A new hydroelectric dam may be erected in the South Fork of the Skykomish River — one of the last free-flowing rivers in Washington.
Snohomish Public Utilities District (SnoPUD) is planning the installation of a 7-foot-tall inflatable dam that would stretch across the river above Sunset Falls, a 114-foot-tall waterfall that marks the end of natural fish migration up river, said Rich Bowers, northwest coordinator at Hydropower Reform Coalition.
The dam could be deflated during times of very low or very high flow, according to SnoPUD, who estimates this would be about four months out of the year.
The Skykomish is one of four rivers included in the Washington State Scenic River System, a legislative program protecting and preserving these rivers’ natural character, said Andrea Matzke, the president of Wild Washington Rivers.
Dams block the flow of water, stopping the upstream and downstream flow of nutrients, salmon and aquatic insects, said John McLaughlin, Western environmental sciences professor.
Dams are a substantial interruption in ecologic and hydrologic connectivity, McLaughlin said. Dams also affect water temperature and flow rate.
In an effort to restore wild salmon and the bull trout population, a trap and haul facility was built in 1958 below Sunset Falls to capture spawning salmon and haul them above the fall, adding more than 50 miles of new habitat.
Because the state no longer has the funds to make necessary improvements to the trap and haul facility, SnoPUD agreed to make the improvements and take over the operation if it is granted the license for the dam, Matzke said.
“But the idea of mitigating for fish by building a dam to improve their situation really doesn’t float in the Northwest,” Bowers said.
The Tulalip tribe supports the dam being built because it would mean the improvements could be made to the trap and haul facility. But Matzke said the tribe was told by SnoPUD they would lose the facility altogether without the dam.
“SnoPUD is abusing the fact that we don’t have the state funds to protect the river,” Matzke said.
Jessica Noble, sophomore, an environmental studies student at Western Washington University, said it’s is good that SnoPUD plans to improve and maintain the trap and haul facility alongside the dam project.
“They have good intentions, because they’re trying to help the salmon reach higher spawning grounds, but they weren’t naturally able to get there in the first place,” Noble said.
SnoPUD has a three-year preliminary study permit to assess the potential effects of building a dam on the Skykomish river.
After this period, they will apply for a federal license before the Federal Energy Regulatory Commission, Bowers said.
The Skykomish has a history of proposed dam projects, none of which were passed.
The last time they applied for a permit to dam the Skykomish was in 1991 under the same general manager, Steve Klein.
The license was denied when the National Oceanic and Atmospheric Administration and the Department of the Interior filed against it.
In 1981, SnoPUD spent two years studying the Skykomish using energy rate payer and tax payer dollars. But SnoPUD’s application for a permit was rejected, Matzke said.
“These changes to the environment are going to affect the young people the most,” Matzke said. “Today’s young people need to get involved because it is their future.”