TVA says dry weather has left river at very low level

A dry end to the summer and unexpectedly little rainfall to start fall left water levels low and the Tennessee Valley Authority adjusting to compensate across the region.

Water levels had been lowered as much as 30, 40 and 50 feet in places throughout the valley in anticipation of heavy rainfall after hurricanes struck the U.S., but Tennessee dodged most of the expected rainfall, leaving water levels low, according to a release from TVA.

“We lowered much of the main river ahead of those storms so that we had ourselves in a good position if we were going to get the kind of torrential rainfall that’s been associated with other hurricanes,” said James Everett, River Forecast Center operations support manager. “As it turned out, we got fortunate and flooding along the Tennessee River was a non-issue.”

Now local authorities will readjust, releasing water from tributary lakes into the river system, according to the release. The trick is raising it enough for power consumption, navigation and recreation but not so much as to flood the area.

The raising and lowering of the Tennessee River is common. It happens throughout the year for different purposes, and those purposes can be in direct competition with one another.

“There’s a balance we have to strike every single day,” Everett said.

Water speed is maintained to ensure the region’s vibrant ecosystem remains healthy. If it’s too fast, plant life is sucked up and floats away, hurting the area’s fishing industry. If it’s too slow, power generation takes a hit, navigation on the river becomes much more difficult and the area’s booming water recreation industry shrinks.

Higher water levels make the river better for navigating and improve some water recreation, but if levels are left high at the wrong time, that can lead to catastrophic flooding.

A lot of it is a guessing game.

“We can’t predict the future that far in advance, we don’t know that there’s not going to be a flood this winter,” Everett said.

So while there are times officials guess wrong, leaving the river too low, there are other times the prevention saves millions of dollars. That was the case in 2013.

TVA lowered the river levels. The rain came, and the agency estimates close to $1 billion in flood damage was averted.

“We call it the flood that never was,” Everett said.

Contact staff writer Mark Pace at mpace@timesfreepress.com or 423-757-6659. Follow him on Twitter @themarkpace and on Facebook at Chattanooga OutdoorsTFP.