TABLE OF CONTENTS In the 1980s stormwater detention or retention basin became one of the most popular and widely used best management practices (BMPs) for quality enhancement of stormwater. In the United States, Congress mandated local governments to research ways to reduce the impact of separate storm sewer systems and CSO discharges on all receiving water bodies. In Europe, most communities use combined sewer systems, with some separate storm sewer systems in newer suburban communities. The CSO problem has received considerable attention in Europe.
Both quality and quantity of stormwater should be considered when protecting water quality and reducing property damage and traffic delay by urban flooding. Stormwater detention is an important measure for both quality and quantity control. Temporarily storing or detaining stormwater is a very effective method. Infiltration practices are the most effective in removing stormwater pollutants (Livingston 1995). When stormwater is retained long enough, its quality will be enhanced.
Several publications (US EPA 1974c, 1983a, 1992 Northeastern Illinois Planning Commission WEF and ASCE, 1992, Wanielista and Yousef 1993, Urbonas and Stahre 1993, Pitt and Voorhees 1995, Shoemaker et al. 1995, Terstriep and Lee 1995, Truong and Phua 1995) describe stormwater management plans and design guidelines for control (e.g. detention or storage facilities) in detail. Storage facilities include local disposal, inlet control at source (rooftops, parking lots, commercial or industrial yards, and other surfaces), on-site detention (swales or ditches, dry basins or ponds, wet ponds, concrete basins, underground pipe packages or clusters), in-line detention (concrete basins,...
