The surprisingly heavy rainfalls over the weekend have flooded the upper reaches of the Tennessee River and its tributaries above Chattanooga, stretching TVA engineers' abilities to control the surging flow of water.
"Mother Nature dealt us a lot more rainfall than we were expecting," said James Everett, manager of operations for TVA's river forecast center. "The forecast on Friday was for 2-3 inches, and it was supposed to push well north of us, but we received in the 4-6-inch range much further south on the main stem of the river between Chickamauga and the Fort Loudon area where we don't have a lot of storage."
As a result, TVA engineers were allowing about a million gallons of water a second to go through the spillways and electrical generating turbines at Chickamauga Dam, even though it was causing some minor flooding downstream (a normal flow on a summer day would be 100,000 gallons per second, TVA officials said).
Tennessee Riverpark officials were forced to close parts of the trail along the riverbank Monday because of flooding.
All of the Riverpark trail behind Chattanooga State University was closed, as well as the fishing piers, the main boat ramp, and the trail near the boat ramp. Access to the South Chickamauga Creek from the Lost Mound area was flooded beneath the Amnicola Highway Bridge so the trail is closed in that area as well, and from the rowing center to the Manker Patten area.
But Everett said TVA had sufficient storage capacity to prevent any serious flooding because the weather appears to be dry for the next several days. "We're using the last little bit of storage we have," he said.
The authority was storing water in several tributaries of the Tennessee River upstream from Chattanooga, including behind dams on the Little Tennessee River and the Hiawassee River, and not allowing any through, even for electricity generation, until more water drains from the area above Chickamauga. But there are still numerous smaller streams such as the Emory River at Oakdale, near Kingston, he said, which flows into the Tennessee above Watts Bar Dam.
"With all the flows we are getting from the unregulated streams, there is not much we can do about that," he said.
The level at Lake Chickamauga was at 684.1 feet Monday afternoon, Everett said. In general, the level was being held about three to four feet above what it should be for the summer.
"We recognize that can make an impact on the shoreline — people have docks," he said. "But we have to balance that with the flows downstream."
The steady rainfall over the weekend forced Hamilton County officials to open schools two hours late Monday morning, although most roads were open.
EPB in Chattanooga reported several hundred customers lost power, largely due to trees that were toppled or uprooted in the storms. But everything was back to normal by Monday afternoon, according to spokesman John Pless.
The Tennessee Department of Transportation closed Hixson Pike near Armstrong Road in Soddy-Daisy overnight because of a mudslide. TDOT officials said several trees had fallen across the road and it was impossible to determine in the dark whether there was a danger of additional mudslides.
But the road was cleared and reopened to traffic Monday afternoon.
Contact staff writer Steve Johnson at 423-757-6673, firstname.lastname@example.org, on Twitter @stevejohnsonTFP, and on Facebook, www.facebook.com/noogahealth.