Proceedings of the 2004 World Water and Environmental Resources Congress, held in Salt Lake City, Utah, June 27-July 1, 2004. Sponsored by the Environmental and Water Resources Institute of ASCE. This collection contains 493 papers that critically examine past goals and practices and provide fresh concepts and models to help engineers build on past accomplishments while providing insight on how to avoid or mitigate past water resources and environmental mistakes. Almost every significant topic important to water resources and environmental engineering professionals is covered. Additionally, papers from six specialty symposia sharply focus on specific, concentrated areas of interest: arid lands; best management practices (BMP) technology; groundwater issues; international water resources issues; river restoration and urban streams; and the 6th Annual Symposium on Water Distribution Systems Analysis. The depth and variety of subjects contained in this collection make it a vital resource for professionals, practitioners, researchers and anyone else involved with water and environmental resources.