Snohomish County Public Utility District No. 1

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Customer Service (M-F 8a-5:30p): 425-783-1000

Small Hydropower

Woods Creek ProjectFor Snohomish County PUD, drawing energy from local waterways is a natural fit. The rapidly growing public utility has moved aggressively on several fronts to research and develop clean energy resources that are located close to home in Western Washington.

The Pacific Northwest offers an abundance of carbon-free natural energy sources.  So it makes sense to tap the solar intensity of the sun, the continuous hydrological cycle that produces flowing rivers and streams, the strong and the virtual limitless heat of the earth’s core. All of these resources can provide clean renewable energy to serve community needs. 

In 2009, the utility acquired two sites near Sultan, WA, for small-hydropower generation. The PUD purchased and renovated a small-hydro project at Woods Creek, which provides enough energy for several hundred homes. Upgrades to turbines have increased the project’s output by nearly 25 percent. The utility also has installed new tailrace and self-cleaning intake screens to reduce debris build up and protect resident fish populations.

In late 2011, the utility began operating its second small-hydro project, Youngs Creek, which generates up to 3 average megawatts – or enough power for about 2,000 homes. Both sites offer attractive characteristics. They’re located outside of sensitive areas, such as designated wilderness lands, and in the upper reaches of creeks, above natural impassible barriers so as not to affect migrating fish populations. These “backyard resources” also reduce the need for hundreds of miles of new transmission line, minimizing both line losses and environmental impacts.

Small-Hydro Potential

Snohomish PUD is assessing several additional small-hydropower sites for potential development in the next five to 10 years. The projects’ generating potential ranges anywhere from 2 to 25 megawatts. If fully developed, the collective energy output could serve tens of thousands of Snohomish PUD customers.

Youngs Creek HydroThe utility has met with a broad range of stakeholders – including local tribes, environmental groups and regulatory agencies – to share its plans. It has worked closely with the Washington Department of Fish & Wildlife to ensure the Youngs Creek facility provides adequate levels of river flow and protects fish.

In assessing potential sites, the PUD is especially mindful of anadromous fish populations, hydrology, geology, environmental issues and access to existing roads and transmission lines. It aims to balance energy generation with the need to protect river flows, water quality and cultural resources.

The PUD small-hydropower facilities are designed as run-of-the–river projects, which divert a portion of the water to a pressurized pipeline that delivers it to a turbine downstream for energy production. Given rainfall patterns in the region, the generating output is naturally maximized during times of high energy demand. It also complements other intermittent energy sources, such as wind and solar.

New small-hydropower sites will require approval by the Federal Energy Regulatory Commission. The utility expects each project will take three to five years from the application stage to completion of construction.

The small-hydro facilities don’t currently qualify under Washington’s renewable portfolio standard (RPS), although state legislators have proposed including new small hydro projects in the standard. Snohomish PUD and other utilities have supported such legislation. Under its RPS, Oregon allows new hydro projects up to 50 megawatts if they obtain low-impact certification.

For Snohomish, the push for more locally generated green energy resources is less about state mandates and more about creating a diverse, carbon-free energy supply. Its Board of Commissioners has made a commitment to meeting growing energy needs through cost-effective conservation and renewable energy resources. The utility faces continued load growth in the coming decades as the region grows.

Snohomish PUD is pursuing a broad range of renewable energy resources. It has secured contracts for wind energy from three facilities in Washington and Oregon. A local cogeneration facility supplies renewable energy using wood-waste. In addition, in 2009 the utility launched a comprehensive solar program to install demonstration projects in the community and offer resources to customers interested in installing their own systems.

Benefits of Small Hydropower

  • Typically located outside sensitive wilderness areas
  • Sited above or near natural barriers to negate impact on migrating fish
  • Negligible impact on oxygen levels, river temperatures and flow rates
  • Non-polluting resource with no heat or noxious gas releases
  • A proven technology, competitive in price to other green resources
  • Complements intermittent energy sources, such as wind and solar
  • Generates green jobs in engineering and construction
  • Hydropower facilities have long lives, up to 100 years or more