 Douglas Lake has a total capacity of roughly of water, of which is reserved for flood control.The water stored in Douglas Lake serves an important purpose during extended dry periods and droughts in East Tennessee and western North Carolina.Then, water is released from this and other dams on the upper tributaries of the Tennessee River in order to maintain an eight-foot-deep navigation channel for barges on the inland waterway of the river from Knoxville down to its mouth at the Ohio River.