Rock Island Hydroelectric Project Update: Chelan PUD Hosts Board of Consultants Meeting No. 4

Strategic Insights -

In a recent meeting conducted virtually on July 22, 2025, the Board of Consultants (BOC) convened to oversee the investigation, remediation, and long-term monitoring of the Alkali Aggregate Reactivity (AAR) occurring at the Rock Island Hydroelectric Project. The meeting was conducted in accordance with the Federal Energy Regulatory Commission's (FERC) guidance and was attended by representatives from HDR, Stantec, and Chelan PUD. The BOC meeting focused on several key areas, including the Rock Island Spillway Construction/Remediation Activities, the 30% Drop Gate Structure design, and Dr. Donald Bruce's Post-Tensioned Anchor Assessment. Chelan PUD is continuing to evaluate long-term risk reduction measures at the Drop Gate Structure and is preparing for site investigation, material testing, and additional instrumentation to advance the design of proposed remedial efforts.

Key Takeaways:

  • Chelan PUD convened the Board of Consultants (BOC) meeting in accordance with FERC's July 23, 2024, letter to Martha Whiteman, Chelan PUD, Project No. 943, Accession No. 20240723-3049.
  • The BOC meeting was conducted virtually on July 22, 2025, and focused on several key areas, including Rock Island Spillway Construction/Remediation Activities, the 30% Drop Gate Structure design, and Dr. Donald Bruce's Post-Tensioned Anchor Assessment.
  • Chelan PUD is continuing to evaluate long-term risk reduction measures at the Drop Gate Structure to address both recognized dam safety risks and future growth as a result of Alkali-Aggregate Reactivity.
  • Chelan PUD is preparing for site investigation, material testing, and additional instrumentation to advance the design of proposed remedial efforts.
  • Chelan PUD intends to hold BOC Meeting No. 5 at the Chelan County PUD Service Center Building on November 18-19, 2025, with a site visit to Rock Island Dam.
  • The meeting will include a review of the 30% Drop Gate Structure design, construction sequencing, and proposed schedule.

Statistics:

  • The Rock Island Hydroelectric Project is located in Chelan County, Washington, and is operated by Public Utility District No. 1 of Chelan County.
  • Alkali Aggregate Reactivity (AAR) is a recognized dam safety risk at the Rock Island Hydroelectric Project.
  • Chelan PUD has submitted a tracking table to track questions, recommendations, and responses between the BOC and Chelan PUD.
  • The tracking table will be actively updated throughout the BOC program.

Sources:

  • Letter from David Capka, Director, FERC, to Martha Whiteman, Chelan PUD, Project No. 943, Accession No. 20240723-3049 (Jul. 23, 2024).
  • FERC, "Board of Consultants Meeting No. 4 Report," August 7, 2025.
  • Chelan PUD, "BOC Comment Tracking Table," August 12, 2025.