Tuesday, November 28, 2023

PG&E Plans to Reduce Lake Pillsbury by 10′ to Reduce Earthquake and Flood Risks

Screenshot from PG&E webinar invitation, Scott Dam at Lake Pillsbury

On April 27, 2023, PG&E presented a webinar hosted by Ron Richardson, North Coast Regional Vice President, to discuss PG&E’s plans to reduce the lake level 10 feet by leaving the spill gates open at Scott Dam. 

Dave Ritzman, Chief Dam Safety Engineer for PG&E spoke about seismic and flood risks. According to Ritzman, public safety is PG&E’s highest priority and its goal is to protect people, property, and the environment. PG&E conducts routine inspections monthly and annually. 

Because Scott Dam is part of a hydroelectric power project, PG&E is regulated by the Federal Energy Regulatory Commission (FERC), which conducts a safety review every five years. Scott Dam is also regulated by the California Division of Safety of Dams, and that agency performs inspections as well. PG&E also uses independent consultants to monitor dam safety. 

Lake Pillsbury sits atop the Bartlett Springs Fault. The last major studies on Scott Dam were done in the late 1990s-early 2000s. The science of seismology is an emerging field, and PG&E decided to do a new study on Scott Dam. One of the slides used in the presentation states: “New findings show an increase in seismic risk and a greater probability of an earthquake impacting Scott Dam.” Using new data and technologies, it is estimated that there is a 63% seismic risk increase at Scott Dam.

By leaving the gates open at Scott Dam, there will be approximately 25% less water stored in Lake Pillsbury, reducing pressure on the dam, lowering seismic risk, and reducing the risk of catastrophic failure. 

Janet Walther, PG&E Senior Manager Hydro Licensing, spoke about this coming summer’s recreational use at Lake Pillsbury. The Pillsbury Pines and Fuller Grove Boat ramps should be open until August. The Lower Elevation Boat Ramp should be open until Labor Day. Lake levels should stay high because there will be less water sent through the diversion.

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Richardson wrapped up the slide show by saying that PG&E will continue to do studies and will continue to release water into the Eel River and the East Branch of the Upper Russian River in order to comply with the amounts needed to protect fish under the Endangered Species Act. This summer, it is expected that the releases will be similar to the amounts released in 2021. 

And now it was time to answer questions from the viewers of the webinar. Here are the questions and answers, summarized and paraphrased for brevity.

Q: Regarding the 63% increase in seismic hazard. How was that measured over time?

A: From Ritzman: The increase in shaking was not measured over time, but our understanding of the conditions has changed.

Q: How much will it cost to increase seismic safety?

A: From Walther: From PG&E’s perspective, we are already in the process of surrender. We don’t have the ability to operate the hydroelectric plant. If another entity wants to step forward to acquire the project, they can look at costs. From Ritzman: It’s preliminary and we can’t quote a cost estimate, but “likely a big number.” The path is toward decommissioning of Scott Dam.

Q: Is there any chance the dam will not be decommissioned?

A: From Walther: There is an opportunity if another entity wants to acquire the dam. PG&E is looking for parties who want to acquire and submit an application to FERC. As of this date, nobody has stepped forward. If nobody steps forward, the dam will be decommissioned.

Q: What about other dams that PG&E controls, are you lowering water level in those?

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A: PG&E is looking into it.

Q: When deciding to decommission Scott Dam, did PG&E take water supply into account, especially for fire suppression?

A: From Walther: That will be part of FERC’s analysis. They will assess the potential impacts.

Q: What is the timeline for decommissioning?

A: From Tony Gigliotti, PG&E Senior Licensing Project Manager: “When we say decommission, both dams [Scott and Cape Horn] will be removed unless a new owner comes forward.” PG&E’s initial surrender application will be submitted to FERC in November 2023. The revised application will probably be submitted in May 2024. In January 2025, the final application should be submitted to FERC.

Q: What is the deadline for another entity to submit an application to purchase?

A: From Walther: The deadline is when PG&E submits the final application to FERC. PG&E wants to know before that deadline because that will affect the preparation of PG&E’s surrender plan. PG&E wants to see any proposals ASAP.

Q: Can FERC deny PG&E’s surrender application?

A: From Walther: No, FERC cannot deny it. FERC cannot require PG&E to own and operate a dam.

Q: Who bears the cost of decommissioning?

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A: From Walther: PG&E has a decommissioning fund. The cost will be borne by the customers. PG&E decided to decommission because that will ultimately be cheaper for the customers.

Q: What is the expected timing of the ultimate decommissioning (dam removal)?

A: From Gigliotti: There is no firm answer. FERC will review and analyze PG&E’s application to surrender. It could be in 2028, but final timing is unknown.

Q: What about FERC’s letter to PG&E saying that PG&E can’t unilaterally decide to lower the water level?

A: From Walther: FERC’s letter said PG&E needs to submit a request to amend the license to make sure we can maintain the required flows.

Q: Would PG&E be willing to host in-person community events with elected officials to discuss this matter?

A: From Richardson: Yes.

Q: Regarding the seismic analysis, have any third-party reviews been done?

A: From Ritzman: Third-party reviews have been done. The analysis was based on seismic science.

Q: Doesn’t a hydroelectric facility align with PG&E’s commitment to clean energy? Why abandon this?

A: From Walther: Yes, but we have to balance what is best for customers. This small hydroelectric project was more about delivering water.

Q: Have PG&E shareholders been notified? What if the shareholders vote not to decommission?

A: From Walther: This is not a shareholder vote matter. PG&E has already committed to decommission the dam and surrender the license. 

Q: What was the length of record used for the seismic analysis?

A: The analysis looked at historical records and geologic mapping.

Q: How much water is expected to be released to the Eel River from July to October?

A: From Walther:  We are working on variances. We will have more information once the variance request is finalized.

Q: Has PG&E considered remodeling Scott Dam into a pumped power facility, like they use in Portugal?

A: PG&E is giving up the entire project under FERC.

Q: What is a rough estimate of the purchase price of the dam and the hydroelectric facility?

A: From Walther: There isn’t a price set. PG&E is willing to negotiate with an interested party.

The time was up. The moderator mentioned that there had been numerous questions from people in Potter Valley and Sonoma County that were not answered. 

Richardson signed off by saying that this webinar was presented to address the safety issues at Scott Dam and the concerns of the Lake Pillsbury residents, and had been requested by Congressman Mike Thompson. There is more work ahead for PG&E and there will be future webinars and meetings about the process. 

In a follow-up phone call with Paul Moreno, PG&E Principal, Marketing and Communications, some of the issues discussed in webinar were clarified, as follows: 

  • The webinar was narrowly focused on the water level and seismic issues at Lake Pillsbury and was intended for the Lake Pillsbury community. PG&E chose to answer questions submitted during the webinar that focused on these issues.
  • The two dams and facilities span Lake and Mendocino Counties. The water supplied from the hydroelectric project into the Russian River is mainly used by Mendocino and Sonoma Counties.
  • The surrender process and the parameters that PG&E works under:
    • FERC licenses hydroelectric projects. The license term is usually 30-50 years.
    • The holders of the license are obligated to generate electricity.
    • The original use of the water that is diverted from the Eel River to the Russian River was intended to generate power for the City of Ukiah. It was never intended to be a water supply. 
    • Over time, it became a money loser for PG&E. PG&E has tried to work with various groups that are interested in taking over the project, but nothing has worked out so far. 
    • PG&E announced that it would not seek a new license for the project.
    • FERC directed PG&E to develop a surrender application. PG&E is developing the surrender application, and will submit it later this year. FERC does not have a specific deadline to respond to the application. The process of dam decommissioning is expected to take years.

For those interested in finding out more about what will happen to the water supply, check out the Russian River Water Forum. The RRWF is looking at ways to form an entity and to secure funding to negotiate with PG&E about taking over the diversion project in Potter Valley. The Planning Group meeting of the RRWF is set for May 17 from 10:00 am to 3:00 pm at the Ukiah Conference Center, and will be open to the public, with a Zoom option available. Sign up for email notifications about the RRWF here.

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Monica Huettl
Monica Huettl
Mendocino County Resident, Annoying Horse Girl.

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