Whether you live in the mountains or foothills of Virginia and Maryland or in the lowlands along the Chesapeake Bay, you affect the Potomac River. This is because the Potomac is not just an isolated waterway, but also the centerpiece of a nearly 15,000-square-mile watershed. A watershed is an area of land in which all rain, snowmelt, and smaller tributaries flow downhill into the same body of water.

The Potomac River Basin is one of the nation’s most geologically and ecologically distinct river basins. It runs over 383 miles from Fairfax Stone, West Virginia to Point Lookout, Maryland and drains 14,670 square miles of land area from four states and the District of Columbia. Due to its size, the Potomac is the second largest contributor of fresh water to the Chesapeake Bay. From its headwaters to the Bay the river has eight major tributaries and crosses five spectacular geological provinces representing over 600 million years of natural history that shaped its landscape. Recent centuries of intense use of the land for agriculture and rapidly expanding urban populations have presented challenges for watershed health.

Many of the river’s tributaries have been altered and degraded as a result of agriculture. Acid mine drainage has polluted its headwaters, while farming has overloaded the waterway with sediments and nutrients. Rapidly expanding urban populations and urban sprawl have created a host of problems, from urban stormwater runoff and altered streams to fragmentation of the forest and destruction of critical fish and wildlife habitat.

The Potomac Watershed Partnership understands that, with nearly 5 million people living in the Potomac River basin, the Potomac River watershed is our common bond—the true heart of the nation’s capital. But the river needs help.