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Agency Reps Mull Where
Removable Spillway Weir Goes Next

by Barry Espenson
Columbia Basin Bulletin - March 19, 2004

The debate over who goes next stretched beyond the lower Snake River Thursday when Oregon's representative to the System Configuration Team suggested that McNary Dam just might be the appropriate site for installation of the next "removable spillway weir" on the Columbia-Snake river hydrosystem.

The fish passage device has been found in an initial two years of testing at the Lower Snake's Lower Granite Dam to be both efficient in its attraction of juvenile salmon and steelhead and in its use of water. The Lower Granite RSW in testing has shown that it attracts and passes about five times the number of fish per volume of water as normal spill.

The young fishes' survival is also equal to or better than that of normal spill, which is considered the safest route of passage. But spill is expensive. Spill utilized expressly to pass fish cannot be used to generate electricity.

The Bonneville Power Administration has estimated that spill at Ice Harbor Dam on the lower Snake costs about $34 million on average annually in foregone revenues. Spill operations associated with an RSW that is scheduled for implementation there are estimated to cost $12 million to $22 million, meaning the power marketing agency will be able to sell as much as $22 million more each year in electricity.

Construction cost alone for the RSW structure are estimated to be about $12 million, so it could literally pay for itself in a year's time. Money for such work is paid for through the Corps of Engineers' Columbia River Fish Mitigation Program. The funds are appropriated by Congress annually with BPA ultimately reimbursing the U.S. Treasury for most of the costs with ratepayer revenues.

The SCT is a multi-agency group that gathers to help prioritize a list of fish passage improvement projects and research that is eligible for a limited amount of funding. It is beginning now to look at a project list for fiscal year 2005, which begins in October.

Federal executives late last year urged that the Ice Harbor project move forward. BPA, NOAA Fisheries and Idaho's fish managers approved of the move, but Oregon and Washington salmon managers would have preferred Little Goose or Lower Monumental to be next. They had lingering worries about spillway survival problems at the dam in low water conditions that have yet to be identified and corrected.

Still, that project is moving ahead with construction set to begin this year and installation planned in time for the 2005 spring fish migration.

The debate continues, however, about which project will be next. The Corps' Walla Walla District office has begun the necessary background work to tee up the Lower Monumental RSW project, but some of the salmon managers would prefer Little Goose to be first.

Ron Boyce of the Oregon Department of Fish and Wildlife feels Little Goose is most appropriate, in large part because it is further upriver. That means about 60 percent of the Snake River migration is still in-river (a portion are collected at Lower Granite and transported downstream via barge).

The merits of the various installation scenarios will be discussed during an April 5 meeting at which the Corps will display the analysis it as completed to-date and where it will hear the technical arguments offered by salmon managers. As of now, the Corps plans to further design work for Lower Monumental this year with construction taking place in fiscal year 2006. Little Goose is one year behind that pace.

Boyce said Thursday that some of the state and tribal salmon managers would like to see the RSW installation process move to more of a systemwide approach and consider the benefits of lower Columbia River installation. The lower Snake improvements benefit runs than include several stocks listed under the Endangered Species Act, including steelhead, sockeye and spring/summer and fall chinook.

McNary should be a candidate for expedited installation if BPA agrees to move ahead with a "modernization" plan at the dam, Boyce says. The agency is analyzing the feasibility of installing turbines that would increase McNary's powerhouse capacity from about 170,000 cubic feet per second to 220 kcfs. If that happens, it would reduce the occurrence of involuntary spill, which Boyce favors as a passage option.

"I'm interested in a way to potentially mitigate" for that loss of spill passage, Boyce said. An RSW at the dam would allow a spill passage alternative that would get more fish past the facility with a lesser amount of water. Boyce hopes to further the discussion during a meeting called next week called by the Corps to discuss a monitoring plan for an altered turbine operation plan for McNary this year.

"It's performing so well in the two years at Lower Granite that it certainly makes sense to go forward with this at the lower Snake River projects," NOAA Fisheries' Steve Rainey said. The technology has potential at McNary, and possibly John Day Dam. But that would require a considerable change in focus. And it would tax resources -- financial and personal.

SCT chairman Bill Hevlin of NOAA agreed to put a McNary project on the table, but wondered aloud how such a "parallel process" might affect the development of the two Snake River projects.

"You may have to put Goose and Lower Monumental on the back burner" if McNary is moved to the top of the list, said the Corps' John Kranda.

Rainey, and the Walla Walla District's Dana Knudtson questioned whether the district had the resources necessary to prepare the analysis necessary to make a decision on the applicability of the RSW analysis at McNary.

"That would tax them severely," Rainey said of the district's staff.

Barry Espenson
Agency Reps Mull Where Removable Spillway Weir Goes Next
Columbia Basin Bulletin, March 19, 2004

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