Published: September 05, 2008 03:30 am      

RUMOR CONTROL

Corps trying to keep handle on flurry of lake rumors

The rumor mill around Lake Cumberland continues to grind.

Because of this predictable phenomenon, the U.S. Army Corps of Engineers provides a forum for questions with a promise of a response within 24 hours.

A “Rumor Control” button on the Corps’ Web site:

www.lrn.usace.army.mil/WolfCreek/

makes it easy for people to get to the bottom of rumors that naturally circulate during the Wolf Creek Dam rehabilitation project.

Following are some of the more recent questions to which the Corps has responded. (Some of the responses are in first person, written or stated by a Corps engineer):

The Corps is not sure how to fix the latest problem.

“We are wrapping up our grouting contracts and are hoping to begin wall construction this fall. Grouting has been successful in all areas except one, the earthen embankment immediately next to the concrete dam.

“We’ve stopped grouting here temporarily in order to install more instruments and get a better understanding of what’s happening in the foundation. These instruments will help us determine the appropriate way to address the openings in the limestone. This is nothing to be concerned or alarmed about; we are confident we will be able to fix it. We are simply taking our time and really investigating this area to be sure we take the proper steps to fix it.”

It was suggested that you get started building a new dam but there is no time to allow for that because the current dam will not hold that long. Money is preventing you from getting the process started on funding a new dam.

“While one of the original options on the table was the building of a new dam, that option was thrown out long ago for many reasons. Building a new dam, while costing exceedingly more than our current project, would be a lengthy construction project.

“Besides taking several years to design and construct, a new dam would likely be tied up in environmental and regulatory disputes for years and years. When this seepage rehabilitation project was begun, Wolf Creek Dam needed immediate attention to stabilize the foundation and to slow seepage.

“Even if we had chosen to take the route of building a new dam, we would still have proceeded immediately with our grouting contracts in order to stabilize Wolf Creek until the new dam could be built.

“Additionally, our studies showed that the construction of a concrete barrier wall would be a long-term fix to the seepage problem at Wolf Creek. In short, the barrier wall combined with grouting could achieve the same success as a new dam, and it would be cheaper and faster.

“Money is always an object, but to date we have received from Congress all funding we have requested, and we have every reason to believe that this project will be fully funded every year until it is complete.

“Wolf Creek is a high-priority project for the Corps, and in that sense, money is not an object for the Corps when it comes to choosing public safety.”

The lake will never be raised back up to its original level.

“We have procedures in place to help us determine when we can raise the lake level. As we complete major structural mile-stones in the construction work, and our instrumentation shows the foundation is stable enough to handle an increase in lake level, we will make the decision to bring the lake up in 10 foot intervals.

“As of right now, we have no current plans to raise the lake this year. We are, however, planning to begin work this fall on the last and biggest portion of the construction project.

“As that barrier wall goes in, we may be able to raise the lake in those 10-foot intervals. Because public safety is our first priority, though, there is no guarantee that the lake level will return to near normal until the construction project is completed. Right now, that date is estimated to be 2012.

“Although the lake level is significantly lower, I would like to reassure you that there is more than enough water on Lake Cumberland for recreation, and boat ramps and marinas have been altered to ensure almost full accessibility to the water.”

Only three boat docks are usable on Lake Cumberland. It is very difficult to access the water now that the lake level is lowered.

“There are 14 Corps monitored and maintained boat ramps that are usable at elevation 680. With a total of 48 boat ramps on the lake, you’re looking at approximately 45 locations where you can access the water.”

Corps monitored and maintained boat ramps on the lake are:

Alligator Dock #1, Alligator Dock #2, Beaver Creek Resort, Burnside Island State Park, Conley Bottom Marina, Cumberland Point, Fall Creek, Grider Hill Marina, Halcomb's Landing, Jamestown Marina, Lake Cumberland State Park-Greasy Creek, Lee's Ford Marina, London Dock, Omega/Buck Creek Dock and Waitsboro.

“We have worked hard with state, county, and commercial entities to ensure that Lake Cumberland remains accessible during the drawdown. Please assure anyone you meet that the lake is accessible, is still huge (nearly 38,000 acres of surface area), and is still a beautiful and viable place for recreation.”

The drills seem to keep changing positions almost daily. There must be a problem the Corps can’t resolve.

“The drilling you see on the downstream side of the earthen dam is being done to install instrumentation. These instruments will monitor the work we’ll be starting soon on the concrete barrier wall, and will also monitor future grouting work.

“The drilling being done on top of the dam on the highway is also instrumentation installation. These are going in an area of the earthen embankment, right next to the concrete dam. In that area, the grouting has not been as effective as in other areas (there are more caves and holes in the foundation there), so the instrumentation will help us determine the next step in addressing that area.

“Although we are changing tactics to address this particular area, there is no reason for alarm or concern, and we feel certain we can close off this area with the wall installation and possibly different grouting techniques.

‘The upstream work platform still has some grouting work wrapping up, and the contractor there is also verifying the quality of the grout line and installing some instruments.”

Wolf Creek Dam is compromised in structure and there is not any remedy to correct this.

“Wolf Creek Dam does have serious seepage problems (water moving slowly through openings in the limestone foundation), but we are two years into a six-year rehabilitation effort.

“Those two years of grouting, increased monitoring, and lowering of the lake, have greatly reduced the risk at Wolf Creek; in other words, our remedy is already correcting the problem. Please rest assured that every day we work at Wolf Creek Dam, we are making the dam safer.

“We have just awarded the final construction contract, and this fall work will begin on installing a concrete barrier wall inside the dam. This wall will be like a dam inside the dam, and will go hundreds of feet into the ground to cut off water that is seeping through the foundation.

“We have hired two of the best contractors in the world to do this highly specialized work, and we are extremely confident that this wall will fix the problems with Wolf Creek’s foundation for the long-term.”

Excessive seepage was observed at Wolf Creek Dam between 2002 and 2004 when the lake level was high due to heavy rainfall. The Corps began to control the lake level in March 2005 and announced in August of that year that a major rehabilitation of the dam is necessary.

Later, the massive dam structure that impounds 101-mile-long Lake Cumberland was declared in high risk of failure. As a result, the lake level was lowered to 680 feet above sea level, or about 43 feet below the tree line, to ease pressure on the dam.

The latest progress report on the Corps’ Web site says production rock drilling, pressure washing and grouting operations are all complete. Grouting in Critical Area 1 will be deferred until the barrier wall contractor is on site.

Arcadis-Boart Longyear, a separate contractor, continues to install four new instruments on the downstream embankment.

There is a total of more than 838,000 gallons of grout in 1,317 holes along the embankment. More than 844,234 gallons of grout have been pumped into the foundation in all areas.

Mobilization will begin soon of new barrier wall contractor. Corps engineers were meeting with the contractors last week.