Published: March 01, 2007 09:13 am         

Dam repair schedule could be shortened

The U.S. Army Corps of Engineers has good news for the “Ohio Navy” and business people in the Lake Cumberland area who serve the tourist industry. Corps officials say they are trying to shorten by two years the time it takes to rehabilitate Wolf Creek Dam.

Mike Zoccola, chief of the Civil Design Branch for the Corps, pointed out that the “ ... official or published schedule” has been seven years -- two years for grouting and five years to insert a diaphragm into the earthen part of the structure. This announced timetable projects the completion in 2014.

However, Zoccola told the Commonwealth Journal Wednesday that if funded at proper levels the repair project could be completed more quickly.

Some $51 million to rehabilitate Wolf Creek Dam are in the current federal budget. Reportedly President Bush’s proposed budget for the 2007-2008 fiscal year includes another $54 million for the dam. Zoccola did not say how much more money will be needed to compress the repair timetable.

Zoccola said the original plan for rehabilitating Wolf Creek Dam called for a five-year repair program. He said if the project is funded at sufficient levels the Corps could revert to the original five-year schedule.

The engineer said separating the grouting from the diaphragm already has put the project a year ahead. Normally, the diaphragm and grouting are in the same contract, he remarked.

Advanced Construction Techniques Ltd., Ontario, Canada, began an accelerated grouting program in December. A contract to insert a four-foot-thick concrete diaphragm through the earthen section of the dam to 100 feet into the bedrock is currently scheduled for awarding this coming December.

The diaphragm called for in the current project will be upstream from a similar concrete wall put in the dam during the 1970s. The first diaphragm was about three feet thick and extended only about 25 feet into the bedrock. It did not go the entire length of the earthen section.

The new diaphragm will go about 75 feet deeper into the bedrock and extend all the way from the concrete section of the dam to the end of the earthen part at the road (U.S. 127). Corps officials say they believe that at 100 feet into the bedrock the diaphragm will be below the limestone karst that causes the leaks.

Wolf Creek Dam was built during the 1940s atop a limestone base honeycombed with cavities. Limestone deteriorates in water and the tremendous pressure on Wolf Creek Dam eventually forces water to find a path beneath or through the dam. Corps officials insist that the current seepage is not nearly as serious as the situation discovered in the late 1960s. Then, sinkholes developed and muddy water was running in the tailrace.

However, mainly because of the way the Corps evaluates dams since Hurricane Katrina, Wolf Creek Dam is considered at “high risk” of failure. Lt. Col. Steven Roemhildt, commander of the U.S. Army Corps of Engineers’ Nashville District, and other Corps officials have said they would feel safe camping at Kendall Recreation Area directly downstream from the dam. Kendall remains open to visitors and the Corps has indicated that improvements are planned at the camping area.

Zoccola said the dam is monitored 24 hours a day, seven days a week. Somebody checks on the dam structure during every shift, he added.

The dam has been under close scrutiny since March 2005 when the Corps decided a major rehabilitation of the structure is necessary. In January of this year, the Corps said the lake level would be lowered to 680 feet above sea level, or 43 feet below the tree line, at least for the remainder of this year.

Roemhildt has said several times that the lake level will be raised only when it is safe to do so. The situation at the dam will be re-evaluated in September or October to see if the grouting now underway has stopped the seepage sufficiently to change the water level. Grouting is forcing liquid concrete into cavities in the dam.

     

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