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Power Council Votes on Proposals for Changing Mainstem Operations by Bill Rudolph NW Fishletter, October 22, 2002

Northwest Power Planning Council members heard last week that Montana's recommendations to cut spill and flows throughout the hydro system may not be as bad for migrating juvenile salmon and steelhead as many have suspected. In some cases, it may actually improve fish survivals over operations now mandated in the hydro BiOp, according to a Power Council staff analysis that used NMFS' own tool to estimate fish survivals. The analysis was part of three days' worth of council deliberations over amending the mainstem part of the Columbia Basin's fish and wildlife program.

On the other hand, recommendations from the state of Oregon, which called for boosting spills and flows throughout the system, were estimated to reduce survival of some stocks up to 4 percent, principally from the Snake River, if Oregon's call for more flows and 24-hour spill at the dams was initiated, according to council staffer Bruce Suzumoto, who analyzed the biological effects of the Montana and Oregon recommendations. The increased spill would keep more juvenile fish from entering the bypass systems at lower Snake dams, which route the smolts to barges, Suzumoto said.

The Oregon proposal would also cost the region up to $47 million annually and reduce winter generation by more than 2500 aMW, according to council staffer John Fazio, who analyzed the power effects of the Montana and Oregon recommendations. Fazio said his numbers didn't include the cost of providing 1 million acre-feet of upper Snake water and another 1 MAF from Canadian storage reservoirs for flow augmentation in the mainstem, as recommended by Oregon.

Montana's recommendations, which also called for limiting summer spill and releasing water from its reservoirs to level outflows, were estimated to save the region about $65 million, according to the analysis. Idaho's proposal to limit spring flow augmentation in the Snake was expected to save another $9.6 million over current BiOp operations.

"The table is now set for a good discussion of the recommendations," said Montana council member John Hines.

Suzumoto used NMFS' SIMPAS passage model in his analysis. He said it's the same model the federal agency used in its 2000 hydro BiOp to estimate fish survivals through the hydro system.

Suzumoto also said the survival differences from changes in spill operations reflect the different passage routes taken by fish. As spill is decreased, more fish pass each dam via its bypass system or turbines. Though studies have been conducted at most dams to estimate survivals by the different routes, the model still makes approximations based on "best professional judgment," Suzumoto told the council.

Model Judgment
Just before Suzumoto's presentation at last week's council meeting in Spokane, NWPPC Chair Larry Cassidy announced that he had received a letter from regional fish and wildlife managers at the Columbia Basin Fish and Wildlife Authority, who cautioned against using the model for several reasons.

"The relations and point estimates used in these simple passage models are far too simple to adequately capture the complexity of salmonid survival relations," the Oct. 16 letter said, "and are, therefore, inappropriate as the primary basis for management decisions."

The fish managers did not suggest an alternative, but said the NMFS model did not consider the issue of delayed mortality of fish that either were transported through the hydro system, or that migrated inriver. They said such mortality can occur at higher rates for fish that are either transported or that use bypass systems, rather than fish that pass dams via spillways, a mechanism long considered to be the least obtrusive way of getting them past the concrete. It's a topic of some debate, which may heat up this fall when new research data is expected to be released.

Oregon council member Erich Bloch questioned the use of the SIMPAS model as well, because it contained no direct flow/survival connection with fish. But Suzumoto said any such effects would be indirectly captured by pool survival estimates from PIT-tag studies incorporated in the model.

Both Hines and Idaho council member Jim Kempton told NW Fishletter they welcomed more analysis of the recommendations. Both endorsed using the UW/BPA CRiSP [Columbia River Salmon Passage] computer model to estimate biological benefits from the proposals to change mainstem operations.

CRiSP modeler Prof. Jim Anderson said later that there are three versions of CRiSP: the earliest one actually does contain a flow/survival relationship, but the current one tracks with SIMPAS. Anderson said the newest version of CRiSP, yet to be calibrated, uses distance and fish travel time as major parameters. He said upper and lower estimates of fish survival for different hydro operations could be generated by running different versions of the model.

The Montana recommendations that call for dumping annual flow targets and flow augmentation in the spring were estimated to have the greatest effect on upper- and mid-Columbia steelhead stocks during high flow years, when they could suffer up to 8 percent higher mortality than during periods of BiOp-mandated spill. Current BiOp-mandated spill levels at dams are capped at levels that limit gas supersaturation levels at 120 percent in the mainstem, 10 percent higher than legal limits.

Montana wants to cap spill at 115 percent gas levels, which effectively reduces spill by nearly half. During medium-flow years, the steelhead stocks would suffer about 6 percent higher losses from the Montana option and about 2 percent more mortality in low flow years.

The SIMPAS model showed only marginal fish losses from Montana's recommendations for reduced summer spill. It estimated that mortality of Hanford Reach fall chinook would increase about 2 percent over current operations during high-flow years, with no difference in mortality in low-flow years. That is because most of the fish are barged, Suzumoto told the council. He said the analysis suggested that spill reduction might be focused at dams where fish were collected for barging to maximize the strategy, but that spill could also be optimized at lower mainstem dams.

After devoting more than half of their agenda time to the task, Power Council members finally voted for a list of preferred alternatives for mainstem operation. The results will be presented to the public by the end of this week.

The council accepted the main thrust of Montana's proposals for spring operations, voting 7-1 (with only Oregon's Bloch voting no) for basic changes to current flow augmentation policy, including reservoir refill by the end of June and removal of the April 10 flood control levels at basin reservoirs, to allow additional flexibility in the system, with some possible caveats. Preferred summer operations are based on each state's proposal for more level outflows than called for in the BiOp.

The members were less clear about the future of flow targets. But their final recommendation is likely to downplay the importance of the targets or call for their outright demise. Oregon's request to add up to 2 MAF of additional water from the upper Snake and Canada did not pass muster with the rest of the council. But Montana member Ed Bartlett said the public may still get a chance to comment on items nixed by the Council. That question will be brought up during this week's meeting of the four members charged with editing the results of last week's deliberations for public review.

The council had split evenly over whether to recommend Montana's call for reducing spill to 115 percent gas supersaturation levels, but later Oregon member John Brogoitti said he had misunderstood the situation and "screwed up" his vote. Brogoitti, who has already been very public about his support for Montana and Idaho recommendations, voted with Washington's two members and Oregon's Erich Bloch to keep the council from putting the Montana spill proposal in with their list of preferred alternatives.

Public comment on the council's recommendations will be accepted until the middle of January, with public hearings expected in each state, a final public airing at the council's January meeting and final adoption expected by the February meeting.

Related Pages:
Power Council Plan Calls for Releasing Less Water for Fish by Jonathan Brinckman, The Oregonian, 10/19/2
ID & MT Seek Reduced Water Spills for Columbia Salmon by Jonathan Brinckman, The Oregonian, 10/16/2
Council Proposes Changes to Mainstem Operations by Barry Espenson, Columbia Basin Bulletin, 10/18/2
BPA Mid-Columbia Customers Favor Montana/Idaho Plan by Mike O'Bryant, Columbia Basin Bulletin, 10/18/2
Dam Operators Propose Changes in Fish Spill by Mike O'Bryant, Columbia Basin Bulletin, 10/25/2