Two comprehensive studies are underway to collect information about the feasibility of removing Enloe Dam. Biologists say a free-flowing Similkameen River could provide hundreds of acres of salmon habitat.
$2.31-million grant funds detailed feasibility study
When it comes time to make a decision about the fate of Enloe Dam, the Okanogan County Public Utility District (PUD) and others interested in the future of the Similkameen River will have detailed information about fish habitat, sediment and costs of various alternatives.
With a $2.31-million grant from the National Oceanic and Atmospheric Administration (NOAA), Trout Unlimited (TU) and the Colville Confederated Tribes are seeking a consultant for a feasibility study and analysis of dam removal and other alternatives.
The dam on the Similkameen River near Oroville, which is owned by the PUD, hasn’t produced power in 64 years.
Trout Unlimited has two years to complete the Enloe Dam Removal Feasibility Study and Alternatives Analysis Project, said Warren Colyer, TU’s western water & habitat program director. Colyer is team lead for the study, which will be conducted in partnership with the Colville Tribes.
A feasibility assessment looks at the full spectrum of alternatives, from leaving the dam in place (“no action”) through partial or full dam removal, Colyer said. It will compare the costs and benefits of different scenarios, taking into account economics, sediment management, and impacts on the river. If removal proves feasible, the study will include a preliminary design for dam removal.
Project managers for the study will closely coordinate with the PUD. The goal is to gather enough information for a decision about the future of the dam, Colyer said.
The PUD commissioners passed a resolution supporting a comprehensive feasibility study and the district submitted a letter of support for the grant. Among the PUD’s requirements for dam removal are an agency that assumes all responsibility and liability, a firm source of funding, and research into the potential for fish habitat in the Similkameen River above the dam and in Canada.
Fish biologists have said that removing Enloe could provide access to more than 300 miles of habitat for endangered steelhead in the Similkameen basin in British Columbia.
“The dam has blocked fish passage for 100 years. Its removal would open access to cold water habitat, improve tribal fishing opportunities, and reduce the risk of flooding,” NOAA said in the announcement of the grant last year.
Study for Legislature
Trout Unlimited is heading up a companion study requested last year by the Washington Legislature to analyze biological, management and legal issues connected with potential dam removal and restoration of the Similkameen River. The Legislature provided $250,000 to the Washington Department of Fish and Wildlife (WDFW) for the study.
There are four components to that research — a roadmap of the project, stakeholder outreach, identification of entities that could take on dam removal, and analysis of strategies for sediment management, Colyer said.
The Legislature is not required to take any action on the study. “We’re in information-gathering mode,” Colyer said.
Some sampling of the huge volume of sediment that’s backed up behind the dam over the past century has been done, but more information is needed to determine an appropriate means for handling it. Sediment management will be an important part of any alternatives they develop, Colyer said.
The study for the Legislature will look at the pros and cons of different entities that could take on dam removal. Across the country, dams have been removed by federal and state agencies, private corporations and nonprofits, Colyer said.
The report to the Legislature is due at the end of June. Researchers should have a draft by the end of May, Colyer said.
