Washington, United States Hydropower generator Puget Sound Energy recently completed construction of a new fish hatchery and an advanced upstream trap-and-haul facility on the North Cascades’ Baker River, projects expected to further increase the river’s once struggling salmon populations.
The new facilities follow PSE’s 2007- 2008 construction of an innovative “floating surface collector” (or FSC) on Baker Lake that lures and safely captures juvenile salmon for downstream transport around PSE’s two Baker River hydroelectric dams. The 1,000-ton, semi-submerged FSC set new records in 2009 and 2010 for outmigration of juvenile salmon. This spring, an all-time high of more than 520,000 fingerling salmon, mostly sockeye, were collected by the FSC and transported downstream.
“Technology can’t replace the natural habitat our salmon need to thrive, but technology can give Mother Nature a helping hand,” said Paul Wiegand, senior vice president of Power Generation at PSE. “We’re thrilled by the positive difference our investments are making for salmon in the Baker River. The future is looking much brighter for these magnificent fish.”
Since the 1920s, annual adult sockeye returns in the Baker River have averaged about 3,500. In the early 1980s, however, the returns plummeted, falling to just 99 fish in 1985. Fisheries managers feared the river’s sockeye population might perish. In response, PSE, resource agencies and Northwest Indian tribes launched a cooperative fish-recovery effort that, by 2003, produced a record Baker-sockeye return of 20,236 fish.
Government fisheries agencies are predicting that PSE’s latest investments in fish recovery will, in coming years, produce returns substantially above the 2003 record.
PSE’s most recent fish-enhancement efforts are directed under the 50-year federal operating license the utility received in 2008 for its two-dam Baker River Hydroelectric Project. Each fisheries project was developed through collaborative discussions between PSE, government resource agencies, local tribes and other parties.
In addition to building a new, larger fish hatchery on the Baker River, PSE is upgrading its nearby sockeye “spawning beach.” The man-made, 20-year-old beach – essentially a series of large, gravel-bottom pools with spring-fed water circulating through them – provides a controlled, predator-free environment for adult sockeye to lay and fertilize their eggs.
The new hatchery and renovated spawning beach are designed to produce five times more fish eggs and hatched fry – up to 11 million, initially – than PSE’s original, 1970s-era fish-culturing facility could generate.
Because PSE’s two Baker River dams are too high for conventional fish ladders, PSE has long trapped migrating adult salmon and hauled them upstream past the dams in specially built, water-filled tanker trucks.
PSE’s new adult-fish trap, a half-mile downstream from Lower Baker Dam, contains fish-friendly design features and automated systems not available in the just-replaced, 1958-vintage trap. The enhancements include higher flows of water into the trap’s riverbank entrance for better fish attraction; an automated system for segregating captured fish by species, with six separate holding pools; a water-filled “elevator” – 60 feet tall and 7 feet in diameter – with a movable floor for lifting trapped fish to the elevated holding ponds; and a sampling station, outfitted with electronic data-management equipment, for collecting biological information about captured fish.
“Hydroelectric dams give our region an abundance of clean, low-cost power, but they also have unavoidable impacts on migratory fish,” Wiegand said. “On the Baker River, we’re not only addressing those impacts, but we’re taking steps, with others, to try building sockeye runs far beyond their historic average. It’s exciting for PSE to be part of this effort.”
In 2013 PSE plans to begin operating another floating surface collector, similar to the Baker Lake FSC, in the Lake Shannon reservoir behind Lower Baker Dam. In addition, the utility is building a second Lower Baker Dam powerhouse to enhance utility control of outflows from the dam for improved downstream flows for fish.