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Upper Patuxent Subwatershed

The Upper Patuxent River forms the boundary between Montgomery County and Howard County and includes all the land draining to the Patuxent River above the Triadelphia Reservoir. The subwatershed on both sides of the river includes large forested areas along with agricultural cropland, pasture, and large-lot rural residential development.

For many, it is hard to believe that this small, high-quality, clear-flowing cold-water stream is the same Patuxent River that enters the Chesapeake Bay at Solomons, Maryland. The Patuxent River originates in Frederick County, above the intersection of Route 27 and Windsor Forest Rd. In the stream above Route 94 is a naturally reproducing brown trout population.

To protect this resource, the Upper Patuxent has been designated a special trout catch and release stream by the Maryland Department of Natural Resources. The brown trout population is part of a generally high-quality cold-water fish community, although sculpins, which are usually found in these communities, are absent.

Image of Upper Patuxent River Watershed

The Upper Patuxent and its tributaries are included in the Patuxent Primary Management Area (PMA). The PMA is a stream buffer and transition zone within which land uses are closely managed to reduce nonpoint source runoff and nutrient loads, and to improve and protect stream conditions. The ultimate goal for the primary management areas along the Patuxent River and its tributaries is to maintain low-density, low-intensity land uses within 1/4 mile of the mainstem and within 1/8 mile of tributaries, and to actively establish a minimum 50-foot forested buffer strip along all streams.

Extensive forested areas in the Patuxent River State Park surround the Upper Patuxent. The mature floodplain and upland forests support a rich wildlife community and offer some of the best forest interior breeding bird habitat remaining in the County. The streams in this subwatershed are among the best remaining in the County, and many serve as reference streams for the County's stream monitoring program.

There has been some concern about accelerated rates of sedimentation, elevated nutrient levels, and depressed dissolved oxygen concentrations being observed at the Triadelphia and Rocky Gorge reservoirs. These two reservoirs supply over 11 billion gallons of drinking water to suburban Montgomery County and Prince George's County and, to a limited extent, Howard County.


How Can I Help the Upper Patuxent Subwatershed?

Individuals interested in the health of the Upper Patuxent can contact the Patuxent Riverkeeper or the Patuxent River Commission to learn how they can help protect this resource.