Repair project at Wolf Creek Dam nears completion

Posted January 23, 2013 at 8:06 pm

After seven years of construction work and lower water levels on Lake Cumberland that affected tourism commerce and even threatened water availability for Albany Municipal Water customers, the Corps of Engineers announced last week that the rehabilitation project at Wolf Creek Dam is nearing completion.

The announcement came Thursday afternoon when marinas were notified of the situation and was made official early Friday morning when the Corps issued a press release from the Nashville District Commander, Lt. Col. James DeLapp.

That announcement contained two positive points, the first being that the project was expected to be completed early this spring several months ahead of schedule, and that it was expected that the level of Lake Cumberland would likely be raised for the upcoming summer tourism season by some 20 feet, to an elevation between 700 and 705 feet.

The news was a welcome announcement to Rick Mercader, general manager at Grider Hill Marina, the only commercial marina in operation on Lake Cumberland that is in Clinton County.

“It’s just great news,” Mercader told the Clinton County News during a telephone conversation as he was traveling to set-up a booth for Grider Hill last week at the Cincinnati Boat Show.

Since construction to repair the leaking concrete and earthen Wolf Creek Dam began, water levels at Lake Cumberland have been lowered in an effort to reduce the pressure created by the water against the dam.

That reduction in level has caused several adverse situations for the marinas on the lake, as well as for several communities such as Albany that depended on Lake Cumberland for it’s municipal water supply.

With a water intake system near Seventy Six Falls originally, the City of Albany was forced to find funding to move that pumping facility to deeper water in order to insure that there would be no interruption in water supply should the Corps be forced to lower the lake level even further.

Held at a level of 680 feet throughout most of the now seven year-long rehabilitation construction process, the announcement of plans to raise the level up to as high as 705 feet was welcomed news to say the least.

“It’s going to be a tremendous boost to our business in so many ways – houseboat rentals, pontoon rentals, gasoline sales,” Mercader told the Clinton County News on Monday of this week, still speaking from the Cincinnati Boat Show via telephone. “The increased traffic to our dock will be tremendous – just a big boost.”

The lower lake levels that have been experienced during the construction process also meant that the lake’s premier gathering spot for summertime boaters – the pool of water below Clinton County’s Seventy Six Falls, was also inaccessible to boaters most of the time.

The increased lake level announced last week by the Corps of Engineers, will change that and allow boaters to once again congregate at the popular attraction.

“7-0-5 puts the party back in the cove at Seventy Six Falls,” Mercader said unable to hold back the excited tone in his voice.

The announced levels of 700 to 705 feet for the upcoming summer tourism season, is still some 20 feet short of the 720 feet elevation that was considered to be a typical “summer pool” level in normal operations.

The problems with Wolf Creek Dam that brought about the extensive rehabilitation project stemmed from the way it was originally constructed back in the 1940s and 1950s.

Built atop a system of karst geology that included caves and caverns below it’s foundation, water began seeping underneath the structure, weakening the integrity of the dam that is a combination of concrete structure joined with a earthen section that makes up the nearly mile-long feature that holds back the Cumberland River to form Lake Cumberland.

The project to repair the leaks underneath Wolf Creek Dam, has involved constructing a barrier wall by drilling a series of large holes that reach depths of as much as 275 feet below the dam’s work platform, into solid bedrock.

Those overlapping drilled holes, referred to as caissons, were then filled with concrete in a “leap-frog” fashion to form a deep cutoff wall that will hopefully prove to be the final fix to stop the water from seeping through and beneath the dam.

Back in the 1970s, a similar problem was discovered and a project similar to the one now nearing completion was made in an effort to stop the leaks and seepage then.

However, it was later determined that the earlier repairs were neither deep enough nor long enough to have been totally successful.

The current repair project was not only considerably deeper in its placement of concrete below the dam’s foundation, but unlike the repair attempts in the 1970s, this time included the entire length of the earthen portion of the dam.

The most recent project also saw crews paying particular attention to the repair efforts where the concrete portion of the structure and the earthen portion joined.

That area was referred to by both the Corps of Engineers, as well as by the construction firm completing the project, as “Critical Area No. 1” and was the area where the most problems were encountered during the project.

During earlier phases of the repair project, when grout was being pumped into the ground to slow the water seepage before the drilling of the large caissons began, crews made several different attempts at getting the grout to stay in place before finally finding the right combinations to successfully get the material to set up.

Although the project is being completed months before the projected completion date of December of this year, the projected costs that were first announced for the construction has nearly doubled.

In January, 2006, at a public hearing held at Burkesville, officials with the Corps noted that they expected to spend just over $305 million to make the repairs.

The most recent figures put the cost for the rehabilitation project at about $594 million.

In last week’s announcement, it was noted that the Corps and the contractor, Treviicos-Soletanche Joint Venture, have been constantly working together to improve efficiencies and work processes, all the while keeping job safety requirements at the forefront. As a result the barrier wall installation has progressed ahead of schedule.

According to Don Getty, project manager, 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.”

“The entire team has been working very hard towards getting this project completed and intends to raise the lake to elevation 700-705 feet by the summer of 2013, which is great news for everyone who loves to recreate at Lake Cumberland. More importantly, completion of the barrier wall will provide the 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 at 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 rip rap 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.

During recent years, while the repair project was ongoing at Wolf Creek Dam, the concrete work platform that had been constructed on the lake side of the structure had been buzzing with construction equipment and activity from one end of the earthen section, nearly a mile away to the other end.

This week, only a small portion of the equipment that had been in place just a year ago on the platform remained in place as it was clear that the project was, in fact, coming to a successful end.

In conjunction with last week’s announcement by the Corps, several other agencies that are directly affected by the news also made announcements of their own concerning how the news effected them, as well as, in the case of the Kentucky Department of Fish and Wildlife Resources, plans of their own to help boost traffic and return usage of Lake Cumberland to pre-construction levels.

“This is great news for tourists, boaters, fishermen and the marinas and other businesses in the Lake Cumberland area,” said Gov. Steve Beshear. “The early completion of the work at Wolf Creek Dam will help bring back much-needed jobs in this area.”

Gerry Buynak, assistant fisheries director for the Kentucky Department of Fish and Wildlife Resources, said adding water atop the lake’s overgrown banks will boost fish populations in Lake Cumberland for the next three to five years.

“This will result in a ‘new lake’ fish population boom, with very good spawns of fish such as bass and crappie expected,” he said. “This vegetation will also provide cover for young fish so survival should increase resulting in the production of very strong year classes.”

Kentucky Fish and Wildlife will stock 150,000 more walleyes and 150,000 more striped bass than normal this year. Altogether, the department will add 1 million walleye and striped bass to the lake this year to give fishing a boost.

Buynak said the department also plans to jump-start the trophy trout fishery in the Lake Cumberland tailwater by stocking 10,000 trout larger than 15 inches next winter.

“This will bring the fishery back quicker as the abundance of the larger rainbow trout in the tailwater has declined drastically due to poor water conditions,” Buynak said.