Low flows, held water threaten salmon

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It's a tough year for mid-Columbia salmon, including the celebrated Upriver Brights, one of the region's last healthy runs of Columbia River chinook.

Their migration started out deadly this spring because of near-record low flows in the mid-Columbia because of drought and the demand for hydropower.

And it could get worse.

The Federal Energy Regulatory Commission (FERC) has recommended eliminating spill this summer at the Priest Rapids and Wanapum dams on the mid-Columbia. Spill is intended to boost salmon survival by pushing juvenile fish through dam spillways, instead of turbines. But water spilled for fish doesn't go through generators, which eliminates its potential to make power.

Eliminating summer spill could kill 4 to 5 percent of migrating juvenile summer chinook in the mid-Columbia, resulting in 200 to 900 fewer returning adult summer chinook over the next two to four years, said Joe Lukas, fisheries scientist for Grant County PUD. The utility operates Priest Rapids and Wanapum dams, which are regulated by FERC.

River operations have already taken a toll.

** Upriver Brights, or fall chinook, died at seven times the normal rate during the first five weeks of their migration through the mid-Columbia. More than 700,000 migrating juveniles stranded on the beach, doomed to cook in the sun through April 29, according to state and tribal biologists. They say they haven't seen anything like this spring in five years of record keeping.

"You would see thousands of fish in potholes and depressions that either drain away or reach lethal temperatures," said Paul Hoffarth of the state Department of Fish and Wildlife, who leads a monitoring team. "In flat terrain, 50 to 100 feet of shoreline would de-water. We've seen salmon trying to survive in deer tracks."

** Upper Columbia chinook and steelhead, both listed as endangered under the federal Endangered Species Act, have been delayed in their migration to the sea. They are languishing in reservoirs upriver because of low flows, which create slow-moving water. Delay can kill juvenile salmon as they fall prey to disease and predators in reservoirs.

The trouble began in winter, when state and federal agencies chose to draft Grand Coulee deeply for three reasons: to keep water on nests of threatened chum salmon in lower Columbia and Upriver Brights in the mid-Columbia, as well as meet the region's winter power demand.

But in a drought year, that meant less water for fish later, when they migrate.

"They hoped for rain and it didn't come," said Scott Bettin, fish biologist with the Bonneville Power Administration (BPA).

The Bureau of Reclamation continued to pull water out of Grand Coulee into mid-May, to keep fall chinook nests covered above the Hanford Reach until fry emerged from the gravel, as required under long-standing protocol. Flows through the mid-Columbia remained low because of the drought. That made fish more vulnerable to stranding as river levels fluctuated when dam operators pushed water through turbines to generate power and then let flows drop when the demand for power did.

When flows are low, fluctuations can strand a lot of fish, which are concentrated in higher numbers in a smaller volume of water.

When power demands peak around Puget Sound, it can kill juvenile salmon in the mid-Columbia because power provided to many Puget Sound utilities, including Puget Sound Energy, Tacoma Power and Seattle City Light, is generated in part by hydropower dams in the mid-Columbia.

Flows dropped even lower in May, when operators of Grand Coulee reduced flows to refill the reservoir. Flows were as low as 20 to 30 percent of average.

Biologists said they recorded the strandings and then rescued the fish they could, even turning over rocks to find them. They gathered them up in buckets and poured them back in the main channel of the river.

The stranding danger is nearly past for the spring migration, as the fish gain size and move out of the mid-Columbia to the main stem of the river. But river operations and drought took their toll.

Lukas estimated 1,000 fewer adult Upriver Brights will return to the Columbia River in three years because of this year's strandings. That's out of an adult return of about 200,000 adult fall chinook to the mouth of the Columbia.

BPA decided to push less water through federal-dam spillways this spring and could cut back spill this summer, too, in order to save water for power generation.

Meantime, FERC's recommendation to end summer spill from Priest Rapids and Wanapum dams would generate an additional 329,400 megawatt hours of power between June 15 and Aug. 31. That's about enough to light 14,000 households for a year and worth up to $132 million at market rates.

Eliminating summer spill would be a boon to Seattle and Portland utilities buying power from Grant County PUD. Those utilities could sell the power to their own customers or market it outside the region, including to California utilities expected to be especially short on power this summer.

FERC is taking public comment until Monday on the recommendation to end summer spill on the two dams. Its ruling may be a mandate or, more likely, be presented to Grant County PUD as an option.

Fish at risk in mid-Columbia

• Upper Columbia spring chinook and steelhead. These fish are so rare that some Methow irrigators have been shut down for more than two years to protect them. Their migration has been delayed because of low river flows. They are listed as endangered under the federal Endangered Species Act (ESA).

• Upriver Brights, or fall chinook. State and tribal biologists painstakingly beach-seine the Hanford Reach each spring to capture and tag migrating juvenile chinook, to track their fate from here to Southeast Alaska.

Some have been killed this spring by stranding. These fish are not listed for protection under the ESA.

• Summer chinook, including Wenatchee River Kings. These giant chinook can get as thick as a thigh, and are ancestors of the fabled June hogs that used to return to the Upper Columbia, weighing 50 pounds and more. These fish could be hurt by elimination of summer spill. They are not listed for protection under the ESA.

Lynda V. Mapes can be reached at 206-464-2736 or lmapes@seattletimes.com.