Pacific Gas and Electric Company Addresses Federal Energy Regulatory Commission Recommendations at Butt Valley Dam

The Pacific Gas and Electric Company has submitted a document to the Federal Energy Regulatory Commission (FERC) detailing its efforts to address recommendations from FERC's 11th 5-year Part 12D safety inspection report and comments regarding Recommendation 8 from the 10th 5-year Part 12D safety inspection report for Butt Valley Dam. The company has completed an updated structural analysis of Butt Valley Dam Intake Tower 2A, which was retained by Structural Integrity (SI). PG&E has reviewed SI's analysis and concurs with the findings and conclusions presented. The company has also prepared a technical memorandum summarizing SI's 2023 evaluation of Tower 2A.

Key Takeaways:

• PG&E submitted its original plan and schedule for addressing Recommendation 3 (R-3) in a letter to FERC dated March 30, 2021.
• The company received FERC Comments 1 (C-1) and 2 (C-2) in a letter dated August 30, 2023, and provided its most recent letter regarding C-1 and C-2 on April 29, 2025.
• PG&E retained Structural Integrity (SI) to complete an updated structural analysis of Butt Valley Dam Intake Tower 2A, which was completed on May 2, 2023.
• The company prepared a technical memorandum summarizing SI's 2023 evaluation of Tower 2A, which is provided in (Enclosure 2).
• A summary confirming the 2023 evaluation incorporated C-1 and C-2 is provided in (Enclosure 4).
• A plan and schedule addressing recommendations from PG&E's technical memorandum is provided in (Enclosure 5).

Statistics:

• The 11th 5-year Part 12D Safety Inspection Report was dated January 2021.
• The 10th 5-year Part 12D Safety Inspection Report was dated November 2015.
• PG&E submitted its original plan and schedule for addressing R-3 in a letter to FERC dated March 30, 2021.
• The company received FERC Comments 1 (C-1) and 2 (C-2) in a letter dated August 30, 2023.
• PG&E provided its most recent letter regarding C-1 and C-2 on April 29, 2025.

Sources:

• Federal Energy Regulatory Commission Division of Dam Safety and Inspections 100 First Street, Suite 2300 San Francisco, CA 94105-3084 (letter to Frank L. Blackett, dated May 30, 2025)
• Pacific Gas and Electric Company (letter to Frank L. Blackett, dated May 30, 2025)
• Structural Integrity (SI) (Nonlinear Seismic Assessment of the Butt Valley Reservoir Intake Tower 2A Plumas County, CA, dated May 2, 2023)