Fish Ladder Crisis Biting Ratepayers Trouble At Bonneville Dam Traps Salmon, Costs Bpa Customers

Trouble with the fish ladder at Bonneville Dam is costing some utility ratepayers $3 million in lost power revenues and $10,000 a day for elaborate rescue and repair maneuvers intended to preserve salmon.

The tale of rescue and entrapment began unfolding at the Columbia River dam 40 miles east of Portland about two weeks ago, when the U.S. Army Corps of Engineers discovered grates at the entrance to a fish ladder had been damaged by this spring’s high water runoff.

Water patterns in the fish ladder didn’t look quite right, so corps staff engaged in the art of plunking: lowering a lead weight on a rope to determine if the grates were intact. They discovered about 10 percent of 250 or so grates were broken.

That made the fish ladder impassable for adult fish, which are migrating to their spawning grounds upriver. Salmon, steelhead, sturgeon and other fish could be affected, biologists say.

The stakes are heightened by the already fragile condition of Columbia Basin salmon. Only about two to seven endangered Snake River sockeye cross Bonneville Dam each year as it is, according to Lowell Stuehrenberg of the National Marine Fisheries Service.

While the sockeye run is mostly past the dam, “there is a potential for one of them to be in there,” Lowell said.

The Bonneville Power Administration pulled the plug on two generators at a powerhouse at the dam a week ago to give any fish trapped in the powerhouse a chance to escape.

Then the corps sent divers plunging into the dark, wet guts of the powerhouse to fix the grates.

While the fish ladder has been repaired to avoid any more fish being trapped, the big mystery is how many are already stranded in the powerhouse.

“One fish, we know for sure. We saw it. Probably a chinook,” said Gary Johnson, the corps’ biologist at the dam.

The corps is trying to attract any migratory fish caught in the powerhouse with a fast current of water experts hope will lure them back into the river.

Nobody knows if it will work, or if trapped fish can be salvaged alive, Stuehrenberg said.

Some environmental groups and tribes are calling for more drastic tactics, beyond the corps’ flushing operation. They want the powerhouse shut down completely, and drained of all water while people have a look around inside and rescue any trapped fish.

Johnson of the corps estimated that could take as long as four months. Crystal Ball, a spokeswoman at BPA, said a longer shutdown could significantly increase the cost to ratepayers for lost power.

The BPA sells its power throughout the Northwest. Its customers include only a smattering of Inland Northwest utilities, however. Washington Water Power Co., which serves most of the Spokane area, doesn’t buy Bonneville energy.

There are other problems with draining the powerhouse and letting it sit idle for a couple of months. Fall chinook and steelhead would have no way over the dam if the fish ladder is inoperable when their migration begins, sometime in September.

Tim Zimmer of the Save Our Wild Salmon Coalition in Seattle said the corps should treat the situation as an emergency. “They can move mountains. They can get this done by Sept. 1.”

Top officials at the corps will meet today to evaluate what to do. A decision is expected early next week.

Johnson had no estimate of what it would cost to drain the powerhouse, clean out debris that broke the grates, and salvage stranded fish.

It’s not the first time there’s been trouble at the powerhouse opened in 1981.

It was regarded as a model of engineering in its day. But the corps has since poured millions of dollars into repairs and alterations intended to help fish survive their trip past the powerhouse.

Six million dollars worth of screens built over intake pipes leading to the turbines were installed to protect fish, but proved largely ineffective.

The powerhouse has been idled often because bypass systems intended to protect fish simply don’t work.

Problems have ranged from the high-tech to the low. An outfall pipe on the downstream side of the dam turned out to be located in the path of hungry squawfish, which prey on juvenile salmon.

The pipe is going to be moved, at a cost of more than $10 million.

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