Shutdown after rain conserves reservoirs

Flows through Thurmond Dam were halted Saturday afternoon as part of an effort to conserve water in upstate reservoirs.

"Right now it's completely turned off," said Billy Birdwell, the spokesman for the Army Corps of Engineers.

The decision was made after heavy rainfall pushed the Savannah River and its tributaries below the dam to near flood stage Saturday, offering the corps a rare opportunity to avoid releasing water downstream to satisfy Augusta industries and municipal intakes.

"We're trying to use this adaptive management process everyone is talking about," Mr. Birdwell said, adding that the dam will be shut down for about a day and a re-evaluation today could yield a longer shutdown if downstream flows remain adequate.

Also on Saturday, a flood warning was issued for Stevens Creek at Modoc, S.C., affecting Edgefield and McCormick counties until this afternoon. A line of thunderstorms that moved through the Augusta area Saturday brought as much as two inches of rain to some areas, causing the river to rise quickly. It was expected to crest to 19.4 feet Saturday afternoon, which would be nearly a half foot over flood stage, affecting mostly farmland along Stevens Creek north of the U.S. Highway 23 bridge near Modoc.

Thurmond Lake, which has a normal full pool of 330 feet above sea level, was at 316.46 on Saturday -- or more than 13 feet low.

In recent weeks, residents, real estate developers, marina operators and others have campaigned for more reactive management programs that could help refill the reservoir -- or at least slow its decline during drought.

One of those remedies includes closer monitoring of local rainfall and subsequent dam flow adjustments.

In an average year, the corps releases about 9,000 cubic feet per second of flow into the Savannah River. In recent months, as part of a drought management program, releases were cut to 3,600 cubic feet per second and were briefly reduced as low as 3,100 cubic feet per second.

Any further flow reductions could jeopardize downstream water users. Mr. Birdwell said, however, that when there is plenty of local rain keeping the lower river full, it offers the corps an opportunity to capitalize on that rainfall by releasing less from the lakes and keeping more water in the reservoirs.

Saturday's shutdown of the dam wasn't unprecedented, but it was a rare occurrence, he said. He did not know the last time such an action was taken.

Reach Rob Pavey at 868-1222, ext. 119 or rob.pavey@augustachronicle.com.