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Economic and dam related articles

Fish Managers get Split Decision
on Winter River Operations

by CBB Staff
Columbia Basin Bulletin - February 20, 2004

Fisheries managers at the Technical Management Team meeting this week proposed threshold criteria designed to help TMT make in-season decisions about when attraction spill is needed for wild steelhead at Bonneville Dam and when to turn off nighttime zero flow at lower Snake River dams.

Dam operators accepted the criteria that determines how many fish must be present before attraction spill at Bonneville Dam is turned on between November and the end of February.

But they rejected the criteria for zero nighttime flow operations on the Lower Snake.

Both are winter operations and neither is governed by NOAA Fisheries' 2000 biological opinion for the federal Columbia River hydropower system.

Operations managers had earlier asked fish managers to propose the criteria for both operations so that TMT would know ahead of time what conditions would drive a change in operations.

The U.S. Army Corps of Engineers said that zero flow at lower Snake River dams would continue December through February regardless of the new criteria proffered by the fish managers, at least until the managers bring to TMT information about the biological impacts on the few wild adult steelhead present.

"The way we read the water control manuals is that we can operate to zero nighttime flows because there are 'few if any' fish present," said Cindy Henriksen of the Corps. "Based on our understanding, with input from NOAA (Fisheries), there are minimum impacts on adults."

The Corps' Water Control Plan says the operation is allowed when there are "few if any actively migrating anadromous fish present in the Snake River.ůZero river flow operations are not recommended at Lower Snake River projects when fish are actively migrating in the Snake River."

The skirmish between fish and operations managers is over how that agreement should be interpreted. The Corps says it means that the determination already has been made in the old agreement that there are "few if any" fish present during the period December through February and that zero flow is allowed regardless of the actual presence of fish at the dams.

However, the fisheries managers understand the description to mean the operation is allowed only when "few if any" fish are present, but that it was up to them to define the "few if any" threshold, which they did this week.

The fishery managers said the Corps is changing the discussion mid-stream and wondered if they had wasted their time developing criteria for an on/off threshold for zero nighttime spill.

"There's been a lot of discussion in previous meetings on this old agreement about the meaning of 'few if any,'" said Dave Wills of the U.S. Fish and Wildlife Service. "This is our attempt to address that (referring to the criteria). The biology is separate. There were 151 wild steelhead at Little Goose (Dam) Feb. 21, 2003, so we shouldn't wait on adopting this criteria."

The Corps has allowed the projects to go to zero flow from Dec. 1 to the end of February on a limited basis since 1987. An agreement between the Corps and fisheries agencies allows for such an operation at night and on weekends for up to six hours in an eight-hour window when power demand is low.

The zero flow mechanism, which is worth about $25,000 per day this year to the Bonneville Power Administration, is used at three of the lower Snake River dams (Ice Harbor was not included). If zero flow in the past had used the current six-hour criteria (in the past it had been 12 hours), BPA used the mechanism 12 percent of the available time in 2000-01, 19 percent in 2001-02, and 50 percent of the time in 2002-03. A December report by the Corps' Cathy Hlebechuk found that BPA used the operation 100 percent of the time from Dec. 4, 2003 to Dec. 16, 2003.

However, fisheries managers understood that zero flow would proceed under the 1987 agreement only on a limited basis and have protested this year's operation.

"Clearly in previous TMT meetings there was a discussion about this or salmon managers wouldn't have been asked to come up with this criteria," said Dave Statler of the Nez Perce Tribes. "Now the Corps says there will be zero nighttime flow regardless of the impacts on fish."

"There may be a disagreement on the semantics," said John Wellschlager of the Bonneville Power Administration. "But the real issue is that you need to show demonstrable biological impacts" of the zero nighttime flow.

The proposal includes a three-day moving average of wild and total steelhead counts at the dams and sets a threshold for the numbers of fish needed before zero flow would stop. That number is based on the size of the run.

For example, if the run to date includes greater than 30,000 but less than 60,000 wild steelhead, when 20 or more fish are present at a dam, zero flow would stop. The size of the Snake River wild steelhead run this year, according to Wills, was about 35,000 fish, so the threshold would be 20 or more wild steelhead present before zero flow would stop. The size of the total Snake River steelhead run, including wild fish, was about 171,000 fish. In that case, 65 or more fish would have to be present to stop the zero flow.

The Bonneville fish ladder attraction spill threshold criteria met with comparatively little resistance from dam operators. Wills said the new criteria are designed to ensure the fish are drawn to the fish ladder at the time they show up. "We hope to get fish into the ladder in the first place, rather than have them sit in front of the dam," he said.

The fishery managers proposed to begin spill when a three-day moving average of wild adult steelhead counts amounts to 10 or more fish. Since steelhead during the winter wander up and down stream, the count is net of wild steelhead moving upstream and those moving downstream.

"Ten is an awfully conservative number," said Wellschlager, who thought the threshold number should be higher.

"In our stock status review, these fish have a high risk of extinction," said Chris Ross of NOAA Fisheries. "There are five to six weeks in the winter when the count is low and the temperature is cold, and we agree there does not need to be an attraction flow. But, when the numbers take off, they do it swiftly and we want to make sure they have good passage."

"The numeric criteria are awkward," said Henriksen. "Someone could adjust a valve and have an impact on movement. When the Fish Passage Plan was developed, it was with the thought in mind that typically November through February was a low count period. When fish start moving, we do have a desire to keep them moving, but March 1 has always been that threshold date."

If there is an upsurge of wild steelhead passing the dam earlier, she said the Corps would entertain doing something to keep them moving.

"I understand that if the numbers shoot up we want to protect the stock, but the threshold is unreasonable," Wellschlager said. "There isn't a justification for the trigger. There's ratepayer dollars on the table and that's why I need to ask these questions."

TMT agreed that for at least this season attraction spill will begin March 1, unless wild steelhead numbers increase appreciably over a three-day time period. Recent passage numbers are 0 to 5 wild steelhead per day at Bonneville Dam.

Related Sites:
Technical Management Team:

Related Page:
No Flow at Night at Snake River Dams to Fill Reservoirs by Mike O'Bryant,Columbia Basin Bulletin, 12/5/3
Zero-Flow Scenario Debated for Lower Snake River Dams by Bill Rudolph, NW Fishletter, 12/19/3

CBB Staff
Fish Managers get Split Decision on Winter River Operations
Columbia Basin Bulletin, February 20, 2004

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