Since the early 1970’s, the most common approach to stormwater management in the United States has been to drain runoff from a developed site as quickly and efficiently as possible, and then detain this runoff and release it to a downstream receiving channel at a controlled rate. Without question, the most popular means by which this management approach occurs is through the use of dry detention basins. In 2007, The Congressional Research Service reported that up to 50 percent of water pollution problems in the United States are attributed to urban stormwater runoff (CRS, 2007). Pollutants washed off of roads, parking lots, and other surfaces include nutrients, hydrocarbons, pesticides, heavy metals, bacteria, as well as larger debris. Stormwater runoff entering a conventional dry detention basin typically does not experience a hydraulic residence time of adequate duration to provide significant gravitational settling of suspended pollutants.