1 of 2 damaged turbines back online at Table Rock dam

A Table Rock hydropower generating unit knocked out by a lightning strike several weeks ago has been repaired, but a second one remains shut down.

Rocky Reed, powerplant supervisor at Table Rock dam, said the lightning strike damaged power distribution lines on two of the four hydropower turbines at the dam during a mid-May storm. The two turbines, which can produce 54 megawatts of electricity each, were shut down while contractors surveyed and repaired the damage.

“We got one running Saturday night, and we’re hopeful we’ll have the second one running within a week,” Reed said.

Loss of the two generators came at an inopportune time. Heavy rains in May and June pushed Table Rock Lake well into its flood pool, and lake manager Greg Oller said the dam partially opened its eight spillways to keep the lake from getting too high.

Some of that extra water was sent through the two undamaged hydropower turbines and more “flood water” could have been used to generate power if the other two units hadn’t been damaged.

“The lake crested yesterday (Sunday) at 6 p.m. at an elevation of 922.81,” Oller said. “We’ve been releasing 22,000 cfs (cubic feet per second) and will continue to do that until the lake gets down to 920 feet.”

The dam’s current rate of water release is far below what occurred in April 2011 when severe flooding forced dam managers to release 68,000 cfs of water over the spillways.