A massive project to fix leaks at Wolf Creek Dam probably will get more expensive and take longer to complete than expected, according to federal officials.
The reason is a switch in the method that will be used to build a concrete wall inside one area of the earthen section of the dam, which forms Lake Cumberland, in Russell County.
The original plan was to drill a line of large holes down through the earthen part of the dam and into the limestone foundation beneath it, then fill the holes with concrete to create a wall, sealing off seepage channels in the foundation. A contractor started that work more than 18 months ago.
Construction of the wall is going as planned in all areas of the dam except one, said David Hendrix, who is managing the project for the Army Corps of Engineers, which operates the dam.
That one area, called Critical Area 1, has proven to be a tougher fix. It's the spot where the 3,940-foot-long earthen part of the dam wraps around one end of the concrete part of the dam.
The problem at the dam is that it was built in an area where the limestone bedrock has cracks and caves. The openings allow water to seep through under the dam, which would undermine its stability if left unchecked.
Critical Area 1 has been the site of the worst seepage since the dam was finished five decades ago.
The plan for fixing that area still involves building a large concrete barrier wall inside the earthen dam — essentially a dam within a dam.
But instead of drilling a hole, pulling out the drill and then filling the hole with concrete, the contractor will create the holes by boring a thick steel casing into the ground, then put the concrete in through the center of the casing.
That will provide more support in the holes and guard against making seepage channels worse during the construction process.
The change is designed to make the dam safer.
However, it also is slower and costs more because it requires more equipment, including the metal casings, Corps officials said.
Hendrix said he expects the price tag to fix the dam will go up and the completion date will be delayed. The Corps did not release an estimate on the new price or a completion date.
The Corps and a contractor are negotiating the new approach. Hendrix said he didn't want to discuss the new cost and projected completion date until the deal is in place.
One early estimate of the cost to fix the dam was $317 million. That had climbed to $584 million before the change in constructions methods in Critical Area 1.
A key contractor predicted at one point that the project would be done by summer 2012, and perhaps sooner, but it appears that date will be pushed back.
That's a disappointment because it probably means it will be longer until the Corps allows the water level in the lake to return to normal, said J.D. Hamilton, owner of Lee's Ford Marina Resort in Pulaski County.
Since early 2007, the Corps has kept the surface level of the lake at 680 feet above sea level — about 40 feet below the normal mark for the summer boating season — to ease pressure on the dam while making repairs.
The reduction hurt tourism, in part because it created a perception that the lake is too small.
Many users of the lake dispute that. Even at the lower level, Lake Cumberland is the third-largest lake in the state, with 38,000 surface acres, and visitors have said there continues to be plenty of room to boat and ski.
Still, raising the water level would provide more room for recreation and would be a positive sign, Hamilton said.
There had been some hope that the repair project would be far enough along for the Corps to raise the water level during the 2012 boating season, Hamilton said.
"We were thinking we only had one more year of this" lower lake level, he said. "Obviously, I'm extremely disappointed."