BMPs, which have little or no data, are accepted for the purpose of monitoring only. Conditional Acceptance implies that the existing performance data available for the technology is sufficient to suggest probable attainment of performance requirements and thus can be widely implemented during the monitoring phase, while GULD means that monitoring is no longer required and the technology is unconditionally accepted.

Select this Article		Low Impact Development and Bioretention Areas in Cold Climates T. M. Nordberg and S. T. Thorolfsson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)390 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Low impact development (LID) is growing as a stormwater management (SWM) practice in more temperate regions, with focus on ecosystem management to preserve local water balance and quality, by mimicking the natural predevelopment hydrology by use of Integrated Management Practices (IMPs). However, in colder climate the performance of LID based IMPs are to a large extent unknown. Cold climate regions require SWM solutions that address winter runoff conditions where low temperatures and repeating cycles of frozen ground, snow cover, rain on snow, snowmelt, and refreezing are experienced. In a harsher, cold climate environment solutions designed for summer conditions often fail to operate satisfactorily or completely shut down during the winter months. The main goal of this research is to test the performance of a bioretention area, an IMP structure, in a cold climate. A test size bioretention area is being built at the Risvollan urban hydrologic monitoring station, which is located in the city of Trondheim (N63° 20', E10° 18'), Norway. The performance of the bioretention area will be evaluated based on peak runoff reduction, detention capabilities, and reduction of total suspended solids (TSS), copper, zinc, and lead in the outflow. The Risvollan station has been collecting high quality hydrology and hydraulic data on a 2 min. time step since 1986, This represents a unique data base for which to compare and complement data for the field work.

Select this Article		An Innovative and Multi Faceted Approach to Reducing Urban Flooding Suresh L. Hettiarachchi, Anthony J. Luft, and Jane Onorati ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)391 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Urban flooding is an issue faced by many major cities around the country. Due to the fully developed nature of older cities such as The City of Minneapolis (City), Minnesota, finding solutions to these flooding problems is not an easy task. Flooding became a prominent topic of discussion in 1997 during a particularly wet month of July. Consecutive severe rainstorms, the first of which was close to a 200‐year rainfall event, caused widespread flooding resulting in significant economic impact to the city. Subsequently, the City developed a report. Flood '97, using complaint reports by residents, field inspections, and preliminary hydraulic and hydrologic analysis, which led to the Flood Mitigation Program for the City. Flood Area 27 (FA 27), which is a residential neighborhood approximately 4 miles southeast of the city center is one of the several watersheds identified in the Flood '97 report. Following is a brief discussion of the development of a Flood Mitigation Project in FA 27.

Select this Article		Urban Storm Water Management: “Understanding Past Flows to Prepare for Future Inundations” James C. Dahl, Jr., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)392 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract What constitutes urban storm water? How do we manage it? These two questions are frequently asked, and are major issues pertaining to public health, safety, and the environment. To understand storm water and its management, a brief discussion of precipitation and the hydrologic cycle will be given followed by a definition of hydrology and hydraulics. This paper will define urban storm water and explore the impacts of urbanization and storm water management practices. Following the discussion, a brief presentation of the 12300/12600 South Design‐Build roadway widening/reconstruction project in Salt Lake County, Utah will be given.

Select this Article		Condition Assessment of Utah Highway Culverts and Determination of Culvert Performance Measures Jesse L. Beaver, Timothy J. McGrath, and Blaine Leonard ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)393 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Utah Department of Transportation installed and manages over 47,000 culverts but has no comprehensive, quantitative method for evaluating the performance of these culverts. UDOT initiated a study to assess culverts throughout the state, develop performance measures to evaluate these installed culverts, and determine performance ratings for their structural and hydraulic performance. UDOT contracted with Simpson Gumpertz & Heger Inc. for this work. Culvert inspections included primarily metal, concrete, and plastic culverts up to five feet in diameter. Numeric performance ratings were determined and used to make recommendations for culvert maintenance and inspection. Inspected culverts are performing well. Average ratings for, all pipe materials are approximately equal. The problems unique to each type of culvert pipe material are discussed.

Select this Article		A Numerical Model for Hydraulic Transients in Drainage Systems M. Politano, J. Odgaard, S. Jain, and W. Klecan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)394 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Most Cities count on networks of underground tunnels for the conveyance of storm water and wastewater. When a storm exceeds the design event, the flow in the tunnels may transition through free‐surface flow to pressurized flow with the potential of generating unacceptable hydraulic transients. A numerical model of the flow during the filling of the tunnels, including transition from free‐surface flow to pressurized flow, was developed at the IIHR. The code was used to predict the hydraulic transients in the West Area CSO tunnels system located in the city of Atlanta. Different design alternatives were evaluated to mitigate the pressure oscillations and overflows during a heavy storm. In this paper, a brief description of the numerical model and some results of the simulations are presented.

Select this Article		NetSTORM — A Computer Program for Rainfall‐Runoff Simulation and Precipitation Analysis Mitchell C. Heineman, P.E. DEE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)395 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The NetSTORM computer program has been used by CDM and its clients since 1991 for rainfall analysis and planning‐level rainfall‐runoff storage‐treatment analysis. This paper introduces NetSTORM and describes its principal functions. NetSTORM adapts the concepts of the old HEC‐STORM program into a modern interface, extends the STORM methodology to simulation of linked structures in a complex collection system, performs intensity — duration — frequency analysis (IDF) of precipitation data, and disaggregates hourly and daily precipitation data to higher resolutions for use in rainfall — runoff modeling.

Select this Article		Selection of a Representative Long‐Term Period for Continuous Model Simulation Mark Yeboah, M.ASCE and Mitchell Heineman, P.E. DEE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)396 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Continuous‐runoff simulation is recognized by USEPA and the United Kingdom's Wastewater Planning Users Group (WAPUG) as the preferred approach for evaluating collection systems and developing long‐term control plans for urban sewer systems. Continuous simulations incorporate hydrologic processes that occur in both storm and non‐storm conditions. The range of processes that affect collection system flows cannot be simulated using the common event‐based simulation approach. Continuous simulation models can simulate storage recovery and loss rates, infiltration capacity recovery, evapotranspiration, and groundwater interaction. Even with the speed of today's computers, it is still often neither desirable nor practical to perform very long‐term simulation of collection systems, as simulation times are long and output becomes very unwieldy. For these reasons, many modelers choose to simulate a single representative year, or a period of five or ten years rather than a typical complete 50‐year or longer record. The representative year or years used in continuous simulation models is typically selected by identifying a period with nearly average precipitation, or by synthesizing a year's worth of storms based on storm return period statistics. However, this approach is likely to err due to the fallacy of assuming that average precipitation yields average collection system behavior. The methods described in this paper ensure that both precipitation and runoff yield statistics that are representative of the long‐term conditions for the study area. A case study for Manchester, New Hampshire is described where representative five‐year periods were identified for continuous simulation.

Select this Article		Evaluating Aquatic Habitat Quality Using Channel Morphology and Multiscale‐Scale Modeling Techniques C. Cianfrani, W. C. Hession, and M. Watzin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)397 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Fifteen streams in Northwestern Vermont spanning five geomorphic classes: stable, and unstable through change in planform, widening, aggrading, and degrading, (according to the Vermont Agency of Natural Resources Geomorphic Assessment (RGA) Protocols) were surveyed to assess the linkages between channel morphology and aquatic habitat quality. Detailed channel surveys were completed including cross sectional and longitudinal profiles, substrate samples, and Rapid Geomorphic Assessments. Habitat assessments included measures of substrate availability, embeddedness, presence of large woody debris and Rapid Habitat Assessments (RHA). Simple regression analysis of geomorphic parameters and habitat parameters shows that the RGA explains a significant amount of the variance in the RHA. In the second stage of this project, watershed‐scale modeling was completed for each watershed using the Soil and Water Assessment Tool (SWAT). The model was calibrated and validated using gauged watersheds within the study region (Lake Champlain Basin). The model was used to generate stream hydrographs and basic watershed parameters (landuse summaries, runoff, sediment loading, etc.) for each watershed in the study. The model was executed for existing landuse and, in the future, will beused to predict impacts of landuse change. Watershed parameters were regressed with geomorphic and habitat condition to assess the ability of watershed‐level characteristics to impact in‐stream condition.

Select this Article		Effects of the Phosphorus Forms of the Watershed on the Speciation of Phytoplankton: A Case Study of the Two Subtropical Deep Reservoirs in Taiwan Yi‐Jing Chen and Shian‐Chee Wu ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)398 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Both the magnitudes and speciation of phosphorus (P) released from the watersheds of two subtropical deep reservoirs in Taiwan, Tehchi and Feitsui Reservoirs were investigated. The dissolved organic P, together with the dissolved reactive P and the particle bound reactive P were categorized as the bioavailable P (BAP) in this study. Field data were used to identify the most important species of P thatfacilitated the growth of the dominating phytoplankton. Dissolved organic P supposedly from the decomposition of rot off in the forested area (mainly the Taiwan Red Pine), accounting for 30 % of the total P, was the leading type of background P from the watershed and served for the prosperity of the dominant algal species, Peridinium spp., in Tehchi Reservoir. Reactive P accounts for 62% of the total P in the runoff in the catchment of the oligo/mesotrophic reservoir, Feitsui Reservoir, with noncalcareous geology. The reactive P is the readily source for the growth of the dominating Cyanobacteria (mainly the Microcystis spp. and Aphanocapsa delicatissima) and many other species of algal in the surface water. The biodiversity of the phytoplankton ecosystem was suggested correlated with the geochemical P cycle in this catchment.

Select this Article		Examination of the Role of Physical Resolution and Scale on Sediment and Nutrient Yields M. Arabi, K. Bracmort, B. Engel, R. S. Govindaraju, and M. Hantush ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)399 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Currently, watershed delineation and extraction of stream networks are accomplished with GIS databases of digital elevation maps (DEMs). The most common method for extracting channel networks requires the a‐priori specification of a critical source area that is required for channel initiation. There are no established guidelines on how to select the critical source area. The critical source area could be selected by identifying an optimal scale of geomorphologic resolution such that further refinement in spatial scale does not contribute to a significant improvement in predicting design quantities at the watershed outlet. In this study, the Soil and Water Assessment Tool (SWAT) model integrated into the BASINS framework was utilized for this purpose. The BASINS framework allows the user to automatically or manually delineate the watershed based on a DEM. The SWAT model was calibrated and validated at Dreisbach and Smith Fry, two subwatersheds of the Black Creek watershed in the Maumee River basin in northeast Indiana. After calibration, several stream definition values were used to estimate total sediment yield for the Smith Fry (Site 2) subwatershed. This study showed that there was no clear critical source area that could be identified for stream definition in SWAT modeling. However, an optimal stream definition value was suggested from a plot of sediment yield versus number of subbasins.

Select this Article		Spatial Optimization of the Synoptic Sampling Network in the Great Smoky Mountains National Park K. R. Odom and R. B. Robinson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)400 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A water quality monitoring network consisting of 83 sampling sites in the Great Smoky Mountains National Park (GRSM) was optimized using a combination of multivariate statistical techniques and simulated annealing (SA). Principal components analysis (PCA), cluster analysis (CA), and discriminant analysis (DA) were used to group similar sampling sites in terms of water quality, watershed vegetation, watershed geology, and watershed geomorphology information. An objective function, incorporating the statistical results and the network costs, was formulated where the objective function was maximized for the benefits of the entire monitoring network using SA.

Select this Article		Dealing with Change: Recreating Missouri River Backwater Habitat K. H. Price, P.E. and S. L. Townsend ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)401 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The U.S. Army Corps of Engineers, Omaha District (Corps), has coordinated with the Nebraska Game and Parks Commission (NGPC), to complete a feasibility study and design for aquatic and terrestrial habitat restoration in Ponca State Park in Dixon County, Nebraska. Tetra Tech, Inc. was retained for environmental analysis, modeling, and civil design. The overall goal of the Ponca State Park Habitat Restoration Project is to restore aquatic and terrestrial habitats that have degraded as a result of hydrologic and sediment transport changes in the adjacent reach of the Missouri River. A series of degraded side channels, backwaters and formerly farmed wetlands are present within Ponca State Park. This project aims to restore these areas into a mosaic of native high‐diversity prairies, wet meadows, shallow low‐velocity backwaters, and emergent and scrub‐shrub wetlands. The creation of several emergent sandbar islands has also been proposed for inclusion in this project.

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RIVER RESTORATION AND URBAN STREAMS SYMPOSIUM

Select this Article		Mississippi River — West Bay Sediment Diversion Gregory Miller ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)402 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The project, located in Plaquemines Parish, Louisiana on the west bank of the Mississippi River at Mile 4.7 Above Head of Passes, diverts water and sediments into West Bay through a dredged conveyance channel. The objective of the project is to restore 10,000 acres of vegetated wetlands in shallow water within the Mississippi River delta over the next 20‐years. The sediment diversion channel is being constructed in two phases: 1) Construction of an interim channel to accommodate a 20,000 cfs discharge at the 50% duration stage of the Mississippi River (completed November 2003), and 2) Modification of the channel to accommodate full‐scale diversion of 50,000 cfs at the 50% duration stage (scheduled September 2005). The enlargement phase will be built upon completion of a period of intensive monitoring of project performance. Prior to construction of the diversion channel, a large natural gas pipeline located in the outfall channel pathway was lowered for safety reasons (completed May 2003). Contingency plans for closing the diversion channel would be implemented if hydrographic monitoring of the Mississippi River navigation channel indicates the Thalweg of the river is migrating toward the diversion channel or if river shoaling substantially increases downstream of the diversion. The project is the largest freshwater and sediment diversion ever constructed for environmental restoration purposes. Lessons learned from this project will be applied to several large‐scale alternatives under development as part of a comprehensive plan to restore and sustain coastal wetland habitats in Louisiana.

Select this Article		Stream Channel Restoration at Bridge Sites Robbie L. Frizzell, P.E., Lyle W. Zevenbergen, P.E., Ph.D., and Ricardo Navarro ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)403 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract There is a growing amount of work and research in the stream restoration area, but relatively little has been done with regard to restoration at bridge sites. The complex flow patterns, high velocities and scour potential make stream restoration at bridge sites more challenging. Stream channel stability and habitat maintenance at bridge crossings are important, and restoration of channel geometry and habitat is a growing need in Georgia, as well as other southeastern states. At many bridge sites in Georgia there is an occurrence, channel widening or blowouts, which has affected the mussel habitat according to aquatic biologists. These over‐widened channels are the result of live‐bed and clear‐water contraction scour. Pier scour and debris accumulation increase the problem in many cases. Application of stream restoration techniques in combination with hydraulic modeling, sediment transport computations and pre‐ and post project monitoring will be utilized at selected bridge sites with the goal of restoring channel geometry and mussel habitats in South Georgia streams. The restored channel geometry may also allow shorter bridge channel spans where the bridges are replaced, providing some economy in these cases.

Select this Article		Temperature Modeling with HEC ‐ RAS Mark R. Jensen and Cynthia L. Lowney ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)404 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Hydrologic Engineering Center ‐ River Analysis System (HEC ‐ RAS) is a one‐dimensional unsteady flow hydraulics program capable of simulating a full network of open channels and hydraulic structures such as bridges, culverts, and weirs, with variable spatial discretization. HEC ‐ RAS is widely used, is in the public domain, and has been applied to a variety of ecosystem function problems such as simulation of floodplain inundation and evaluation of fish passage through culverts; but no capability has been provided for water quality until now. An advection‐dispersion module for water quality and temperature simulation has recently been added to HEC ‐ RAS. It employs the QUICKEST‐ULTIMATE explicit numerical scheme. Water temperature simulation has been implemented using a full energy budget approach. Model input requirements include hydrodynamic information and system geometry both of which are passed from the HEC ‐ RAS unsteady flow model, as well as temperature at hydrodynamic boundaries, and meteorological data. Output from the water temperature model includes results of intermediate calculations such as computation of individual energy budget terms, as well as computed water temperatures. Results from the water temperature model may be combined with output from the hydrodynamic model to facilitate graphical output such as combined time series and profile plots of simulated water temperature, discharge and velocity. A plan view of the river schematic may be color coded to describe spatial distribution of model results. HEC ‐ GeoRAS is an ArcView (and ArcGIS in development) extension that facilitates export of geo‐referenced information from and import of model simulation results to a GIS. For example, GeoRAS produces flood inundation maps that identify the intersection of water surface and land surface grids, and color coded overlays of simulated water temperatures so that model results may be viewed in context of important spatial information such as areas of critical habitat.

Select this Article		Evaluating Flow Regime Management Using River 2D and ArcGIS P. G. Deering and S. J. Kenner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)405 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Flow regime management practices have a critical impact on the health of urban fisheries and are a potential limiting factor for instream habitat. In 2000, the South Dakota Department of Game, Fish, and Parks began a four‐year study on the brown trout (Salmo trutta) fishery in Rapid Creek through Rapid City, South Dakota. As a part of this study, the stream's hydraulic habitat (depth and velocity) was simulated and analyzed using the two‐dimensional model River 2D. This analysis was linked to operating procedures of Pactola Reservoir. Results are presented in the form of weighted useable area per 100 meters of stream over a range of discharges for four life stages: spawning, fry, adult and juvenile. Analysis of the results showed that the habitat availability for fry, juvenile and adult stages were comparable throughout the range of flows, with the fry stage being limiting by a small margin. Time‐series analysis of the adult life stage showed that above Canyon Lake, where a limestone loss zone influences the flow regime, dry years and winter months are the limiting time periods. Below Canyon Lake the summer months and extreme wet years are critical. At high flows (discharges greater exceeding the 90‐day average flow 10% of the time), mean velocities in the study area begin to exceed recommended values for resting velocities. This may cause displacement and an increase in energy expenditure. Recommendations for future management practices include assuring a minimum flow of 0.57 m³/s above Canyon Lake and maintaining summer flows below 3.14 m³/s. The conclusion of this study is that under the normal operating range (10% to 90% flow duration) of releases from Pactola, the suitability of depth and velocity habitat suitability based on depth and velocity is not adversely impacted.

Select this Article		Comparison of One‐ and Two‐Dimensional Hydraulic Habitat Models for Simulation of Trout Stream Habitat John Loranger and Scott Kenner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)406 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In the 1990's, the number of brown trout (Salmo trutta) in Rapid Creek (within the city limits of Rapid City) have declined and the South Dakota Department of Game Fish and Parks initiated a study to identify potential limiting factors that affect the Rapid Creek Fishery. One component of the study is characterization and analyses of the hydraulic habitat. Historically, instream habitat characterization has been done using one‐dimensional hydraulic analysis. One of the most common one‐dimensional techniques is the Physical Habitat Simulation System (PHABSIM). PHABSIM uses the methodology known as the Instream Flow Incremental Methodology (IFIM) and is one of the most widely used tools for assessing flow management practice. IFIM was designed for analysis of alternative management practices, and includes a framework for the decision‐making process as well as techniques for quantifying instream habitat at different flow regimes. Recently, two‐dimensional models (RIVER 2D and SMS) have been developed for detailed hydraulic analysis of spatially explicit habitat units at the microhabitat scale. River 2D was chosen for this project because of the ease with which the model reaches a steady‐state solution without compromising accuracy. River 2D also contains a fish habitat module based on the IFIM and provides for a direct comparison between one‐ and two‐dimensional models.

Select this Article		Two‐Dimensional Hydrodynamic Modeling of the Rio Grande to Support Fishery Habitat Investigations R. A. Mussetter, C. G. Wolff, M. R. Peters, D. B. Thomas, and D. Grochowski ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)407 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Habitat‐simulation modeling studies were conducted for several sites along the Middle Rio Grande and lower Rio Chama to support efforts to protect and enhance Rio Grande Silvery Minnow and other aquatic species. In traditional habitat‐simulation modeling, the distribution of depth and velocity at the study site that is used in the habitat evaluation is typically estimated using one‐dimensional (1‐D) modeling techniques, which assume that the flow follows essentially parallel streamlines. The Middle Rio Grande has a wide, braided channel with multiple diverging flow paths and considerable variability in depth; thus, the 1‐D approximation is subject to considerable uncertainty. To provide improved estimates of the hydraulic conditions at the sites, two‐dimensional (2‐D) hydrodynamic modeling was used in lieu of the traditional 1‐D approach. The analyses were conducted with the RMA2 computer program, a depth‐averaged, finite‐element model that computes water‐surface elevations and horizontal velocity vectors in a 2‐D flow field, with the BOSS Surface Water Modeling System graphical user interface. The 2‐D hydrodynamic results were then combined with habitat use data in an ArcView GIS format to evaluate the quantity, quality, and distribution of habitat at the study sites. Although many technical challenges were encountered in the modeling, the results are believed to be a significant improvement over those that could be obtained from a 1‐D analysis, and the approach has the potential for wide application in aquatic‐habitat simulation.

Select this Article		Merging River Mechanics and Fluvial Morphology for River Management James Grant MacBroom, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)408 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The sciences of classical hydraulic engineering and fluvial morphology have evolved along separate and sometimes divergent paths. The former is based on empirical, laboratory, and theoretical data while the latter emphasizes field observations and measurements of natural systems. However, neither system provides a complete and independent understanding of stream stability and sediment behavior. This paper explores how they compliment rather than compete with each other.

Select this Article		Applicability of Geomorphological Procedures for River Restoration R. D. Hey ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)409 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A geomorphological procedure, based on scaling reference reach data, is now being widely adopted for developing natural stable channel designs for river restoration and riverine habitat creation. Considerable controversy exists about the appropriateness or otherwise, of the method. This paper critically examines the various key steps in the procedure. Success depends on choosing an appropriate reference reach. Not only has it to be stable and of the same stream type as that required for the restoration site, it also has to have the same bankfull width/depth ratio and sinuosity as these values are transferred to the restoration reach. For these dimensionless shape parameters to be equivalent at the reference and restoration sites, the ratios of their bankfull discharges, bed material sizes and loads, valley slopes and equivalent bank vegetation densities are prescribed. UK regime equations for the stream type in question define these critical ratios. The use of reference reaches that do not match these critical ratios will result in failure of the restoration design. These ratios are confirmed by US field data.

Select this Article		Evolution of Piedmont Floodplains and Stream Channels: Implication for Urban Stream Restoration P. Alan Schlindwein, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)410 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Urban stream restoration is commonly attempted without knowledge of the history or future of the affected watershed, floodplain and stream system. When the past, present and future anthropogenic changes in the watershed can be identified, the associated sediment transport mechanics can be estimated and the stream evolution pattern predicted. If the predicted floodplain and stream conditions are detrimental to society's values, then stream restoration work may be appropriate. This paper will discuss the aggregation, degradation and recent urban remobilization of Piedmont floodplain deposits and the resulting stream channel changes since European settlement. A method to reconstruct urban stream channels to nature‐like conditions based on observations will also be presented.

Select this Article		Using Effective Discharge Analysis Methods and a Sediment Transport Reference Reach in the Design of an Urbanizing Sand‐Gravel Channel P. Alan Schlindwein, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)411 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Relocating the East Fork White Lick Creek in Indianapolis required that the biological integrity of the stream be maintained, while providing stream stability in a rapidly urbanizing watershed. The Effective Discharge Analysis method proved uniquely capable of handling these watershed changes in a deterministic manner. In what may be its first design application, the sand‐gravel streambed was modeled using a new transport function. However, the primary innovation of this engineering effort was to inverse the Effective Discharge Analysis method for use in design and then to develop an appropriate downstream scaling method for use with the upstream sediment transport reference reach.

Select this Article		Hydrologic Controls of Riparian Vegetation on the Geotechnical Stability of Streambanks: Experimental Results Andrew Simon and Natasha Pollen ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)412 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Riparian vegetation can provide both mechanical and hydrologic benefits to the shear strength of streambanks. Recent research has shown that the hydrologic effects of water withdrawal on streambank stability can be significant, and far exceeds that provided by root reinforcement during certain times of the year. To accurately quantify the hydrologic effects of riparian vegetation on streambank stability and to determine optimum species for bank stabilization, experiments with common riparian species were conducted in large soil monoliths. Pore‐water pressure data from depths of 30 and 70 cm within soil monoliths containing common riparian species of the USA were monitored for the period February 2002 through November 2003. Over the period of monitoring, River Birch showed the greatest overall effect on increasing matric suction and shear strength at both 30 and 70 cm, Black Willow the least. Averaging the difference in matric suction values at the two depths and multiplying this difference by tan ϕ^b provides an indication of the average increase in apparent cohesion that each of the woody species would provide to a hypothetical streambank. Thus, River Birch would provide a 310% increase in apparent cohesion due to matric suction, followed by Sycamore (200%) and Black Willow (100%). These values are significant in light of typical values of effective cohesion in many silt‐clay systems.

Select this Article		Developing a Bed‐Sediment Protocol for Discriminating between Reference and Impaired Conditions Amanda Heins and Andrew Simon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)413 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Excessive erosion, transport, and deposition of sediment in surface waters are major water quality concerns in the United States. The deposition of fine sediment may smother underlying coarser bed‐material, which reduces rock surface area needed for fish and macroinvertebrates for shelter, spawning, and egg incubation. Additionally, filling of interstitial voids with fines lowers interparticle dissolved oxygen levels. The term embeddedness describes the degree to which deposited fine sediments (sand, silt and clay) surround coarse grained material (gravel, cobbles and boulders). Differences in embeddedness were investigated by the USDA‐ARS National Sedimentation Laboratory at locations on two streams using two methods. At Shades Creek, AL (Ecoregion 67), a particle count was conducted and a sediment sample was taken on coarse‐bed channels, and the percentage of material sample finer than 2 mm was quantified. On the San Juan River, NM (Ecoregion 22), a grid method was used to assess percent of fine sediment on the channel‐bed surface. In both locations, Rapid Geomorphic Assessments (RGA) were conducted at each sampling site to establish the stage of channel evolution and provide a stability rank based on erosional and depositional processes. Reference conditions were developed by analysis of field data collected at other USGS gaging stations in that ecoregion, with the references set to: (1) the median value for stable sites in the ecoregion, and (2) interquartile range. Of locations dominated by coarse bed material, unstable channels were shown to have a greater percentage of fine material than stable channels. Embeddedness appeared to result largely from deposition of failed bank material, and was generally a feature of unstable channels.

Select this Article		Meander Geometry Trends of Urbanized Beal Slough in Lincoln, Nebraska B. J. Ripp, P.E., P.G., CPESC, R. D. Prager, P.E., and E. Ubben ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)414 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract We have determined the meander wavelength/bankfull‐dominant discharge width ratios and the meander radius/bankfull‐dominant discharge width ratios in relation to the longitudinal course on a selected urban reach of Beal Slough in Lincoln, Nebraska. At this location, the stream meanders are advancing at varying degrees. During the geomorphic assessment of this reach, which was an integral part of designing the stream interventions, the specific locations of prominent meander fronts were located. When the locations of these fronts were plotted along the longitudinal axis, in conjunction with the more recent ratios, the plots revealed that the upstream ratio trough and subsequent downstream ratio increase coincided with the active meander fronts. These relationships also correlated well with historical meander geometries and supposed locations of active meandering. Based on the numerical analysis of the meander geometry for this stream, the plotting of changes in meander ratios on the longitudinal axis show promise as a predictive tool to: assess the relative rate for further meander migration; better site and design the placement of stream interventions; design less extensive and costly preventative interventions; and prioritize the construction of these interventions as funding becomes available.

Select this Article		Fine Sediment Dynamics in Coarse‐Grained Streams; Implications for Biological Productivity in Urbanized Western Streams M. D. Harvey and R. A. Mussetter ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)415 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Urbanization of previously undeveloped or agricultural lands can lead to significant changes in watershed discharge and sediment yields. Increased fine sediment loads can have deleterious effects on instream biological productivity in gravel‐ and cobble‐bed streams since both periphyton and macroinvertebrates are adversely affected by fine sediment deposition. Previous studies have shown that flushing of fine sediment to appreciable depths requires mobilization of the bed material. In the 15‐Mile Reach of the Colorado River, although most of the annual sediment load in the river is transported during the snowmelt runoff period, summer storms and resulting runoff have a major impact on the spatial and temporal dynamics of in‐channel fine sediment (mud) deposition and erosion that strongly influence the biotic assemblages in the river and their productivity. Mud deposition occurs where shear stress is less than 1.4 N/m². Remobilization occurs when the shear stress threshold for the mud is exceeded, but these shear stresses are much lower than those required to mobilize the underlying gravel and cobble bed material. Results from 2‐D hydrodynamic modeling indicate that the amount of fine‐sediment‐free area in riffles and runs can be predicted for a wide range of flows. Reservoir releases in the late summer period following thunderstorm events can be used to remove fine sediment without mobilizing the bed material, and can, therefore, be used to improve biological productivity.

Select this Article		Organic Carbon Concentrations in Hyporheic Zone Sediments: A Tool for Measuring Stream Integrity John M. Stofleth, F. Douglas Shields, Jr., and Garey A. Fox ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)416 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Effects of channel incision on sand‐bed stream carbon reservoirs were examined. Channel incision may deplete hyporheic zone C stores due to bed erosion, less frequent hydrologic exchanges between stream and floodplain, and paucity of riparian vegetation and large woody debris. Presented are organic C concentrations found in hyporheic sediments before and after an incised stream rehabilitation project and in three adjacent streams in northern Mississippi. The sampled streams comprise a spectrum of physical conditions corresponding to the conceptual channel evolution model (CEM). Carbon concentrations in the upper 10 cm of the bed ranged from 0.24 ± 0.36% for a nonincised reference site to only 0.01 ± 0.02% for aggradational incised channels. Carbon concentrations generally declined with increase in stage of the CEM, increased with increasing percent canopy over the study reach and were not directly related to large woody debris (LWD) density. These findings suggest factors linking ecological degradation to channel incision and prospective pathways for stream rehabilitation design.

Select this Article		The Influence of Habitat Mosaics on Species Assemblage in a Channelized Midwestern Stream Catherine Marcinkevage and Edwin E. Herricks ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)417 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Regulators have realized the need for ecosystem‐based water resources management that goes beyond the typical focuses on flood protection and water quality control. Understanding and incorporating the connections between hydrology and ecology is important in furthering holistic watershed‐scale resources protection. This paper describes the characterization of in‐channel habitat mosaics, which result from the interactions between flow and physical channel features, in providing flow‐specific areas of refuge and connectivity through a second‐order agricultural stream. Fish communities are used to compare the dynamic nature of habitat mosaics at different reach locations. Analyses of the communities illustrate the role of mosaic characterization in understanding the importance of hydrologic connectivity in watershed management and stream restoration. The results of this study promote understanding of the links between physical and ecological processes, as well as the effects of source areas, habitat suitability, and mosaic dynamics on fish communities.

Select this Article		Assessment of Alternative Streamflow Augmentation Schemes for the Restoration of the Quinebaug River Watershed Neil M. Fennessey, Piotr Parasiewicz, and Michael T. Goettel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)418 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A decision support system (DSS) simulation model consisting of eight lakes and reservoirs is used to explore alternative streamflow augmentation policies being considered for the Quinebaug River Study. The DSS modeling effort is part of a multi‐disciplinary study exploring ways to enhance and restore the river habitat along the mainstem of this 453 km² (175 mi²) watershed, which is located in south‐central Massachusetts and northeastern Connecticut. As part of the study, fishery habitat specialists are recommending a pulse streamflow augmentation strategy that was devised by constructing Continuous Under Threshold (CUT) curves. CUT curves are developed from the frequency and duration characteristics of habitat time series negative run lengths. The efficacy of this flow augmentation policy is compared with the more typical New England fishery habitat recommendation that prescribed continuous releases be made to sustain target instream flows during low flow periods.

Select this Article		Restoring Form and Processes in Urban Streams: The State‐of‐the‐Art Sue L. Niezgoda and Peggy A. Johnson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)419 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Stream restoration and channel design projects are often based on morphological form or stream type, and as a result there needs to a clear tie established between form and function of the stream. A state‐of‐the‐art examination of the literature will identify numerous relationships in naturally forming streams that link morphologic form and stream processes. Due to infrastructure constraints, design protection hard‐points, and highly altered hydrologic and sediment discharge regimes, channel processes and the resulting channel forms and patterns that are observed in urban streams will differ significantly from those observed in naturally adjusting streams. As a result, the design and construction of channel projects in the urban setting is fraught with uncertainty. In this paper, we examine existing relationships between form and processes, the strengths and weaknesses of existing relationships, and the uncertainty in applying these relationships to stream restoration designs in the urban environment.

Select this Article		Introducing Geomorphic Engineering into Standard Stormwater Designs in the Kansas City Metro Area Robert Prager, Munsell McPhillips, Tom Jacobs, Jeff Henson, and Bill Heatherman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)420 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Kansas City metro area is incorporating stream mechanics into its stormwater design standards. Here as in other urban areas, streams have degraded with the rapidly changing hydrology of the urban landscape. Streams disappear, incise, widen, meander or aggrade as the rate of delivery of water and sediment radically changes. The standard response in Kansas City metro as in much of the country is hard armor or channelization in an effort to maintain flood conveyance and control erosion. The hydraulic skills necessary are well established in the civil engineering community. However, the geomorphologic knowledge necessary to manage sustainable urban streams is not. In their 1999 report to Congress, the Federal Emergency Management Agency identified the shortage of professionals with expertise in fluvial process as a barrier to better stream management. Cities cannot fail to protect infrastructure or respond to citizen's complaints while local designers try to learn a new discipline. The Kansas City metropolitan area addressed the knowledge gap through a set of design standards requiring a more complete analysis of stream condition. The region is promoting a better understanding of stream mechanics while solving the most common infrastructure and water quality problems. This approach explicitly acknowledges that there are a set of tasks customarily assigned to engineers specializing in infrastructure design rather than stream mechanics. Standard site development, pipeline crossings, outfalls, bridges and culverts in most urban areas are the province of the general civil engineer. However, by their very number, these types of stream interventions are responsible for much of the damage to urban stream stability. To remedy this problem, fluvial process must be translated into language familiar to and applicable by the general civil practitioner.

Select this Article		Using Concepts of Work to Evaluate Hydromodification Impacts on Stream Channel Integrity and Effectiveness of Management Strategies Gary E. Palhegyi, P.E. and Jill Bicknell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)421 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Urbanization modifies the natural watershed and stream hydrologic and geomorphic processes by altering the landscape and introducing impervious surfaces and drainage infrastructure. Increases in volume, frequency, and duration of runoff from urban development are defined as hydromodification. Hydromodification intensifies sediment transport and leads to stream bank erosion and channel incision. The Santa Clara Valley Urban Runoff Pollution Prevention Program (Program) is required to develop a Hydromodification Management Plan (HMP). As part of developing the HMP, the Program in cooperation with the Santa Clara Valley Water District, developed and tested a method for predicting channel instability, and is in the process of establishing in‐stream stability criteria, runoff control design criteria, and management measures, which include a combination of on‐site, in‐stream, and regional control strategies. The method predicts erosion potential (Ep) using an index representing the effective work done by flow energy in excess of the amount required to transport the available sediment load. The predicted Ep was compared to observed conditions in a test watershed and found to accurately predict stable and unstable channel conditions. A “threshold of adjustment” is identified that distinguishes between stable and unstable conditions. The Ep and threshold of adjustment are intended to be used to set management criteria and evaluate effectiveness of proposed solutions. The Ep concept also has been used to evaluate the effectiveness of control strategies.

Select this Article		The Status of Urban Stream Restoration in the United States Donald Carpenter, Ph.D, John Schwartz, Ph.D, P.E., Louise Slate, P.E., Sanjiv Sinha, Ph.D, P.E., Kelly Brennan, P.E., and James MacBroom, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)422 \| Cited 1 time Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The modernization of society and the growth of population centers have led to a subsequent decline in the quality of numerous watersheds and associated riverine ecosystems. In recent years there have been significant efforts to “restore” river systems to a more natural state thereby reversing the effectives of development. Examples of typical urban stream restoration projects include bank stabilization, de‐channelization of artificially straightened and hardened reaches, channel daylighting of closed conduit streams, dam and culvert removal, creation of stream access points, and aquatic and terrestrial habitat improvement. To promote and further river restoration efforts, the River Restoration Committee was formed in 1996 inside the Environmental and Water Resources Institute's Hydraulics and Waterways Council. As knowledge in the restoration field increased, it became apparent that there are distinct differences between urban and rural restoration projects and that urban stream restoration needed to be one of the core focuses of the committee. Restoration of urban streams requires unique approaches because human activities associated with urban development permanently alter a stream's hydrology, geomorphology, water quality, and ecology from its original “natural” state.

Select this Article		Downstream Effects of Urbanization in Fountain Creek, Colorado M. D. Harvey and C. E. Morris ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)423 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Fountain Creek watershed (1,300 km²) lies within the Arkansas River Basin. Erosion and flooding have caused loss of river‐related infrastructure (roads, bridges, utility crossings) and of riparian lands both within urbanized areas and downstream. A significant increase in the population of the City of Colorado Springs and El Paso County occurred in the mid‐1970s. The USGS estimated that the amount of impervious area in the basin increased from 220 to 427 km² between 1964 and 2000. The hydrological and sedimentologic impacts of urbanization on Fountain Creek were assessed by comparing the pre‐ and post‐1976 flow records at six gages located within the basin. The magnitude of the more frequent peak flows had increased both within the urbanized areas and downstream as far as the City of Pueblo (about 48 km). Transbasin flows are imported into the Fountain Creek basin as well, which increases the annual runoff volume by about 15 percent. Discharges that are equaled or exceeded 1 percent of the time have increased by about 100 percent within the developed area and about 50–60 percent downstream. Discharges that are exceeded or equaled 90 percent of the time have increased downstream of the urbanized areas by a factor of about 20 because of wastewater discharge to the creek and management of return flows, which allows Colorado Springs to exchange return flows from transbasin imports to other locations in the Arkansas River Basin. Urbanization has increased suspended sediment yields from the watershed by a factor of about 17, and has increased the measured rates of bank erosion by about 65 percent Increased baseflows have encouraged the establishment of riparian vegetation on braid bars and on the floodplain, which has, in turn, increased the rate of bank erosion at unprotected locations downstream of the urbanized area. Future development (2010) within the Fountain Creek Basin is projected to increase the impervious area by about 10 percent, and this in the absence of an integrated management plan for stormwater runoff, will further exacerbate downstream impacts.

Select this Article		Application of Normative Flow on Small Streams in Washington State — Hydrologic Perspective Jan Cassin, Robert Fuerstenberg, P.E., Felix Kristanovich, Lucinda Tear, and Kelly Whiting, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)424 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Normative Flow is usually defined as a flow regime that resembles the natural flow regime sufficiently enough to sustain all life stages of diverse native species, including salmon. King County in Washington State is part of the Central Puget Sound, which watersheds and rivers have been dramatically altered by population growth, and where native species have also been consequently affected by all aspects of human use. The human uses of land and water and their impacts on the hydrologic regime offer unique challenges to the efforts to revive maintain and enhance fish population, including salmon. The application of the Normative Flow Concept consisted of (1) choosing a set of indicators that could be used to evaluate the state of hydrologic and biological condition in small urban streams, (2) refining this set to include metrics for which causal linkages between hydrology and biologic response may exist, and (3) using two test streams to test those linkages. The Indicators of Hydrologic Alteration (IHA) Method was used as a screening methodology to study relationships and anthropogenic changes in hydrologic regime during the last one hundred years.

Select this Article		Analysis of Potential Dam Removal Impacts to Habitat, Flooding and Channel Stability in the Carmel Valley, California R. A. Mussetter, S. C. Trabant, and C. G. Wolff ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)425 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The California Department of Water Resources, Division of Safety of Dams (DWR‐DSD), has determined that San Clemente Dam on the Carmel River in Monterey County, California, does not meet seismic safety standards. Alternatives that are being considered to bring the dam to a safe condition range from thickening of the approximately 22‐m‐high, concrete arch dam to complete removal. The 31‐km reach of the Carmel River downstream from the dam passes through urbanized areas within the Carmel Valley; thus, flooding, channel stability, and in‐channel habitat are a matter of significant concern. Several alternative dam retrofit/removal scenarios were considered in this study. Sediment‐routing studies of erosion that would occur in the reservoir were performed for each of the scenarios. The subsequent movement of the released sediment through the downstream reach of the river between the dam and the Pacific Coast, was modeled to assist the owners of the dam and the resource agencies evaluating the potential public safety impacts due to increased flooding and channel instability, as well as the potential for habitat restoration as the river recovers from the increased sediment loading. Sediment data collected throughout the reservoir deposits, in conjunction with available topographic information and simulated hydrologic data, was used as input to the model. Execution of the HEC‐6T model was performed in an interactive manner that allowed for management of complexities associated with the size and distribution of the reservoir deposits and control of the dam configuration. Results obtained from the modeling studies are believed to realistically describe the magnitude, and temporal and spatial distribution of erosion within the reservoir, and deposition and subsequent erosion in the river as the elevated sediment loads pass downstream. This information provided a basis for evaluating changes in flood potential, channel stability, and the ultimate potential for restoring instream habitat.

Select this Article		Sediment Transport and Stream Behavior upon Dam Removal — A Primer Gary E. Freeman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)426 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Dam removal and decommissioning is the new environmental war cry. While on the surface it would appear straight forward to remove a dam and return the river to its “natural condition”, in practice the management of sediment upon dam removal or decommissioning is a major obstacle to successful decommissioning for larger dams. Sediment deposits and moves based upon fairly well understood principles and will, in combination with the stream hydraulics, seek an equilibrium state that balances energy and sediment transport through the former pool area. The release of sediment downstream due to a badly planned decommissioning can cause geomorphic changes both in the pool area and downstream from the dam. These changes can cause major damages due to flood events or deposition of the stored sediment. This paper will present a basic overview of sediment transport upon dam removal. The goal of the paper is to present basic sediment transport and geomorphic theory and its importance to dam decommissioning projects.

Select this Article		Regional Survey of Performance Monitoring of Stream Restoration Projects Shannon Perry and Jim Gracie ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)427 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Over the past decade an increasing number of projects to restore streams have been undertaken throughout North America. Approaches such as the natural channel design approach, river engineering techniques, structural habitat improvement projects, and bank stabilization projects have been used. Many of these projects have no performance monitoring efforts associated with them. Even when there is a monitoring effort there is little standardization on how the monitoring should be conducted. Since stream restoration is a rapidly developing technology, it is important that practitioners have an opportunity to review performance monitoring results on new techniques, structures or treatments, and new approaches. These results, in order to be meaningful to a wide audience of regulators, designers and clients, must be conducted in some manner, which can be reproduced and clearly understood by a diverse audience. While standardization may be premature at this stage of development of the technology, it is important for standards of practice on monitoring protocols to be developed. In the meantime, there is a great need for a widely accepted set of monitoring protocols which includes the number and kind of measuring techniques performed, who should be responsible for conducting the monitoring, what reviews of monitoring programs should be made. Physical and biological components should be included in a comprehensive monitoring program. This paper will present a survey of monitoring approaches being used, discuss the advantages and disadvantages, and will offer some suggestions on an approach to developing a monitoring program which will improve the quality of information being used to evaluate the success of stream restoration projects. It is hoped that this paper will spark discussion of an initiative to develop standards of practice for monitoring stream restoration projects.

Select this Article		Learning from River Restoration Projects G. M. Kondolf and P. Downs ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)428 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In funding and planning river restoration projects, agencies tend to focus on physical implementation, and include monitoring only as an afterthought. The situation is improving, with more funding agencies requiring monitoring of projects to assess the effectiveness of their investments, but most river restoration projects constructed today are still not monitored well enough to learn effectively from them. In the relatively rare cases where a large number of projects have been systematically monitored, typically half or more of the projects are shown to be failing or not meeting design objectives. Because of the hydraulics of alluvial channels are indeterminate, we must live with uncertainty in the outcome of our interventions. With an adaptive management approach, each restoration project can be treated as an experiment, from which we can learn, but only provided we undertake adequate post‐project appraisal based on good baseline data and a sound study plan. Examining a range of channel reconstruction projects, we can often find commonalities that can inform future restoration efforts.

Select this Article		Form and Process Relationships in a Sand Channel as they Relate to the Bombing Run Remediation Site on Fort Bragg, NC P. Alan Schlindwein, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)429 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Over the last two years, the Ammunition Ramp wetland and stream mitigation site on Bombing Run has undergone significant fluvial modification and abandonment of the constructed, mitigation stream channel. This paper will explore three common causes of stream restoration failures and examine the failure of form based design to represent the stream channel processes found in Bombing Run. This paper will also discuss the proper linkage between sand channel processes and channel form design, which will be necessary to remediate the abandonment failure at this mitigation site.

Select this Article		Impact of Urbanization on Sediment Budget of Peachtree Creek Diana Weber, Terry W. Sturm, and Richard Warner ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)430 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Urbanization of stream watersheds in a major metropolitan area changes not only the hydrology of the stream but also the sedimentary response to increased runoff peaks and volumes, and to increased sediment input from construction sites during the period of rapid urban development. The stream response can include major geomorphic changes that continue to occur over a long time period due to stream instability caused by an imbalance of sediment supply and sediment transport capacity. Quantitatively assessing the contribution of streambed degradation and bank erosion to the total sediment budget becomes an essential step in developing sediment TMDLs, identifying stream restoration strategies, evaluating changes in floodplain and channel storage in flood analyses, and determining the consequences of external forcing functions such as channel dredging. This paper reports the results of a study of changes in the sediment budget over a time period of three decades from the 1970s through the 1990s in the Peachtree Creek drainage basin located in the Atlanta metropolitan area. The results show a significant in‐stream contribution to the total sediment discharge that continues to change over time even though urbanization of the watershed has reached a mature state.

Select this Article		Ecosystem Goals, River Dynamics, and River Restoration Design Peter Klingeman, M.ASCE, Merri Martz, Holly Walla, M.ASCE, Janine Castro, and Frank Groznik ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)431 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Natural river systems are characterized in terms of river processes. Impacts of past alterations are discussed and related to river rehabilitation/restoration activities. River restoration is then addressed in terms of ecosystem goals and associated considerations. Guidance is proposed for river restoration design to better include river dynamics as part of overall project development to meet ecosystem goals.

Select this Article		The Uses of Sediment Transport and Morphodynamic Modeling in Stream Restoration G. Parker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)432 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Many streams have become morphologically and ecologically compromised because their sediment budget is out of balance. Examples include a) stream reaches upstream and downstream of dams, b) streams subject to gravel/sand mining, c) streams subject to urban encroachment, d) streams the drainage basins of which have been made largely impermeable and e) streams subject to sediment disposal, toxic or otherwise. Restoration of such streams can be greatly aided by considerations of sediment balance. Depending on the type of project under consideration, the calculations involved can be as simple as those implemented with a spreadsheet or sufficiently complex to require a custom‐made numerical model. An example is given in the presentation.

Select this Article		Sediment Transport in the Restoration of Gravel‐Bed Rivers Peter R. Wilcock, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)433 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A successful stream restoration design must be able to transport the sediment supplied to it with the available flow. Although this guidance is widely cited, only water supply is routinely incorporated in a consistent manner in restoration design. A number of factors can alter both the caliber and rate of sediment supply to a stream. Exact forecasts of sediment supply are seldom available and it is often possible to reliably estimate only the sign of changes in sediment supply. Channel design methodology, including estimates of sediment transport, must account for large uncertainty in future sediment supply. This paper examines sediment transport in coarse‐bedded streams with the goal of identifying robust methods that provide reliable estimates of present and future transport. The response of bed composition and elevation to changes in sediment supply rate and caliber is examined. The accuracy and cost of methods for estimating sediment flux are evaluated. Emphasis is placed on determining the transport of different grain sizes, including the number of size fractions needed to adequately address potential channel change.

Select this Article		Initial Assessment for the Feasibility of Erodable Bank Models Kurtis L. Eisenbath, M.S., E.I, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)434 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Physical hydraulic models have been used in the past and are still used today to model the hydraulics of a prototype before it is built. Primarily, these models are fixed boundary models and bed sediment transport models. However, these models do not address the stability of the channel banks. With increased interest in stream restoration and stabilization were the impacts of control measures on the stream banks is of greater interest a model capable of analyzing the banks is desirable. The purpose of this investigation was to determine if the use of an erodable material for the banks in physical hydraulic models is feasible. This would allow the modeler a more rigorous investigation of the potential erosion of the banks. This paper presents an initial assessment of the use of erodable bank models, identifying the pros and cons in the use of such models. Erodable bank models are physical models that are constructed with a material that will erode similar to the prototype. This allows the modeler to see any effects of the flow on the banks of the model directly without having to determine if the flow patterns will cause erosion or not. This allows the modeler to see where the stream will erode and how much over time. A case study was investigated as an example to help determine the feasibility of erodable bank models. Three erosion control measures, riprap, bendway weirs, and brush piles and tree plantings, were investigated as part of a potential stream stabilization project.

Select this Article		Erosional Narrowing after Dam Removal: Theory and Numerical Model M. Wong, A. Cantelli, C. Paola, and G. Parker ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)435 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Experiments carried out in a flume at St. Anthony Falls Laboratory, University of Minnesota have shown an interesting phenomenon that we refer to as “erosional narrowing”. This occurs immediately after the sudden removal of a dam that is filled with sediment. A channel incises into the deposit after failure of the leading front of the sediment deposit. In the early stages of incision this channel may become significantly narrower as it undergoes degradation. Both incision and narrowing propagate upstream on a relatively short time. In the long term however, the depositional contribution from the side slopes eventually balances and then surpasses erosional narrowing, so the channel widens toward some new equilibrium state with a lower streamwise slope. This picture is at variance with the general belief that the incisional channel widens from the very beginning. A simplified 1‐D model of the phenomenon is developed and implemented numerically; in it the time evolution of channel width depends on the streamwise gradient of sediment transport and fluvial erosion of the channel banks (sidewalls).

Select this Article		Sediment and Phosphorus Loads from Streambank Erosion in Vermont, USA Matthew N. DeWolfe, W. Cully Hession, and Mary C. Watzin ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)436 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Streambank erosion is a poorly characterized, though potentially important, nonpoint source of sediment and phosphorus contributing to water quality degradation in Vermont. We conducted field research to obtain quantitative estimates of sediment and phosphorus loads due to streambank erosion on ten stream reaches in the Lake Champlain Basin of Vermont. Results were placed in context by comparison to simulated phosphorus and sediment loads from other nonpoint sources using the EUTROMOD watershed model and loading coefficients. Streambank erosion rates, while variable between stream reaches, were moderate (average 0.26 m/year) compared to published results for similar‐sized watersheds. The importance of streambank erosion relative to other nonpoint sources of sediment and phosphorus was also highly variable between stream reaches, ranging from the smallest to the largest single contributor.

Select this Article		Sediment Transport in Some Eastern United States Streams James W. Gracie and William A. Thomas ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)437 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Sediment transport rate is a key issue in many streams that are out of equilibrium due to recent changes in land use which result in changes in peak discharges. Streams subjected to these changes undergo a process of erosion and channel enlargement that often results in excess sediment supply from the eroding channels. When this supply rate exceeds the rate at which the stream can transport it, the sediment transport regime is said to be in disequilibrium. This condition results in a positive feedback process in which excess sediment creates depositional features which cause more erosion which generates still more excess sediment and on and on. Rosgen and others have described these processes, but the quantitative relationships have been difficult to demonstrate largely because of the difficulty in measuring bedload sediment transport rates in small storm‐flow dominated stream systems. Quantities of sediment eroded can be calculated with a monitoring program which surveys bank profiles of eroding banks, but the missing ingredient has been quantitative data on transport rates of bedload sediment.

Select this Article		Development of Process‐Based Assessment Protocols in the Kishwaukee River Basin, Illinois: Watershed Integration of Hydrology, Geomorphology and Ecology John S. Schwartz, Edwin E. Herricks, A. Catherine Marcinkevage, Jian‐Ping Suen, Bruce L. Rhoads, Praveen Kumar, and Stephen S. Russell ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)438 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In recent years use of GIS natural resources databases has greatly improved watershed analysis techniques. These techniques have provided excellent inventories of watershed attributes supporting management strategies, but it has become evident that analysis techniques must include process‐based assessments from the inventory data. Assessments must also include an integration of hydrology, geomorphology, and ecology observations. Protocols for process‐based assessments are critical to achieving restoration project sustainability. The Kishwaukee River watershed, a 1,340‐mi² watershed located in northern Illinois was chosen to test development of process‐based protocols for watershed analysis. Stream power was found to be an important environmental driver correlating with physical habitat maintenance, recovery from stream channelization, and instream pollutant assimilation. The greatest impacts to ecological integrity appeared to be from rapid urbanization and agricultural practices in low‐gradient subwatersheds. It was found that protocol development of ecological metrics could be greatly improved if bio‐inventory data were consistently collected with respect to methodology and sample locations/times.

Select this Article		The Practical Application of Fluvial Geomorphology in Watershed Master Planning Munsell McPhillips, Ben Higgins, Robert Prager, Andrea Stone, and Brian Kwiatkowski ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)439 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a method for using fluvial geomorphology to guide watershed planning. The method is illustrated in Stevens Creek watershed, a basin along Lincoln, Nebraska's eastern edge now undergoing a rapid conversion from agricultural to urban land use. The City wishes to accommodate the impending development while protecting Stevens Creek as a natural resource and avoiding stormwater damage so common in urban areas. The use of fluvial geomorphology to evaluate the current physical stability of watersheds is an increasingly common practice. The science is less commonly used to infer the likely stream response to a range of future conditions associated with urban development. The greatest utility is achieved by integrating geomorphic, ecologic, geologic, hydraulic and hydrologic information to shape the master plan. Throughout the US, watershed plans range from natural resource inventories, infrastructure‐based land use plans to stormwater plans based on hydraulic models and accompanied by capital improvement projects. While each type of plan includes valid information, all are limited by the absence of data regarding the effect of land use changes on systemic channel stability. The unintended consequences include soaring stormwater management costs, loss of the natural resources and property loss. Incorporation of fluvial geomorphology into watershed planning enables rational decision making on stream setback ordinances, priority setting for stream intervention, identifying areas of high erosion hazard, and the value of low impact development practices.

Select this Article		Urban Hydrology Characteristics and their Influence on Urban Stream Restoration Technology M. L. Clar, P.E. and J. Gracie ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)440 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Many if not most streams in existing urban areas have been significantly impaired and thus are often perceived as candidate sites for urban stream restoration efforts. The technology currently in use for stream restoration, especially natural channel design is based on hydrologic regime conditions for rural watersheds, and for the most part this technology has not been adapted or verified for use in urban watersheds. Urban land use practices, particularly the creation of impervious surfaces can result in significant alterations to the hydrologic regime of urban watersheds and the receiving streams. These hydrologic regime alterations can exert significant influence on a number of fundamental concepts currently is use in natural channel restoration technology. Some of these concepts include; the bankfull discharge concept; regional curves of bankfull discharge and channel geometry; the Rosgen and Schumm stream classification systems; and the use of reference stream characteristics. This paper examines the influence of urban hydrology on these commonly used concepts and offers some preliminary guidance.

Select this Article		St. Louis Metro East Region Sediment and Geomorphic Study T. D. Straub ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)441 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Judy's Branch, a small basin (8.64 mi²) near Glen Carbon, Illinois, is selected as a pilot site to determine sediment yield and channel erosion of streams draining the bluffs of the American Bottoms in the Metro East area of Illinois. This paper presents results of an on‐going sediment and geomorphic study in Judy's Branch. The average suspended‐sediment yield from two upland sub‐basins (drainage area equals 0.23 and 0.40 miles² is 851 tons/mile²‐year between October 2000 and September 2003. The suspended‐sediment yield at the Route 157 gage (2,188 tons/mile² ‐year) (near outlet of the watershed; drainage area = 8.33 miles²) is approximately 1300 tons/mile²‐year greater than the average of the upland gages for the same time period. This result is unexpected in that generally the suspended‐sediment yield decreases as the watershed area increases because of sediment being stored in the channel and floodplain. The difference indicates a possible increase in yield from a source, such as streambank erosion, and supports the theory that land‐use changes increase streamflows that may result in higher rates of streambank erosion. The best estimate of sediment yield from streambank erosion is 1,009 tons/mile²‐year at Route 157. This value is obtained utilizing both bank‐rod data and resurveyed cross‐section data.

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WATER DISTRIBUTION SYSTEMS ANALYSIS

Select this Article		Operational Optimization of WDS Based on Multiobjective Genetic Algorithms and Operational Extraction Rules Using Data Mining Ivaltemir B. Carrijo, Luisa Fernanda R. Reis, Godfrey A. Walters, and Dragan Savic ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)442 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The growth of cities, associated with the lack of investment in basic infrastructure, has rendered water supply systems complex and difficult to operate. The efficient operation of such systems is a fundamental tool for extending the system's service life as much as possible, thus ensuring a reliable service to the consumers while keeping electrical energy and maintenance costs at acceptable levels. Efficient operation requires knowledge of the system, supported by tools such as models for hydraulic simulation, optimization, and definition of rules, provides the operator with proper conditions for the rational operation of the system's units. This paper aims to develop a computational model for the optimal operational control of macro water distribution systems using the EPANET2 hydraulic simulator, SPEA (Strength Pareto Evolutionary Algorithm) multiobjective genetic algorithms, and data mining to extract operational rules for the system. The studies were conducted on the macro system of the city of Goiânia, Brazil, chosen due to its complex characteristics, showing that solutions for its satisfactory operation can be quickly produced as a substitute to the personal judgment of the operator.

Select this Article		Self‐Adaptive Penalty Cost for Optimal Design of Water Distribution Systems Z. Y. Wu and T. Walski ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)443 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Optimal design and rehabilitation of a water distribution system is a constrained non‐linear optimization problem. A penalty function is often employed to transform a constrained optimization problem into a non‐constrained optimization problem in the framework of genetic algorithm search. A penalty factor is often used for defining the penalty function and calculating penalty cost for the solutions with constraint violations. Effective penalty factors vary from one optimization model to another. In this paper, a self‐adaptive penalty approach is introduced to simultaneously optimize both the penalty factor and the design. It relieves modelers from tuning the penalty factor/cost and facilitating practical optimization modeling for water distribution design.

Select this Article		Water Quality Implication of Using SCADA Data Directly within the Unified Hydraulic Solver F. J.‐C. Bouchart, M. He, and J. W. Davidson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)444 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Unified Hydraulic Solver (UHS) provides solutions to water distribution networks that are consistent with available Supervisor Control and Data Acquisition (SCADA) data. Measured flows and pressures are incorporated directly within the hydraulic network formulation. In contrast, conventional hydraulic solvers (e.g., EPANET) allow for only nodal demands and heads at reservoirs as inputs to their formulations. In real time modeling, the UHS produces improved hydraulic solutions that are closer to the actual conditions within the water distribution system. The current paper demonstrates that these improved hydraulic solutions subsequently yield better estimates of water quality parameters, such as chlorine concentrations.

Select this Article		Pilot Study of Greater Boston Drinking Water Quality Changes — Impacts of Ozonation and Distribution System Irvine W. Wei, Xin (Cindy) Huang, and Windsor Sung, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)445 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Massachusetts Water Resources Authority (MWRA) provides drinking water to 2.2 million people in Greater Boston. To ensure good water quality without filtration, the MWRA is about to replace chlorination with ozonation as the primary disinfection at the new Walnut Hill Water Treatment Plant, scheduled to be on‐line in 2005. The objective of this study was to understand the influence of ozonation on monochloramine decay and pH change in the MWRA system. The influence of the distribution system, which consists of old cast‐iron pipes, on the ozonated water was also investigated. A pilot plant, including a simulated distribution system with actual 100 year old corroded cast iron pipes, was set up near Wachusett reservoir to simulate the new treatment scheme. Stagnant samples were taken and compared with circulated samples to study the influence of the distribution system. The stagnant samples represented the best scenario, i.e. a very clean distribution system. The circulated samples simulated the worst, where in the real world may be dead ends far from the main. This study suggested that corrosion and biological activity inside the pipe were the major causes of water quality change in circulated samples. Actual water quality is expected to be somewhere in between the best and the worst scenarios.

Select this Article		General Regression Neural Networks for Modeling Disinfection Residual in Water Distribution Systems R. J. May, H. R. Maier, G. C. Dandy, and J. B. Nixon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)446 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water treatment plant (WTP) operators set disinfectant levels such that a balance is maintained between achieving adequate disinfection and minimising the undesirable effects of excessive disinfection residuals. Control systems for the optimal maintenance of disinfection residuals are based upon a model that attempts to describe the non‐linear dynamics of the water distribution system (WDS). A system identification approach, based on artificial neural networks (ANNs), offers an expedient methodology for the development of control‐oriented models. An advantage of ANNs is their ability to describe non‐linear systems with greater accuracy than linear empirical models that are traditionally used for system identification. In this paper, the parallel development of a general regression neural network (GRNN) model and an autoregressive model with exogenous inputs (ARX) is described for the Myponga WDS in South Australia. The results indicate the superiority of the GRNN model and support further investigation of WDS control systems that incorporate ANN identification models.

Select this Article		A New Versatile Technique for Hydraulic Models of Water Distribution Networks J. W. Davidson and F. J.‐C. Bouchart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)447 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents the Unified Hydraulic Solver, a single algorithm that can perform a variety of forms of hydraulic analysis on water distribution networks from conventional modeling to state estimation. The mathematical basis for the algorithm is explained in the context of five different techniques, conventional exactly‐determined problems, unconventional exactly‐determined problems, the Proportional Demand Method, the Target Demand Method and state estimation. A small example network is presented and each of the five techniques is demonstrated on the network.

Select this Article		Application of Optimization Methods to Calibration of Water Distribution Systems Bart G. van Bloemen Waanders ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)448 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Inversion algorithms are used to calibrate demands of water distribution systems by minimizing the difference between observed and predicted chemical concentration values. A systematic approach was implemented using a combination of numerical experimentation, parameter studies, global methods, and local gradient based algorithms. An appropriate finite difference step was determined to calculate objective function gradients for the inversion problem. The inversion of demands for a model calibration using field tracer observations resulted in a 26% reduction of the objective function. As a result of the inversion problem, an error in the numerical model was identified that could be responsible for some of the remaining mismatch. Future work includes improving the numerical model and developing more accurate history of concentration observations. Optimization under uncertainty strategies are proposed to help characterize variability in the model calibration problem.

Select this Article		Tracer Tests for Network Model Calibration D. L. Boccelli, F. Shang, J. G. Uber, A. Orcevic, D. Moll, S. Hooper, M. Maslia, J. Sautner, B. Blount, and F. Cardinali ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)449 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Typical distribution system network model calibration approaches adjust roughness coefficient values to match observed pressure and supervisory control and data acquisition (SCADA) equipment data assuming known user demands. Pressure data alone, however, do not contain information related to hydraulic residence time and travel path, making such data less useful for calibrating both the hydraulic and water quality portions of a distribution system network model. This study presents a network‐wide dual‐tracer field‐scale study, coupled with water quality monitoring, to collect a rich data set for evaluating hydraulic and water quality issues. The raw data illustrate the path‐specific information that can be generated beyond the use of pressure measurements alone. The observed data are used to minimally calibrate a distribution system model that is provided by the utility, and illustrates the use of tracer data for providing confidence with respect to the predictive ability of the network model. Additional considerations related to automated calibration techniques and the potential benefits of more accurate distribution system models are discussed.

Select this Article		Pipeline Size Optimization Steve Ainsworth, M.S., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)450 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water Transmission Pipeline size selection is often based on “rule‐of‐thumb” maximum velocity or maximum headloss constraints that are policy for a particular water agency. This method which is based on facility wear and surge concerns works well when the power costs for pumping are not high enough to also be required components in the pipeline size selection. With today's emphasis on reducing power consumption, the old “rule‐of‐thumb” common practice figures may not always be accurate enough. This paper outlines a straight‐forward method to include pumping costs in evaluating pipe sizes. Pipeline size optimization is the process of including both installation cost and the time value of energy cost for a particular diameter of pipe, and selection of the pipe diameter that has the lowest life cycle costs if the diameter also works hydraulically in the system. The energy requirement is computed from the energy required to overcome the friction losses caused by velocity and is a function of the flow rate and pipe diameter. The total energy cost over the life span of the pipe is expressed in present worth dollars. The total life cycle cost for a particular pipe diameter is equal to the sum of the present worth of the total energy cost and installation cost.

Select this Article		Comparison of Two Approaches for the Least Cost Design of Water Distribution Systems under Uncertain Demands Artem V. Babayan, Zoran S. Kapelan, Dragan A. Savic, and Godfrey A. Walters ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)451 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Due to inherent variability in instantaneous water consumption levels, values of demand at nodes in a water distribution model remain one of the most uncertain quantities in the network design process. In this paper two stochastic least‐cost design approaches which incorporate uncertainty in demand into problem formulation are presented and compared. In the first approach, the original stochastic formulation is replaced with a deterministic one, using standard deviation as the natural measure of the variability of the pressure in the nodes caused by uncertainty in demands. This approach allows the use of effective numerical methods to quantify the related uncertainties. The second approach solves the stochastic optimisation problem directly by linking a modified standard GA with stochastic hydraulic model. In this approach, a small number of Latin Hypercube samples is used when evaluating each solution's fitness. Both methodologies were applied to the New York tunnels case study. The optimal network rehabilitation solutions were identified for different levels of robustness. The robustnesses of the optimal network configurations determined were also compared with known optimal solutions for deterministic formulation, using full Monte Carlo simulation. Finally, advantages and disadvantages of the two analysed approaches are identified.

Select this Article		Optimal Scheduling of Pumping and Chlorine Injections under Unsteady Hydraulics Avi Ostfeld, M.ASCE and Elad Salomons ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)452 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the methodology and application of a genetic algorithm (GA) scheme, tailor‐made to EPANET for simultaneously optimizing the scheduling of existing pumping and booster disinfection units, as well as the design of new disinfection booster chlorination stations, under unsteady hydraulics. The objective is to minimize the total cost of operating the pumping units and the chlorine booster's operation and design for a selected operational time horizon, while delivering the consumers' required water quantities, at acceptable pressures and chlorine residual concentrations. The decision variables, for each of the time steps that encompass the total operational time horizon, include: the scheduling of the pumping units, settings of the water distribution system control valves, and the mass injection rates at each of the booster chlorination stations. The constraints are domain heads and chlorine concentrations at the consumer nodes, maximum injection rates at the chlorine injection stations, maximum allowable amounts of water withdraws at the sources, and returning at the end of the operational time horizon to a prescribed total volume in the tanks. The model is demonstrated through an example application.

Select this Article		A Metamodeling Approach to Water Distribution System Optimization D. R. Broad, G. C. Dandy, and H. R. Maier ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)453 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Genetic Algorithms (GAs) have been shown to apply well to optimizing the design and operations of water distribution systems (WDS). The objective has usually been to minimize cost, subject to hydraulic constraints, such as satisfying minimum pressure. More recently, water quality considerations have also been incorporated into WDS optimization by requiring a minimum chlorine disinfection level throughout the system. Due to uncertainty in WDS data, such as the demands and pipe roughness factors, reliability has also been incorporated into optimization. However, to date, there have not been any attempts to simultaneously incorporate reliability and water quality into the optimization of WDS. This is due to the fact that the computational time requirements are extremely large. Considerable time savings can be achieved by using a technique known as metamodeling. A metamodel is a surrogate, or substitute for a complex simulation model. The type of metamodel used in this research was an Artificial Neural Network (ANN). ANNs are capable of approximating the non‐linear functions that govern flow and chlorine decay in a WDS. A metamodeling approach has been applied here to optimize a water distribution design problem that includes water quality. The ANNs were calibrated so as to provide a good approximation to the simulation model. Large time savings occurred from training the ANNs to approximate chlorine concentrations (over 600 times faster than the simulation model) and reliability (expected to be 10⁷ times faster). The solutions obtained by linking an ANN to a GA were shown to be similar to those when using a simulation model linked to a GA, with the added benefit that the solutions were found much faster.

Select this Article		A Stochastic Early Warning Detection System Model for Drinking Water Distribution Systems Security Avi Ostfeld, M.ASCE and Elad Salomons ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)454 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Following the events of 9/11 2001 in the US, a deliberate contamination intrusion into a drinking water distribution system is considered a major terrorist threat. Chemical or biological injected agents can spread throughout the system causing sickness or death among the people consuming the water. A methodology is developed and demonstrated in this paper to enhance water distribution system security, linking EPANET and a genetic algorithm in an overall framework for optimally allocating monitoring stations, aimed at capturing deliberate external terrorist hazards intrusions through water distribution system nodes: sources, tanks, treatment plant intakes, consumers — subject to extended period unsteady hydraulics and water quality conditions, for a given defending level of service to public — a maximum volume of polluted water exposure at a concentration higher than a minimum hazard level. The methodology developed and demonstrated extends previous work of the authors on this topic by treating the demands and the injected pollution rates quantities as random variables, and by explicitly taking into account a delay between the pollution event and the monitoring equipment response capability.

Select this Article		A General Integer‐Programming‐Based Framework for Sensor Placement in Municipal Water Networks Jonathan Berry, William E. Hart, Cynthia A. Phillips, and James Uber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)455 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract We present a new integer‐programming formulation for sensor placement in municipal water systems. Berry, Fleischer, Hart, and Phillips introduced a time‐independent sensor‐placement model. To avoid explicit references to time, this model assumed consumers are protected only if every path from a contaminant introduction site is guarded by a sensor. The model also assumed flow within the pipes was reasonably swift, if not quantified, so that flow patterns will not shift before a contaminant is detected. We decouple contaminant transportation from sensor placement decisions and explicitly consider time. We use discrete‐event simulation, using velocity information derived from EPANET, to calculate contamination timing in the network for each of an enumerable number of attack scenarios. We use an integer program to select a set of sensor locations that minimizes the expected amount of contaminant delivered to consumers across all these attack scenarios. Initial computational experience on two real networks shows that the discrete‐event simulator is very fast and the resulting integer programs are tractable for moderate‐sized attack sets.

Select this Article		A Multiple‐Objective Analysis of Sensor Placement Optimization in Water Networks Jean‐Paul Watson, Harvey J. Greenberg, and William E. Hart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)456 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Terrorism concerns have recently led to increased interest in the potential use of sensors to detect malicious attacks on municipal water systems. A key deployment issue is identifying where the sensors should be placed in order to maximize the level of protection. Researchers have proposed several algorithms for constructing such sensor placements, each optimizing with respect to a different design objective. The use of disparate objectives raises several questions, in particular (1) What is the relationship between optimal placements obtained under different design objectives? and (2) Is there any risk in focusing on speci?c design objectives? To answer these questions, we develop mixed‐integer linear programming models for the sensor placement problem over a range of design objectives. Using two real‐world water systems, we show that optimal solutions with respect to one design objective are typically highly sub‐optimal with respect to other design objectives. The implication is that robust algorithms for the sensor placement problem must carefully and simultaneously consider multiple, disparate design objectives.

Select this Article		Addressing Modeling Uncertainties in Sensor Placement for Community Water Systems Robert D. Carr, Harvey J. Greenberg, William E. Hart, and Cynthia A. Phillips ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)457 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract We present a model for optimizing the placement of sensors in municipal water networks to detect contaminants that are maliciously or accidentally injected. An optimal sensor configuration is desirable to minimize the cost and maximize the information provided by the sensors. We formulate sensor placement problems as mixed‐integer programs, for which the objective coefficients are not known with certainty. We present three robust optimization models that differ in how the coefficients in the objective vary. Under one set of assumptions there exists a sensor placement that is optimal for all realizations of the coefficients. Under other assumptions, we apply sorting to solve each worst‐case realization. The most difficult case is where the objective parameters are bilinear, for which we propose a branch‐and‐bound method.

Select this Article		Stochastic Analysis of Water Distribution Systems H. A. Kretzmann and J. E. van Zyl ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)458 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A software package called Mocasim II has been developed to perform stochastic analysis on water supply systems. This allows the relationship between the reliability of the supply system and the capacity of its storage tank(s) to be quantified using Monte Carlo analysis. In a Monte Carlo analysis the factors which influence the reliability of the system such as water demand, fires, and pipe failures are simulated stochastically over a long period of time. A reliability/capacity relationship is quantified by analyzing the failure behavior of different storage tank sizes. A previous version of Mocasim used a simple mass balance model for calculating the flows in simple, linear distribution networks. Mocasim II extends the functionality of its predecessor by enabling the probabilistic modeling of more complex water distribution models. This was achieved by integrating the stochastic modelling technique into the Epanet hydraulic analysis software package. Mocasim II was designed using an object‐oriented model which has various advantages such as ease of testing, upgrading and maintaining as well as minimum repetitive code and a logical structure. Additional capabilities of Mocasim II include the determination of probability distributions for network properties such as flow rate, pressure and water quality at any node in the network. This will assist in estimating the levels of service of a water supply system.

Select this Article		Stochastic Residential Water Demand Characterization V. H. Alcocer Y., V. G. Tzatchkov, S. G. Buchberger, F. I. Arreguin, and D. Feliciano ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)459 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper reports some results of an ongoing project conducted in the City of Culiacan, Mexico, to obtain stochastic residential water demand parameters and use them in a large scale hydraulic and water quality network model. Instrument packs were installed on the service lines of 4 homes, and the water demand was monitored with a one‐second time resolution for 101 days. The frequency (utilization factor), intensity, and duration statistics of the registered demand pulses were obtained. A Poisson Rectangular Pulse (PRP) model was used to generate water demands for individual homes and for other portions of the distribution network. Three levels of detail in the distribution network were analyzed: all‐pipe model, all‐pipe model excluding dead‐end mains; and sources, tanks and global water demand model.

Select this Article		Modeling Solute Transport in Distribution Networks with Variable Demand and Time Step Sizes Sean A. McKenna, Chad Peyton, Lane Yarrington, Steven G. Buchberger, and Roger Bilisoly ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)460 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The effect of variable demands at short time scales on the transport of a solute through a water distribution network has not previously been studied. We simulate flow and transport in a small water distribution network using EPANET to explore the effect of variable demand on solute transport across a range of hydraulic time step scales from 1 minute to 2 hours. We show that variable demands at short time scales can have the following effects: smoothing of a pulse of tracer injected into a distribution network and increasing the variability of both the transport pathway and transport timing through the network. Variable demands are simulated for these different time step sizes using a previously developed Poisson rectangular pulse (PRP) demand generator that considers demand at a node to be a combination of exponentially distributed arrival times with log‐normally distributed intensities and durations. Solute is introduced at a tank and at three different network nodes and concentrations are modeled through the system using the Lagrangian transport scheme within EPANET. The transport equations within EPANET assume perfect mixing of the solute within a parcel of water and therefore physical dispersion cannot occur. However, variation in demands along the solute transport path contribute to both removal and distortion of the injected pulse. The model performance measures examined are the distribution of the Reynolds number, the variation in the center of mass of the solute across time, and the transport path and timing of the solute through the network. Variation in all three performance measures is greatest at the shortest time step sizes. As the scale of the time step increases, the variability in these performance measures decreases. The largest time steps produce results that are inconsistent with the results produced by the smaller time steps.

Select this Article		Effect of Time Scale on PRP Random Flows in Pipe Network Zhiwei Li and Steven G. Buchberger ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)461 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper examines the effect of time scale on variability, regimes and stagnation probability of random flows generated by the Poisson Rectangular Pulse (PRP) water demand model. Two methods are presented to estimate the variability and probability of regimes for homogeneous PRP flows at any time scale. The results show that variance of PRP random flows is inversely proportional to time scale (time step); the effect of time scale on flow regime depends on the mean of random flows; the probability of stagnation for PRP flows decreases exponentially with the increase of time scale. The results provide insight on how to identify appropriate time scales for water quality modeling in peripheries of distribution networks.

Select this Article		The Simultaneous Multi‐Objective Optimization of Anytown Pipe Rehabilitation, Tank Sizing, Tank Siting and Pump Operation Schedules R. Farmani, D. A. Savic, and G. A. Walters ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)462 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper investigates the application of multi‐objective evolutionary algorithms in the identification of the pay‐off characteristic between cost and reliability of Anytown water distribution system. 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. Optimization tends to reduce costs by reducing the diameter of or completely eliminating pipes thus leaving the system with insufficient capacity to respond to pipe breaks or demands that exceed design values without failing to achieve required performance levels. Resilience index is considered as second objective to increase the hydraulic reliability and the availability of water during pipe failures. The goal attainment method is used to direct the optimization towards the desired solutions. Results are presented for the pay‐off characteristics between cost and reliability, for 24 hour design and five loading conditions. The probability that the nodal demand is met at or over the prescribed minimum pressure for all solutions on the pay‐off curve is considered under random nodal demands.

Select this Article		Demand Modeling and Statistical Probability in a Regional Water Facilities Master Plan Jennifer Nakayama, A.M.ASCE, B.S. ENVE, M.S. CE and Richard C. Pyle, P.E., M.ASCE, B.S. CE, M.B.A. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)463 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The San Diego County Water Authority (Water Authority), San Diego County's regional water wholesaler, was formed in 1944 for the purpose of importing water to the region. At the time of its formation, the Water Authority supplemented local supplies with imported water. Today, the Water Authority provides 75 to 95 percent of the water used in its service area. The Water Authority has continually added facilities over its history to meet growing water demands. Following a period of large population growth in the 1980s, the Water Authority completed the Water Distribution Study in 1987. This report described the additional facilities that would be needed to meet regional demands until the year 2010. These recommendations became the basis of the Water Authority's Capital Improvement Program (CIP). The most significant addition to the CIP occurred in 1998 with the inclusion of the Emergency Storage Project (ESP), the purpose of which is to protect the region against the impacts of a catastrophic interruption of imported water supply, a severe drought, or other similar events that would dramatically decrease the amount of water supplied to the region.

Select this Article		A GIS Based Pipeline Route Selection Process Jason Luettinger, P.E. and Thayne Clark, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)464 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Metropolitan Water District of Salt Lake & Sandy (MWDSLS) recently began the design process for the Point of the Mountain Aqueduct (POMA). This 60‐inch diameter pipeline must convey finished water from the proposed Point of the Mountain Water Treatment Plant (POMWTP) approximately 12 miles to the Little Cottonwood Treatment Plant (LCWTP) and to a number of delivery points in between. The selection of the pipeline route was a key part of the overall project conceptual design. The POMA alignment will be constructed through highly developed areas of two major cities. The majority of this area consists of residential and commercial development, with very little available open space remaining for new pipeline right‐of‐way (ROW). The aqueduct will cross railroads, canals, creeks, and parks that are located between the two plants. It will be located within existing narrow rights‐of‐way including canals and residential streets. In addition, the pipeline may encounter sensitive seismic areas that include liquefaction zones along the valley floor and the Wasatch Fault zone near the foot of the mountains. An alignment for the POMA was established that would minimize impacts to neighboring communities, and that would be cost effective to construct in terms of length and difficulty of construction within the established ROW.

Select this Article		Performance Assessment of Water Distribution Networks Based on Quality Parameters Using Head Driven Simulation Method A. Dolatkhahi and M. Tabesh ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)465 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract In this research, a new approach for hydraulic performance assessment of water distribution networks considering quality parameters and press dependency of demand is presented. The proposed method is base on two steps. In the first step hydraulic of the system is analyzed by head driven simulation method (HDSM), For quality analysis the discrete volume element method (DVEM) is used witch incorporated in the hydraulic simulation engine. In the second step quality performance of water networks are evaluated. Based on the standard cods some penalty curves are defined for evaluation of quality parameters produced by the hydraulic simulation engine. Then, the quality performance index of network elements (nodes or pipes) is generalized for the entire system, using some mathematical functions. To evaluate the developed software, a few test networks are used and the results are compared with EPANET outputs, witch its hydraulic engine is based on demand driven simulation method (DDSM). The result of the proposed method illustrates some improvements in comparison with demand driven simulation based results.

Select this Article		Isolating Subsystems in a Water Distribution Network H. Jun, G. V. Loganathan, A. K. Deb, W. Grayman, J. Snyder, J. Hammell, and S. McCammon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)466 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Recent concerns regarding protecting, identifying, isolating, redundant routing and dewatering of subsystems of water distribution networks have led to the realization of the importance of valves in these systems. Valves serve two purposes namely, flow and pressure control and isolating subsystems due to breakage or contaminant containment. In this paper, valves are considered from the point of view of subsystem isolation.

Select this Article		Physical Probabilistic Models to Estimate Failure Rates in PVC Pipe Networks P. Davis, M. Moglia, S. Gould, and S. Burn ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)467 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper uses physical probabilistic modelling to estimate failure probabilities in buried PVC pipelines. The limited reported failure data in newer pipe materials (such as PVC and Polyethylene) has identified a need for alternative approaches to support existing statistical techniques to estimate failure probabilities. Fracture mechanics theory is used to develop a physical failure model for buried PVC pipes. To account for random variation in larger pipe networks, the factors that govern pipe failure are represented by stochastic variables. Monte Carlo simulation is then used to estimate the probability of brittle fracture failure over time for a pipe with a defect in its wall. These physical probabilistic failure models are compared against actual pipe failure data recorded by a Melbourne water authority.

Select this Article		Delineation of Contamination Spread Potential over Extended Time Modeling F. J.‐C. Bouchart, P. W. Jowitt, and S. J. Cavill ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)468 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The delineation of contamination spread is a critical task in responding to an emergency involving water quality. Conventional modeling techniques can be used to trace the movement of a contaminant through a distribution network. However, this trace is valid only for the demand load specified in the extended time simulation. If the actual demand loads across the network change as a result of, for example, a public health notice, then the actual spread of the contaminant may be significantly different — making containment much more difficult. The connectivity matrix approach overcomes this problem of limited real‐time knowledge of demands, yielding a delineation of the spread potential consistent with the cautionary principle of starting with the worst possible scenario. One remaining challenge to the use of the connectivity modelis that the matrix is defined for a single point in time, whereas contamination spread is time dependent. The current paper presents two alternative methods to address changes in the connectivity over time. The first of these methods relies on the convolution of connectivity matrices over time, while the second approach relies on a decay mechanism to transition from one connectivity matrix to the next.

Select this Article		Time Dependent Contamination Source Determination: A Network Subdomain Approach for Very Large Water Networks Carl D. Laird, Lorenz T. Biegler, Bart G. van Bloemen Waanders, and Roscoe A. Bartlett ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)469 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents an approach for identifying contamination sources in very large municipal water networks. The vulnerability of municipal drinking water networks to intentional and accidental contaminations requires investigation of alternative protection measures. If a contamination occurs, it is important to identify both the time and location of the contamination source. A dynamic optimization approach for estimating contamination sources was previously presented. The approach developed an origin tracking algorithm that reformulated the partial differential pipe expressions, removing the need to discretize in space. Although this allowed for efficient solutions using a direct simultaneous technique for a network of approximately 500 nodes, the approach does not scale indefinitely to very large networks. This current paper handles very large water networks by performing the optimization on a smaller, subdomain of the entire network. This approach considers the hydraulics and sensor measurements for the entire network, but formulates the dynamic optimization problem for a subset of the network nodes. A subdomain approach is introduced, forming a geographic window around the first sensor to detect contaminant. Numerical results indicate that this subdomain approach is effective at identifying contamination sources. Furthermore, since the required subdomain size is not dependent on the size of the entire network, this approach scales to very large municipal water networks.

Select this Article		Threat Assessment of Water Supply Systems Using Markov Latent Effects Modeling Vincent C. Tidwell, J. Arlin Cooper, Consuelo J. Silva, and Sariah Jurado ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)470 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Recent amendments to the Safe Drinking Water Act emphasize efforts toward safeguarding the nation's water supplies against attack and contamination. The Terrorist and Other Intentional Actions Section establishes requirements for each community water system serving more than 3300 people to “conduct an assessment of the vulnerability of its system to a terrorist attack or other intentional acts intended to substantially disrupt the ability of the system to provide a safe and reliable supply of drinking water.” Integral to evaluating system vulnerability is the threat assessment, which is the process by which the credibility of a threat is quantified. Unfortunately, full probabilistic assessment is generally not feasible, as there is insufficient experience and/or data to quantify the associated probabilities. For this reason we propose an alternative approach predicated on Markov Latent Effects (MLE) modeling that provides a framework for quantifying imprecise subjective metrics through possibilistic or fuzzy mathematics and then aggregates this information to rank the credibility of alternative threat scenarios. Here we introduce the MLE approach and demonstrate how it might be applied to water supply system threat assessment.

Select this Article		Simulating Accidental Exposures to Deliberate Intrusions Kenneth A. Nilsson, Steven G. Buchberger, and Robert M. Clark ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)471 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Water distribution systems deliver water to consumers in a very efficient manner, but are inherently vulnerable to a full range of terrorist threats including physical attacks, cyber disruption and biological contamination. In this paper, Monte Carlo experiments are used to simulate a deliberate bio‐chemical assault on a municipal drinking water distribution system. The Monte Carlo approach links a well‐known network solver (EPANET) with a new water demand generator (PRPsym). Following a deterministic “base‐case” template for average hourly consumption, the demand generator simulates stochastic water use at all nodes in the pipe network for a 55‐hour period. The bio‐chemical attack is modeled as a 6‐hour injection that delivers 3600 g of contaminant at one of the nodes on a main trunk line. Migration of the contaminant plume is tracked through the pipe network and the cumulative mass dose is computed at two nodes — one on a looping link and the other on a dead‐end branch. The bio‐chemical attack and mass dose analysis are repeated for over 100 independent trials to produce a distribution of consumer dose exposures at both demand nodes. Results reveal that minor variability in network demands can lead to a broad range of contaminant doses delivered to the nodes. This suggests that Monte Carlo techniques linking demand generation with network simulation can be a useful tool for revealing the potential severity of a bio‐chemical assault and for developing strategies to minimize drinking water system vulnerability.

Select this Article		Future Trends Towards an Integrated Algorithm for Hydraulic Network Simulation in Steady, Transient and Oscillatory Flow E. Koelle ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)472 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The complete knowledge of the behavior of a hydraulic network comprises steady (and extended period) simulation, transient analysis and oscillatory investigation in order to determine the “personality” of the network, that is to say, its natural modes of vibration, the knowledge of which is necessary to avoid acoustic resonance. All these analyses may be done on a common basis, that is to say, with the same topology and calculation procedure in the time domain using the MOC — Method of Characteristics, as shown in this paper. The Method of Characteristics (MOC), which includes friction, inertia and elasticity of liquid/pipe, provides engineers with the necessary and most efficient tool to understand the influence of such effects in a network subjected to slow and fast maneuvers. The boundary conditions, which are related to the dynamic behavior of the non‐pipe elements, such as valves, pumps and protective devices subjected to cavitation and choked flow phenomena, must be carefully investigated to distinguish their operational effectiveness and guarantee the safe operation of the network. The purpose of this paper is to present and discuss such ideas in order to increase the presently existing steady‐state software potentialities.

Select this Article		Effect of Skeletonization on Transient Analysis Results Thomas M. Walski, Jean‐Luc Daviau, and Samuel Coran ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)473 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract It is widely recognized that transient pressure waves tend to attenuate more quickly in water distribution systems, as opposed to long pipelines, partly because of the effects of loops and branches and partly due to the impacts of customer water use. In this study, a model of a realistic water distribution system is skeletonized with an automated program to determine the impacts on the calculated transient pressure extremes.

Select this Article		Field Tests for Leakage, Air Pocket, and Discrete Blockage Detection Using Inverse Transient Analysis in Water Distribution Pipes Mark Stephens, Martin Lambert, Angus Simpson, John Vítkovský, and John Nixon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)474 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract It has been suggested over the last ten years that the application of fluid transients could potentially lead to improved leak detection and calibration of pipe roughness in pipe networks using a technique referred to as Inverse Transient Analysis (ITA). During the intervening time, a large amount of numerical and laboratory research has not addressed the complexities involved in the application of ITA to the field. This paper presents preliminary results for an implementation of ITA in a field environment. Leaks, air pockets and discrete blockages with defined characteristics are introduced into two single branch field pipelines in a “controlled manner” and their effects on an induced transient are measured. ITA is used, in some instances, to detect the introduced phenomena. To the best knowledge of the authors, it is the first time transient analysis has been applied to the detection of air pockets and blockages. Findings are made regarding the sensitivity of each type of pipeline phenomena to detection and, where possible, ITA is also used to locate and size leaks and air pockets.

Select this Article		Detection and Location of a Partial Blockage in Pipeline Systems Using Damping of Fluid Transients Xiao-Jian Wang, Martin F Lambert, and Angus R Simpson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)475 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract A new blockage detection method using blockage-induced transient damping is developed based on a linear analytical solution for the transients in a pipeline with a blockage. The linear analysis indicates that pipe friction damping on a pipe transient is exactly exponential, while the blockage damping is exponential for each of the individual harmonic components. For each individual component, the blockage-induced damping depends on the blockage magnitude and position and is independent of measurement location and the transient event. The proposed blockage detection method is successful in detecting, locating and quantifying a pipe blockage based on the laboratory experiments.

Select this Article		Understanding the Hydraulics of Water Distribution System Leaks Thomas Walski, William Bezts, Emanuel T. Posluszny, Mark Weir, and Brian Whitman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)476 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Pressure control can be an effective means of leakage reduction in some situations. This paper first presents the results of an experimental study to determine the appropriate equation to describe leak flow. In general, the orifice equation is most appropriate for situations when the dimensionless OS number (defined in the paper) is large, which is the case for most systems. This means that flow emitters are a good way to model leaks. The second part of the paper describes the application of computer modeling to a realistic system and shows how a model can be used to evaluate pressure settings and estimate the leak reduction and possible pressure problems. In general, pressure reduction is most attractive when leakage and pressure are both relatively high, flow is controlled by a PRV or variable speed pump, and the terrain is relatively flat. Time of day control or control valves of tanks may be needed to make pressure control work.

Select this Article		Identifying Dependencies in Input Data in Hydraulic Network Problems J. W. Davidson and F. J.‐C. Bouchart ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)477 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Unified Hydraulic Solver (UHS) is a new technique that is better suited to real‐time modeling based on a combination of SCADA data and demand estimates than conventional solvers or state estimation methods. However, some of the UHS methods are vulnerable to problems created by dependencies that may exist in the SCADA component of the input data. The paper describes and demonstrates a preprocessor that is capable of locating and removing the most common form of dependency, direct dependency. A second form of input dependency, implicit dependency, is explained and methods to avoid singularity associated with implicit dependencies are described.

Select this Article		Implications of Over‐ and Under‐Determined Networks in State Estimation F. J.‐C. Bouchart, O. Adaramola, and J. W. Davidson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)478 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The Unified Hydraulic Solver (UHS) provides an effective formulation to solve water distribution systems that are under‐determined in terms of known parameters, and over‐determined in terms of the sum of the known and estimated parameters. This UHS formulation allows for the full spectrum of analyses from the conventional hydraulic solution to state estimation, where model results can be reconciled with SCADA measurements. Furthermore, an effective SCADA data validation technique can be devised using the UHS formulation. This application of the UHS suggests however the need to understand the impact of the locations of the SCADA measurement points on the ability to detect demand deviations. Using an example network taken from the literature, this paper demonstrates that deviations occurring within an over‐determined section of the network are more accurately computed than if the same deviations are located outside the over‐determined section.

Select this Article		Optimal Simultaneous Design and Operation of Multi‐Quality Water Distribution Systems under Unsteady Hydraulics Avi Ostfeld, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)479 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This paper extends previous work on management of water distribution systems by explicitly addressing the design and operation problem of quantity, pressure, and quality simultaneously under unsteady hydraulics — a problem that has not been solved yet. The methodology is a straight forward genetic algorithm formulation linked to EPANET with the decision variables been the pipe diameters, the unit pumps heads and maximum power, the tanks storages, and the treatment plants operations and constructions. An illustrative example is explored showing high potential to real world design problems involving quantity, pressure, and quality explicit considerations.

Select this Article		Economic Viability of Gravity‐Sustained Pipe‐Flow Systems Prabhata K. Swamee ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)480 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract As the gravity‐sustained pipe‐flow systems do not require power input, these systems are preferred in comparison to pumping systems. Furthermore, in the absence of moving parts, gravity‐sustained systems have greater reliability. For a gently sloping topography the gravitational system involves large pipe diameters. In comparison to a pumping system such a gravitational system may be uneconomical. A review of literature indicated that there is no guideline available for adoption of a gravity‐system for such a terrain. In this paper optimal cost functions of various pipe‐flow configurations have been investigated to find the conditions under which gravity‐sustained systems are economic.

Select this Article		Greedy Heuristic Methods for Locating Water Quality Sensors in Distribution Systems James Uber, Robert Janke, Regan Murray, and Philip Meyer ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)481 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract Monitoring and surveillance systems for drinking water distribution networks are intended to provide real time warning of drinking water contamination events and mitigate their public health consequences. Drinking water distribution networks often serve large populations over vast areas. There exist a large number of access points where contaminants could be introduced, and these are spread throughout the service area. Transport of contaminants from these access points to consumers would occur through a multitude of pathways, and be dominated by water flows that change magnitude and direction in response to frequent changes in water use and system operation.

Select this Article		The Threat Ensemble Vulnerability Assessment (TEVA) Program for Drinking Water Distribution System Security Regan Murray, Robert Janke, and Jim Uber ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)482 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract The increased risk of terrorism to our nation's critical infrastructure has focused national attention on the vulnerability of drinking water systems to the intentional introduction of chemical, biological, or radiological contaminants. EPA is developing the Threat Ensemble Vulnerability Assessment (TEVA) Program to analyze the vulnerabilities of drinking water distribution systems, measure public health and economic impacts, and design and evaluate threat mitigation and response strategies. TEVA is a probabilistic framework for assessing the vulnerability of a water utility to a large range of contamination attacks. Monte Carlo simulations generate ensembles of scenarios, and statistics are analyzed to explore the feasibility of scenarios, identify vulnerable areas of the water distribution network, and analyze the sensitivity of the model to various parameters. Preliminary results are available that illustrate applications of TEVA to three drinking water distribution systems of different sizes.

Select this Article		Characterizing the Pipe Wall Demand for Free Chlorine in Metallic Pipes Robert M. Clark, M.ASCE and Roy C. Haught ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)483 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract As water moves through a distribution system water quality deterioration can take place in the bulk phase or through interactions at the pipe wall. These transformations can be physical, chemical or microbiological in nature. Perhaps one of the most serious aspects of water quality deterioration is the loss of disinfectant residual that may take place in the network and 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. Recent studies have suggested that with older unlined metal pipes chlorine wall demand varies significantly with flow rate. In order to systematically study the loss of free chlorine in corroded metal pipes subject to changes in velocity, the authors conducted a controlled study in specially constructed pipe loops located at EPA's Test and Evaluation (T&E) Facility in Cincinnati, Ohio. The distribution system simulator (DSS) is designed to maintain continuous flow conditions through unlined ductile iron pipe. It consists of two sets of three individual 6‐inch diameter cast iron pipe loops (a total of six loops). The pipes in the loops have been in service for a number of years and there is considerable corrosion and tubercle buildup on the inside surface. For purposes of this study, one loop was selected for the set of experiments discussed in this paper and modified so that it could be operated over a wide range of flow rates.

Select this Article		Simulation of Chlorine Decay in Drinking Water Distribution Systems Alper Ucak and Osman N. Ozdemir ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)484 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract This work presents a model that evaluates the decay of the chlorine concentration in drinking water distribution networks. The model may use either Lagrangian based time driven or event driven methods depending on the hydraulic characteristic of the pipes. The decay of the chlorine within a pipe is evaluated by using a single equation that incorporates the bulk decay, radial diffusion and subsequent pipe‐wall reaction of chlorine. The equation is embedded into a computer program called DYNAQ, which can perform dynamic water quality analysis in drinking water distribution networks. The developed model is also applied to an existing water distribution network and the comparison of the model results with a currently available model is presented.

Select this Article		Corrosion Control and Chloramination: Discolored Water and Nitrification Windsor Sung, Ph.D, P.E., DEE, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)485 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract MWRA's untreated source water is corrosive. An interim corrosion control facility became operational in June 1996 to adjust the pH and alkalinity levels for better corrosion control. There is evidence pointing to the formation of a protective iron carbonate scale on pipe walls, reducing the amount of iron releases that could lead to discolored water episodes. MWRA uses chloramination to maintain a residual in the distribution system. Monitoring results indicate that the reduced iron levels in bulk water may have also contributed to reducing the degree of nitrification within the distribution system.

Select this Article		Extensions to EPANET for Fate and Transport of Multiple Interacting Chemical or Biological Components James Uber, Feng Shang, and Lewis Rossman ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)486 Online Publication Date: 7 October 2004 Full Text: \| Download PDF
	+ -	Show Abstract EPANET, like most other distribution system water quality models, is limited to track the dynamics of a single component as it is transported throughout the network of pipes and storage tanks. Such models can not consider interactions between bulk components that are transported with the water velocity, and surface components that are fixed to the pipe wall. These are serious limitations, since all water quality indices result from reactions between chemical or biological components that may be suspended or dissolved in bulk water, or attached or adsorbed to the pipe wall. A single specie model implies that distribution system water quality can not be described mathematically in a way that mimics the underlying mechanisms. It is a restrictive framework that precludes experimentation with alternative process models, and has limited research and development of network water quality models for the last 15 years. Aside from significant software and algorithmic improvements, today's distribution system water quality models have progressed little beyond those first reported in 1988.

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ADDITIONAL PAPERS

Select this Article		Application of Sap Flow Measurement in Real Time Soil Moisture Management S. Takeuchi and T. Yano ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40737(2004)487 Full Text: \| Download PDF
	+ -	Show Abstract An automatic irrigation system based on sap flow measurement was developed and examined on sweet pepper cultivation with drip irrigation. Two types of real time soil moisture control system were constructed and compared with general automatic irrigation system based on soil moisture monitoring determined by soil moisture sensor. The priority of an irrigation technique based on actual sap flow rate employed in this study was confirmed because the total information of plant canopy and structure under ground related to water consumption is included.