The Potomac River is the lifeline of the metropolitan Washington, DC area. Not only does more than 80% of the metro population rely on it for its water supply, but the Potomac is also home to many rare and endangered species.

Every day, countless threats jeopardize the health and vitality of this amazing resource. The largest threat to the quality of the Potomac River is non-point source pollution, which is a result of precipitation washing over the land, picking up pollutants (oils, pesticides, fertilizers, animal waste, etc.) and sediment (topsoil), and carrying them into the river as run-off. This problem has been intensified in recent years by widespread development, which has introduced more and more manmade impervious surfaces—such as roads, parking lots, and rooftops—that do not absorb water. As a result, water rushes across the hard surfaces, picking up speed that hastens erosion and non-point source pollution. At new development sites, exposed soil is quickly washed into the river. Non-point source pollution is also worsened when landowners or developers cut down riverside trees, diminishing their cleansing effects. Waterside forests serve as buffers to non-point source pollution, reducing erosion and absorbing much of the pollutants that would otherwise taint the water.

View another panorama just downriver