The Bay Watershed

The Chesapeake Bay watershed is huge.  The watershed:

  • Is 64,000 square miles, larger than 30 U.S. states, and 96 percent the size of New England
  • Covers parts of six states:  Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia, as well as Washington, D.C.
  • Is home to 17 million people and includes more than 100,000 streams, creeks and rivers; wherever you are in the watershed, you’re within 15 minutes of a Bay tributary
  • Runs from the Susquehanna River’s headwaters at Cooperstown, N.Y., home to baseball’s Hall of Fame, until emptying into the Atlantic Ocean on Virginia’s Eastern Shore
  • Drains five major rivers: the Susquehanna, Potomac, Rappahannock, York, and James, which provide more than 90 percent of the Bay’s fresh water

Human activity in the watershed is damaging the Bay, with excess nitrogen and phosphorus pollution destroying habitat and causing fish kills.  Leading sources of these pollutants are agriculture, sewage treatment plants, urban and suburban runoff, and air pollution from cars, factories, and power plants.  Human impact on the Bay is dramatic:

  • Since colonial times, the Bay has lost half of its forested shorelines, over half of its wetlands, nearly 80 percent of its underwater grasses, and more than 98 percent of its oysters.
  • During the 350 years between 1600 and 1950, approximately 1.7 million acres of the Bay watershed were developed. During the 30 years between 1950 and 1980, the Bay watershed lost an additional 2.7 million acres to development.

For more information on these bullet points and more information on the Chesapeake Bay watershed, please visit the Chesapeake Bay Foundation website at, the Chesapeake Bay Program website at and Maryland's restoration tracking website at

Electronic versions of these and related materials are available at under Media Room.