Millions of dollars in electricity is being sacrificed as the U.S. Army Corps of Engineers tries to free as many as 1,000 salmon and steelhead trapped in dark chambers beneath Bonneville Dam.
The fish were trapped when a massive buildup of debris blew holes in steel grating in the system that supplies water to the fish ladder near the dam’s second powerhouse. Trapped along with them are uncounted sturgeon, carp, lamprey and squawfish.
Tribal and National Marine Fisheries Service biologists were pushing for an immediate, complete shutdown of the second powerhouse and a draining of the fish ladder while the debris is cleaned up, a process that the corps says would take two months. A decision on whether to shut down the powerhouse could come when federal, state and tribal fishery managers talk Wednesday.
The second powerhouse, located on the Washington side of the Columbia River, produces 400 to 600 megawatts, enough electricity to serve the city of Portland. Production already has been reduced by 200 megawatts as the dam’s configuration was altered to lure fish away from the damaged ladder, Bonneville Power Administration spokeswoman Crystal Ball said.
The curtailment in power generation comes despite high demand caused by hot weather in the West.
“It is a critical time and the demand is up,” Ball said. “We’ve got really warm weather. It’s hot here and it’s hot in California. But our first priority is the fish.”
The BPA estimated last week that it would lose at least $3 million worth of electricity because of the problems at Bonneville. The loss could increase significantly depending on what further action is taken, Ball said.
The reservoir behind the dam has little storage capacity, so water not used in the turbines must be sent through the spillways and potential electricity is lost.
Bob Heinith, fish passage specialist for the Columbia Inter-Tribal Fish Commission, said many of the trapped fish probably are steelhead, some of them part of the Snake River run that is expected to be declared a threatened species by the National Marine Fisheries Service Aug. 11.
He and other biologists are concerned that anything less than a shutdown of the ladder and the second powerhouse would increase the risk that more grates will break in the coming weeks, when hundreds of thousands of fall chinook are moving upriver, including fish from the endangered Snake River run.
“A lot of people, myself included, are leaning toward saying, ‘Let’s just shut the ladder down now, go full tilt, try to get three crews out there working 24 hours a day,”’ Heinith said.
He said he believes the cleanup could be completed within three weeks to a month if the corps is willing to provide the necessary resources.
The system of chambers where the fish are trapped is designed to augment the flow in the channel downstream from the fish ladder, thereby luring the fish into the system so they can safely bypass the dam.
The auxiliary system was shut down when the holes were discovered by divers last week. Beginning Thursday, the corps plans to try to change the direction of the flow in the auxiliary chambers, coaxing the fish back into the river through a sluiceway designed to funnel debris and ice out of the system.
“It’s a total experiment and a flip of the coin as to whether it will work or not,” Heinith said.
He said any shad or sockeye trapped in the chambers probably already are dead.
The corps has boosted the flow of water in the dam’s spillways from 75,000 to 120,000 cubic feet per second to lure approaching fish away from the damaged ladder.
Heinith faulted the corps for failing to clean out debris after last year’s high runoff. That compounded the problems caused by an even bigger runoff this year, he said.
“From the tribal perspective, we hate to see this happening, but we’ve been like the canary in the mine telling the corps and the region that there hasn’t been near enough attention to the adult passage system,” Heinith said.
The situation is complicated further because the fall chinook runs naturally migrate toward the Washington side of the Columbia.
“It is, in a word, a mess,” Heinith said.
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