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Latest Spill Analysis: A Costly Strategy with Small Benefits for Fall Fish by Bill Rudolph NW Fishletter, July 22, 2003

Several members of the Power Planning Council seemed surprised last week that Montana council members had struck out on their own to initiate a strategy to evaluate a reduced summer spill program. Montana says its just part of the program that the Northwest states had agreed to already.

Montana called for the evaluation of flow augmentation and spill at a July 2 meeting of the Technical Management Team, the forum of hydro and fish managers that meet weekly to set river operations. The request has now been elevated to the Implementation Team for more discussion at the policy level for this Thursday. "It's when heads will be counted," said Montana council member John Hines.

But after a staff presentation on economic and biological effects of reducing summer spill at last week's council meeting, it became obvious that Washington's council members were not aware that Montana had formally requested a reduced spill strategy, and like most other council members, weren't ready to support it.

The staff analysis estimated that cutting summer spill altogether in average flow years would reduce the future harvest of Hanford Reach chinook by a few thousand fish and have little effect on ESA-listed Snake River fish, while saving tens of millions of dollars' worth of water for power generation.

Based on numbers of Hanford fish migrating to sea this year, staffers said ending summer spill would reduce the numbers of returning adults by about 3,000 fish, and would cut the numbers reaching the spawning grounds by 3,800 fish. That's not much considering the average annual escapement of the healthy run over the past ten years has been more than 80,000 fish. In 2002, it was nearly twice that figure.

Nearly half the run is harvested each year by both ocean and inriver commercial and sport fisheries; yet even more would escape to spawn but for harvest constraints to ensure that enough the Snake fall chinook make it home. Before the fish were listed for protection under the ESA, about 80 percent of the Hanford Reach run was caught every year, according to council staffer Bruce Suzumoto.

The analysis found that only seven fewer ESA-listed Snake River fall chinook would be harvested from the no-summer-spill strategy and escapement would be reduced by eight fish. The 10-year average escapement of that run has now reached over 3,600 fish, boosted in large part by last year's return of more than 12,000 wild and hatchery fish.

But Washington council member Larry Cassidy said he wasn't ready to write off 3,800 adults. "Before we make a policy decision, we have to mitigate for losses," Cassidy said. "I gotta see equating benefits."

Council staffer John Fazio estimated summer spill would cost $90 million to $100 million this year. A simple math exercise by several council spectators had Cassidy's fish penciling out to about $15,000 apiece.

According to the council analysis, ending spill by August would save about $40 million a year and save about half the Hanford fish that would be lost if no summer spill took place. Such a strategy would add only five more Snake River fish than if no spill was initiated during the summer months. Most Snake fish are barged around the dams, hence changing spill strategies has little relative effect on their numbers.

However, Montana has only called for spill to be halted the last two weeks of August. BPA has already estimated the potential loss to both recreational and commercial fishermen from such a strategy at less than $8,000, but could save ratepayers up to $20 million a year.

Montana member John Hines explained that his state would support using "a substantial amount of money for relief" to aid listed stocks from any savings attributed to changes in the spill regime. He pointed out that the pikeminnow predation project could be increased to improve juvenile survival. As for now, the council has recommended that program's funding be cut in half.

Council staffer Suzumoto noted that ending spill could have a positive benefit by reducing fallback at dams. He said recent studies conducted by the University of Idaho suggested little or no fallback at all when spill was stopped at Bonneville Dam. Such a condition might actually improve the adult migration and automatically mitigate for juvenile losses, though no quantitative analysis was readily available to back up such a claim.

Members discussed what to do next, with council chair Judi Danielson noting that the group has called for spill studies in its mainstem program. She said that ratepayers "are extremely interested in this issue."

Hines suggested it was time to start working with utilities.

Washington's Tom Karier agreed that the council needed to follow up on its own program. "We've got to be sure we're not erring on the side against the fish," he said.

"The council needs to spend more than forty-five minutes to hash out this issue," said Oregon's Melinda Eden. She suggested that comments be accepted from other parties like the Columbia Basin Fish and Wildlife Authority to help design experiments.

A July 9 letter from CBWFA to the council had already been distributed at the meeting that called for a new process to begin that would culminate in a joint technical recommendation from agencies and tribes for spill evaluation. Others have already observed that future research efforts may be thwarted by the small numbers of available fish and high water temperatures that make PIT-tagging fish unfeasible.

Montana member Ed Bartlett said he agreed with the points made by Karier and Eden. "We supported the TMT effort because we had the opportunity to start something," he said. "If it ends at the IT, fine."

An evaluation of the mainstem summer spill strategy is a major element in the council's recently adopted amendments to the region's fish and wildlife program However, since the strategy calls for potential changes to the hydro BiOp, federal agencies have been reluctant to support it while the biological opinion is being remanded. A federal judge ruled in May that the document be remanded for a year to allow federal authorities to re-write the section that deals with offsite mitigation efforts for fish recovery so they are more certain to occur.

Meanwhile, it has become evident that years of spilling water for half a year at a time is more than many dams were designed to do, Corps of Engineers biologist Jim Athearn told NW Fishletter. Athearn said stilling basins are deteriorating below spillways at some dams like Lower Monumental on the Snake, and the mainstem project at The Dalles, and may soon compromise the projects' structural integrity unless they are repaired or spill is reduced. Athearn said the dams were only designed to spill water for two months a year during the spring freshet. BiOp spill operations are simply wearing out the concrete, he said. Summer spill to aid fish passage now occurs from June through August at Ice Harbor Dam on the Lower Snake, and at John Day, The Dalles, and Bonneville dams.