Making Way for Florence

The Tennessee Valley is insulated from the brunt of the hurricane, but the eastern region could see several inches of rain. Here’s how TVA’s river managers are preparing for it.

SEPTEMBER 13, 2018—It’s going to be a dark and stormy night for the Carolina coast as Hurricane Florence finally makes landfall later this evening. It’s been a hard storm for trackers to pin down, but prudent planners throughout the southeastern U.S. are readying for several inches of rain.

That’s the case at TVA, where river managers are busy moving water out of the big mountain tributary reservoirs—in areas forecasted to potentially receive four to six inches of rain—and down the Tennessee River.

TVA typically begins releasing water from the reservoirs to make room for winter and spring rainfall, starting just after Labor Day and continuing through mid-December.

But with Florence rains on the way, the schedule is stepping up in the eastern Valley in order to reduce flood risks, according to James Everett, senior manager of TVA’s River Forecast Center. “We began more aggressive releases from tributaries earlier in the week, even while the path of the storm and rainfall amounts were still quite uncertain,” he says. “We’ll continue to fine tune those releases heading into next week once we start to get a clearer picture on just how much rainfall Florence might bring.”

Meanwhile, tributary Dams like South Holston, Wilbur, Ft. Patrick Henry, Fontana, Ocoee 3 and Apalachia are generating, sluicing and/or spilling. And spilling for the purpose of flood control is happening at Cherokee Dam for the first time since 1994 (see photo at top of page).

As water moves through the system, higher than normal releases and spilling are happening downstream as well at Fort Loudoun, Watts Bar, Chickamauga, Nickajack, Guntersville and Pickwick dams.

It’s tempting to think of the rainfall, predicted for the eastern end of the Valley, as a local phenomenon. But in the world of integrated river management, it’s not. “The Tennessee River is like a tree, and the tributaries are branches that feed back to it,” Everett explains. “People think of these events as local, but they are actually regional events. The river system as a whole will be impacted.”

TVA staff at the River Forecast center and at the hydro facilities will be working around the clock over the next few days as rain hits to ensure that water gets to where it needs to go. “We are very grateful to the dedicated staff at TVA’s dams who maintain and operate the spillway and sluiceway gates, which are especially critical before, during and after these big storms,” Everett says.

While flood control operations are happening, it is advisable to use extreme caution if boating or swimming in the river, and to avoid being in the water near any dams spilling, sluicing or generating.

It’s not unusual for dams to spill at a rate of millions of gallons per second, creating extremely hazardous conditions for recreational lake users. Always heed warning signs, horns and lights, which are meant to warn you away from potentially deadly situations. (To read more about the warning systems in place near dams, click here.)

The River Forecast Center

TVA’s River Forecast Center, located in Knoxville, Tenn., is staffed around the clock, 365 days a year, monitoring the river to minimize flooding, as well as to track water quality data, availability and demand—all with the goal of routing water through the system to provide the most public value given changing weather conditions and water demands. Read more about the River Forecast Center.