Despite a forecast for clear skies, the Savannah River will begin to rise Friday as flows reach a velocity of more than twice the river's average.
The increased flows, averaging 23,000 cubic feet per second, will continue off and on for about 10 days as the U.S. Army Corps of Engineers conducts its annual "pulse" exercises to help migratory fish reach spawning grounds in the rocky shoals above Augusta.
In preparation for the controlled releases, the corps stored additional water at lakes Thurmond, Russell and Hartwell.
Water levels in each lake will fall by more than 1 foot during the exercises, corps spokesman Billy Birdwell said.
The releases began in 2004 as part of a partnership with The Nature Conservancy, the U.S. Fish & Wildlife Service and state wildlife agencies.
Their timing and the duration are designed to mimic natural seasonal flooding, which occurred before the dams were in place, said Amanda Wrona, the Savannah River project director for The Nature Conservancy.
American shad, for example, once swam upstream past Augusta by the millions each spring and thrived all the way to north Georgia. In the past century, however, dams have blocked their access and transformed many shoal areas into reservoirs. Today, only 200,000 to 300,000 fish make the journey.
The higher flows create conditions suitable for shad and other fish species to swim beyond New Savannah Bluff Lock and Dam - located eight miles downstream from Augusta.
To further encourage upstream fish migration, the city of Augusta will begin opening and closing the New Savannah Bluff locks March 31.
Fish lockage will take place at the New Savannah Bluff Lock and Dam from 8:30 to 9:45 a.m. Mondays, Wednesdays and Fridays through May 15. This action is expected to pass additional fish upstream to the Augusta Shoals spawning area, Mr. Birdwell said.
He said the downstream flows will increase significantly between Friday and March 20, posing a potential hazard to users.
"Swimmers, boaters and recreational users below Thurmond Dam should exercise extreme caution. All users are urged to wear life jackets when on or near the water," Mr. Birdwell said, adding that dock owners should plan to make any needed adjustments.
Reach Rob Pavey at 868-1222, ext. 119, or email@example.com.