Bay Facts

The Bay is surprisingly shallow. Its average depth, including all tidal tributaries, is about 21 feet. A person who is six feet tall could wade through more than 700,000 acres of the Bay and never get his or her hat wet.

The Bay receives about half its water volume from the Atlantic Ocean in the form of saltwater. The other half (freshwater) drains into the Bay from the enormous 64,000-square-mile watershed.

During the winter, the Bay supports 87 species of waterbirds. Of these wintering waterbirds, 14 species rely on the Bay to serve as habitat for more than 10% of their continental populations.

The formation of the Chesapeake Bay happened 35.5 million years ago when a meteor collided with Earth, forming a massive crater.

Water temperatures in the Bay fluctuate widely throughout the year, dropping as low as 34 degrees in winter.

There are 6,282,718 acres of accessible green space within the Chesapeake Bay watershed.

Major rivers emptying into the Bay include the James, York, Rappahannock, Potomac, Patuxent, Patapsco and Susquehanna from the west and the Pocomoke, Wicomico, Nanticoke, Choptank and Chester from the east.

The Chesapeake Bay’s land-to-water ratio is 14:1: the largest of any coastal water body in the world. This is why our actions on land have such a big impact on the Bay’s health.

There have been 10 U.S. presidents from the Chesapeake Bay watershed, including George Washington, Thomas Jefferson, James Madison, James Monroe, William Henry Harrison, John Tyler, Zachary Taylor, Woodrow Wilson, James Buchanan and Joe Biden.

Mallows Bay is the final resting place for more than 200 historic shipwrecks dating back to the Revolutionary War. Commonly referred to as the “Ghost Fleet” of Mallows Bay, it is the largest collection of shipwrecks in the Western Hemisphere.

Water temperatures in the Bay fluctuate widely throughout the year, reaching as high as 84 degrees in summer.

The 110-mile-long Patuxent River is the longest river to flow exclusively within the borders of Maryland.

The Bay and its tidal tributaries have 11,684 miles of shoreline—more than the entire U.S. west coast.

The Chesapeake Bay watershed contains three distinct geologic regions: the Atlantic coastal plain, the Piedmont plateau and the Appalachian province.

The Chesapeake Bay holds more than 18 trillion gallons of water.

Eighty-six percent of watershed residents believe if people work together, water pollution can be fixed.

A few deep troughs run along much of the Bay’s length and are believed to be remnants of the ancient Susquehanna River.

In 1524, Italian Captain Giovanni da Verrazano became the first recorded European to enter the Chesapeake Bay.