Pacific Gas and Electric Company Submits Drilling Program Plan to Federal Energy Regulatory Commission

The Pacific Gas and Electric Company (PG&E) has submitted a drilling program plan to the Federal Energy Regulatory Commission (FERC) for a third-party exploration project located between Cape Horn Dam and Scott Dam in the Potter Valley Hydroelectric Project, FERC No. 77. The project aims to advance Sonoma Water's design for the Potter Valley Project New Eel-Russian Facility (NERF), a proposed run-of-the-river facility that will divert water from the Eel River to the Russian River basin.

The drilling program plan will be used to obtain data to support the design of the NERF, which will be operated by Sonoma Water and other stakeholders. The plan has been reviewed by PG&E and is believed to have minimal impacts on the Cape Horn Dam and appurtenant facilities. The project includes constructing a pump station and modifying the Van Arsdale tunnel intake infrastructure on the Eel River.

Key Takeaways:

• The drilling program plan has been submitted to FERC for authorization to proceed with a third-party exploration project located between Cape Horn Dam and Scott Dam in the Potter Valley Hydroelectric Project, FERC No. 77.
• The project aims to advance Sonoma Water's design for the Potter Valley Project New Eel-Russian Facility (NERF), a proposed run-of-the-river facility that will divert water from the Eel River to the Russian River basin.
• The project will be conducted by Sonoma Water and will include constructing a pump station and modifying the Van Arsdale tunnel intake infrastructure on the Eel River.
• The drilling program plan has been reviewed by PG&E and is believed to have minimal impacts on the Cape Horn Dam and appurtenant facilities.
• The project will be monitored by a PG&E inspector, and project-specific procedures for emergency preparedness will be developed.
• PG&E has requested FERC authorization to proceed with the drilling program plan.

Statistics:

• September 2025: Sonoma Water plans to mobilize for drilling.
• 60 feet: Minimum distance from the concrete spillway portion of Cape Horn Dam where drilling activities will take place.
• 130 feet: Minimum distance from the embankment portion of Cape Horn Dam where drilling activities will take place.
• 60 feet: Minimum distance from the Van Arsdale Diversion where drilling activities will take place.

Sources:

• Correspondence from Robert O. Ellis, Deputy Chief Dam Safety Engineer, Pacific Gas and Electric Company, to Frank L. Blackett, Regional Engineer, Federal Energy Regulatory Commission, dated July 3, 2025.