By Becky Kramer, The Spokesman-Review

SPOKANE — A federal judge is forcing discussion of a radical step to save endangered salmon: taking out four dams on the Lower Snake River.

The public will get a chance to weigh in at meetings throughout the Northwest starting next month.

“Scientists tell us that removing the four Lower Snake dams is the single most important action we could take to restore salmon in the entire Columbia-Snake river basin,” said Sam Mace of Save Our Wild Salmon.

The four dams produce about 5 percent of the Northwest’s hydroelectric power. They allow barges to ship goods between Lewiston and Portland. But they also hamper salmon migration to some of the best remaining fish habitat.

Commercial interests have long opposed removing the Lower Snake dams.

“We think those dams need to stay in place because of the multiple benefits they provide,” said Terry Flores, executive director of Northwest River Partners, which represents public utilities, port districts and farm groups.

“They provide clean, carbon-free energy . We think they’re an important part of the Northwest economy and the environment,” she said.

Three federal agencies will hold public hearings across the region this fall to discuss the creation of a new salmon plan.

Back in May, U.S. District Court Judge Michael H. Simon sided with fishing groups, environmentalists, the state of Oregon and the Nez Perce Tribe, finding that the latest of five federal plans for protecting the fish wasn’t adequate. He ordered the agencies to prepare a new one by early 2018.

Simon said federal agencies had “done their utmost” to avoid considering breaching the Snake River dams, ignoring strong suggestions to do so by a previous federal judge.

While Simon said he wouldn’t dictate what options agencies should consider, he said a proper analysis under federal law “may well require” considering breaching, bypassing or removing one or more of the four Lower Snake River dams.

Salmon advocates said the ruling is the closest the region has come to dam breaching since 2000, when the Army Corps of Engineers did a study of taking out the Lower Snake dams.

The four dams produce about 1,000 megawatts of electricity on average, which is enough to meet the needs of about 800,000 households each year. But despite millions of dollars spent on fish passage improvements, adult salmon still die in the reservoirs behind the dams.

“The four dams on the Lower Snake River have had a devastating impact on salmon, steelhead and Pacific lamprey, and in turn on the Nez Perce people,” said McCoy Oatman, vice chairman of the tribe, which is also advocating dam removal.

The Snake River is the gateway to millions of acres of pristine, high-elevation habitat in central Idaho, southwest Washington and northeast Oregon, which could help salmon survive in a warming climate.

“We have the healthy rivers, but the salmon aren’t making it back,” Mace said.

In a typical year, only about 40 percent of the Idaho sockeye counted on the Lower Columbia River make it back to their Idaho spawning grounds. During last year’s drought, mortality was in the 99 percent range. Warm water in the four Lower Snake reservoirs is a contributor.

The economic argument for the dams isn’t as strong as it once was, Mace said.

The Lower Snake dams were built from the 1950s to the 1970s, with navigation as a primary goal. But that barge traffic has dropped in recent years as the region has invested in rail capacity, Mace said.

“These dams weren’t built for flood control. They’re not big water storage dams . and their power benefits are replaceable,” she said. “It’s time to call the question on them.”

Salmon advocates “downplay the value of the dams,” said Flores, of Northwest River Partners.

Dams provide more operating flexibility than other renewable energy sources, such as wind and solar, Flores said. Electricity generated from wind turbines and solar panels can’t be stored easily. But dams can store water, releasing it during periods of high demand for electricity.

Breaching the four Lower Snake dams would require the Northwest to build a natural-gas-fired plant, the Bonneville Power Adminstration said this spring.

Even a highly efficient gas-fired plant would increase the region’s carbon dioxide emissions by 2 million to 2.6 millon metric tons annually, which is like adding 421,000 passenger cars to the road, according to the BPA.

The agency sells the electricity produced by 31 federal dams.

Replacing the Lower Snake dams’ electric production with natural gas would cost between $274 million and $372 million each year, the agency said. The estimates include the capacity to keep the Northwest power grid running smoothly.

Another study found that dam removal would have a minor impact on electricity costs. A 2015 study done by the Northwest Energy Coalition said residential customers of public power companies would pay about $1 more per month.

John Harrison, a spokesman for the Northwest Power and Conservation Council, said he’s not aware of an “objective, independent, bipartisan” analysis of the economic impact of dam removal.

The information available at this time either comes from agencies or interest groups, he said