Snohomish County Public Utility District No. 1

Skip navigation and go to content

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

Sunset Fish Passage and Energy Project

The PUD received a preliminary permit from the Federal Energy Regulatory Commission (FERC) to study and assess the potential of a hydropower project on the South Fork Skykomish River. This project is proposed as a 30-megawatt, run-of-the-river hydroelectric, renewable resource facility, to be located near the base of Sunset Falls (in conjunction with refurbishing the trap-and-haul facility already there), one mile south of Index, Washington.


2/27/15: Preliminary Permit Progress Report No. 6 posted. (Select Documents, then Prelim Permit Progress Report from left pane.)

2/27/15: CSR Meeting Summary posted (Select Meetings from left pane.)

2/27/15: SP12 Technical Conference Follow-up scheduled. (Select Meetings from left pane.)

2/13/15: CSR Meeting presentation slides posted. (Select Meetings from left pane.)

2/13/15: SP12 Technical Conference Call scheduled. (Select Meetings from left pane.)

2/2/15: Updated Process Plan and Schedule as detailed in CSR. (Select Process, then Process Plan and Schedule from left pane.)

1/30/15: Compilation Study Report (CSR), Updated Project Design, Updated Communication Protocol posted. (Select Documents, then Study Reports from left pane.)

1/30/15: Final Technical Reports (Appendices to the CSR) posted.  (Select Documents, then Study Reports from left pane.)

1/30/15: IFIM Report and River Process Technical Memo posted for 30-day review.  (Select Documents, then Study Reports from left pane.)

Redesigned Project Requires No Dam, Weir or River Barriers:

After a series of studies and design analysis, the PUD has developed a highly innovative plan that requires no dam, weir or river barriers. It reduces construction costs by $10 million. The no-dam design is possible due to the unique geography of the South Fork Skykomish River. Upstream from Sunset Falls, the river turns sharply – a complete 180 degrees – creating a deep pool of water, which can accommodate an underwater intake structure. The water for the project would flow from the upstream intake through an underground tunnel a half-mile to the PUD powerhouse. Sufficient water would remain in the river for fish, aesthetics and recreation.

The PUD’s updated design modifies the water intake area and fish screens to cut excavation needs in half. It also reduces construction time by about six months. In addition, more efficient turbines at a proposed powerhouse would increase annual energy production. Diverse, locally owned power sources, such as the Sunset Fish Passage & Energy Project, help make the PUD and its customers more self-sufficient, resilient and energy secure.

Project Benefits Include:

  • It’s a non-polluting, renewable resource, with no heat or noxious gas releases.
  • Provides energy at the times of the year when it’s needed the most.
  • One of the best priced renewable energy sources available.
  • A locally generated resource right in the PUD’s backyard, minimizing the need for expensive new transmission systems.
  • Upgrades to the trap-and-haul facility would ultimately increase fish populations by improving the health of fish being transported upstream to 90 miles of spawning habitat, currently accessed by more than 25,000 fish annually.
  • PUD funding for the Washington State Department of Fish & Wildlife’s trap-and-haul facility would provide fishery benefits for years to come.