After a deluge of nearly a foot of rainfall in parts of the Tennessee Valley over the past week, the Tennessee River has risen above flood stage in parts of northern Alabama and lake levels in TVA's upstream reservoirs have jumped by up to 20 feet — and could rise another 10 feet from rains predicted today through Wednesday.
The Tennessee Valley Authority, which manages the 652-mile Tennessee River and its tributaries, has opened flood gates on all of its nine mainstream dams on the Tennessee River and is holding back water in its upstream storage reservoirs.
"We're managing all of this water as best we can," TVA spokesman Travis Brickey said today. "We're in flood control mode working with the Army Corps of Engineers."'
The increased water flow has shut down barge traffic through Chattanooga and boosted the river level in Chattanooga by 7 feet from last Wednesday until today. Although still seven feet below flood level at the Market Street Bridge in downtown Chattanooga, TVA has opened all 10 floodgates at the Chickamauga Dam, where 107,000 cubic feet per second (or more than 802,000 gallons of water per second) are flowing through the dam and the hydroelectric turbines that generate power at the dam. The river is expected to rise another 2 feet in Chattanooga, according to TVA projections.
At the Guntersville Dam in Alabama where rainfall was even greater, 1.4 million gallons per second are flowing through that TVA dam today.
In nearby Moulton, Ala., 11.6 inches of rain has fallen in the past week and more than 10 inches of rain fell at the Guntersville Dam.
In Chattanooga, the National Weather Service has recorded more than 4.2 inches of rain in the past week and up three more inches of rain is forecast for parts of the Tennessee Valley this week.
Brickey said water levels rose in Lake Fontana by 20 feet and could rise another 10 feet until TVA is able to again begin drawing down its storage reservoirs. TVA lakes are kept at a lower levels during the winter to provide more flood storage for heavy rains like what hit the Valley over the past five days.
In Whitesburg, Ala., the Tennessee River crested at 22.3 feet — more than five feet above flood stage and the highest river level since May 2003. In Florence, Ala., the river crested at 23.2 feet — also five feet over minor flood level and the highest since December 2004, according to TVA records.
TVA will have to reduce the flow from its Kentucky Dam into the Ohio River later this week to limit the crest expected on the Ohio River from heavy rains draining through that river system from throughout the Midwest and Southeast over the past week.