August 1, 2013 Share

Lake level to be lowered after holidays

The annual drawdown of Lake Cumberland has begun and the target for Labor Day weekend is at or about 698 feet above sea level. That will be about 6 feet lower than the current level.

After summer’s final holiday, the drawdown will continue until the lake is at 690 feet above sea level (14 feet lower than now) by early to mid October. The lake will remain at this level for several months while the remaining rock used to stabilize the earthen section of the dam during rehabilitation is removed from the work platform. Also, large riprap (broken stones loosely deposited to provide a protective foundation) will be put in place.

Don B. Getty, manager of the Wolf Creek Dam Rehabilitation Project, said all boat launching ramps in use now at recreational areas will be usable at the 698 level during Labor Day weekend.

He emphasized that lowering the lake at this time of year is not unusual. Historically, Getty said, the median level of Lake Cumberland is 691 feet. (Median means 50 percent of the time the lake is above 691 and 50 percent of the time it is below).

Completion of the $594 million rehabilitation of Wolf Creek Dam is scheduled in December. From January 2007 until this past spring the lake was held at or near 680 feet above sea level to facilitate repairs to the dam.   

An outside panel of experts in early 2005 declared Wolf Creek Dam in “high risk” of failure and a complete rehabilitation of the structure was necessary. A protective concrete barrier wall, at least two feet thick, some 4,000 feet long and 275 feet deep was inserted in the earthen section of the dam to stop uncontrolled seepage.

The barrier wall was completed in March and the U.S. Army Corps of Engineers in April allowed the lake to rise 20 feet, to a target level of between 700 and 705 feet above sea level during this summer.

Getty said another safety review will be done early this winter. “If we get the green light after the safety review the lake will return to historical operation,” he said.

“(Engineers) want to see how the dam has performed (since the barrier wall was completed and the lake was allowed to rise 20 feet),” Getty said.  He emphasized the Corps has seen no problems thus far.

Getty emphasized that historical operation of the reservoir does not mean the lake will reach pool stage (723 feet above sea level at the tree line) during summer 2014.

That’s not a done deal. It depends on Mother Nature. There must be sufficient rainfall … typically there will be,” said Getty.

by Bill Mardis
Commonwealth Journal