10 Things You Should Know About The Nation's River

The Potomac River and its watershed are an incredible resource for our nation's capital and the surrounding areas. Learn all about it and how The Nature Conservancy is working to protect it.

1. Potomac Gorge

Kathryn E. Arion/The Nature Conservancy

Protecting a Regional Hot-Spot of Biological Diversity:

The Potomac Gorge is one of the most biologically rich areas in the eastern United States. Located at the Fall Zone, the transition from the rocky bedrock of the Piedmont to the sandy deposits of the Coastal Plain, the Potomac Gorge is a meeting place for northern and southern species, as well as Appalachian and Coastal Plain species. It contains a diversity of habitats, including scoured bedrock terraces, mature upland woods, rich floodplain forests, streams and wetlands.

Over millennia, the Potomac has eroded down into a deep valley. After big storms or snowmelts, the river's floodwaters rage through the narrow Gorge, creating a dynamic, highly disturbed environment where rare species and natural communities have adapted to intense flood scouring. The Nature Conservancy has helped protect land in the Potomac Gorge for more than 50 years and continues to work in partnership with the National Park Service to help conserve and restore this natural area.

2. Washington Aqueduct Dam above Great Falls

Adam Fagen / Via Flickr: afagen

Do You Know Where Your Water Comes From?

The Potomac River is the primary source of drinking water for more than four million people in the Washington, DC metropolitan region, home to 75% of the watershed's population. This is the water that Congress uses to brew their coffee, and that the President uses to wash his hands. Since the early 1960's, the three largest DC regional water utilities have worked with the Interstate Commission on the Potomac River Basin to ensure a reliable and continuous supply of water to the region, even in times of drought.

3. Anacostia River

Chesapeake Bay Program / Via Flickr: 29388462@N06

Slowing Down Stormwater:

Development in the Potomac watershed is creating more man-made, hardened surfaces that increase the volume and speed of water running into nearby streams, eroding stream banks and carrying pollutants that harm water quality and the river's health.

The use of "Low Impact Development" stormwater catching technologies like green roofs, rain gardens and rain barrels are environmentally friendly ways to reduce runoff of pollutants and sediments from the built landscape to the river and the Chesapeake Bay.

4. Goose Creek Watershed

Mary Porter

Facing a Growing Regional Population:

The Potomac watershed's population now exceeds six million people; it has grown by an average 74,000 people each year over the last 30 years. Driven by sprawling development from the Washington, DC metropolitan region, the Potomac watershed is expected to lose 180,000 acres of forestland while gaining 346,000 acres of urban land over the next 20 years.

Despite those tremendous growth pressures, there are smaller watersheds within the Potomac basin that remain surprisingly intact, such as Goose Creek, a Potomac River tributary in Virginia's fast-growing Loudoun and Fauquier counties. In these watersheds, targeted land protection and restoration work can secure lasting results.

(Date: ICPRB estimated and ICPRB calculations of USGS data)

5. Nanjemoy Creek

Alan Eckert Photography

Forests Helping Fishes:

With an approximately 80% forested watershed, Nanjemoy Creek, a tributary of the Potomac in Maryland's Coastal Plain, provided historical spawning grounds for ecologically and economically important migratory fish species like shad, herring, perch and striped bass. These species divide their lifetime between rivers and streams, the Chesapeake Bay and the Atlantic Ocean. Protecting all portions of their habitat is critical for the survival of these wide-ranging species.

The Nature Conservancy has protected nearly 5,000 acres at Nanjemoy, helping to limit the amount of sediments and nutrients that get washed into the creek and adjacent Potomac River.

6. Blue Plains Wastewater Treatment Plant

John Sonderman / Via Flickr: johnsonderman

Treating the Waste of Two Million People:

Do you know where the water goes when you flush the toilet? If you're one of the 2.2 million people living in Washington, DC or its four surrounding counties, it likely goes to the Blue Plains Advanced Wastewater Treatment Plant, the largest advanced wastewater treatment facility in the world. At this 150-acre facility in Southwest Washington, DC, wastewater undergoes three levels of treatment before it is returned to the Potomac River on its path to the Chesapeake Bay. Water quality improvements from wastewater treatment plants has helped populations of submerged aquatic vegetation, an important aquatic habitat, recover in the tidal Potomac downstream of Washington, DC.

7. Sideling Hill Creek

Harold E. Malde

From Forests to Faucets:

Protection and smart management of source water areas upstream of population centers is critically important for downstream water quality. Natural area conservation and management plays an important role in safeguarding water resources and providing supplies of clean drinking water. Targeted land protection and restoration can help reduce the input of pollutants, sediments and pathogens to our water supply.

In nearly 20 years of conservation action at Sideling Hill Creek, the Conservancy has helped protect 1, 674 acres of one of the most pristine streams in Maryland.

8. Shenandoah River

http://U.S. National Park Service / Via Flickr: 119886413@N05

O Shenandoah, How Can We Help You?

The Shenandoah River is one of the larger Potomac tributaries, draining 20% of the Potomac watershed. The Shenandoah receives excessive levels of nutrient pollution from wastewater and the region's farm industry, sources of nitrogen and phosphorus that degrade habitat and water quality in the Potomac River and Chesapeake Bay.

To improve the health of the Chesapeake Bay and the rivers that flow to it, The Nature Conservancy works with partners to advance public policies and funding to improve water quality.

9. Dams, Diversions and Development

Bob Marquart / Via Flickr: lostbob

Protecting Environmental Flows:

The Potomac River is one of the most free-flowing large rivers in the eastern United States. Even with some 300 small dams in the watershed, few large dams alter its natural flows. Analyses of the river's flows suggest that land conversion from forests or fields to urban land is more disruptive to natural flow patterns in the Potomac watershed than dams or water diversions.

The Nature Conservancy is working with the U.S. Army Corps of Engineers, the Interstate Commission on the Potomac River Basin, the National Park Service and other partners to identify the river's natural flow needs and to determine how to provide water for human uses while ensuring enough water remains in the river for wildlife, recreation and other uses.

10. South Branch of the Potomac

Kent Mason

Helping Headwaters in West Virginia:

Near the headwaters of the Potomac River's South Branch, The Nature Conservancy works in West Virginia's river-carved Smoke Hole Canyon/North Fork Mountain landscape to protect and restore rare habitats and ecological processes. Here, vacation home development and invasive non-native species threaten both special habitats and water quality.