The Flood Control Act of 17 May 1950 authorized the Hartwell Dam and Reservoir as the second unit in the comprehensive development of the Savannah River Basin. The estimated cost was $68.4 million based on 1948 price levels and preliminary designs. The original project provided for a gravity-type concrete dam long with earth embankments at either end, which would be long on the Georgia side and long on the South Carolina side. The long dam was to be topped with a roadway wide. The main dam was to consist of two non-overflow concrete sections on the right and left banks and long, respectively; a gravity-type concrete spillway long equipped with 12 tainter gates 26 feet by 40 feet in the channel; and a powerhouse on the South Carolina side of the river. Full power pool was designed to be 660 feet above mean sea level.