Fish kills on the Upper Deschutes River.

Fish kills on the Upper Deschutes River.

Erik Mobley/ODFW

The Oregon Department of Fish and Wildlife estimates that 500-1,000 fish died recently because of low water in the Upper Deschutes River. The fish kills are a recent annual occurrence tied to water management in the basin.

The Upper Deschutes is fed from the Wickiup Reservoir. A few weeks ago, river flows were about 2,000 cubic feet per second. But once irrigators were done with water for the season, dam operators cut back water releases by at least 75 percent.

“What happens is the river channel below Wickiup gets de-watered, basically,” said ODFW fish biologist Erik Moberly.

He and dozens of volunteers rescued several thousand fish earlier this week. Many were stuck in pools surrounded by dry land.

“As the river decreases, there’s some stranding of fish in the Upper Deschutes,” Moberly said. 

The Bureau of Reclamation and the Oregon Water Resources Department manage how much water is released. They hold back water in the fall to start recharging the reservoir.

Environmental groups sued over water management in the Upper Deschutes earlier this year, but those lawsuits are pending.