Grayson Lake was authorized by Section 203 of Flood Act of 1960. Primary project purposes are flood risk management, water quality, water supply and recreation. Dam was completed in January 1968 and serves a drainage area of 196 square miles. The lake is impounded by an earth and random rock-fill dam, 120 ft. tall and 1,460 ft. long with an uncontrolled, broad-crested saddle spillway located at the left abutment of the dam.