The Cabin John Creek Watershed is located in southern Montgomery County, Maryland, just northwest of Washington, DC. The headwaters of Cabin John Creek originate in the city of Rockville. The creek flows south about 10 miles, passing under Interstate 270, through Cabin John Regional Park under the Capital Beltway (I-495) and the historic Cabin John Bridge to its confluence with the Potomac River near the towns of Cabin John and Glen Echo. The major tributaries of the Creek are Bogley Branch, Booze Creek, Buck Branch, Congressional Branch, Ken Branch, Old Farm Branch, Snakeden Branch and Thomas Branch (also called Beltway Branch).

Larger map of watershed
Very detailed map of watershed
Photo tour of watershed

Zip code boundaries do not align with watershed boundaries but the Cabin John Creek Watershed overlaps:

  • 20854 Potomac
  • 20852 North Bethesda
  • 20850 Rockville
  • 20818 Cabin John
  • 20812 Glen Echo
  • 20817 Bethesda (and a small portion of 20814 Bethesda)
Cabin John Creek Watershed Map

The watershed is in Maryland's Piedmont Plateau geologic province, with an area of about 16,022 acres (25 square miles), and has been significantly affected by high-density residential and commercial development. There are parks, trails and natural areas throughout the watershed. In addition to the Regional Park, there are wooded park lands and buffer areas along several miles of the creek mainstem and tributaries. At least 30 species of fish have been identified in the Cabin John Creek mainstem and tributaries.

Cabin John Creek Mainstem Photo
Cabin John Creek mainstem north of MacArthur Boulevard

Urban development in the watershed has a major impact on the health of Cabin John Creek and its tributaries. Stormwater runoff carries pollutants that wash off of roads, parking lots, sidewalks and rooftops. These impervious surfaces concentrate and accelerate the velocity of runoff, which results in stream erosion. A government study has documented these problems.

Washington Beltway Photo
Washington Beltway (I-495) at I-270 junction. Thomas Branch, a tributary of Cabin John Creek, parallels the left edge of the roadway.

Presently there are very few measures in place around the watershed to protect the streams from erosion and pollutants. FOCJC is working with Montgomery County's Department of Environmental Protection and other organizations on projects to clean and restore the Cabin John stream system.

Cabin John Creek Erosion Photo
Streambank erosion on Cabin John mainstem created by excessive stormwater runoff