“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.”
http://www.wildsalmon.org/projects/lower-snake-river-waterway/