Chinook catch a break
TRAIL — This ongoing series of unseasonable spring storms literally have bailed out this year’s runs of chinook salmon in the Rogue River, much to the delight of the man charged with keeping them alive.
Pete Samarin is the Oregon Department of Fish and Wildlife biologist charged with forging water-release plans for Lost Creek Lake to best benefit migrating spring chinook and, later, fall chinook.
It was a daunting task in early April, with drought plaguing water storage needed to keep the Rogue from natural disease outbreaks that have killed up to two-thirds of the spring chinook run in past years.
But storm after storm, including what’s forecast to fall Friday in the Rogue Basin, has shot the basin’s snowpack to 84% of average — likely enough to stave off drought-triggered diseases in the lower Rogue.
“It’s beyond comprehensible, how we feel today versus how we felt two, three weeks ago,” says Samarin, as he rows his ODFW-issued driftboat down the upper Rogue in Thursday’s drizzle. “And it’s only getting better.”
For the past two decades, Samarin has set Lost Creek Lake summer release schedules for the U.S. Army Corps of Engineers.
The goals are first to protect wild spring chinook, and later fall chinook, from natural hot-water diseases like columnaris, which attacks fishes’ gills and suffocates them. And then release enough water in late spring to flush juvenile salmon to the ocean.
Samarin typically has about 185,000 acre-feet of stored Lost Creek water to work with. That’s a combination of water specifically stored for salmon as well as unallocated municipal, industrial and agriculture water.
Normally, it’s plenty to meet these various needs. But this year, the lack of runoff into Lost Creek Lake — even after Samarin and the Corps dialed down Lost Creek winter releases to historic lows — leaves Samarin with just 140,000 acre-feet for salmon releases.
But just a month ago, that water bank was looking more like 110,000 acre-feet of water. That was so low that computer models were predicting the first significant chinook die-off since 2001, when about a quarter of the spring chinook run died from columnaris.
This year’s early forecasting was showing a die-off in the fall chinook run. But recent rains and snows has shot the Rogue Basin’s water production to 84% of average and growing.
That’s enough to wash much of Samarin’s anxiety away.
“Now we feel pretty good about the releases for spring chinook and fall chinook adults,” Samarin says. “The juveniles might suffer some, but our bucket is increasing every day.”
The current plan calls for releasing as much as 2,650 cfs per day in late May and early June to help spring chinook migrate through the lower Rogue River Canyon.
The best way to cripple diseases is to keep water temperatures cool at Agness. And the only way to do that in hot weather is with higher flows.
Flows out of Lost Creek likely will hang around 1,200 cfs through July. The normal “spike” in flows to help migrating fall chinook will be up to 1,750 cfs from Aug. 11 to Sept. 1.
Lost Creek Lake won’t fill this year, but it’s suddenly way higher than last year, when the lake crested at an elevation of 1,840 feet above sea level. That’s 32 feet short of full.
The reservoir bottomed out at 1,771 feet above sea level last year. That’s 41 feet below the normal bottoming out elevation in normal years.
This year, the extra water releases will allow the reservoir to bottom out 20 feet higher than last year.
That’s good news for water skiers and others who rely on Lost Creek as their go-to summer playground.
Obviously, they would like higher lake levels, because that takes away more navigation hazards. But the Congressional act that created the reservoir in 1962 made lake recreation a secondary benefit and deemed downstream salmon needs a higher priority.
For more than three decades, ODFW has crafted releases to benefit spring chinook first and fall chinook second.
Wild spring chinook are the Rogue’s most troubled salmon run, and just three weeks ago they seemed on the cusp of trouble this year.
But the heavens have opened, and Samarin’s water bucket is close enough to full to make him an optimist.
“Things look like they’ve turned around,” Samarin says. “Last year, the reservoir elevation was at 1,840. We were hoping to hit that. This week, we went flying past that. And it’s still raining. Incredible.”
Reach outdoors columnist Mark Freeman at 541-776-4470 or email him at firstname.lastname@example.org.