By Billy Birdwell, Public Affairs Specialist
We recently posted on Balancing the Basin that the system entered drought level 1; however, just two days later, the basin has climbed out of drought status all together. As the three reservoirs operated by the U.S. Army Corps of Engineers on the upper Savannah River continue to rise, Corps officials announce the end of drought operations.
On May 7 the water level at J. Strom Thurmond Dam and Lake at Clarks Hill rose above 328 feet above mean sea level (ft-msl) for the first time since March 30, 2011. Thurmond Lake’s last extended time above 328 ft-msl was in February 2010.
“Once the winter and spring rains started, the reservoirs recovered very quickly,” said Col. Jeffrey M. Hall, Savannah District commander. “Nature came through even better than we predicted earlier this year. The reservoirs will be full before Memorial Day and should remain full at least throughout June.”
The full pool levels are 660 ft-msl at Hartwell Lake, 475 ft-msl at Russell Lake, and 330 ft-msl at Thurmond Lake.
The dramatic rise in reservoir levels came from consistent, widespread rainfall throughout the upper Savannah River basin, according to Stanley L. Simpson, the district’s senior water manager. Beginning in December, weather systems produced enough rain to saturate the soil and cause runoff into the Corps-operated reservoirs.
“Tributaries feeding the reservoirs continue to run high from recent rains which cause a rapid increase in water levels,” Simpson said. “Our inflows were almost 10 times as much as we were releasing, resulting in rapid increases in the pool elevations.”
The Savannah District’s drought plan requires restricted outflows from the Thurmond Dam until levels at Hartwell Lake reach 658 ft-msl and Thurmond Lake reaches 328 ft-msl. Hartwell Lake exceeded 658 ft-msl on April 29 but outflow restrictions remained in effect until Thurmond Lake reached 328 ft-msl. Rising to these levels puts the dams in “normal operations” with no outflow restrictions.
Under normal operations all of the congressionally mandated purposes of the reservoirs can be met – flood risk reduction, hydropower production, downstream navigation, recreation, water supply, water quality, and fish and wildlife management.