Officials with the U.S. Army Corps of Engineers expect the Savannah River below Thurmond Dam to exceed channel capacity by this evening due to recent rainfall causing a significant increase in local inflow.
In other words, the Savannah River below Thurmond will see higher and faster flows, with water overflowing the riverbank.
In anticipation of these increased natural flows, Corps officials reduced the water releases from the J. Strom Thurmond Dam (JST) near Augusta, Georgia. By reducing the releases from Thurmond Dam, Corps officials avoid contributing to local flooding risks.
Recent rainfall has caused tributaries to the Savannah River below Thurmond Dam to push flows through downtown Augusta, Georgia, and North Augusta, South Carolina, above 30,000 cubic feet per second (cfs) which can exceed the natural capacity of the river’s channel. Natural flows are expected to recede on Saturday.
As natural flows decrease, the Corps of Engineers will increase the outflows through the Thurmond Dam to hold the peak flow through Augusta. This will allow water managers with the Corps to increase holding capacity in Thurmond Lake as they discharge water from Hartwell Lake and Russell Lake upstream of JST. High flows through Augusta will continue for several days as managers lower the reservoirs to manageable levels.
Officials advise caution to people on or near the Savannah River below Thurmond Dam for the next several days. Some local flooding remains a serious possibility. Residents should monitor the news media for updates and heed local officials’ warnings.
“Safety remains our highest priority throughout this high-water event,” said Col. Daniel Hibner, Savannah District Commander. “Although we’ve experienced above-average rainfall in the past 30 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 reservoir will be closed for public safety reasons as facilities become unusable.
Areas below the New Savannah Bluff Lock and Dam can expect water spreading even further beyond the river’s banks than has happened in recent days.
~Billy Birdwell, Corporate Communications Office