The Northwest Branch watershed is the largest sub-watershed of the Anacostia River with the majority of the watershed located in Montgomery County and Prince George's County Maryland. It stretches over 19 miles from the headwaters in Sandy Spring, MD to Bladensburg, MD where it joins with the Northeast Branch to form the Anacostia River. The watershed in Montgomery County includes portions of the communities of Norwood, Bel Pre Manor, Colesville, Layhill, Glenmont, Wheaton, Hillandale, White Oak, Silver Spring, Kemp Mill, Four Corners and Takoma Park. The Prince George's County portion of the watershed includes Langley Park, University Park, Chillum, Hyattsville, Avondale and Brentwood. The total watershed area, including a small portion of land in NE Washington, D.C., is 53.5 sq. mi. (139 sq. km.), with a resident population of about 254,000.

We, the Neighbors of the Northwest Branch, are committed to protecting, promoting and restoring the water quality, natural habitat, and ecological well-being of the Northwest Branch watershed. We intend to:
  1. foster environmental awareness and education,
  2. take action by engaging in various water quality, habitat restoration, land preservation and trash reduction efforts, and
  3. enlist broad-based public participation in and support of the foregoing goals and activities.