Millions allotted for maintenance of Lake Shelbyville dam

July 27, 2010
By: Herb Meeker

SHELBYVILLE - Every time someone talks about dam repairs, the darned stories get started.

Did you ever hear about a giant catfish supposedly stuck in a spillway pipe in one Illinois dam? It was just a whopper of a fish story with no factual basis whatsoever.

Or how about the credibility gap involving a Chicago television station story a few years ago claiming a huge crack was spreading deep inside the Lake Shelbyville dam. Actually, there was no gap; it was a divide between two monoliths on the dam that opened 40 years ago. In other words, that line down the concrete wall is how the dam was built, not a sign of potential disaster.

Ricky Raymond, operations project manager for the U.S. Army Corps of Engineers at Lake Shelbyville, said rumors about the demise of the dam are greatly exaggerated.

"For two years, we were at flood stage. People got used to it. When the water level when down to a normal level, people asked, ‘What happened to all the water?' Some asked if there was a hole in the dam," Raymond said with a grin.

This month, U.S. Sen. Dick Durbin announced Lake Shelbyville will receive $5.51 million in energy and water funds for flood control, recreation, conservation of fish and wildlife, and dam repairs. These are routine appropriations for the fiscal year.

Raymond and other Corps of Engineers personnel at Lake Shelbyville realize the words "dam" and "repairs" could create some new rumors on the stability of the structure. But there is nothing to worry about, especially because the dam, which is mostly an earthen man-made mountain, is undergoing a long-term safety study to check on exterior pressures and other factors, he said.

"If there were serious concerns, there would be a flurry of activity on the dam," Raymond said. "You have to understand the dam is 40 years old. There is a need to check on it. That is just prudent."

The dam was built to collect the waters of the Kaskaskia and Okaw rivers near Shelbyville to create better flood control and a recreational draw to Central Illinois. But old coal mines in the Shelbyville area required measures to reduce underground pressures to the dam structure, Raymond said. Those included cutoff walls and underground spaces filled with grout.

"We're in the third year of a safety study to make sure those measures are working," he explained.

Seismic and hydrostatic pressure measures have been conducted to make sure the dam, including its earthen core, is holding up well to water seepage, a factor all earthen dams must face. Maintaining slope stability is another part of dam maintenance.

"Once the survey is complete, some specific work will be identified for repair work," Raymond said.

Right now, the only water going through the dam on a daily basis is whatever is released as part of water control plan. The roar of those double jets of flowing water measured thousands of gallons per second over the weekend.

Raymond and his co-workers plan to keep the man-made marvel in good shape for years to come.