The District’s Green Alley Projects are designed to reduce the quantity and improve the quality of stormwater within the city’s right of way (ROW). Although alleys constitute a significant portion of impervious surface, most do not have stormwater controls, such as water quality catch basins or grate inlets. To mitigate this, Green Alleys use sustainable design and Low Impact Development (LID) techniques that reduce the amount of stormwater and pollutants entering the sewer system by increasing water infiltration and treatment on site.
Typical cross section of a green alley with permeable pavement:
The District Department of Transportation (DDOT) constructs Green Alleys by removing gravel, impervious concrete, or asphalt surfaces and replacing them with a permeable surface such as pervious concrete, porous asphalt or permeable pavers in areas where the storm sewer and sanitary sewers are separated. Permeable pavement has pores or openings that allow water to pass through the surface, then percolate down through a gravel layer and into the soil below.
Completed Green Alley Projects:
For a complete list of the District's Green Alleys, please click here.
Locations:
- Alley between Klingle Pl., Cathedral Ave., 39th St., and Massachusetts Ave., NW
- Alley between Klingle Rd NW, 29th St NW, Cortland Pl NW and Cathedral Ave NW
- Alley between Woodley Rd NW, Klingle Rd NW and 34 St NW
- Alley between 22nd St NW, R St NW and Massachusetts Ave NW
- Alley between Taylor St., Shepherd St., 18th Pl., and 19th St., NE
- Alley between Hamlin St NE, 27th St NE and Vista St NE
- Alley between 22nd St., 24th St., Rand Pl., and R St., NE
- Alley between Alabama Ave SE, Knox Pl SE, Irving St SE and 24th Pl SE
- Ashley Terrace Alley between Highland Place, Ordway St., and 30th St., NW
- Alley between 34th Pl., Broad Branch Rd., Rittenhouse St., 33rd St., and Quesada St., NW
- 5 Alleys between Iowa Ave., Allison St., and Webster St., NW;
- 5 Alleys between 32nd St., Broad Branch Rd., Rittenhouse St and Patterson St., NW
- Alley between 54th St, Blaine St., 55th St., & Clay St., NE
- Alley between 56th St, Eads St., & 57th St., NE
- Alley between 58th St, Dix St, 59th St., & Clay St., NE
- Alley between 49th Pl, Nannie Helen Burroughs Ave., 50th St, & Hayes St., NE
- Alley between Q St., Q Pl. and 45th St., NW
- Alley between Jenifer St NW, 41 St NW, Ingomar St NW and Reno Rd NW
- Alley between 9th St NW, Georgia Ave NW and Dahlia St NW
- Alley between 14th St NW, Leegate Rd NW and Roxanna Rd NW
- Alley between Erie St SE, Denver St SE, 34th St SE and Branch Ave SE
Upcoming Green Alley Projects:
- Alley between Rittenhouse St NW, Utah Ave NW, 28th St NW and Nebraska Ave NW
Please contact DDOT Stormwater with any questions or comments about this program.