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Oregon Council Member Questions Value of Summer Spill by Bill Rudolph NW Fishletter, April 15, 2003

Oregon's newest Northwest Power Planning Council member, Gene Derfler, dropped a bomb at the group's March 29 meeting when he proposed a last-minute amendment to the council's mainstem program. Derfler wanted to end all summer fish spill in the hydro system.

Derfler told other council members that he decided it was an issue worth looking into when he realized that the region was spilling $80 million worth of water every summer that could otherwise be generated into electricity at a time when the Northwest was in a recession.

During the summer, water is spilled at most lower mainstem Columbia River dams to help fall chinook downstream, but not at three of the four lower Snake dams or McNary Dam, where efforts to barge the fish are maximized.

With some number-crunching backup by council staffer Bruce Suzumoto, Derfler pointed out that the spill continues through August, "when there are very few fish in the river."

Suzumoto told the council that the federal hydro BiOp mandates a "spread the risk" philosophy for ESA-listed spring chinook in the Snake by barging only a portion of that run. The BiOp also calls for barging as many protected fall chinook as possible during the summer. As a consequence, few listed fish benefit from summer spill at mainstem Columbia dams, he said.

Suzumoto pointed to an earlier analysis that looked at the effect on fish of reducing summer spill to reduce total dissolved gas levels from the BiOp-mandated 120 percent to 115 percent. Its value in terms of additional power generation was pegged at roughly $25 million.

Suzumoto said there would be little benefit for the Snake fall chinook because there were so few in the river. For every 100 fall chinook that pass Lower Granite Dam on the Snake, Suzumoto said about 87 fish are put into barges. After predation by pikeminnow and other predators, only two fall chinook are still inriver by the time they reach McNary Dam, and only one makes it to Bonneville Dam.

Suzumoto said other unlisted stocks migrate in the lower Columbia, like those from the Klickitat, White Salmon, Deschutes and Umatilla rivers. They would be affected by reduced spill, along with the large migration of fall chinook from the Hanford Reach--although many of them are barged from McNary in the summer. During high flow years, he said lowering spill would reduce the Hanford run by about 2.2 percent and in low flow years, by only 0.7 percent.

However, up to 50 percent of the Hanford fall chinook are harvested, Suzumoto said. "When you look at this, you have to understand that we're talking about two adults here that we're saving as compared to 50 adults that are being harvested."

Suzumoto also said the region may not be using spill to its best advantage. He presented a graph that showed how few fish were actually passing through the system in August. He said it may by possible to use spill more strategically to help disperse predators at dams that feast on fall chinook.

Montana member John Hines suggested there may be ways to fine-tune the spill strategy to improve BPA's financial condition while preserving fish survival.

"I'm not saying that we should necessarily shut off spill completely during all the months," because survival should be promoted in all segments of any one population, Suzumoto said.

"We could be wasting a lot of resources that could be used for other things." Derfler said, adding that it was important to look at the economics of the spill issue. Other council members, including Washington's Larry Cassidy and Oregon member Melinda Eden, downplayed the cost of spill, saying it was just a tiny percentage of BPA's overall revenues.

After an animated discussion, members supported an amendment calling for immediate tests of summer spill's benefits, which made it into the council's mainstem amendment plan at its regular council meeting last week