Excessive rainfall during the past couple of weeks in the Cumberland River Basin has raised the lake about 10 feet above the target 680-foot level. Some 21,320 cubic feet per second are being released through the dam to reduce the water level.
Completion of the barrier wall did not completely finish the rehabilitation project. Weddle Enterprises, Somerset, is currently narrowing the work platform on the upstream side of the dam from 75 feet wide to a 30-foot-wide platform that will remain. The platform was built to accommodate heavy equipment that fashioned the barrier wall by drilling 50-inch, overlapping holes filled with concrete.
The wall, a minimum of two feet thick, extends from the work platform 275 feet downward to about 100 feet into limestone bedrock beneath the dam. The project, of a scope never done anywhere in the world, is designed to stop uncontrolled seepage that has plagued the dam since it was completed in December 1950. Wolf Creek Dam in 2005 was declared in high risk of failure and the water level was lowered 40 feet in January 2007 to facilitate the current rehabilitation project that is nearing completion.
Part of the information available to ongoing meetings of Corps engineers is core drillings into the newly inserted wall to assure integrity of the concrete. This type of evaluations has been going on throughout the construction process and is winding down now, Getty said.
Wolf Creek Dam is bolstered with two additional walls: A shorter barrier wall extending about 15 feet into the limestone bedrock was installed during the 1970s following a near breech of the dam during the late 1960s, and a protective concrete embankment wall fashioned with 6 feet-by-9 feet concrete panels to stabilize the earthen embankment while the most recent wall was inserted.
The near-vacant work platform is testimony the dam rehabilitation project is nearing an end. Most of the equipment has been moved and many of the up to 275 workers are no longer on site.