Stormwater detention vault

A stormwater detention vault is an underground structure designed to manage excess stormwater runoff on a developed site, often in an urban setting. This type of best management practice may be selected when there is insufficient space on the site to infiltrate the runoff or build a surface facility such as a detention basin or retention basin. [United States Department of Transportation. Federal Highway Administration. Washington, DC. [http://www.fhwa.dot.gov/environment/ultraurb/3fs6.htm "Stormwater Best Management Practices in an Ultra-Urban Setting: Selection and Monitoring."] Fact Sheet – Detention Tanks and Vaults. May 2002.]

Detention vaults manage stormwater quantity; they help prevent flooding and can reduce downstream erosion. They do not provide treatment to improve water quality. [Atlanta Regional Commission. Atlanta, GA. [http://www.georgiastormwater.com/vol2/3-4-3.pdf "Georgia Stormwater Management Manual."] Section 3.4.3: "Underground Detention." August 2001.]

Design and installation

Underground stormwater detention allows for high volume storage of runoff in a small footprint area. The storage vessels can be made from a variety of materials, including corrugated metal pipe, aluminum, steel, plastic, fiberglass, pre-cast or poured-in-place concrete. [City of Duluth, Minnesota. [http://www.lakesuperiorstreams.org/stormwater/toolkit/underground.html "Tools for Stormwater Management: Underground Storage."] Accessed April 15, 2008.]

The vault is typically buried under a parking lot or other open land on the site. In the latter case this underground vault may be preferable to a surface detention pond if other uses are intended for the land (e.g. a pedestrian plaza or park). In other situations a vault is used because installing a pond might pose other problems, such as attracting unwanted waterfowl or other animals. In some sites a vault may be installed in the basement of a building, such as a parking garage. [United States Environmental Protection Agency. Washington, DC. [http://www.epa.gov/owmitnet/mtb/runoff.pdf "Storm Water Technology Fact Sheet: On-Site Underground Retention/Detention."] September 2001. Document No. EPA-832-F-01-005.]

ee also

*Best management practice for water pollution
*Detention basin
*Retention basin

References