The Pacific Rock Mine expansion between Camarillo and Thousand Oaks will permanently alter Conejo Mountain, with visual impacts that cannot be fully mitigated, the county found.

Despite warnings of damage to a critical wildlife corridor and rare-plant habitat, the Ventura County Board of Supervisors voted 4-1 Oct. 20 to approve the expansion, rejecting an appeal by the Center for Biological Diversity. Supervisor Vianey Lopez dissented.

The approval extends operations through June 2086, allowing excavation and export of about 29.7 million tons. The permit area in unincorporated Ventura County would grow from 111.5 to 204.4 acres, and the mining and facility area from 62.5 to 172.8 acres. Concrete and asphalt recycling and imported reclamation soil are also allowed.

The mine at 1000 S. Howard Road supplies rock and riprap for construction, flood control and coastal stabilization.

Pacific Rock says local production reduces long-distance trucking, while conservation groups warn the expansion would destroy irreplaceable habitat.

The county’s environmental impact report found mitigation could reduce several effects to less-than-significant levels. But expanded excavation would permanently alter the hillside, creating exposed slopes and stepped cuts visible from U.S. 101.

Landscaping could soften but not eliminate the visual impact, planning manager John Novi said, calling it “significant and unavoidable.”

The Center appealed the Planning Commission’s 4-0 approval in June, citing inadequate analysis of impacts to wildlife, rare plants, oak woodlands, greenhouse gas emissions and air quality. It also argued the report evaluated a 30-year permit, not the proposed 60-year term, and should have been recirculated.

County staff said the review complied with the California Environmental Quality Act and the longer permit did not require a new review. The report evaluated six alternatives and includes 61 mitigation measures.

Tiffany Yap, a senior conservation scientist with the Center who studies wildlife connectivity and mountain lions, said the mine lies within a narrow corridor linking the Santa Monica Mountains with habitat to the north. The expansion would destroy more than 100 acres of habitat and narrow a key passage from about 1,500 feet to 800 feet, she said.

Tracking data show mountain lions use the area, Yap said. Southern and central coast mountain lions are threatened under California law, and isolation can increase inbreeding and extinction risk.

“Any habitat destruction in this area is going to affect how these mountain lions move,” Yap said.

Conejo Mountain also supports ‘ Conejo buckwheat, found nowhere else in the world, and b other rare plants. Yap said the expansion would reach the world’s largest contiguous patch of buckwheat, while dust and invasive species could affect plants and pollinators.

The Center said the proposed 6.7 acres of conservation land falls short of state wildlife officials’ recommendations.

Associate attorney Evan Levy said the report downplays the corridor and relies on outdated science.

Speakers cited habitat loss, dust, emissions, noise and the lengthy permit. The Center said all 62 comment letters opposed the project.

Levy cited the mine’s history of permit violations. Novi said the county resolved a previous grading violation and no violations were active.

“This is a 60 year industrial mining project in one of the most biodiverse areas of the country with an applicant who has a history of permit violations,” Levy said, adding that the project warranted extensive mitigation under CEQA.

“If the board approves this project you can’t walk it back. A future board can’t walk it back for 60 years,” Levy said.

Project representatives defended the review and local rock supply. Consultant Graham Stephens said extensive studies, enforceable mitigation and further biological surveys would help limit impacts. He called the mitigation package the most extensive he had seen for a mining project.

Pacific Rock representative Nicole Corey said the family business has served the region since the late 1800s. Consultant Jane Farkas said conservation easements could protect parts of Conejo Mountain permanently.

Lopez said she remained concerned about the environmental impacts of a 60-year permit and urged the board to consider limiting it to 30 years, despite the EIR finding little difference between the terms.

Supervisor Janice Parvin supported the 60-year permit, saying truck traffic and community impacts would not increase significantly. She noted some mines in her area have 100-year permits and residents can report blasting or air quality concerns to the county.

Board Chair Jeff Gorell, whose district includes the mine and who lives in Dos Vientos, said he felt “anxiety and apprehension” about the expansion and was concerned about the wildlife corridor.

Gorell said Rincon residents recently sought boulders and riprap to protect homes from El Niño-related erosion. A local source avoids trucking materials from elsewhere, he said, and factors into weighing environmental costs and benefits.

“If I can wave a magic wand and have it be (elsewhere), maybe,” Gorell said, “but it’s a good thing to have these minerals and assets and resources locally so we don’t have to have it trucked in.”

Gorell said he trusted staff to prioritize environmental protection and monitor compliance, and that the owners could create conservation protections.

“I think some of the most amazing work is yet to happen,” Gorell said, adding the company could leave “an amazing legacy of conservation and open space and environmental protection.”

‘If the board approves this project you can’t walk it back. A future board can’t walk it back for 60 years.’

— Evan Levy attorney