Dry Extended Detention Basin

Operation and Maintenance Agreement

A dry extended detention basin temporarily stores incoming stormwater, trapping suspended pollutants, and reducing the peak discharge from the site.   As the name of this Best Management Practice implies, these basins are typically dry between storm events. A low-flow outlet slowly releases water retained over a period of days. This BMP can be applied in residential, industrial, and commercial developments where sufficient space is available. The primary purpose of dry extended detention basins is to attenuate and delay stormwater runoff peaks. They are appropriate where water quality issues are secondary to managing peak runoff, since the overall pollutant removal efficiency of dry extended detention basins is low.  The dry extended detention basin system is defined as the dry detention basin, outlet structure, pretreatment including forebays and the vegetated filter if one is provided.  

O&M_Dry Detention Operation and Maintenance Agreement,_Rev 3. [pdf/80kb/4p]