This DDOT project aims to retrofit areas in the District’s public right-of-way to collect and manage stormwater runoff using green infrastructure (GI) techniques, and to meet the requirements of the Municipal Separate Storm Sewer System MS4 Permit issued to the District of Columbia by the United States Environmental Protection Agency (EPA). This permit sets water quality requirements for each of DC’s waterways – the Anacostia and Potomac Rivers, and Rock Creek – related to discharges from DC’s storm sewer system.

Four sub-watersheds draining to the Anacostia River have been identified for improvements, as part of DOEE's Clean Water Construction Grant Program, that provides funding to this project: Hickey Run, Nash Run, Fort Dupont, and Pope Branch. These sub-watershed areas collect a significant amount of rainwater (runoff) from the streets (impervious surfaces). During storm events, the runoff from these impervious areas wash away dirt, oil, trash, and debris from the roads into gutters and storm drains. This rainwater enters the storm sewers, which discharge the dirty rainwater and trash to the Anacostia River. In addition to water quality issues in the Anacostia River and its tributaries, high volumes and increased flows can cause significant erosion problems at the outfalls.

The Green Infrastructure improvements will help reduce the quantity of rainwater runoff and improve the quality of the water which ultimately discharges into the Anacostia River. The GI improvements are made up of several small neighborhood practices which will be located at multiple locations within the streets, alleys, and sidewalk areas throughout the four sub-watersheds. These small GI sites will combine to contribute in a major way to keeping the Anacostia River clean and reduce flood impacts.

The four sub-watersheds have a total area of approximately 2,200 acres. The paved areas within the streets, alleys, and sidewalks in these locations account for approximately 12% (275 acres) of the entire four areas. DDOT has completed  a comprehensive planning analysis process for identifying potential locations within these areas to incorporate green infrastructure best management practices (BMPs).