TVA to Lower Great Falls Reservoir to Clear Debris

June 27, 2017

KNOXVILLE, Tenn. ― The Tennessee Valley Authority will be adjusting operations over the next few weeks at Great Falls Dam to lower the reservoir in order to remove logs, tree limbs and other debris that has accumulated from recent storms.

The debris is blocking closure of the dam spillway gates, allowing water to run through and preventing operators from bringing the reservoir up to full summer pool of 800 feet above sea level.

Because of flow through the open spillway gates, the reservoir is currently about 6 feet below normal summer pool. TVA plans to draw the reservoir down to about 10 feet below normal so workers can safely access the spillway gates and remove the debris, close the spillway gates and raise the reservoir to full summer pool.

The drawdown is expected to begin by next week, when the dam’s two hydro generation units are activated to help lower the lake level. The two hydro generation units are currently undergoing scheduled maintenance and cannot be activated until the maintenance work is completed. Heavy rainfall could delay the drawdown as well.

Once the debris is cleared and spillway gates closed, TVA will work to start raising the reservoir level back to normal. The rate of fill and the time it takes to reach full summer pool of 800 feet will depend on the amount of rainfall and runoff over the next few weeks. With normal rainfall the rest of the summer, a gradual fill rate of about one foot per day can be expected.

“We will begin the drawdown as soon as possible after the generating units are back on line to allow us to lower the water,” said James Everett, manager of TVA River Forecast Center Operations Support. “Heavy storms have lodged an unusually large amount of debris at the dam. We plan to remove it as quickly and safely as possible. After that, the amount of rainfall we receive over the remainder of the summer will determine how fast the lake can be returned to its normal level.”

Great Falls recently celebrated its 100th anniversary and it is the only TVA dam located outside the Tennessee River watershed. The dam is one of seven acquired by TVA from private companies. It has two generating units with a net dependable capacity of 36 megawatts. Great Falls is located about 75 miles southeast of Nashville on the Caney Fork River. It is named for the falls that plunge into the Caney Fork, a short distance below the dam

The area surrounding Great Falls Reservoir is a scenic wilderness with numerous waterfalls; world-renowned whitewater rapids for kayaking and canoeing; hiking, camping, swimming and boating at nearby Rock Island State Park and Center Hill Lake; an old mill site on the river below the dam; and spectacular fishing in the scenic gorge of the Caney Fork River.

The Tennessee Valley Authority is a corporate agency of the United States that provides electricity for business customers and local power distributors serving more than 9 million people in parts of seven southeastern states. TVA receives no taxpayer funding, deriving virtually all of its revenues from sales of electricity. In addition to operating and investing its revenues in its electric system, TVA provides flood control, navigation and land management for the Tennessee River system and assists local power companies and state and local governments with economic development and job creation.

 

Contact

Travis Brickey
TVA Public Relations, Knoxville, (865) 632-6000

tvainfo@tva.gov
(865) 632-6263
Knoxville, TN