About 200,000 young salmon and steelhead were killed recently when a pump failed at the Lower Elwha Klallam fish hatchery, a controversial component of the $325 million federal project to remove two dams on the Elwha River.

Hatchery workers are still assessing the loss, but it appears to represent about half of the fish that were to be released next spring, said Doug Morrill, natural-resources manager for the Lower Elwha Klallam tribe.

“It’s substantial,” he said.

The immediate cause of the failure was an electrical glitch. But in the bigger picture, the problems at the hatchery are part of a chain reaction that started with the breakdown of a $48 million water-treatment plant, Morrill said.

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Removal of the dams on the Olympic Peninsula is releasing vast amounts of sediment that built up behind the structures over the past century. The treatment plant was designed to remove that sediment and provide clean water to Port Angeles, local industries and the tribal hatchery.

But the plant quickly choked on levels of sediment it was supposed to be able to handle easily.

The treatment-plant woes have delayed removal of the upper dam and complicated operations at the $16 million hatchery — also built at taxpayers’ expense. No water is flowing to the hatchery from the treatment plant, so the tribe had to tap wells and use a backup pump to recirculate water through the raceways, Morrill explained.

It was that pump, which was never meant to operate continuously, that failed.

“This is the biggest river restoration, the biggest dam-removal project in the United States,” Morrill said. “We’ve got to expect these kinds of hiccups and deal with them as best we can.”

Most of the dead fish were coho fingerlings, about an inch long. But about 2,000 year-old steelhead also perished in the stagnant water, Morrill said.

Morrill said he suspects the blow will be softened now that some coho and steelhead are spawning naturally in channels opened up after the lower dam was removed.

He said he can’t put a dollar value yet on the loss and doesn’t know whether the tribe will seek compensation from the National Park Service, which is overseeing the dam-removal project.

Park Service spokeswoman Barbara Maynes said the agency is focused on fixing the water-treatment plant.

Repairs should be finished by mid-September, she said.

The hatchery’s existence is being challenged in court by conservation groups that argue hatchery-reared fish can harm the wild-fish populations the dam-removal project aims to revive.

But the tribe, which prevailed in earlier court rulings, contends that hatchery fish will ensure that tribal members will be able to resume fishing after a five-year moratorium ends, even if it takes wild salmon and steelhead longer than that to rebound.

Sandi Doughton at: 206-464-2491 or sdoughton@seattletimes.com