Upper Savannah River Reservoirs Enter Drought Level 1
SAVANNAH, Ga. – The three reservoirs on the Upper Savannah River operated by the U.S. Army Corps of Engineers, Savannah District, declared the first drought level Sunday, Sept. 10, 2023, in response to the pool elevation at J. Strom Thurmond Lake dipping below 326.0 feet above mean sea level (ft-msl).
Entering Drought Trigger Level 1 activates the Corps’ Drought Management Plan which conserves water in the reservoirs by reducing the outflows from the Thurmond Dam.
The drought management plan was developed based on scientific data and in coordination with various state/federal/local agencies and public input. To view the chart for trigger action levels, visit Drought Trigger Action Levels. To view the plan, click Drought Plan.
The pool elevations on Sept. 10 were 656.28 ft-msl at Hartwell Lake, and 325.98 ft-msl at Thurmond Lake. Under the current drought plan, the Corps limits outflow from Thurmond Dam to a daily average of 4,200 cubic feet per second (cfs), when in Drought Trigger Level 1.
Water managers also adjust Hartwell releases as needed to stay in balance with Thurmond. Reducing outflow decreases the amount of hydropower generated through the dams but conserves more water in the reservoirs.
In addition, if the 28-day average stream flow at the Broad River gauge near Bell, Georgia, falls below 10 percent of normal, managers will further reduce the flow from Thurmond to a daily average of 4,000 cfs. The Corps expects the pools to stay in Level 1 and continue to gradually decline through December. (Currently 39%)
June-August 2023 inflows (rain) were about 70% of the average inflows, and the reservoirs haven’t experienced sustained inflows that low, during those months since last year at this time.
Currently, swim beaches and boat launching lanes are open, camping, boating, skiing, fishing and other forms of recreation continue unabated. As always, safety officials urge the public to use caution when boating, swimming or fishing, as the reservoir levels decline, underwater obstructions will be closer to the surface.
Boaters and skiers should use extra caution when out on the lakes. All visitors should wear a life jacket when swimming, boating, skiing or fishing. For information about boat ramp closures, visit Thurmond Boat Ramp Status and Hartwell Boat Ramp Status.
“This year, the reservoirs have remained at full pool thru July. As is typical, inflows have declined across the summer months leading to a declining pool. Last year, we were near the same pool levels and had already triggered drought operations,” said Stan Simpson, senior water manager for the Savannah District. “The reservoirs experienced a typical late summer decline that has been intensified by a deficit in rainfall across the basin over the last three months.”
The congressionally authorized purposes of the reservoirs include water supply, water quality, recreation, flood risk management, navigation, hydropower production, and fish and wildlife management.
More than 10 public water systems and industrial users draw water directly from the reservoirs and even more draw from the Savannah River downstream of Thurmond Dam.
Collectively, water from the three reservoirs is used or withdrawn by municipalities intakes (not released through the dam) at an average of 51.1 million gallons (MGD) per day.
Downstream users include the cities of Augusta and Savannah in Georgia and North Augusta and Jasper County in South Carolina. Additionally, threatened and endangered species as well as the Savannah National Wildlife Refuge depend on the river. During the summer, an estimated 650 MGD is lost each day to evaporation from the three reservoirs.
For more information on current lake levels and projections, visit the district’s lake-level website at Savannah District Water Management.