The historic wooden flume that carries water from the Ocoee No. 2 diversion dam to its hydroelectric station has begun refilling after being closed for a year to replace a 70-foot section destroyed by a rock slide on April 28, 2010.
The flume, which began refilling Monday, April 18, is an elevated 14-by-11-foot pine corridor built on a steep slope above the Ocoee River. The flume transports water 5 miles downstream from the dam to the power house.
The power house has not operated since the flume was damaged, and no water has been in any part of the flume since the rock slide. The flume is built as it was originally in 1911. All the boards are secured in place and the water that runs through it causes the wood to swell and keep the flume from leaking without mortar or fillers between the boards.
"The filling and swelling process takes several weeks and a lot of water will leak from the flume until it has swelled and sealed itself," Jeff Munsey, Ocoee No. 2 repair project manager, said.
The repairs began in May 2010, with the rock face having to be scaled and secured using 90 bolts, some 40 feet long. About 1,000 tons of rock had to be broken up to be removed from the area. Working in tight quarters, repair crews had to bring their water and electric generators with them. The only way to get equipment to the damaged area was to move it through the remaining portion of the downstream side of the flume.
"We faced a number of obstacles as we made the repairs, including two 10-inch snow storms, but we managed the work safely and were able to repair the flume and return it to its original condition," Mr. Munsey said.
TVA began generating power at the plant again on Wednesday, April 20.
A mud slide on Thursday, April 21, caused by heavy rain and water leaking from the recently repaired flume, pushed debris into the Ocoee River about 2 miles downstream from the Ocoee No. 2 diversion dam. TVA engineers are determining the best course to clean up and stabilize the area while removing the debris from the river. Commercial rafting on the Ocoee River is not affected.