In Apr. 10-16 issue
By Greg Wells
Times Journal Managing EditorABOVE: Work continues by the contractor inserting grout into the dam. The process is taking longer than originally expected.
WOLF CREEK DAM - The new Resident Engineer for the Wolf Creek Dam Seepage Project is Tyrone Crear. Crear said he came to this project after 29 years with the U.S. Army Corps of Engineers, most recently in the Detroit District.
"This is an exciting project and I'm thrilled to be working on it," Crear said. "We're working as hard as we can everyday."
As to what the results of that work was doing to the seepage at the dam, Crear suggested the Nashville District office would be the better place to find those answers.
There is no certain news yet on when a decision about the lake level for the coming year will come, though sometime in mid-May was suggested as a possibility when the last date that the Corps had suggested was passed without a decision.
Just 18 years after it was completed, the first problems were detected at Wolf Creek Dam and the first grouting to stop up the leaks took from 1968 to 1970. After that the U.S. Army Corps of Engineers began installing a seepage cutoff wall and that concrete diaphragm was burrowed into the side of the earthen portion of the dam from 1975 to 1979.
During that construction project the water level in the lake was lowered to take pressure off the dam during the work.
In January 2007, when the Corps announced the newest round of repair work, they again lowered the lake level, and after significant public and political pressure the Corps announced last winter that they would, in the spring, announce if the lake's water level could be increased.
Since then they have pushed the announcement to this month or possibly next, depending on the success at halting water infiltration through the dam. That first line of grout is not yet completed and according to individuals at the site they are going back for the fourth or even more times to work on some of the areas of the dam.
The last time they were interviewed, officials said the area near the center of the earthen portion of the dam as well as the "wrap-around" section where the earthen dam meets the concrete dam were in need of more grout before the Corps would be happy with the results.
Following heavy rains, this week the lake has been about 15-16 feet above the level set for it by the Corps during this repair, 680 feet above sea level. Corps officials have stated that the highest level they could approve this spring would only be 690.
On Wednesday morning, Apr. 9, the lake was just over 695 feet, higher than at any time since 2006.
Besides the rains, the Corps had also announced they were operating the entire Cumberland River system in "flood reduction mode" due to the extensive rains in the downstream river and Ohio and Mississippi River valleys.
However, by Wednesday, the Corps was again releasing a continuous high flow from Wolf Creek Dam, apparently to mitigate the higher levels of the lake.
At a press junket to the dam last summer the Corps had stated that high water levels in the lake because of flooding downstream had been the likely cause of the present leaks. They have explained that caves in the bedrock are allowing water to pass below the dam, and surface downstream.
In 1968, the lower slope of the down-stream side of the dam developed a slump and a sink hole while there was muddy water showing up in the tailwater, from underground.
This recent seepage has not produced either of those tell-tale events, according to the Corps.
There have been areas below the dam that would not dry up, however, and some of the instruments installed during the previous repairs were showing more water passing through the dam than was acceptable.
Over $300 million is the projected cost of the repairs to the dam this time around.
According to the Corps plan, the earthen section of the dam will be filled with a concrete wall extending from the bedrock on the northern shore all the way past where the concrete portion of the dam begins.
The new "diaphragm" wall is to be driven further into the bedrock below the dam than the original concrete dam and extend farther on both ends than the first repair wall.