The California Coastal Commission found the Pacific Gas and Electric Company’s (PG&E) mitigation plan to be too thin to warrant permits to keep Diablo Canyon nuclear power plant running.
“We’re talking about decades of staggering and devastating environmental impact that demand action not delay,” Commissioner Raymond Jackson said during the Nov. 6 meeting. “We need the meaningful protection for the more than 12,000 acres of irreplaceable coastal lands, not vague promises of future mitigation and uncertain outcomes.”
Since it became active in the 1980s, Diablo Canyon has been operating under two U.S. Nuclear Regulatory Commission licenses for its twin reactor units. Those licenses were set to expire in 2025. Before that expiration date, state legislation in the form of Senate Bill 846 and California Public Utilities Commission actions allowed PG&E to keep the plant open until 2030.
The utility company filed a license renewal application in 2023 with the Nuclear Regulatory Commission to keep the reactors running for an additional 20 years.
On Nov. 6, PG&E needed the Coastal Commission to review a consistency certification for the new 20-year federal operating licenses and approve coastal development permit applications for operating the units for a shorter time—until Oct. 31, 2029, for Unit 1 and Oct. 31, 2030, for Unit 2. The state has only approved running the units through those dates.
According to the Coastal Commission staff report, PG&E initially declined to not only submit a permit application but also to acknowledge that mitigation was necessary to offset Diablo Canyon’s impact on coastal resources.
The most adverse of these impacts, Coastal Commission staff said, is to marine life, as the nuclear plant cycles 2.5 billion gallons of water every day from the Pacific Ocean to cool its depleted fuel pools and safety components.
“For context, this made up roughly 62 percent of the total volume of cooling water used by all coastal power plants in California in 2024,” the staff report said. “The most recent available entrainment studies show that the DCPP’s use of seawater results in an annual loss of marine life equal to that produced in up to 9,360 acres, or more than 14 square miles, of nearshore waters.”
In October, PG&E submitted the permit application and a mitigation proposal that would be carried out in two phases. But many officials and community members want the company to do more to protect the land surrounding the plant.
“You need to find ways to protect all the 12,000 acres of this pristine coastal area,” Coastal Band of the Chumash Nation Vice Chair Michael Khus told commissioners. “This staff recommendation that strips 11,000 acres of protection from the bulldozering and the heavy development is not what the Coastal Commission stands for.”
Coastal Commission staff recommended approving the permits and consistency certification for PG&E based on four outlined mitigation measures—setting up a conservation easement across roughly 1,100 acres of the North Ranch portion of PG&E’s property directly adjacent to Montaña de Oro State Park; an offer to dedicate a public access trail easement for roughly 10 miles of new trail alignments; an offer of $5.6 million to accompany the trail easement for planning, construction, management, and maintenance of public access trails; and establishing a right of first refusal for government, nonprofit land conservation organizations, or California native American tribes to purchase land interests in Wild Cherry Canyon.
State Sen. John Laird (D-Santa Cruz) wanted PG&E to extend conservation easements across the entirety of North Ranch and South Ranch (which contains Wild Cherry Canyon), which makes up the 14-mile stretch of Diablo Canyon Lands located in the Irish Hills region of San Luis Obispo County.
“Bluntly put, the proposed mitigation plan in the staff report is grossly inadequate, given the impacts associated with Diablo’s continued operations,” Laird wrote in a letter to the Coastal Commission.
SLO County supervisors were divided on the issue. While 2nd District Supervisor Bruce Gibson said he supported Laird’s call for more land conservation, 1st District Supervisor John Peschong, 3rd District Supervisor Dawn Ortiz-Legg, and 5th District Supervisor Heather Moreno supported the Coastal Commission’s staff recommendation at the meeting.
“We’re talking about affordability,” said Ortiz-Legg, who represents the Diablo Canyon region. “We’re talking about creating this path to open spaces but also doing it not on the back of ratepayers.”
Coastal commissioners voted to continue both the permit application and consistency certification reviews to December, giving staff and PG&E more time to work on the mitigation plan. The commission will next meet from Dec. 10 to 12. ∆
This article appears in Nov 13-23, 2025.
The California Coastal Commission is just one dramatic plot twist away from crowning itself Supreme Ruler of Shorelines and Everything Within Eyeshot. At the rate it’s going, don’t be surprised if it starts issuing edicts about where sand is allowed to exist and whether waves have the proper permits before coming ashore.