Fishery Managers Seek Changeby Mike O'Bryant
Northwest fisheries managers over the last couple of weeks have asked federal agencies, Grant County Public Utility District and other mid-Columbia River dam operators to modify their dam operations to reduce the size of flow fluctuations at Priest Rapids Dam that they say is causing increased mortality of fall chinook fry emerging and rearing along Hanford Reach.
The Columbia River Inter-Tribal Fish Commission places the number of fish killed this spring when water levels fluctuate and fry are trapped in pools as high as 400,000.
But Joe Lukas, Grant PUD senior fisheries scientist, said that estimate hasn't been peer reviewed and that final estimates by the Washington Department of Fish and Wildlife aren't expected until this summer. "At this point researchers have no mortality estimates, just raw data," he said.
In addition, he pointed out the huge number of fall chinook that spawned along Hanford Reach last year could mean that as many as 100 million fry are emerging and so the mortality rate could be a small proportion (less than 0.5 percent) of the total emergence. "In past years the agencies were not uncomfortable with two to three percent mortality," he said.
"To understand this you have to place the stranding losses in their proper biological context," Lukas said. "How do you determine how stranding losses influence the year class strength?" That is something that is unknown at this point, he said.
CRITFC's Bob Heinith, who predicts the fry emergence at 40 million, which would place mortality at about 1.0 percent, said that CRITFC, along with WDFW and NOAA Fisheries sought Thursday this week from federal dam operators and Grant PUD "some sort of agreement to limit the wild flow fluctuations" at Priest Rapids Dam. He said that even the Alaska Department of Fish and Game is getting involved because up to 30 percent of chinook harvest originates with Hanford Reach brights.
Most of the mortality is occurring over weekends, according to fisheries managers, when mid-Columbia River operators and federal agencies drop river flows because electricity demand drops. According to Paul Wagner at NOAA Fisheries, the Hanford Reach juvenile protection program operated by Grant PUD sets limitations on flow fluctuations during the week, but not on weekends. He said the only limitation on weekends is the minimum flows set by the Vernita Bar Agreement, so flows could potentially be 130,000 cubic feet per second during the week when electricity demand is high, but drop overnight Friday to as low as 70 kcfs, and that's when the stranding occurs.
Lukas explained that Grant PUD implements a daily reshaping of flows at Priest Rapids Dam during weekdays, but operates on the weekends as a separate 48-hour period.
Much of the weekend problem this year was taken care of when in late April, fisheries managers asked for and received approval from the Technical Management Team to provide flows from Grand Coulee Dam that would allow weekly average flows at Priest Rapids of 135 kcfs, Wagner said. Most of the stranding occurs at lower flow levels in the 70-90 kcfs range, but that improves as flows rise above 110-120 kcfs, he said. Although the request by fisheries managers was for 135 kcfs flows through June, TMT will review next week whether the hydro system can continue to provide the flows from federal dams without putting refill at Grand Coulee at risk.
Still, Wagner thinks there is a larger picture to consider. That has to do with what Grant PUD includes late this summer in its draft license application to the Federal Energy Regulatory Commission for its two mid-Columbia River projects, Priest Rapids and Wanapum dams. That would set in stone the operation for as many as 30 years and that is a reason to seek a change in the utility's juvenile protection program now. If all the parties can't agree on a protection program before August, then the debate could move to FERC, he said.
"Grant wants to include this program in its licensing agreement," Wagner said. "An aspect that's not specific in the current program is weekend operations when a good deal of the stranding occurs. It seems we have a difference of opinion on what level of protection is acceptable."
NOAA Fisheries, CRITFC and WDFW put together a proposal that would apply to the remaining emergence and rearing season. They asked the federal and mid-Columbia dam operators to adopt the plan through the end of the season this year to see if it reduces stranding, but Wagner said the plan wasn't adopted.
Lukas bristles when he hears the debate directed solely at Grant PUD. "That fosters a misunderstanding of how the hydro system operates," Lukas said. "This is all about the operations of the hydro system as a whole."
He said when the power demand drops significantly over weekends, so does flow through upstream dams. The amount of water Grant PUD can reshape drops and "so we draft our reservoirs at a significant cost to us to help smooth out the fluctuations. We hear that's not good enough," Lukas said. "This is a bigger, broader regional issue than just cutting fluctuations at Priest Rapids. These projects do not operate in isolation."
He pointed to the fact that the discussion among river operators and fisheries managers at Thursday's meeting ranged from water in Canada to water available at Dworshak reservoir on the Snake River as an illustration of how far-reaching are dam operations in the Columbia River basin. He added that due to biological requirements on the Columbia River hydro system, there is very little flexibility left in the system to change operations.
Both the Vernita Bar Agreement and the spring protection program are joint operations of all the operating agencies, he said, and it requires regional cooperation to make it work. "I guess FERC could be an alternative to a regional cooperation agreement, but FERC doesn't have jurisdiction over federal projects," Lukas said.
Grant PUD: www.gcpuc.org
Columbia River Intertribal Fish Commission: www.critfc.org
NOAA Fisheries, Northwest Regional Office: www.nwr.noaa.gov
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