The Richard B. Russel Dam, on the Savannah River, the border between South Carolina and Georgia, is a mile-long dam built by the Army Corps of Engineers, primarily for flood control, and secondarily for electrical production. It was finished in 1985. Four 75 megawatt reversible pump/turbine units were added to the four regular turbines already in the dam in 1992, giving the dam 300 megawatts more electrical production during peak periods, especially in hot southern afternoons, when air conditioning use is at its highest. It is one of three pumped storage facilities in Georgia that use existing reservoirs along rivers, not isolated off-stream storage reservoirs.