Wanapum Dam crack forces $7M in fish-ladder work

WENATCHEE — A crack in the Wanapum Dam on the Columbia River and the ensuing reduction of water levels have prompted crews to carry out about $7 million worth of work on fish ladders for chinook salmon. Existing fish ladders at the Rock Island and Wanapum dams are being extended to allow the chinook to reach their spawning grounds, The Wenatchee World reported.

“This fish coming up are a way of life for the Pacific Northwest,” said Keith Truscott, director of natural resources for the Chelan Public Utility District. “A lot of effort has been put into recovering and increasing the fish runs to the Upper Columbia. We shouldn’t allow an unplanned incident like this to deter us from our goal to be good stewards of the environment.”

Divers discovered a 65-foot crack across part of Wanapum Dam’s concrete spillway in February, and workers have lowered the water level 26 feet to reduce pressure on the dam. That left the upstream exits of the fish ladders there high and dry — unusable for the migrating fish.

At the Rock Island Dam 36 miles upriver, the ladders are usable for now, but crews are worried they won’t be as levels drop further this summer.

The Chelan Public Utility District will pay about $4.3 million to extend the ladders on the Rock Island Dam’s Chelan and Douglas County shorelines. The Grant Public Utility District’s cost to modify its ladders on the Wanapum Dam is estimated at $3 million. The work is expected to be completed by Tuesday.

Thousands of spring chinook are already headed up the Columbia, and about 1,200 to 1,500 spring chinook will soon be passing the Wanapum Dam per day. Those numbers will climb to a peak of about 25,000 migratory fish per day during the summer run, said Ray Ellis, Grant Public Utility District’s hydro supervisor.

Until they see that the migrants are adjusting well to the ladder changes, public utility district officials plan to trap as many as 1,500 fish per day as they arrive at Priest Rapids Dam, downriver, and haul them by truck to release points above Wanapum or, possibly, above Rock Island Dam.

All modifications will have to be removed when the cracked spillway is fixed and the reservoir level is raised to normal, officials from both utilities say.