On October 21, 1950 the valve gate closed and water began backing up to create South Holston Reservoir.

Work began on the dam in December 1941, but in November 1942, the War Production Board requested that the operation be suspended because of a shortage of critical materials.

The dam now impounds the South Holston Lake of 7,550 acres (3,060 ha), which extends northeastward across the Tennessee-Virginia state line.

The dam site is situated in an area where the river descends out of the Appalachian Mountains and enters the upper Holston Valley.

The dams would also produce electricity to help TVA meet the high demand for power at the outbreak of World War II.

TVA spent several weeks securing the dam sites, and the South Holston project was stalled until the end of the war.

This auxiliary spillway— known as the "Bent Branch Spillway" after the stream into which it empties— is located about 1.5 miles (2.4 km) south of the main dam.

The weir helps to deal with the fact that the water coming out of the bottom of the dam is cold, dense, and oxygen depleted.

The weir also prevents the water from refluxing back up to the turbine at the dam, and calms it down for recreational users such as those boating, fishing, and swimming.