Update: Horse Heaven Hills Wind Project — Public Comments Open

Update: Horse Heaven Hills Wind Project — Public Comments Open

The Washington State Energy Facility Site Evaluation Council (EFSEC) is now considering Resolution 357, which would accept a mitigation plan for the Horse Heaven Hills Wind and Solar Project in Benton County. Below is a summary of Resolution 357. 

This large-scale project — spanning more than 70,000 acres south of the Tri-Cities — has raised serious local concerns about its impact on our views, wildlife, recreation, and community character. Despite years of public input and EFSEC’s own recommendation to reduce the project size, the current proposal moves forward with limited changes and unclear protections for the environment and nearby residents.

Now is the time to speak up.
Public comments on Resolution 357 are open until October 13, 2025, 11:59 p.m.
Submit your comment at: https://comments.efsec.wa.gov
You can also email [email protected]

Your voice matters—help protect the Tri-Cities landscape and ensure local perspectives are heard.
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What is Resolution 357?
Resolution 357 is a draft resolution issued by EFSEC staff to guide the implementation of the “Spec-5” mitigation measure for the Horse Heaven Wind Project. The public comment period for it runs from September 30 to October 13, 2025.
“Spec-5” is a specific mitigation condition embedded in the Site Certification Agreement (and earlier proposals) that relates especially to buffer zones around ferruginous hawk nests, avoidance of sensitive habitat, and restrictions on siting of turbines, solar arrays, and battery systems in areas of high environmental risk.

What does Spec-5 (and thus Resolution 357) address?
Here are the primary elements Spec-5 and Resolution 357 are supposed to control:

1. Buffer zones around hawk nests
   Spec-5 proposes prohibiting turbines within certain buffer distances of both historic and active ferruginous hawk nests. It also restricts placing solar arrays or battery energy storage systems (BESS) too close to known hawk nesting sites.
2. Avoidance of “Class 3 Impact” zones
   The Council recommended excluding sections of the micrositing area designated “Class 3 Impact” (often within 2 miles of nest sites) from development for turbines.
3. More protective habitat limits
   Spec-5 would strengthen prior mitigation by prohibiting solar arrays in certain shrubland or priority habitat areas and avoiding siting in other especially sensitive zones.
4. Flexibility and enforcement
   Resolution 357 is meant to clarify how Spec-5 is applied, how compliance is monitored, and how deviations or exceptions would be handled.

Why it matters & what’s uncertain

• Scale reduction implied: Because of the stricter buffers and exclusions, the project may be reduced by roughly one / third in affected areas to meet Spec-5 mandates.
• Interpretation & enforcement risk: Resolution 357 must define how much discretion the developer or EFSEC has to “bend” the buffers or grant exceptions — that’s a key point of contention.
• Cultural, visual, and ecological impact: Spec-5 is one of the last major mitigation tools left to protect hawk habitat, viewsheds, and sensitive land before construction would begin. If weakly applied, many of the objections raised by opponents may persist regardless of this resolution.

Learn More about the Horse Heaven Hills Project

• EFSEC Resolution 357 – Draft Mitigation Plan:
  Review the official draft and submit public comments by October 13, 2025.
  efsec.wa.gov/hearings-and-meetings/2025/october-2025-horse-heaven-draft-resolution-357-implementation-spec-5-mitigation-measure-comment
• Public Comment Portal:
  Share your thoughts directly with EFSEC before the deadline.
  💬 comments.efsec.wa.gov
• Background Reporting:
  Cascade PBS – “Horse Heaven wind farm faces one-third cut over hawk protections”
  Read Article ›