PGE reports ‘record’ numbers of adult steelhead returning to Pelton Round Butte hydro project

“Record” numbers of adult steelhead returned to the Pelton Round Butte hydropower project on the Deschutes River during the 2024-2025 run, which ends this month, Portland General Electric (PGE) has reported.

With more than 950 fish passed upstream of Round Butte Dam, the Upper Deschutes Basin is now home to more steelhead than at any time since the 1960s. Scientists attribute this year’s returns to beneficial ocean conditions and improvements in fish management practices.

The Confederated Tribes of Warm Springs and PGE – co-owners of the three-dam Pelton Round Butte hydropower complex – began an effort in 2010 to reintroduce ocean-going salmon and steelhead to the Deschutes River after more than 50 years without passage for these species. Scientific modeling completed in the 1990s established an annual goal of 955 steelhead adults upstream, based on the available habitat for fish.

“While the return of steelhead fish to the watershed marks a significant milestone, the journey toward full restoration continues,” said Austin Smith Jr., natural resources manager for the Confederated Tribes of Warm Springs. “The Confederated Tribes of Warm Springs remain committed to ongoing conservation efforts, adaptive management, and education.”

Of the 950 adult steelhead passed upstream, 675 traveled through Pelton Round Butte’s fish collection facility as juveniles. Young fish from the Upper Deschutes, Crooked, and Metolius Rivers are collected in Lake Billy Chinook at the Selective Water Withdrawal (SWW), a structure that enables fish to be safely transported around three dams to continue their migration to the ocean. The SWW also facilitates more natural conditions in the Lower Deschutes River by reducing temperature impacts from the dams.

“We’re excited to welcome these steelhead back to the Upper Deschutes Basin. Their journey is remarkable,” said Megan Hill, senior environmental science manager at PGE. “Most of these fish passed through the SWW, traveled 100 miles down the Deschutes to the Columbia River, then migrated another 200 miles past Bonneville Dam to the ocean. After spending about two years at sea, they made the 300-mile journey back. This year’s run highlights the power of strong ocean conditions combined with our collaborative efforts to improve fish passage and reintroduction strategies.”

Most of the returning steelhead traveled through the SWW as juveniles in 2022, a record-breaking year for juvenile collection. Since 2010, the Tribes and PGE say they have improved their ability to safely capture more fish through science-based strategies. These include the installation of a net that guides fish toward the collection area, a new stress-relief pond to allow fish time to recover after handling, and collaboration with the Oregon Department of Fish and Wildlife in the practice of smolt acclimation: holding young fish in-stream for a period of time to imprint and adjust to the river’s conditions.

Additionally, with more than two thirds of the steelhead lifecycle spent in the Pacific, recent beneficial ocean conditions likely played a “significant” role in steelhead survival and return rates, PGE said.

In addition to the 675 reintroduction program fish, 275 Deschutes River hatchery-origin steelhead were also released upstream – a reintroduction strategy adopted in recent years. These adults, referred to as excess broodstock, are screened for disease, monitored post-release, and are genetically identical to the other steelhead from the upper basin.

Using radio tracking technology, biologists will continue to monitor the adult steelhead released upstream to gather data about their movement and spawning activity. A subset of the adults, known as kelts, will travel through the SWW and to the ocean a second time. Others will remain in the upper basin to lay their eggs in gravel nests called redds, which have already been discovered in the Upper Deschutes Basin. In a few years, the offspring of these adults will begin their own journey to the ocean, following the current downstream to start the cycle over again.