March is in coming in like a lion - and it’s one wet, unhappy cat. Pretty much no matter where you are in the Tennessee Valley, it’s been a rainy couple of days. In some portions, such as north Alabama and west Tennessee, it’s very rainy - with four to six inches already on the ground or expected to fall in short order.
That’s on top of a month that’s already been extraordinarily wet. February 2018 has already been at 224 percent of normal rainfall levels, meaning TVA’s been generating, spilling and sluicing at many of its dams to keep water running through the system and storing water where needed to minimize flooding.
To date, those efforts have been very successful, warding off nearly $40 million worth of damage in Tennessee alone - including $26 million in Clinton and $8 million in Chattanooga.
However, with the intensity of rainfall levels yesterday and today - with four to six inches on the ground across large portions of the Valley and more on the way - operations have taken a tactical turn, says Tom Barnett, general manager of River Management for TVA.
“In recent days, we’ve been trying to recover from the last rain event to prepare for the next one - which is happening now,” Mr. Barnett said. “Now we’ve shifted into flood control operations, which means we have slammed the brakes on the tributaries in east Tennessee and we’re storing water there to help relieve pressure on the main stem Tennessee River to minimize flood impacts from Lenoir City, Tenn., all the way to the Ohio River.” Some eastern tributary reservoirs—such as Douglas and Fontana - will store several more feet of water during this event, he notes.
TVA’s River Management team operates the river system for multiple benefits, including navigation, power production, water quality, water supply and recreation. But chief among his duties is flood prevention, he says: “TVA was charged with managing the river to minimize flooding impact since our inception, and we draw down the reservoirs in the fall and winter months for precisely this purpose - to have storage space for floodwaters.”.
Even as releases halt on the eastern tribs, they will continue at Guntersville, Wheeler and Wilson in north Alabama to help minimize flooding in the western half of the region; water will be held back in capacious Kentucky reservoir to help reduce flooding on the Ohio River, which is already happening.
James Everett, senior manager of TVA’s River Forecast Center, noted that minor flooding is expected at some Valley cities - places where there simply isn’t enough storage available to keep water within the banks of the river. Affected cities include Florence and Whitesburg in Alabama; Fayetteville, Savannah, Perryville, Clifton and Shelbyville in Tennessee; and Paducah, Ky.
“We can’t control what Mother Nature is doing, but we are doing everything we can to keep flooding to a minimum, and prevent structural damage,” Mr. Everett said.
When flooding is probable, or even just possible, the River Forecast Center also moves into communication mode, continuously updating city and state governments; homeowners, businesses (such as marinas) and farmers that may be affected; and the National Weather Service, which then issues the appropriate flood watches and warnings.
“What we do is very much behind the scenes, but we’re working 24/7 right now to keep water levels low and flooding to a minimum,” Mr. Barnett said. “That’s not only to save property, but to save lives - that’s our first priority, always.”
What Tom Barnett and James Everett do is heavily based on science, of course - and TVA’s River Forecast Center runs on some of the most sophisticated river modeling software available. The place is staffed around the clock with engineers working to tackle the problems that naturally arise with flood conditions. But there’s an art to flood management, too.
“We don’t have a cookbook for how to fix flood conditions; we don’t have a manual that dictates do this, do that,” Mr. Barnett said. “No two storms are ever alike. It takes a lot of intuition and accumulated experience along with the science to manage the river. We have 85 years of history doing this, and we are standing on the shoulders of giants.”