Detention vs Retention Basin

The Difference Between a Detention and a Retention Basin

A detention basin/pond temporarily stores stormwater runoff. The basin is designed to manage stormwater runoff by storing it and releasing it gradually until completed drained.

Unlike a detention basin, a retention basin or pond is designed to permanently hold water. Retention basins are commonly used when the groundwater is near the surface of the ground. A retention basin will not have an outlet structure. The water collected by a retention basin will either infiltrate into the ground or evaporate.

The advantage of a retention basin over a detention basin is the higher removal of pollutants. Retention basins can also serve as an aesthetic or recreational amenity, as well as a habitat for some wildlife. They will become their own ecosystem.

Who is Responsible for Detention/Retention Basin Maintenance?

While we are all responsible for protecting the quality of our water, you, as the property owner, homeowners association or business is most likely responsible for maintaining stormwater management facilities on your property. Most recently, Stormwater Management Maintenance Agreements have been required for all stormwater management plans and those documents have been recorded at the Lancaster County Recorder of Deeds Office.