Subaru Bioretention Project

The South River Federation received a $35,000 grant from the Chesapeake Bay Trust for a stormwater Best Management Practice (BMP) series at the Annapolis Subaru dealership. This project was designed to alleviate stormwater flows across two commercial properties before the runoff enters the top of our large-scale “Church Creek Headwaters Project,” which begins just 500 feet downslope of Annapolis Subaru.

The stormwater retrofit plan reduces the approximate 199,923 gallons of runoff which reach the Subaru site in a 1 inch rain event. The BMP series was designed to capture and infiltrate runoff starting at the most upstream property line at the Medical Center. BMP #1 is an infiltration swale which addresses off-site runoff and slows down and infiltratse the volume which goes into the existing pipe. Midway down, a large, sunken swale was converted to into a bioretention cell for BMP #2 where ponding and infiltration of the runoff can occur. The existing pipe daylights at the lowest point of the Medical Center property (and beginning of the Subaru property) where BMP #3 is located. The proposed BMPs are crucial to the reduction of volume which carries significant sediment loads to the headwaters.

Volunteers from the community, Bywater Boys and Girls Club, and the Department of Corrections Public Safety Works crews help to plant and mulch the project site.