HARTWELL – If drought con-ditions continue, reduced flows from Hartwell Lake in the winter months are OKed by a new study released by the U.S. Army Corps of Engineers.
The resulting changes in the Corps’ drought plan could see outflows reduced from 4,000 cubic feet per second to 3,600 cfs from Nov, 1 through Jan. 31, if conditions remain at Drought Level 2. If conditions fall to Drought Level 3, the flow will fall to 3,100 cfs.
Under the current plan, Level 2 calls for a flow of 4,000 cfs year round.
The environmental assessment, required as part of the Corps’ the Savannah River Basin Drought Contingency Plan, produced a finding for the plan of “no significant impact” affecting “the qual-ity of the human environment” or on such concerns as endangered species or wetlands.
Col. Jeffrey Hall, commander of the corps’ Savannah District, approved the conclusions on July 30.
Hartwell Lake has been at Level 2 for almost a year, but barring significant rain-fall, a slip to Level 3 seems likely, as of Oct. 1.
The Oct. 1 lake level was 647.8 feet, less than two feet above the 646-foot trigger for Level 3 and near one and one-half feet low-er than the three-year low point of 649.26 feet that the lake reached on Aug. 3.
Full pool for Hartwell Lake is 660 feet. Drought Level 1 is triggered at 656 feet and Level 2 at 654 feet.
The Corps of Engineers last updated its Drought Contingency Plan in 2006.
The 135-page assessment okaying the changes in the Corps’ drought plans capped 10 months of study that took into account such diverse factors as dissolved oxygen content of downstream waters, anticipated water needs downstream, the impact of reduced flows on the breeding of several species of fish, and even issues of “environmental justice”.
Another change resulting from the new assessment is that stream flow of the Broad River, a large and unrestricted tributary, will be used as a gauge of natural inflow to the Savannah River Basin.
The flow will be measured using the U.S. Geological Survey gauge near Bell, Ga.
In a statement issued along with the assessment, Col. Hall said the study provid-ed the grounding needed to reduce flows based the Broad River’s inflows while deal-ing with the various drought levels and set lower wintertime outflows.
“These actions will allow us to improve water storage for the current and future droughts,” he said.
Another study is planned for this fall, involving the Corps, the Nature Conservancy and Georgia and South Carolina environmental management agencies, that will recommend measures for managing the Savannah River Basin during droughts.
According to Corps officials, the recommendations of that study, which has no announced completion target date, will re-place the drought plan based on the assessment released in July.