A three-man commercial dive team hired by the Rock-Koshkonong Lake District (RKLD) aided in reconnecting a chain to a “dewatering plug” used to empty river water from within a powerhouse turbine chamber housing one of two wicket gates. The work was performed by Iowa-based GOE on Aug. 24.
The gate had recently become blocked by debris, which was later dislodged, likely by water pressure, and expelled, returning the gate to its full range of operation, RKLD Chairman Al Sweeney said. Inspection of the gate was still recommended and steps were underway to perform that work, he said.
On July 17, hydro technician and Wild Rose Machine Shop, LLC, owner Chris Cutts was asked to assess the condition of the west wicket gate after it became unable to fully close. Cutts outlined a plan, involving the reinstallation of dewatering slide gates, which had earlier been removed, so that he could enter the sealed turbine pit through a 2-foot in diameter manhole and inspect the wicket gate for damage and maintenance. He said the gate was likely blocked by debris.
During the Aug. 10 RKLD annual meeting, former RKLD Commissioner Ray Lunder told the Milton Courier that the debris within the west wicket gate had dislodged.
During his assessment, Cutts advised RKLD board members that the wicket gates within both turbine pits should be inspected as a matter of maintenance, and the west turbine gate should be further inspected for potential damage sustained during the blockage.
Three dewatering slide gates were recently placed in front of the west turbine chamber in the powerhouse to block river water from entering, Sweeney said.
A manhole and shaft leading into the pit is approximately 16 feet deep, and there is still about 12 feet of water inside, Sweeney said.
On Saturday, the dive team reattached the chain to the plug, Sweeney said.
“We did get the chain connected to the hinged cover (of the plug) and we did get it open. We fastened it wide open,” he said.
Sealing the dewatering gates is the next step, Sweeney said.
Sweeney also described a section of trash rack that had been removed from the west side of the powerhouse. With the dewatering gates in place, debris could not pass through into the turbine pit on the west side, he said. The rack was removed because it was damaged. The section, a 3-foot by 10-foot panel, was twisted, and not staying properly in place, he said.
He said the damaged section could have been responsible for allowing passage of the debris, which had earlier obstructed the wicket gate.
Following up by email, Sweeney wrote on Thursday, Aug. 29, Cutts, with help from recently hired dam and powerhouse principal operator Kim Bothom, placed two trash racks and inspected the west wicket gate carousel under the powerhouse floor.
“The first trash rack was very difficult to place because of lack of proper tools. The second, with the help of (Bothom’s) wrecker boom … was placed without much difficulty,” Sweeney wrote. He cited Bothom’s expertise as a significant help.
Relative to wicket gates, he wrote: “The inspection was successful with the wicket system in good operating condition.” The manhole cover was replaced and tightened, leaving all the equipment in “operational” condition, he noted.