Due to recent above-normal rainfall in the upper Savannah River Basin, Savannah District anticipates a need to operate the spillway gates early on the morning of Dec. 31 at the three major dams in the Savannah River system: Hartwell Dam, Richard B. Russell Dam and J. Strom Thurmond Dam.
Once spillway gates are opened they will likely remain opened for five to seven days, until water from the recent storm event can be safely evacuated from the reservoirs making room for future storms. Although high volumes of rainfall are causing these conditions, water managers said there is no cause for concern, and that the dams and reservoirs were designed and equipped to handle this kind of eve
nt; they are well within their operating parameters.
Normal access to dam sites may be restricted due to road closures and limited staffing. Typical viewing areas will be closed as a precautionary measure. The road to the Hartwell Power Plant will also be closed to vehicle traffic. Project offices will be coordinating with Georgia and South Carolina law enforcement officials to regulate traffic flow near the dams.
Record-breaking December rainfall is the cause of increased water levels at all three reservoirs. The scheduled operational releases will increase flood storage capacity allowing the reservoirs to manage additional rain and inflows.
Above-average precipitation began in October when the upper basin received more than 200 percent of normal rainfall for the month. The large volume of inflow caused lake levels to rise beyond normal levels. Throughout this time water managers continued to aggressively operate the system via controlled releases in order to make room for additional rainfall.
November rainfall continued in high volumes, exceeding 200 percent of normal again, keeping water levels into flood storage despite release rates matching safe downstream capacity. December rainfall has continued at about 200 percent of normal and reservoir levels are expected to exceed normal flood storage, which will require operation of spillway gates with controlled releases to sustain flood storage capacity in the reservoirs.
Officials advise caution to people who might be near the Savannah River below Thurmond Dam for the next several days. Based on the forecast from the National Oceanic Atmospheric Administration (NOAA), the Savannah River below Thurmond Dam may exceed channel capacity if current rainfall causes a significant increase in local inflow. In other words, the Savannah River below Thurmond may see higher and faster flows with additional rainfall.
“Safety remains our Number 1 priority throughout this high-water event,” said Col. Marvin Griffin, Savannah District Commander. “Although we’ve experienced above-average rainfall in the past 90 days, the system is well equipped to handle much higher water volumes than what we are seeing now. Nevertheless, just like in all high-water events these conditions will result in circumstances that require caution for those in the surrounding areas, especially below Thurmond Dam where local inflows are unregulated.”
Potentially hazardous conditions resulting from high water and increased flows include floating debris, submerged retaining walls and higher river velocity downstream of Thurmond Dam. Additionally, high water is also a possibility in properties between Stevens Creek Dam and Thurmond Dam. As lake levels rise, some Corps managed recreation areas upstream near the reservoirs will be closed for public safety reasons as facilities become unusable.
Daily updates will be posted on the Savannah District Facebook page and the district’s Twitter feed: @SavannahCorps.
For more information on impacts to specific areas around the lakes, please contact the Hartwell Project office at 888-893-0678, or the J. Strom Thurmond Project office at 800-533-3478.
~Russell Wicke, Chief of Corporate Communications Office