Spill Attraction Flow for Listed Fishby Mike O'Bryant
The U.S. Army Corps of Engineers has been spilling a small amount of water at one of the Bonneville Dam spillways since Dec. 1, 2003, in order to attract salmon and steelhead to one of the dam's fish ladders. With a combined average of four hatchery and listed fish passing the dam per day, the Technical Management Team this week agreed to end the spill until more fish are present, but it didn't agree on how many fish must be present before the attraction spill should be turned on again.
The 1,800 cubic feet per second of spill during daylight hours at the dam's unit one next to the Cascade fish ladder could cost the Bonneville Power Administration as much as half a million dollars if it were to stick to its scheduled ending date on April 1. The operation is not required by the NOAA Fisheries 2000 Biological Opinion, nor is it outlined in the Fish Passage Plan that federal action agencies use to guide annual operations at dams, said Scott Bettin of BPA.
Bettin said he already had asked the Fish Passage Operation and Maintenance (FPOM) group, a committee of fishery and dam operators overseen by the Corps, two times to stop the flow due to a lack of fish passing through the dam and that's why he brought the issue to TMT.
"It's day 52 of the issue for me, and that's why I've chosen to bring the issue here because it's appropriate to river operations," Bettin said. "The benefit of stopping the spill is strictly a dollar issue, the potential energy lost to the project."
He added that the operation was new for the project and that the spill at the dam and other lower Columbia River dams normally is shut down between the end of August and April.
Chris Ross of NOAA Fisheries said that when fish ladders are in operation, his agency would recommend adding some type of attraction flow.
"On the other hand, the passage numbers are low and we're into single digit passage," Ross said. "I'm leaning towards stopping spill now and looking closer at historic passage data and to continue to monitor fish passage at the dam to determine when we can expect to begin again in February. There may be a short term benefit for stopping now."
"I appreciate the concern about spill, but this issue is not ripe for that decision," said Ron Boyce, Oregon Department of Fish and Wildlife. He said spill is important to stocks that are depressed and that a decision shouldn't be made so quickly in a "knee jerk" fashion.
Cindy Henriksen of the Corps said that the count of fish during January 2004 has ranged from minus one (fish that go downriver) to 18, but that is showing that there is likely not a directed migration of fish at this time.
Shutting down spill now with so few fish passing the dam seems reasonable, said Russ Kiefer of the Idaho Fish and Game. But he asked: How does TMT develop the criteria needed to warrant turning the operation back on?
"How do we develop the criteria when we're no longer in that 'few, if any' category?" Kiefer asked. "So, we get to mid-February and Ron (Boyce) says there are 20 fish and we should turn it back on, and you (Bettin) say no. What happens?"
He noted this is a similar issue for TMT as setting criteria for the "few, if any" fish present criteria that needs to be developed when determining when BPA can go to zero spill at Snake River dams. BPA asked TMT in December to drop flow at lower Snake River dams to zero for six hours per night in order to generate electricity when it is needed most and then to refill reservoirs when the power is needed least. BPA would gain as much as $48,000 per day in additional benefits with the operation. The agreement that allows the operation, which has been in effect since 1987, refers to a "few, if any" criteria for the presence of migrating fish before the operation can be approved.
The question is how many anadromous fish are "few, if any" when making the determination of turning off or on zero nighttime flow, or, in the case of this week's conversation at TMT, for turning on or off attraction spill at Bonneville Dam.
Henriksen said that, based on 1995-2002 studies, average passage at the dam in late January to late February is 10 steelhead or fewer per day, but that will typically increase in early March. Even then, the highest count for those years was 60 fish.
"Based on that information -- single digit counts, the multipurpose use of the projects and that salmon managers will continue to review this -- the Corps is prepared to stop spill at spillbay number one until further criteria are developed by salmon managers," Henriksen said.
Technical Management Team: www.nwd-wc.usace.army.mil/TMT/index.html
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