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Sligo Creek Subwatershed

Image of stream and trees around Northwest Branch Watershed.The subwatershed of Sligo Creek, a tributary to the Northwest Branch of the Anacostia River, is one of the County's most urbanized subwatersheds. It is also the location of extensive efforts to restore an urban stream system.

Sligo Creek is notable for the success being achieved in controlling urban stormwater runoff and reestablishing a viable biological community. Until recently, the only fish identified in Sligo Creek were blacknose dace, goldfish, and creek chub—species that are highly tolerant of polluted urban conditions. Many subwatershed residents can remember the signs once posted throughout the subwatershed, particularly in the lower reaches, warning of polluted water conditions.


A Journey Through Sligo Creek

Many high-density commercial and residential areas are located in the Sligo Creek subwatershed, including the Wheaton Triangle area and part of the Wheaton Central Business District, large areas of Takoma Park, and much of downtown Silver Spring. These areas and surrounding residential neighborhoods developed rapidly during the 1950s and 1960s, before today's environmental standards for stream valley protection and stormwater management.

All that remains of Sligo Creek's natural stream network are mainstems of streams; most small streams have been paved over and piped into storm drains. The remaining stream system has been heavily armored with rock in many areas to reduce channel erosion. These alterations might improve bank stability, but they provide limited habitat value. Areas that have not been armored show bank instability and erosion problems due to uncontrolled storm flows.


DEP Restoration Efforts

Sligo Creek was the first Anacostia River subwatershed targeted for restoration efforts within the County. Since the early 1990's, these efforts have included new runoff controls, improvements to the sanitary sewers, and stream channel restoration. This has led to notable increases in stormwater management and improving in-stream habitat stability.

Efforts to control urban runoff in this subwatershed are limited by the small number of opportunities to do modifications and improvements. Large areas of the subwatershed still remain uncontrolled. To ensure lasting success in reestablishing a viable biological community, strong local stewardship of this subwatershed must become a central part of the daily activities of residents and businesses.


The Future of Sligo Creek

New runoff controls at the Wheaton Branch, University Boulevard, and Sligo Golf Course retrofit ponds, as well as improvements to the aged and leaking sanitary sewers, have brought positive changes to the streams. Since completion of the Wheaton Branch pond and associated stream channel restoration, DEP has reintroduced native fish from other similar Anacostia watersheds to allow the recovery of fish populations in Sligo Creek. Although downstream blockages still restrict fish movement, monitoring has shown the number of fish species in the Upper Sligo Creek mainstem has increased from 3 in 1988 to 16 species as of 2011. This is extremely encouraging.

Despite high levels of urbanization, the Sligo Creek stream valley park system has preserved trees and shrubs along the stream side that serve as high-quality habitat. Flow conditions and impaired habitat are being addressed through joint efforts by DEP, the Maryland-National Capital Park and Planning Commission, the Interstate Commission on the Potomac River Basin, and the Metropolitan Washington Council of Governments as part of the regional Anacostia Watershed Restoration Project.


How Can I Help Protect the Sligo Creek Watershed?

Image of Takoma Park Community Center.


Community groups and schools frequently contribute to efforts to clean up streams throughout the subwatershed. The Sligo Creek stream valley is heavily used by local residents and visitors, and it is one of the County's most important urban natural environments. The successes achieved thus far in Sligo Creek are setting the standard for other urban watersheds in and beyond the County, and they reflect Montgomery County's emerging national leadership in stream restoration.

Individuals interested in helping to protect the health of Sligo Creek can contact the Friends of Sligo Creek. This organization of local citizens prides itself in restoring the health, water quality, natural habitat and ecological well-being of the subwatershed through community awareness.