Corps of Engineers cancels salinity test on Savannah River; cautions river users

SAVANNAH, GEORGIA – Officials with the Savannah District, U.S. Army Corps of Engineers, have cancelled a previously announced salinity test on the lower Savannah River due to high river flows following heavy upstream rains. The test required low river flows during the mid-November high tides.

Water managers for the Savannah District had reduced outflows from the J. Strom Thurmond Dam in order to test how much impact, if any, low flows and high tides would have on the fresh water intake for the City of Savannah on Abercorn Creek upstream from the city. The test was part of the proposed Savannah Harbor Expansion Project. Heavy rains from the remnants of Hurricane Ida caused river flows of approximately 20,000 cubic feet per second (cfs) near Augusta, Ga., which will also increase flows near Savannah before the November high tides. The Savannah River normally flows at approximately 7,000 cfs and Corps researchers hoped for a flow significantly lower for the test. Officials can not reschedule the test due until predicted tides and river flows match needed conditions. 

River flows will remain high for three more weeks or longer, District water managers said, in order to bring Thurmond Lake down to its winter level of 326 feet above mean sea level (ft-msl) by Dec. 1. Thurmond Lake is expected to rise to approximately 334 ft-msl before it begins to recede. Thurmond Lake last exceeded 330 ft-msl on Mar. 20, 2007.

Rains also caused Lake Hartwell, the uppermost of the Savannah District reservoirs, to rise above 660 ft-msl on Nov. 12, or two feet above the desired level for that date. It is expected to rise to approximately 662 ft-msl where it will remain for two or more weeks until Thurmond’s level has declined enough to accept more water.   Hartwell Lake was last above 660 ft-msl on Sept. 7, 2005.

Dock owners on Lakes Thurmond and Hartwell should be prepared to move their docks quickly to avoid damage due to high water. Boaters on the Savannah River below Thurmond Dam should exercise extreme caution due to high river velocities and floating debris from the heavy rains.