Russell County, KY —
Problem was, when Wolf Creek Dam was constructed before and immediately after World War II, cavities in the limestone base were packed with clay. Over time, the clay washed out, leaving caverns, some 40 feet tall, inside the dam.
Two huge sinkholes in the electrical grid below the dam and muddy water in the tailrace during the late 1960s signaled a near breach of the structure. Cities along the Cumberland River, from Burkesville to Nashville, got nervous and there was talk of mass evacuations.
A too-short barrier wall and extensive grouting (pumping liquid concrete in the dam) during the 1970s provided a temporary fix, but the leaks continued.
An outside panel of experts in 2005 declared Wolf Creek Dam in high risk of failure. In August 2005, the Corps announced publicly that a complete rehabilitation of the dam was necessary.
The first grouting contract was let in 2006 and, in January 2007, the water level was lowered 40 feet to ease pressure on the dam and facilitate the rehabilitation project. Treviicos-Soletanche JV, an Italian-French corporation, was selected as general contractor in July 2008 to insert a permanent barrier wall in the dam to make it safe.
The wall, fashioned with overlapping 50-inch holes filled with concrete, extends 275 feet from a created work platform on the upstream side of the dam to about 100 feet into the limestone bedrock beneath the dam. The project is of a scope never before done in the world.
The earthen section of the dam is bolstered with two additional walls: A shorter barrier wall extending about 15 feet into the limestone bedrock was installed during the 1970s following the near breech of the dam during the late 1960s, Also, remaining in the dam is a protective concrete embankment wall fashioned with 6 feet-by-9 feet concrete panels to stabilize the earthen embankment while the most recent wall was inserted.
“I think the Corps has done a fantastic job,” said J.D. Hamilton, owner of Lee’s Ford Marina Resort. “I believe it is a 100 year fix for the dam.”