Bioretention

Bioretention Installations in Prince George's County, MD

Greenbelt, MD

These facilities were installed in 1992 in a shopping mall parking lot in Greenbelt, MD.  The bioretention areas are set up along the length of the parking areas and receive runoff from the parking area through curb cuts.  The bioretention area is depressed, with a porous soil.  A perforated PVC underdrain extends the length of each facility.  Water pools in the facility, infiltrating to the underdrain, which leads to a traditional storm drain.  A manhole grate is set as an overflow for water exceeded the design ponding depth.  This manhole leads directly to the storm drain, bypassing any bioretention treatment.  

A mixture of grasses, shrubs, and small trees are planted in the facility.  The grasses are mowed and the facilities cleaned annually.

The top photo at the right shows a facility after the annual clean up.  The lower photo shows the facility in full growth in June during one of our studies.  The photo below shows a newer cell at the Plaza.

Landover, MD

Two Landover facilities were constructed in 1998.  They were constructed in two existing parking lot islands with conventional inlets.  A T-shaped perforated underdrain was added to collect infiltrated runoff and to convey the water to the existing inlet.  A curb cut was added to direct runoff from the parking lot into the facility.  The media is a mixture of construction sand, topsoil, and leaf mulch.  The facility surface is dominated by a mulch layer, with selected plants and shrubs added.

Hyattsville, MD

Several facilities were constructed in 2001 as part of a school renovation.  Most have a perforated underdrain along the length.  Curb cuts were placed to direct runoff into the facilities.  

Largo, MD

A large facility was constructed in Spring 2002 at a condominium complex.  Parking lot runoff is directed into the facility at both ends, one through a curb cut and the other through an inlet and outfall.  The surface is predominantly mulch

Upper Marlboro, MD

These three facility were constructed at a business park in Spring 2002. 

College Park, MD

Two paired cells are were constructed on the University of Maryland Campus in Spring 2003.  These cells are being monitored and are being used for research and education on bioretention.  

Washington DC

Four different bioretention areas are shown from throughout the city.  Two are in residential areas, receiving runoff from parking, roof and lawn areas.  One facility is near a recreation center and receives runoff from tennis courts, walkways, and grassed areas.  The other facility is in a parking area at the Washington Navy Yard.  

College Park, MD

Several bioretention facilities were installed on the University of Maryland Campus in Spring 2004 as part of a demonstration project for LID in the Anacostia River watershed.  One cell will be monitored for water quality improvement to nearby Campus Creek.  

   ^  Same parking area 2 years earlier before bioretention installation.