Bonneville Spills Water for 7.5 Million Hatchery Fishby Mike O'Bryant
Columbia Basin Bulletin - March 14, 2003
River operators this week spilled water at Bonneville Dam to help 7.5 million tule fall chinook smolts released from the U.S. Fish and Wildlife Service's Spring Creek hatchery safely negotiate the dam.
The action, which represents a reversal of a previous decision by the Bonneville Power Administration not to provide spill for the hatchery fish this year due to low water conditions, was made possible by heavy rainfall, some snow melt and the shut down of Energy Northwest's Columbia Generating Station (WNP2).
In other years, BPA has provided an average of five days of spill to ensure the safe passage of the smolts. BPA initially denied spill last March to aid the hatchery-bred fish, but then found a spare 200,000 acre feet of water in the Columbia River system. It provided four days of spill, but ended that March 15, 2002 after only about 50 percent of the 7.8 million hatchery juveniles had passed the dam, according to a Fish Passage Center report at the time.
While spill this year occurred for just 36 hours, BPA's Scott Bettin said it was better targeted and should be nearly as effective. To ensure greater effectiveness of the operation, the USFWS waited for the recent heavy rainfall before releasing the fish and BPA waited for the largest portion of the fish to arrive at the dam before beginning spill.
"It's always debatable if spill is long enough," Bettin said. "Most fish show in the first three days and this year we waited for the fish to show before spilling."
He added that there were enough of the fish waiting to pass the dam at 4 p.m. Monday, March 10 for spill to proceed as planned at 6 p.m. that evening. It continued for 36 hours to 6 a.m. Wednesday morning, March 12.
The Technical Management Team made the decision March 7 in a conference call meeting the day before USFWS released the hatchery fish for their downstream migration to the ocean. Driven by a Fish and Wildlife systems operations request (SOR), supported by fisheries managers and tribes, BPA asked for top-level management approval before pushing spill into motion.
"We were concerned about the cost," Bettin said, pinning the 36-hour cost of spill at 50,000 cubic feet per second at the dam at $461,000. "We had a discussion at the executive level with Steve Wright and this is the compromise."
The cost of spill is the value of the water if it were used instead to generate electricity at a market value of about 65 mills (6.5 cents) per kilowatt-hour. The market price late last week hit 85 mills per kilowatt-hour, Bettin said.
USFWS, the Columbia River Inter-tribal Fish Commission and the Oregon Department of Fish and Wildlife supported more spill for a longer period of time, but chose not to raise the issue to the regional Implementation Team for a ruling.
Although the spill is to aid hatchery fish, not for Endangered Species listed fish, fisheries managers defend the spill based on the importance of the hatchery stock to commercial, sport and tribal fisheries. According to the SOR, the Spring Creek Hatchery fall chinook is an important buffer to ESA listed stocks present in ocean and Columbia River mixed stock fisheries.
The 2003 SOR, which was sponsored last week by USFWS, NOAA Fisheries and the Washington Department of Fish and Wildlife, called for 36 hour 50 kcsf spill, which is less than the 100 to 150 kcfs spill used in previous years for the operation.
Dave Wills of USFWS said the request reflects this year's unique conditions, according to notes from the conference call meeting. Those conditions are an expected low water supply forecast, but also includes several short-term conditions that make the operation possible.
One is that BPA is willing at this point to incur some cost for spill, according to Bettin. He also said that the recent slug of rain is adding both water to the system and snowpack in the mountains and that some of that snowpack in the upper Columbia River Basin is providing a small amount of snowmelt.
In addition, the 1,150-megawatt Columbia Generating Station (CGS) is temporarily shut down for repairs. That has required additional generation at some dams, including Dworshak Dam, in order to make up for the CGS's generating capacity, which puts more water in the river from storage dams.
While that action has the potential to use important water stored for spring and summer fish operations, Bettin said the storage dams may not be affected because of the heavy rain and snow. He expects Grand Coulee Dam to achieve its April 10 flood control rule curve target, which is an elevation at or below 1,283 feet. However, the outflow at Dworshak Dam was increased to 4.8 kcfs to make up for CGS generation and that might affect the dam's ability to reach its flood control rule curve target. Much of the precipitation falling in the Clearwater River Basin is ending up in the snowpack, not in the river.
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Bonneville Spills Water for 7.5 Million Hatchery Fish
Columbia Basin Bulletin, March 14, 2003
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