ARIEL — PacifiCorp says it will prepare rough estimates by mid-July regarding rebuilding or abandoning salmon acclimation ponds damaged by winter flooding in the Muddy River and Clear Creek in the upper North Fork of the Lewis River watershed.
For 2016, the 38,000 young spring chinook salmon that would have spent a few weeks in the ponds before release in the fall will be put directly into the Muddy River and Clear Creek, plus a functioning acclimation tank near the mouth of Crab Creek, streamflows permitting.
Restoration of spring chinook, coho and winter steelhead in the upper North Fork of the Lewis River is part of the 2008 federal license for PacifiCorp to operate Merwin, Yale and Swift dams.
Flooding in mid-December tore up the ponds, which are side channels with water control structures in the two streams in the Gifford Pinchot National Forest.
Ruth Tracy of the Forest Service said the December flooding was the highest since 1996.
“I knew these ponds would face flooding,’’ said Frank Shrier, principal scientist for PacifiCorp. “I didn’t know they’d be destroyed.’’
The Muddy River pond is in the worst shape.
A water intake system that was along the edge of the river and is connected to a 2-foot-diameter pipe to carry Muddy River water approximately 1,300 feet to the side channel now is in the middle of the river
“It stands there like a monolith,’’ said Shrier.
Tracy said the Muddy River is a candidate for inclusion in the national wild and scenic river system.
As such, a large water intake structure in the middle of the stream is not allowed.
“There are a lot of challenges here if you’re thinking you’re going to reconstruct,’’ she said.
Members of the Lewis River Aquatic Coordination Committee took a tour of the Muddy River and Clear Creek ponds last week.
PacifiCorp has declined repeatedly to say how much the two ponds cost to construct.
The Lewis River committee includes officials of PacifiCorp, plus representatives from the Gifford Pinchot National Forest, state and federal fish agencies, Cowlitz Indian Tribe, Lower Columbia Fish Recovery Board, Cowlitz PUD and others involved with salmon and steelhead restoration in the upper watershed.
“My preference is just to abandon the Muddy,’’ Shrier said. “It’s got too many problems, including the water quality.’’
Too high of levels of iron in the pond compromised salmon rearing even before the flood.
Aaron Roberts of the Washington Department of Fish and Wildlife said the Muddy River pond was impressive when it was built.
“It looked like it was going to work,’’ he said.
The Clear Creek channel was filled in by cobble and other rock. The side channel still exists, but is shallow now and dry part of the year.
“I never thought we’d get this kind of deposition,’’ Shrier said.
PacifiCorp officials said the Clear Creek channel would be cheaper to fix than the Muddy River channel, but still would cost more than $100,000.
“I’d be more inclined to put money in this channel,’’ Shrier said about Clear Creek. “It’s less onerous than to try to make the Muddy work.’’
The utility is committed to the concept of getting young spring chinook acclimated to the upper watershed so they will return as adults from the ocean and be trapped at Merwin Dam for transport upstream of Swift, he said.
But the Muddy and Clear Creek ponds might not be the method used.
An acclimation facility near road No. 90 at Eagle Cliff has been mentioned as an alternative, but is not favored.
Shrier said the Eagle Cliff area is populated by bull trout, which likely would prey substantially on the young spring chinook once they are released to make their downstream journey.
The young salmon are collected in a facility at Swift Dam and then trucked downstream and released in the lower Lewis River at Woodland.
In-water work in the Muddy River and Clear Creek is allowed only from July 15 through Aug. 31. That means whatever decisions are made, work will not be attempted until 2017.
The settlement agreement between all the parties with an interest in the North Fork of the Lewis River does not specify how many acclimation ponds are enough.
“To me, it’s all an open question,’’ Shrier said.
