| Rock Creek | |
|---|---|
 Rock Creek inWashington, D.C., in 2015 | |
 | |
| Location | |
| Country | United States |
| States | Maryland,District of Columbia |
| Counties | MD:Montgomery DC:City of Washington |
| Physical characteristics | |
| Source | |
| • location | Laytonsville, Maryland |
| • coordinates | 39°11′56″N77°08′20″W / 39.1990012°N 77.1388044°W /39.1990012; -77.1388044 |
| • elevation | 560 feet (170 m) |
| Mouth | |
• location | Potomac River |
• coordinates | 38°53′58″N77°03′26″W / 38.899556°N 77.0572°W /38.899556; -77.0572 |
• elevation | 0 feet (0 m) |
| Length | 32.6 mi (52.5 km) |
| Basin size | 76.5 mi2 (198 km2) |
| Discharge | |
| • average | 63.7 cu ft/s (1.80 m3/s) |
| Basin features | |
| Landmarks | Rock Creek Park |
| Waterbodies | Lake Needwood |
Rock Creek is atributary of thePotomac River, in the United States, that empties into theAtlantic Ocean via theChesapeake Bay. The 32.6-mile (52.5 km)creek[1]drains about 76.5 square miles (198 km2). Its final quarter-mile (400 m) is affected bytides.[2]
The creek rises from aculvert under Dorsey Road at the north edge ofLaytonsville Golf Course inMontgomery County,Maryland. A dam forms a small lake near its source. After exiting the golf course, Rock Creek flows between residential developments until it meets Agricultural History Farm Park, where the Upper Rock Creek Trail starts. It flows underneath theIntercounty Connector, which crosses it on a large arch bridge visible from the trail.
It then flows intoLake Needwood at Rock Creek Regional Park in Maryland'sDerwood–Rockville area.[3] South of the Lake Needwood Dam, Rock Creek flows in a deep gorge and is paralleled by the main Rock Creek Trail, and is joined by the North Branch Rock Creek. It exits the gorge near theTwinbrook neighborhood ofRockville and theParklawn Memorial Cemetery.
AtNorth Kensington,Beach Drive begins to parallel the creek. The creek eventually crosses theCapital Beltway and later reaches theWashington, D.C., border.
The creek flows for about 9 miles (14 km) throughRock Creek Park in Washington, where it is fed by several small creeks (Piney Branch, Pinehurst Branch, Broad Branch, Soapstone Branch, and Luzon Branch) and numerousstorm sewers.
TheChesapeake and Ohio Canal joins Rock Creek inGeorgetown; the creek's mouth is the canal's eastern terminus. Just below this confluence, the Canal Company in 1831 completed amole, causeway, andwaste weir. This area, which the company dubbed "Rock Creek Basin",[4]: 251 silted up and was dredged several times for the Canal's use.[4]: 22 The creek (and the canal) empty into the Potomac River at theTidewater Lock near theWatergate complex.
The Maryland portion of thewatershed comprises the second-largest watershed in Montgomery County, about 60 sq mi (160 km2). About 21 percent of the creek's watershed is in Washington. Total land usage in the watershed is 896 acres (3.63 km2) of wetlands or water, 22,272 acres (90.13 km2) of residential and commercial areas, 15,488 acres (62.68 km2) of forest or grasslands, and 10,304 acres (41.70 km2) of agricultural areas. The creek has a fairly steep gradient, with rapid changes in elevation. The man-madeLake Needwood is located on the creek, north of Rockville.
The conditions of Rock Creek are monitored by theUnited States Geological Survey.[5]
In Maryland, most of the northern Rock Creek watershed has good to excellentwater quality, according to studies conducted by the Montgomery County government. In 2004, to preserve water quality in partially developed areas, the county imposed restrictions ondevelopment (i.e., designation of "Special Protection Areas") in parts of this sub-watershed.[6] The southern portion of the Maryland watershed is highlyurbanized. Most of this portion of the creek and its tributaries have poor water quality.[7] Between 1995 and 2023 the county completed 25stream restoration projects on the Rock Creek main stem or tributaries. As of 2025 the county is planning for 7 additional projects.[8][9]
The D.C. segment of Rock Creek also has poor water quality. In addition to typical urbanstormwaterpollution problems such asrunoff from streets and otherimpervious surfaces, the creek has highbacteria levels due to leaking sewer pipes andcombined sewer overflows (CSOs).[10][11] The D.C. government, which has a stormwater discharge permit from theUnited States Environmental Protection Agency, is improving its stormwater management to raise water quality in Rock Creek.[12] In 2009, theDistrict of Columbia Water and Sewer Authority began a planned two-year effort to replace portions of the combined sewer with separate storm sewers, and so eliminate CSO-related problems in the creek.[13]
As of 2021, the bacteria levels in the creek remained dangerously high due to the leaking sewer pipes, even during dry weather, and the public has been warned not to wade into the creek.[11]
In May 2025, Health and Human Services SecretaryRobert F. Kennedy Jr. swam in Rock Creek with his grandchildren.[14]
Fish species observed in Rock Creek and its tributaries includeeastern blacknose dace,bluntnose minnow,yellow bullhead,satinfin shiner,swallowtail shiner,longnose dace, andAmerican eel.[15]
In 2006, theNational Park Service finished a project to remove or bypass eight fish barriers in the creek by adding afish ladder to bypass the 1905Peirce Mill Dam, modifying historicfords, and removing abandonedsewage lines and fords. The effort was designed to restoreAmerican shad,river herring, and other migratory fish to the creek and their historic upriverspawning grounds.[16] An estimated two million fish migrate up the creek each year.[citation needed]
The D.C. government completed a restoration project on the Milkhouse Run and Bingham Run tributaries in 2013. As of 2014, ongoing restoration projects in the watershed include the Broad Branch and Klingle Run tributaries.[17][18]
(Listed in order from the mouth upstream)
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| National | |
| Other | |
