As summer becomes a dry and warm early fall—and TVA works to meet minimum flows needed for navigation, power production and water quality—lake levels continue to drop.
The Tennessee Valley escaped the damaging weather that Harvey and Irma brought to other parts of the Southeast, but was still susceptible to follow-on tropical rains.
To be prepared, TVA’s River Forecast Center began dropping water levels.
“We lowered much of the main river ahead of those storms so that we had ourselves a good position if we were going to get the kind of torrential rainfall that’s been associated with other hurricanes,” James Everett, River Forecast Center operations support manager, said. “As it turned out, we got fortunate, and flooding along the Tennessee River was a nonissue.”
Since then, rainfall has been at only 15–20 percent of normal levels, and the outlook is for October to be dry as well. TVA has now been slowly and steadily releasing water from tributary lakes into the main river system to meet winter flood guide targets, as well as to ensure other benefits, including water quality and electric generation.
Another thing we’re working hard on right now is coordinating water levels to maintain minimum depths for navigation. We have to consider the Tennessee River, but also conditions on the Ohio and Mississippi, which do have a big impact on our coal plants and barge movements in the Tennessee and Cumberland valleys. We need to make sure barges can get through the entire inland waterway system with minimal problems.
Water temperatures are now an issue also. A cool spell in August may have been favorable for operations, but now, water flows need to be enough to keep temperatures under control at nuclear and fossil plants. Dissolved oxygen levels and water quality are under careful observation as well.
“We are always maintaining our minimum flows to support aquatic life,” Everett said.
Recreation is still a priority for the River Forecast Center.
“We’re still doing recreation releases; we’ll continue them for the Ocoee into October,” Everett said. “We just accommodated a large Ironman event in Chattanooga, and we receive flow requests for bass tournaments and we try to work with them if the weather is favorable—we take them on a case-by-case basis.”
TVA puts a lot of work into their river management system in order to ensure high water quality and safety, and they encourage outdoors enthusiasts to get out and enjoy autumn on the water.
Learn more about TVA’s River Forecast Center, located in Knoxville, here.