Low Water Levels Continue on Reservoirs, Drawdown To Begin

After the Labor Day weekend, TVA will begin drawdown of the Tennessee River system reservoirs to reach winter levels.

Because water levels of tributary reservoirs are well below normal for this time of year, TVA plans to continue releasing only enough water from the reservoirs to provide minimum flows throughout the Tennessee River system.  As a result, tributary reservoir levels should drop at a slower rate than usual this fall.

Although the rainfall during the past week provided some relief of drought conditions, levels of tributary reservoirs in the eastern half of the Tennessee Valley are averaging almost 15 feet below normal.  South Holston Reservoir in Upper East Tennessee is almost 30 feet below normal.

Water levels in the Tennessee River reservoirs are near normal because they have less storage space than the tributary reservoirs, and because the main river channel must have water deep enough to accommodate commercial barge traffic.

“Although the reservoir system is in better shape than it was last year at this time, it will take rainfall well above normal over an extended period of time to break this three-year drought and return normal flows back to the Tennessee River Basin,” said TVA Senior Vice President of River Operations Janet Herrin.  “We are continuing to manage the reservoir system in a conservation mode ― only withdrawing enough water from the tributary reservoirs to meet minimum flow commitments downstream.”

Herrin said the latest rainfall resulted in an average of about 3 inches of rain for the Valley east of Chattanooga.

As part of the Reservoir Operations Study implemented in 2004, TVA restricts how much water it releases from the tributary reservoirs from June 1 through Labor Day, so there’s more water for recreation.  Throughout the summer during dry conditions, TVA releases only enough water from upstream reservoirs to protect aquatic species and meet other downstream needs.

On Aug. 1, TVA increased its water releases from the tributary reservoirs downstream through Chickamauga Dam from 13,000 cubic feet per second to 25,000 cubic feet per second to protect water quality and aquatic habitat and to provide cooling water for power plants.

Herrin said all tributary reservoirs are drawn down proportionately as TVA maintains the minimum flows.  “We draw water from the tributary reservoirs in a balanced manner so the impacts are the same,” she said.

In the eastern part of the Valley, rainfall for the year is 27 percent below normal, and runoff (the amount of water that reaches the reservoirs) is 50 percent below normal.

No additional water has been withdrawn for hydro generation.  As a result, hydro generation is 61 percent of normal for the year, and TVA has been forced to buy more power than planned to meet the power demands this summer.

For information on each reservoir’s daily level, go to www.tva.com/river.

Media Contact:

TVA News Bureau, Knoxville, (865) 632-6000

TVA Newsroom