From Wikipedia, the free encyclopedia

Rock Creek is a free-flowing tributary of the Potomac River, which empties into the Atlantic Ocean via the Chesapeake Bay. The creek is approximately 33 miles (53.1 km) long, with a drainage area of about 76.5 mi² (198 km²). The last quarter mile (402 meters) of the creek is affected by tidal activity.^[1]

The creek rises from a spring near Laytonsville in Montgomery County, Maryland, and joins with the Potomac near Georgetown and the Watergate in Washington, D.C. Beginning in the Derwood / Rockville, Maryland area, the creek flows through Rock Creek Regional Park southward to the Washington, D.C. boundary. About 9 miles (14.5 km) of the creek flow though Rock Creek Park in Washington, D.C., where it is fed by eight small creeks — including Piney Branch, Pinehurst Branch, Broad Branch, Soapstone Branch, and Luzon Branch — and numerous storm sewers.

About 21 percent of the creek's watershed is in Washington, D.C. Total land usage in the watershed is 896 acres (3.6 km²) of wetlands or water, 22,272 acres (90 km²) of residential and commercial areas, 15,488 acres (63 km²) of forest or grasslands, and 10,304 acres (42 km²) of agricultural areas.

The Maryland portion of the watershed comprises the second largest watershed in Montgomery County, about 60 mi². The southern portion of the watershed is highly urbanized. The majority of this portion of the creek and its tributaries have poor water quality, according to a study conducted by the county government.^[2] The county is managing several stream restoration projects throughout the watershed.^[3]

The creek has a fairly steep gradient with rapid changes in elevation. The man-made Lake Needwood is located on the creek, north of Rockville.

In December 2003, the National Park Service announced plans to remove or bypass eight fish barriers in the creek, including adding a fish ladder to bypass the historic 1905 Peirce Mill Dam, modifying historic fords, and removing abandoned sewage lines and fords. The effort is designed to restore American shad, river herring, and other migratory fish to the creek and their historic upriver spawning grounds.

In order from the mouth upstream

In DC:

• Dumbarton Oaks
• Normanstone Creek
• Klingle Valley Creek
• Piney Branch
• Melvin Hazen Valley Branch
• Broad Branch
• Luzon Branch
• Pinehurst Branch
• Fenwick Branch

In Maryland:

• Donnybrook Tributary
• Coquelin Run
• Capitol View Tributary
• Kensington Heights Branch
• Stoney Creek
• Alta Vista Tributary, formerly Bethesda Run
• Luxmanor Branch
• Stoneybrook Tributary
• Josephs Branch
• Turkey Branch
• Sycamore Creek
• Croydon Park Tributary
• Southlawn Branch
• North Branch (Lake Bernard Frank)
• Lake Needwood (in-line on Rock Creek)
• Crabbs Branch
• Mill Creek
• Pope Farm Branch
• Airpark Road Branch

• List of District of Columbia rivers
• List of Maryland rivers
• Rock Creek and Potomac Parkway
• Rock Creek Park
• Tidewater Lock

• Friends of Rock Creek's Environment
• Countywide Stream Protection Strategy: Rock Creek Watershed Montgomery County Department of Environmental Protection