A panel of experts, called a Vertical Team, will make a recommendation to Brigadier General Margaret W. Burcham, commander of the Great Lakes and Ohio River Division of the Corps, following a two-day final safety review and field trip to Wolf Creek Dam this week.
Burcham, hopefully, will allow Lake Cumberland to return to normal operation next year. She did not take part in the Nashville meeting but apparently will base her decision on recommendations from the Vertical Team.
The lake level has been lower than normal for the past seven years while a permanent concrete barrier wall, 4,000 feet long, at least 2 feet thick and 275 feet deep, was inserted in the earthen section of the dam to stop uncontrolled seepage. The dam was declared in high risk of failure in 2005 and the lake was lowered for repairs to the mile-long structure in January 2007. The barrier wall, a project unprecedented in the world, was completed in March and wrap-up work continues at the dam.
Don B. Getty, manager of the rehabilitation project, said a decision from Burcham probably won’t be made for a couple of months. Recommen-dations to the division commander will be based on technical, environmental and water management issues among other considerations, he noted.
A decision by the middle of February will be sufficiently early for normal operation next summer if, in fact, the commander gives the go-ahead, Getty indicated.
The lake is currently rising due to flooding on the Cumberland River. The water level at 6 a.m. Wednesday was 703.70 feet above sea level, almost 14 feet above the Corps’ target of 690 feet. An effort is being made to keep the lake at about 33 feet below the tree line to facilitate continued work at the dam site. The lake is normally lower during fall and winter.
“We will aggressively lower the water level (to the 690 level),” Getty said. Water is currently being released through the dam at the rate of 21,800 cubic feet per second. If the go-ahead is given for normal operation, Getty emphasized it will take plenty of rain this spring for the lake to reach pool stage of 723 feet by the summer vacation season.
Among the projects now under way at the dam is reducing to 30 feet the width of the work platform on the upstream side, and laying riprap to prevent erosion.
Treviicos-Soletanche JV, general contractor for the dam project, is still at the dam site extending a cutoff wall near the electrical switchyard immediately below the dam. Engineers believe rapidly rising and lowering of water in the tailrace may be undermining the switchyard where two large sinkholes developed during the late 1960s.
The 180-foot extension of the cutoff wall is about half completed and will be finished by late winter, Getty said this week. The below-ground cutoff wall is being fashioned the same as the permanent concrete wall in the dam by drilling overlapping 50-inch holes. The cutoff wall is not as deep as the wall in the dam.
Other work at the dam includes redesigning the sharp intersection at U.S. 127 and the road leading to Kendall Recreation Area, fish hatchery and tailwater.
“This (redesigned intersection) will make it easier for boats and trailers to make the turn,” said Getty.
Drainage issues along U.S. 127 atop Wolf Creek Dam will be corrected, Getty noted. The Kentucky Transportation Cabinet is designing a new section of 127 that will take the highway off the dam, but apparently no decision has been made about the future of the roadway atop the dam.