By Christine Pratt / The Wenatchee World
WENATCHEE — Seen a helicopter dipping a basket into the Columbia River below Rock Island Dam lately? It wasn’t fighting a wildfire.
The Grant County PUD is using a helicopter to release tagged juvenile salmon into the river to track their movements through Wanapum and Priest Rapids dams.
The two dams are both south of the Interstate 90 bridge at Vantage. The Wanapum Dam reservoir backs up to the Chelan County PUD’s Rock Island Dam.
The helicopter should be in the vicinity of Rock Island Dam, possibly in the Tarpiscan area, between 9:30 and 10 a.m. daily for the next two weeks to release the fish, PUD spokesman Chuck Allen said.
As the released fish reach the dams, crews can study their mortality in different areas in hopes of determining if deaths are caused by predators, dam operations or other hazards that could be mitigated.
Crews are using a helicopter to reduce the time it takes to transport the fish and to release them in the center of the river, Allen said.
The releases are one requirement of agreements under the PUD’s license to operate Wanapum and Priest Rapids dams.
Fish are loaded into the helicopter, transported and then lowered in baskets for release into the river, Allen said.
The operation resembles a helicopter’s water-dipping duty in helping fight a wildfire, he said.
Grant PUD recently completed a $28 million juvenile-fish bypass system at Priest Rapids Dam.
The bypass allows the utility to get the same number of ocean-bound juveniles past the dam with about one-quarter the water, a PUD news release said.
This leaves more water in the reservoir for hydroelectric power generation, officials say.
Juvenile migrants are on their way downriver now, officials have said.