EPHRATA – All of the salmon are making it past Wanapum and Rock Island dams after changes to the fish ladders.
The Grant and Chelan PUD modified the ladders to allow the fish to travel upstream after a crack was discovered at Wanapum Dam.The crack in a pillar supporting the spillway forced the utility to lower the water level behind the dam to relieve the pressure.
Lowering the water made the ladders at Wanapum Dam unusable by the fish, so the utility spent $1.5 million to fix them before the first salmon began to swim upstream. The ladders were changed by May. Similar changes were made at Rock Island Dam because of the lower water level.
To test the changes, the 250 fish were released with tags to test how well the fish were traveling on the river. All of the fish have made it past both dams on their way upstream.
“Fish passage has been a priority for us since we realized the Wanapum fracture would impact fish passage,” said Jeff Grizzel, Grant PUD’s director of natural resources. “Without the cooperation of the tribes, agencies and other hydro operators this positive outcome would not have been possible.”
Officials from both utilities stated the amount of fish traveling upstream this year is larger than normal. Roughly 20,000 spring Chinook salmon traveled past Rock Island Dam by June 3, which is about 1.5 times the normal amount for this time of year.
“Biologists will continue to monitor and evaluate the sockeye and summer Chinook,” according to the utilities. “A record, or near-record, return is expected through the summer and early fall months.”