By BILL MARDIS, Editor Emeritus Commonwealth Journal
There is a “high probability” the level of Lake Cumberland may rise 20 feet this summer!
The U.S. Army Corps of Engineers in a statement embargoed until 8 a.m. Friday said the Wolf Creek Dam Remediation Project is ahead of schedule and the Corps is now making plans to raise the water level this summer.
Don Getty, project manager, told the Commonwealth Journal current projections are to have the lake between 700 and 705 feet above sea level for the upcoming vacation season. This is about halfway to the historical 723 feet, or tree line, he noted.
“It’s not an absolute,” said Getty. “There is still a risk ... but a high probability that we can raise the lake about 20 feet this summer.” He said there are a “lot more risks” in the level between 705 and 723 that the first 20 feet.
“Our goal is to have the lake at the historical 723 feet above sea level by summer 2014,” Getty said. “There are still a lot of concerns ... a lot of unknowns,” he added.
Congressman Hal Rogers was pleased with the news.
“Lt. Col. James DeLapp personally called me Thursday with wonderful news that construction at Wolf Creek Dam is ahead of schedule, meaning the crown jewel of Southern Kentucky will be ready for the summer tourism season,” Rogers said. “Our marinas, local businesses, and local lake enthusiasts have been patient, suffering business lows due to the low pool levels at Lake Cumberland and continuous delays in construction at the dam.
“However, I commend Lt. Col. DeLapp for bringing a renewed vigor to this project over the last year and understanding that Wolf Creek Dam is a national priority,” Rogers added. “Now it’s time to spread the word, Lake Cumberland is open for business.”
Lake Cumberland has been held as nearly as a possible to 680 feet, or about 40 feet below normal, since January 2007. The lower level relieved pressure on the mile-long structure during the remediation work made necessary because the dam was in “high risk” of failure.
Getty said the concrete barrier wall being installed in the dam to stop uncontrolled seepage is about 96 percent complete. The contractor, Treviicos-Soletanche Joint Venture, “ ... has done a fantastic job.”
Work has been in Critical Area 1 since September and Getty said the contractor has been able to get three drills instead of two in the fragile section, thus advancing the schedule. Critical Area 1 is a cavern-laced section of the dam near the wraparound of the earthen section with the concrete monolith. The area initially wouldn’t accept grout and ended up delaying the remediation project about a year.
The concrete barrier wall is complete except in the critical area. The wall is formed by drilling overlapping holes 50 inches in diameter 275 feet deep from the work platform on the upstream side of the dam to about 100 feet into bedrock beneath the dam.
Getty said the entire project is about 85 percent complete but most of the remainder is site work.
The barrier wall is currently on track to be completed by the early spring 2013, significantly ahead of the previously planned completion date in December 2013. The barrier wall is the most critical component of the dam safety project and will have to be completed prior to raising the lake level.
Also before raising the lake, a dam safety team composed of an outside advisory panel of experts and experts within various Corps offices nationwide will review data on the completed barrier wall to ensure it meets requisite safety and quality standards.
“We expect this review to happen within one month of the barrier wall completion,” Getty said.
“The purpose of this initial increment is to determine how the dam reacts to these higher sustained lake levels before raising the lake further,” Getty said. “Instruments installed in the dam will be monitored and analyzed during this time. If the dam performs as expected during the initial incremental pool raise and after another safety review, the goal is to return the lake to its historical operating levels without further increments.”
“Completion of the barrier wall will provide safety to the dam and protection to the communities downstream. It will also enhance our ability to generate power and reduce low water environmental impacts,” said Lt. Col. James A. DeLapp, Nashville District commander.
Achieving this level is dependent on completing the barrier wall and obtaining safety approval by early spring, Getty added.
“Sufficient rainfall after approval of the barrier wall will also be part of the equation of raising the lake for the 2013 summer recreation season,” he said.
The lake is expected to be operated in its normal range in the fall of 2013 which means it could be lowered to elevation 685 feet as part of the normal water management cycle during the fall and to facilitate final riprap placement on the upstream face of the earthen portion of the dam.
Although the barrier wall will be complete, the project will still have work to remove the work platform extension and its associated rock fill on the dam’s embankment.
A final concrete placement and public completion ceremony is being planned for Spring 2013, the Corps said.