Chattanooga's river artery remains off limits for barge traffic this weekend after heavy rains boosted the flow of the rain-swollen Tennessee River.
"The entire Chattanooga industry that is tied to barge transportation is affected," said Mark Mayfield, vice president and general manager for Tennessee Valley Towing Co. in Paducah, Ky., which has more than a dozen barges stalled in and around Chattanooga. "The last time we were able to get a boat into Chattanooga was Jan. 22 and even then we were running only daylight hours due to the high water in the river."
Barge operators say this has been an unusual winter in which river shipments from Chattanooga have been restricted by the high water and heavy flow in the Tennessee River.
The Tennessee Valley Authority, which controls the flow of the Tennessee River through its network of 49 dams, has been spilling water through its dams for 103 of the past 132 days. After three years of drought, above-average rains during 2009 and so far this year have forced TVA to open spillways on most of its dams and kept the Tennessee River on the Nickajack Reservoir in Chattanooga above levels acceptable for most river navigation.
Rainfall in Chattanooga during 2009 was more than 8 inches above normal and precipitation so far this year is nearly 2 inches above normal, according to the National Weather Service.
Chuck Bach, TVA's general manager for river scheduling, said the South Chickamauga Creek in Chattanooga is projected to crest at 6 a.m. today at 17.8 feet -- just a few inches shy of the 18-foot flood stage where water in the creek spills over into nearby properties. To limit potential flooding from the rain-swollen creek, TVA will limit its flow through the Chickamauga Dam on the Tennessee River early today, Mr. Bach said.
By the numbers* 28 billion -- Number of gallons of water flowing through the Chickamauga Dam on Friday* 17.8 feet -- Elevation the South Chickamauga Creek is expected to crest at today -- 0.2 feet short of flood stage* 2 million -- Tons of cargo shipped in a typical year through the Chickamauga Lock. Such shipments are now stalled by heavy water flow* 62.59 inches -- 2009 rainfall total in Chattanooga, 8.07 inches above normalSources: TVA, National Weather Service
But on Friday, 86,000 cubic feet per second of water was still passing through the Chickamauga Dam, including 44,000 cubic feet to power all of the hydroelectric turbines plus another 42,000 cubic feet through the dam spillways. Mr. Bach said the above-average flow will force the suspension of
river navigation on most of the Nickajack Reservoir through the weekend.
"We're expecting another inch or more of rain on Monday, so we are likely to be spilling water through our main channel dams for at least the next week," Mr. Bach said.
By mid-January, TVA lowered its reservoirs down to the desired winter levels for flood control. But rains and snow over the past three weeks have again filled creeks and streams flowing into TVA reservoirs, Mr. Bach said.
Although above normal, Mr. Bach said TVA doesn't anticipate any flooding problems from the recent rains.
"This has definitely got our attention and kept us spilling at most dams, but we're not worried about it like when we get a great big rain storm," he said.