TVA officials said if it were not for its dams, the river level at Chattanooga would be 14 feet higher from the Christmas rain event.
TVA operations averted $130 million in damages, the agency said.
Still, the river was running high with all the TVA dams spilling water, and many area creeks were overflowing after days of rainfall over the Christmas break.
By one calculation, 800,000 gallons per second were coming through at Chickamauga Dam.
Sections of North Alabama were receiving even higher rainfall totals than Chattanooga - with Bear Creek watershed accumulating six inches.
TVA was storing as much water as possible in its tributary dams.
With additional rain on Monday, the flooding effect for South Chickamauga Creek was changed from minor to minor severity.
A flood warning is in effect for South Chickamauga Creek until Wednesday evening.
At 8:15 p.m. Monday, the stage was 16 feet and rising. Flood stage is 18 feet. Minor flooding is forecast.
It is forecast to rise above flood stage by Tuesday early afternoon and continue to rise to near 20 feet by early Wednesday morning. The creek will fall below flood stage by Wednesday early afternoon.
At 20 feet, Mack Smith Road is closed. Water crosses Lovell Field Loop, the access road around the north end of the airport runway.
The flood warning continues West Chickamauga Creek near Fort Oglethorpe affecting Catoosa and Hamilton counties and Lookout Creek.
The flood warning is in effect for Lookout Creek until Wednesday afternoon.
At 7 p.m. Monday, the stage was 12.2 feet and rising. Minor flooding is occurring and is forecast. The flood stage is 12 feet. The creek will continue rising to near 14.5 feet by Tuesday morning. The creek will fall below flood stage late Wednesday morning.
At 15 feet, minor flooding continues to expand along Sells Lane in Trenton, Mason Road near Rising Fawn and Creek Road near New England. These roads and other roads with creeks flowing into Lookout Creek will flood causing the roads to be closed. The water will be a few feet deep on portions of these roads. Also minor flooding will continue to expand downstream as the creek crosses the Tennessee border into the Lookout Valley area.
Strong winds are also forecast going into Tuesday.