Hatchery strives to recover from flooding

November hasn't been a great month for the Issaquah salmon hatchery. When the rains started Nov. 3, debris clogged the facility's fresh water intake, killing 200,000 baby coho salmon — nearly half the hatchery's annual production.

A few days later, floods began. Logs hurtled down Issaquah Creek, damaging dams and fish ladders; mud jammed the hatchery's water filter and seeped into fish ponds. Hatchery foreman John Kugen expects that he and the hatchery's one other employee will spend the next month repairing flood damage.

On Tuesday, about 4,000 coho salmon continued their journey upstream when Kugen and his colleague fixed a fish ladder a quarter mile from the hatchery, which is the only route upstream.

At the Issaquah hatchery, state workers harvest millions of chinook and coho salmon eggs, as well as rainbow trout, raising the young fish in trays and fish pools until they're old enough to make it on their own.

The state hatcheries keep stocks high enough for sport fishing and protect the salmon population from disasters like the recent floods, which may have dislodged salmon eggs from the stream bed, or buried them under heaps of silt. Biologists won't know how much damage was done to the wild-salmon population for a few years, when the remaining eggs mature and the fish return from the wild.

Some fisheries were hit even harder than Issaquah. Department of Fish and Game officials estimate that statewide, hatcheries sustained $1 million in damage. At Cedar River Hatchery, which raises sockeye salmon for the same river system as Issaquah, heavy water flows damaged the fish weir and fish traps.

On Nov. 3, heavy rains drove Issaquah Creek's water at speeds of up to 150 cubic feet per second, Kugen said, about five times its usual rate. Leaves and other debris clogged a small waterway that brings creek water into the hatchery, choking off the supply of fresh oxygenated water and killing about 200,000 fish in one crowded pond before a hatchery worker saw the problem in the morning.

The 450,000 coho salmon released each year from the 70-year-old hatchery don't come back to the creek for four or five years, so the effects of the salmon loss won't be noticed by fishermen until then.

There's no way to replace the salmon that have died with more from other hatcheries, Kugen said, because that could disrupt the ecology of another river system.

The flood-generated silt is in evidence throughout the hatchery. Fishery workers can't trap any salmon to harvest their eggs at present, because the "crowding machines" that push the fish around their pools are blocked by piles of silt that will have to be vacuumed out. Early in the flood, silt clogged the filtration machine that cleans out roots and dirt from the water that flows to hundreds of trays full of incubating fish eggs.

"This guy gave up the ghost on us," said Kugen, slapping the machine. "The manufacturer's going to say we need a third filter. That's about $18,000, and our department doesn't have it."

The eggs are at greater risk of getting scratched by the dirt, which can expose them to bacteria and disease.

Logs that damaged a dam upstream will have to be dragged out by a construction crew, Kugen said. The dam has to be fixed, or low water levels could threaten the fish again by February.

"Our construction crews have been stretched thin," Kugen said. "They're all out there trying to save these other hatcheries."

Joe Mullin: 206-464-2761 or jmullin@seattletimes.com