 With a full conservation pool, the lake, controls a drainage area of 263 square miles, and is about 5.5 miles long and has a surface area of 952 acres.The lake, which serves as an emergency reservoir for the Washington, D.C. metropolitan area, is managed by the Corps of Engineers.Coordination of the lake's use for water supply purposes is managed by the Interstate Commission on the Potomac River Basin (ICPRB).