Test of emergency siren at dam postponed

By BILL MARDIS, Editor Emeritus

Somerset — A routine test of an emergency evacuation siren at Kendall Recreation Area directly below Wolf Creek Dam has been postponed because of publicity about material movement in the dam that resulted in suspension of work in a critical area.

“In light of recent attention on the dam, we thought it prudent to delay the test,” said Tom Hale, Corps of Engineers operations manager for the Eastern Kentucky Area.”We did not want the siren to cause any unnecessary confusion or concern regarding the safety of the dam.”

The Corps announced last week a partial suspension of the seepage rehabilitation work at the dam. The suspension was triggered when instrumentation used to monitor the foundation indicated movement and increased hydrostatic pressure since work began in the area adjacent to the concrete section of the dam.

“This suspension is strictly a precautionary measure,” said David Hendrix, manager for the rehabilitation project. “We want to take the time to review our data and ensure that our treatment methods are effective and safe before we proceed,” Hendrix continued.

The emergency evacuation siren is tested four times a year, and Hale indicated the test would likely be postponed for three to four weeks. The Corps will announce the rescheduled date prior to the test.

The siren serves the Kendall Recreation Area and U.S. National Fish Hatchery, but would possibly be heard by neighboring communities and private landowners adjacent to the dam. In the unlikely event of a breach of the dam, the siren would be activated and an evacuation plan put into effect to assist the visiting public in the Kendall and Fish Hatchery areas, Hale said.

A rumor making the rounds that disaster drills have been scheduled in communities downstream from the dam apparently is not true.

“It is a rumor,” emphasized Greg Cary, emergency management director for Cumberland County. “When the situation (at the dam) first developed we met and formulated a plan. We have a plan ... we feel we are prepared (in case of a breach in the dam),” said Cary.

Cary said people in his area are concerned. “We are 35 miles downstream from the dam. There is concern, but no total chaos,” he noted.

Bill Guffy, graphic artist at Cumberland County News, a weekly newspaper in Burkesville, said the problems at Wolf Creek Dam remain a conversation piece in Cumberland County, but are no longer on the front burner.

“At the first, people were concerned ... but since then it has calmed down. People still talk about it quite a bit, but there’s no great concern,” Guffy said.

Some people who work at the courthouse in Burkesville look differently at the situation. Judge-Executive Tim Hicks was not available for comment, but a spokeswoman in his office said “ ... there’s major concern around here ... major concern.”

Asked about the rumor of newly scheduled disaster drills in communities below the dam, Allison Jarrett, public affairs specialist at the U.S. Army Corps of Engineers Nashville District office, said the Corps would not be involved in any type of disaster drills or exercises in cities and counties below the dam. She said this type of thing would be coordinated by emergency management personnel in the various counties.

Responding to fears that the recent work suspension in a 600-foot area of the dam may be a harbinger of further lowering of the lake level, Jarrett declared: “ We’re not discussing that at all.” Lake Cumberland has been held about 40 feet below pool stage since January 2007 to ease pressure on the dam during the rehabilitation project.

The material movement that caused suspension of work in what is dubbed Critical Area 1 was in the limestone stratum at the base of the dam. Jarrett said the movement was “about an inch” in “soft material” in a limestone cavity.

Critical Area 1 is in the wraparound section at the point where the concrete and earthen sections of the dam join. The problem developed in an area where grouting was being done to stabilize the section where seepage has been difficult to control. It is one of two areas labeled as critical in the earthen section of the dam.

“We expected some movement” while drilling and pumping grout (liquid concrete) into (Critical Area 1),” Jarrett said. The movement that triggered the work suspension was detected by an inclinometer, an instrument for measuring angles of slope (or tilt), elevation or inclination of an object with respect to gravity. Jarrett said she does not know how much material was involved in the movement.

No emergency was declared, but Hendrix said emergency management personnel in communities downstream were notified to keep them informed of what is going on at the structure.

Wolf Creek Dam has been plagued with seepage since Lake Cumberland was impounded nearly 60 years ago. A major leak, apparently more serious than the current problem, developed in the dam during the late 1960s. Grouting and an initial barrier wall temporarily solved the problem, but seepage continued and became worse. The Corps announced in August 2005 that the dam was in high risk of failure and a major rehabilitation of the structure was necessary.

A second barrier wall, longer and deeper than the original wall, is currently being installed in the earthen structure of the dam. The $584 million project, ballyhooed by the Corps as a permanent fix, is currently scheduled for completion in December 2012.

The Corps has emphasized from the onset of problems that Wolf Creek Dam is not about to fail. However, engineers realize that the mile-long structure holds a massive amount of water and a major breach would flood numerous towns downstream all the way to Nashville.

The Cumberland River, impounded to form Lake Cumberland, turns south through Burkesville and several other communities in Kentucky and into Tennessee, where the Obey River drains Dale Hollow Lake into the Cumberland River. The Cumberland flows southwest through dam-created Cordell Hull Lake, then past Carthage, and through Old Hickory Lake (impounded by Old Hickory Dam). From Nashville it turns northwest and flows through Lake Barkley, back into Kentucky and Land between the Lakes, and continues to the Ohio River.

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