Don Getty told the Commonwealth Journal ( http://bit.ly/VKX6us ) that the project, which began in 2007, is about 85 percent complete.
Getty says he expects lake levels to rise in 2014, though how much depends on several factors — including the amount of rainfall.
He said the depth of the lake will be increased in increments after the barrier wall is complete. After each increment, officials will inspect the dam to make sure the structure is safe. The lake is considered to be full when it is 101 miles long and an average of 90 feet deep.
Getty said all primary holes have been drilled along the unstable portion of the dam, which lessens the risk of a setback.
"There are still risks," Getty said. "But not as much."
The $594 million project to stop the seepage includes inserting a deep underground wall along the dam's 4,000-foot long earthen embankment and filling underground karst formations with cement.
Engineers have said Wolf Creek Dam will be permanently repaired when the current rehabilitation is finished.