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Fish Managers Urge Spill Continues at McNary Dam to June 30 by CBB Staff Columbia Basin Bulletin - June 18, 2004

Salmon managers at the Technical Management Team meeting this week urged dam operating agencies to continue spilling water at McNary Dam through June 30, or at least as long as "spring-like conditions" persist.

The Systems Operational Request said that new information supports bypassing fall chinook subyearlings through spill rather than by fully transporting the fish in barges when certain conditions exist.

The U.S. Army Corps of Engineers said at last week's TMT meeting that spill at the dam would likely stop June 20 and that the Corps would immediately begin collecting juveniles at the dam for transporting down river. That prompted the salmon managers to submit the SOR this week asking for operations at the dam that reflects the requirements of the NOAA Fisheries 2000 Biological Opinion for the federal Columbia River dams and to consider the new information about the effectiveness of spill and transportation.

"We recommend that you go through June 30, as long as the spring-like flows and temperature continue," said Dave Wills of the U.S. Fish and Wildlife Service.

That would mean that spill would continue as long as flows remained above 220,000 cubic feet per second, the flow target designated by the BiOp, and water temperature remains below 62 degrees Fahrenheit, said Rudd Turner of the Corps.

The current tailwater temperature at McNary Dam is 60-61 degrees and daily average flow Tuesday, June 15, was 241.2 kcfs, he said.

"That criteria does not take into account some new information from transportation studies," said Ron Boyce of the Oregon Department of Fish and Wildlife. "Under a range of conditions, transportation does not work well with early summer migrants. I'm not as concerned with the criteria, as I am with this new information."

He was referring to four reports cited in the SOR. They are:

• A May 6, 2004 NOAA draft technical memorandum, "Effects of the Federal Columbia River Power System on Salmon Populations," is a review of information about transporting fall chinook. It concluded that for "juvenile fish detected prior to September, in 4 of 6 years the combined bypassed group exceeded the smolt to adult return rate (SAR) of the combined transport group," according to the SOR. "NOAA concludes that for subyearling chinook salmon transportation appears to neither greatly harm nor help the fish and thus a combination of transportation and providing good passage conditions for fish not collected and transported is consistent with a spread-the-risk strategy until more is known."

• A draft Corps report by Andersen et al concluded that in-river fall chinook return at a higher rate than transported fish.

• The Bouwes analysis, completed in 2004, also suggests that in-river fish had higher SARs than those that were transported.

• A Fish Passage Center preliminary analysis in an April 6, 2004, memorandum concluded that the "assumed benefits of transportation of fall chinook are overestimated and not supported by the available data," said the SOR.

"Our thinking is to stay the course with the BiOp," Turner said. "So, when we stop spill at McNary, we will start transportation."

"The SOR is completely consistent with the BiOp," said Paul Wagner of NOAA Fisheries. NOAA, along with ODFW, USFWS, Idaho Department of Fish and Game, Washington Department of Fish and Wildlife, Nez Perce Tribe, Shoshone-Bannock Tribes and the Columbia River Inter-Tribal Fish Commission all signed the SOR.

Wagner said the BiOp calls for spill to the gas cap at McNary as long as spring like conditions persist and gives a planning date of June 30. It is also clear, he said, that flows higher than 220 kcfs and temperature lower than 62 degrees are the criteria for spring like. "The SOR clarifies the BiOp," he said.

However, those conditions ended about June 20 last year and are likely to also end this year close to June 20, Turner said. The Corps expects flows to hold above 220 kcfs for just a few more days. In addition, Jim Adams of the Corps predicted that the already rising tailwater temperatures would go above 62 degrees and not drop again during the summer at about the same time.

"The flow forecast is showing that this might be the last week above the 220 mark," Turner said, adding that the flow forecast for next week is 190 kcfs. "The remaining trigger would be temperature and that is rising, too. So, this will probably happen before June 30."

Salmon managers agreed that when flow is lower and temperature is higher than the criteria and appears to persist for a few days, that spill could stop and transportation could begin. But, after BiOp spill ends, they also asked that any available involuntary spill be shaped to spill to the gas cap at night and transport fish in the bypass system, or if involuntary spill volume is greater than 20 percent of the river to continue 24 hours spill. Related Sites:
Technical Management Team: www.nwd-wc.usace.army.mil/TMT/index.html