Conservation and fishing groups say four dams on the lower Snake River keep many migrating salmon from getting to Idaho. (Bureau of Land Management)

LEWISTON, Idaho - A "Free the Snake Flotilla" is floating the Snake River on Saturday, calling for the removal of four dams on the lower Snake to help improve salmon and steelhead habitat. The second annual event includes members of the Nez Perce Tribe, sport fishermen, biologists, and others who believe dam removal is key to saving native, endangered salmon and steelhead.



Kevin Lewis, executive director of Idaho Rivers United, said fish numbers in Idaho began to drop even before the Snake River dams, when four dams were built on the Columbia River.



"When they built the four lower Snake dams, the numbers then dropped below the point of self-sustaining," he explained. "So, you basically had crossed that tipping point of the fish being able to survive eight dams in each direction."



The groups want the Ice Harbor, Lower Monumental, Little Goose and Lower Granite dams to be removed. This summer the U.S. Army Corps of Engineers installed fish ladders on two Snake River dams to try and help the fish. Last year, of the 250,000 Snake River sockeye that made the run, only about 40 made it to central Idaho.



Lewis said climate change is another factor in low fish numbers. Warmer temperatures have led to lower river flows, and dams create reservoirs where water tends to heat up. He said a federal judge recently ruled federal agencies need to reconsider dam removal as an option to save these fish.



"This judge issued a scathing opinion that the federal government had repeatedly failed to do enough, including taking dam-breaching off the table as not being an alternative when clearly, it needs to be an alternative," he said.



It would be the largest dam removal project in U.S. history. Lewis said the dams produce about three percent of the power on the Northwest grid, and that the region currently has a 15 percent energy surplus. But the Bonneville Power Administration said the dams play an important role at peak-demand times.