The Lowering of Lake Cumberland

By now, most people have heard about the repairs that are taking place to Wolf Creek Dam, located on Lake Cumberland in Russell County. Wolf Creek Dam, which is about 55 years old, has always had a seepage problem, and although some seepage is normal, over the years, the seepage under the dam has increased to a point that it is causing great concern and leading to emergency measures by the Corps of Engineers.

And while the Corps’ decision to lower the lake level to an elevation of 680 feet above sea level for repairs to the dam has impacted many things such as the area’s tourism industry and water supplies for many municipals in our area, South Kentucky RECC found itself at the center of another real concern – if Lake Cumberland is dropped below 675 feet, the John Sherman Cooper Power Station, located in Burnside, Kentucky, may have to be shut down unless additional measures are taken.

Cooper Power Station is part of the East Kentucky Power Cooperative (EKPC) System, which is owned by South Kentucky RECC and 15 other electric cooperatives in Kentucky, and provides power and critical voltage support for SKRECC and the entire region.

Kevin Osbourn, spokesman for EKPC, says the water levels of Lake Cumberland are a major concern for EKPC because the lake provides water that is critical to power and cool two electric units generating 341 net megawatts. “Cooper Station is vital to the entire region,” Osbourn said. “We will take the necessary steps to keep the plant operating.”

Osbourn said that plans are being developed to ensure adequate water supply because if Cooper Station ceases production, the financial impact to buy replacement power would be extremely serious for EKPC and member systems serving 500,000 Kentucky homes, farms, businesses and industries in 89 counties.

If Cooper Station de-rates its two units or goes black, there could be regional problems with the power grid due to the loss of voltage support, possibly causing load shedding across South Central Kentucky and Tennessee. The plant provides critical voltage support to EKPC, Kentucky Utilities and the Tennessee Valley Authority transmission systems.

Osbourn explains that load shedding is the cutting off of electric current on certain lines when demand is greater than supply to prevent a cascading blackout.

Osbourn hastens to add, however, that EKPC does not expect load shedding to become a factor, because they do not anticipate the shutdown of Cooper Station.

“EKPC will be watching the water levels closely as the repair work continues. If the lake stays around 680 feet, we do not anticipate a problem generating power. We are working closely with Corps officials to ensure we continue operating without trouble.

In February, Corps officials announced that if the current grouting repairs on Wolf Creek Dam are not successful, they would drop the lake further to 650 feet after December 31. Osbourn stressed that whatever decision is made, EKPC will have a plan in place to keep the plant operating, whether the Corps decides to go to 650 feet in September.

“EKPC is exploring several options to ensure that the plant continues operation whether or not the Corps decides to lower the lake further. Those options include the construction of a coffer dam around the plant’s water intake lines; construction of a cooling tower; and building or extending new intakes deeper into the lake.”

A coffer dam would feature a wall built around the intakes. Water would be pumped into the retaining area to maintain adequate water levels and pressure.

A cooling tower would work in conjunction with a new pump and intake system, using a fraction of the water now needed for the current cooling system, to remove heat from water and exhaust it as water vapor.

Finally, building a new intake system to feed the existing equipment would extend the lake pipes 30 to 50 feet deeper into the lake.

Short-term, Osbourn says, EKPC will be using supplemental water pumps on floating structures or barges. At current lake levels, these should be able to pump enough water to keep Cooper Station fully functional.

South Kentucky RECC CEO Allen Anderson says he feels sure that the co-op should not have any problems with the dam renovation.

“In addition to all this information that we are sharing with our members concerning the present status of Wolf Creek Dam, I want to reassure all our members that that as long as things go as planned, with proper notice, we have all the confidence in EKPC’s ability to keep Cooper Station up and producing. We know this has been a concern of our members as indicated by the number of phone calls we have received about the issue, but please understand that we always have to be prepared for the worst case scenario. And we will be prepared; so our members should see no disruption of service.”

Anderson adds that lake levels are being monitored daily, as are the renovations that are being made to the dam, and should there be any drastic changes, members will be notified.

“South Kentucky RECC is also planning for a continued power flow, and we have been very much involved in preparation in the event of a total failure of the dam. However, the majority of the time, the worst case is not end result. We just want to make sure, for our members, that we are ready in the event it might take place.”