Approximately 90 percent of the drinking water for the Washington, D.C. area comes from the Potomac River. An average of approximately 486 million gallons (1.8 million cubic meters) of water is withdrawn from the Potomac River daily in the Washington area for water supply. This is equivalent to a mid-size river with a flow of 750 cubic feet per second. At 464 miles (747 kilometers) long, the Susquehanna River is the longest river on the American east coast that drains into the Atlantic Ocean. When its watershed area is included, it is the 16th largest river in the United States and the longest river in the continental United States without commercial boat traffic today. The Susquehanna River: is almost a mile (1.6 kilometer) wide [...]