In July 3-9 issueBy Greg WellsTimes Journal Managing EditorABOVE: Drilling on the earthfill part of the dam near the concrete portion closed one lane of U.S. 127 as new measuring devices were added.
WOLF CREEK DAM - Information has come recently at a pace not seen since the original news of problems at Wolf Creek Dam.
There was an attempt to notify emergency officials late last week, which the U.S. Army Corps of Engineers now said took too long.
That notice was caused -- according to the agency's district engineer -- by a bad instrument reading. Because of that reading the Corps came close to quickly drawing down the water level in Lake Cumberland with an emergency release.
All of that was going on behind the scenes as the Corps was putting out releases saying that the work on the dam would be halted in one area while they examined the situation.
Through all of the information, two common threads have emerged: the water level in the lake will not be increased or decreased by the Corps in the foreseeable future and everyone is safe since this incident proves they are monitoring the dam closely.
Monday the Nashville District office of the Corps released a notice that traffic on the dam will be limited as they drill exploratory wells in the road to find out what is happening inside the dam.
In an interview that same day, David Hendrix, who is in charge of the work at the dam, said they have seen as much movement in the dam over the last six weeks as they have historically seen over 12 month periods.
"Historically, it has been moving downstream and to the left at a rate of about a quarter-inch a year," Hendrix said. "Over the last six weeks that area moved an additional quarter-inch."
Another Corps engineer, Barney Davis Jr., chief of the Corps' engineering-construction division in the Nashville District office, put the yearly movement at one-eighth of an inch and was reported as saying that the dam has moved nearly an inch in the last year.
Hendrix explained that all dams move, and that movement occurs as they settle, but it is expected to stop or significantly slow down at the least as the dam matures.
Wolf Creek Dam is nearly 60 years old.
Those movements are monitored through readings taken monthly by survey crews and every six months exceedingly precise measurements are taken, Hendrix said.
It was during the most recent detailed survey that the increased movement was noticed in the first 300 feet of the earthen dam north of where the road changes to concrete on top of the dam.
"That's been the worst area (of the dam) geologically since the beginning," Hendrix said.
But he explained that the trend in direction and speed of the movement in that area has been very regular, until this most recent measurement.
The more intense concern last week was caused by an instrument which Hendrix said measures movement within the dam.
That "inclinometer" indicated increased movement deep within the dam. However, he said that was not the case after they re-read the instrument, and altered the procedure for reading it.
Part of the purpose for the new drilling on the dam is to install a new measuring device to replace that inclinometer.
"That one instrument was giving readings… well I wouldn't say they were inaccurate. Just hard to interpret," Hendrix said.
Barney Davis Jr., chief of the Corps' engineering-construction division in the Nashville District office has been quoted recently as saying that the engineers decided that particular instrument's readings were off, based on comparison to data from other nearby instruments.
Steven Foshee, a public information officer with the Corps' Nashville office confirmed that there was an effort to contact the emergency response officials when that incorrect reading came from the one instrument, but he stressed that it was not done through the emergency notification system.
He said they were simply calling the officials at home, during the evening, to let them know that the Corps was addressing issues at the dam.
Russell County Emergency Services Director H.M. Bottom said the Corps called him Friday and then again Tuesday to update him on the condition of the dam.
"They didn't have any trouble getting hold of me," Bottom related.
In the meanwhile, the nature of the work on the dam has been altered.
In the area adjacent to the concrete dam, the Corps said in their release that they "are reevaluating our grouting program - we are finding that closing the grout line with our current grout processes is not possible."
It was completion of that grout line that has been the benchmark for any decision to raise the lake level, a move desired by tourism officials.
All of the reports from the Corps indicate the process for awarding the bid for the next stage in the process at the dam will not be affected by this recent incident.
That portion of the project to improve the health of the ailing dam involves putting a wall inside the entire length of the earthen portion of the dam.
Hendrix explained Tuesday that the would involve drilling and filling a series of holes down through the bedrock under the dam.
Almost one-half of the he diameter of that concrete filling for each hole would then be drilled out for the next hole that would be filled with concrete.
These overlapping concrete columns would then form one solid wall extending all the way from deep in the bedrock at the northern shore of the dam to an overlap of where meets the concrete portion.
Viewed from above, his description outlined something like a series of circles where every circle overlapped the other to create a solid wall.
He said there would be time in between the pouring of the concrete in a hole and the next hole being drilled into that column, to allow the concrete to harden.
Hendrix said the contract for that work should be awarded in July, and that the grouting process should be completed quickly enough to prevent any delays in that portion of the project beginning.
"In all this shows that our procedures for monitoring the dam are working," Hendrix stressed.
Barney Davis, Nashville District Chief of Engineering-Construction Division advised: "The Corps will continue to monitor the project 24/7 and work transparent with the local Emergency Management agencies. Public health and safety will always be the Corps' primary concern."