Savannah River reservoirs equipped to handle Irma rainfall, officials urge caution downstream of Thurmond Dam

Published Sept. 9, 2017

SAVANNAH, Ga. – Officials with the U.S. Army Corps of Engineers Savannah District said today that the Hartwell, Russell, and Thurmond Reservoirs are equipped and able to safely capture forecasted rainfall from Hurricane Irma.

The current NOAA forecast predicts approximately 7 inches of rainfall from the storm throughout the upper basin. Currently Hartwell and Thurmond Reservoirs are in a drought status and have more than 12 feet of storage capacity available for rising water levels. Based on the rainfall forecast water managers estimate Hartwell will rise about 3.5 feet and Thurmond 6 feet, bringing the reservoirs welcome relief from drought.  

Although high volumes of rainfall are forecasted, there is no cause for concern over the structural integrity of the dams. The dams and reservoirs were designed and equipped to handle this kind of event and are well within their operating parameters.  They are in sound operating condition.

However, officials advise caution for those who might be near the Savannah River below Thurmond Dam for the next several days. Although the Corps’ dams can capture inflow upstream of the structures, rainfall below Thurmond flows into unregulated tributaries resulting in dangerous conditions on the Savannah River downstream of the dam through Augusta, Georgia, and beyond the New Savannah Bluff Lock and Dam.

Water managers said they intend to reduce or halt Thurmond discharge downstream if the river below Thurmond Dam is forecasted to climb above its channel capacity, at 30,000 cubic feet per second (cfs). The River below Thurmond is currently flowing at approximately 4,200 cfs. Although halting discharge from Thurmond will mitigate river swelling below the dam, localized inflows are still expected to result in dangerous conditions downstream of Thurmond.

“Safety remains our Number 1 priority throughout this storm event,” said Col. Marvin Griffin, Savannah District Commander. “Just like with any intense rainfall event, conditions are expected to result in circumstances that require caution for those in the surrounding areas, especially below Thurmond Dam where local inflows are unregulated.”

Excessive rainfall downstream of Thurmond Dam may result in hazardous conditions due to increased river flows on the Savannah River, including areas near Augusta, Georgia. Hazards from high river flows include floating debris, submerged retaining walls and higher river velocity downstream of Thurmond Dam. High water is also a possibility in the New Savannah Bluff Lock and Dam Park and at Fury’s Ferry.


Russell Wicke

Release no. 17-033