This story was updated Thursday, Feb. 6, 2020, at 8 p.m. with more information.
With a normal month's worth of rain falling in the Tennessee Valley in just the past two days, the Tennessee River in Chattanooga is expected to rise another 6 or 7 feet from the rainfall runoff, shutting off barge traffic through Chattanooga and potentially flooding some low-lying areas and parks along the river.
"We've seen very heavy rainfalls, anywhere from 2 inches to 6 inches of rain in the past couple of days, and we could see another wave of heavy rain again near the end of next week," James Everett, the senior manager for the TVA River Forecast Center in Knoxville, said Thursday.
River levels in Chattanooga are projected to rise at the Market Street Bridge from the normal winter pool of 21 feet up to about 28 feet as TVA releases up to 167,613 cubic feet per second — or more than 1.2 million gallons of water a second — by Sunday to help cope with the heavy rains, Everett said.
The anticipated river level in Chattanooga is still 2 feet below flood stage and 2 feet lower than what the river reached in February 2019 when more than 11 inches of rain fell in the Tennessee Valley and raised river levels by 9 feet a year ago.
But Everett said the heavy rains through most of TVA's 41,000-square-mile area in the Tennessee River watershed this week will raise most lake levels near or above summertime pool levels and cause some flooding in low-lying areas, especially in parts of northern Alabama and western Tennessee.
Due to the heavy flow and high water on the Tennessee River, the U.S. Coast Guard has suspended river barge traffic through the Nickajack gorge west of Chattanooga, shutting down most river navigation probably for the next couple of weeks. Fort Loudon and Watts Bar dams also are not handling barge traffic due to the high water.
"It looks like we're going to be scrambling for the next couple of weeks," said Cline Jones, executive director of the Tennessee River Valley Association, the trade group that represents the region's barge industry. "We're keeping our fingers crossed that we don't get a whole lot more rain and it isn't as bad as last year."
During February 2019, river navigation was shut down for most of a month due to record high rains.
"We're going to see very similar levels to what we had last February, with lake levels on many of TVA's reservoirs getting above summer pool levels," Everett said. "We do expect most of the heavy rain to push through the Valley today with only scattered activity over the weekend and limited rain early next week."
But the National Weather Forecast is predicting a good chance of heavy rains again near the end of next week.
With the ground already saturated after heavier than normal rain last month and the second highest rainfall on record in 2019, the additional rainfall next week could keep TVA storage reservoirs upstream of Chattanooga well above their normal winter levels for weeks to come.
TVA uses its network of 49 dams to help limit flooding, especially in Chattanooga, which is the drainage route for thousands of acres of the Tennessee River watershed. TVA estimates its flood control measures helped avert $1.6 billion of flood damages in Chattanooga last year alone.
In 2019, 66.47 inches of rain fell in the Tennessee Valley, second only to the record high 67.02 inches that fell in the region in 2018. Normal rainfall across the Tennessee Valley averages 52.5 inches a year, according to TVA.
Contact Dave Flessner at firstname.lastname@example.org or at 423-757-6340.