Cedar fish weir removed ahead of storm; about 2.9 million sockeye eggs collected

The fish weir crossing the Cedar River near Interstate 405 downtown was removed Wednesday in advance of the "pineapple express" storm that is pummeling the region.

The City of Seattle and the Washington state Department of Fish and Wildlife, which are jointly harvesting sockeye salmon next to Cedar River Park, have been watching the weather forecast closely for about a week.

About 1,800 sockeye – roughly an equal number of male and female salmon – were trapped and then trucked to the state sockeye hatchery at Landsburg in the upper reaches of the Cedar River, where about 2.9 million eggs were collected and fertilized.

Officials were concerned whether the weir, made of plastic pipe, could withstand the high flows the storm was expected to generate, according to Gary Sprague, the Landsburg mitigation manager for the City of Seattle.

Likely, the weir would have been fine, he said, but the city and state weighed the potential threat against the fact the number of fish being collected was dropping off.

"We wanted to act on the safe side" Sprague said. Now, the city and state can install the same weir across the river next fall, he said.

However, it's likely the high river flows have scoured out the redds or nests, damaging or killing the eggs, Sprague said.

The two agencies had hoped to collect salmon for another week or so. The goal was to collect about 18 million eggs, Sprague said.

Sprague said he wasn't "feeling too badly" about the 2.9 million eggs, which is about the same number that was collected last year at the weir near Cavanaugh Pond. Significantly, this year is the lowest return of sockeye since the counts began at the Ballard Locks in 1972, he said. Sockeye move through the locks into Lake Washington and finally up the Cedar River at Renton.

He doesn't feel the effort this year would have been as successful at the previous weir, he said.

Elsewhere in Renton, the massive storm out of the Pacific had only a minor effect, although sandbags were at the ready.

"We are fine here," said city spokeswoman Preeti Shridhar.

The Cedar River was running high through Renton, but still below flood level. No road closures were reported in the Renton area; hardest hit by rising river levels were traditional flood-prone areas in the Snoqualmie Valley.

Before the storm hit, the river was running at about 500 cubic feet per second (cfs) through Renton on Thursday, low enough to make for easy viewing as the sockeye tended to their.

Then the rains hit and the river rose rapidly, hitting about 1,000 cfs at Thursday midnight. Officials become concerned about damage to the sockeyes' redds when the river flow reaches about 1,800 cubic feet per second, according to Sprague. That is when the scouring can start to occur, he said.

The river's flow was above 1,800 cfs at about 5:15 a.m. on Friday, jumping up to about 2,000 cfs for about 45 minutes starting at about 9 a.m. The flow dropped, but remained at above 1,800 cfs on Friday, Sprague said.

"We do believe we have probably lost some eggs," he said.

The extent of any damage isn't known right now, but Seattle and state officials will be able to determine next spring whether the damage from this storm and later storms was significant, he said.

The sockeye dig a nest, then cover it with four to eight inches of gravel, according to Sprague. The nest of a Chinook, which is a bigger fish, is deeper, 10 to 14 inches.

Unocovered eggs will wash away and die. Also, the river now is full of sand and silt, which can cover the eggs and suffocate them.

Any impact would not be as bad as flows in 2006, which reached about 5,000 cfs, he said.

"That was devastating," Sprague said. "This isn't good, but it isn't horrible."

Seattle and the state plan to return next year to the same spot with the weir, he said. He expressed appreciation to City of Renton officials for their work and cooperation with Seattle and state officials to make the weir happen in Renton.

Contact Renton Reporter Editor Dean Radford at editor@rentonreporter.com or 425-255-3484, ext. 5050.

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