Board accepts Coastal Commission modifications, directs implementation steps for Los Osos plan and habitat program

The San Luis Obispo County Board of Supervisors voted on Oct. 29 to accept the California Coastal Commission’s suggested modifications to the Los Osos Community Plan and to move forward with a conservative, data-driven approach to resume limited building in the sewer service area.

County planners recommended a three-part path to lift the decades-long building moratorium in Los Osos: accept the Coastal Commission’s suggested modifications to the local coastal program so the plan may be certified; implement a growth management ordinance tied to a five-year rolling average basin-yield metric (with interim annual rates of 0.4% in 2025, 0.6% in 2026 and 0.8% in 2027, rising to a metric-driven cap in 2028); and require project participation in the Los Osos Habitat Conservation Plan (LOHCP) so the county can confer programmatic incidental-take coverage to applicants.

“We believe this is a balanced, conservative path that both protects our groundwater and habitat while providing a predictable pathway for property owners who have been waiting for years,” said Claire Momberger, planner in the county’s long-range division. Momberger and other staff described the LOHCP as a community-wide approach: the county or an implementing partner would acquire and restore habitat to generate mitigation credits that project proponents could purchase, simplifying permitting versus project-by-project permitting with the U.S. Fish and Wildlife Service.

County staff described three principal constraints that have stymied development in Los Osos: historical septic-related nitrate problems (largely addressed by the 2016 sewer), groundwater sustainability and the presence of four federally protected species. Staff noted the Basin Management Committee’s 2023 basin-yield metric of 69% (production versus the modeled sustainable yield) and said the GMO would use a five‑year rolling average to reduce sensitivity to wet or dry years.

Blaine Realy, the county’s groundwater-staff representative to the Basin Management Committee, said the BMC produces an annual recommendation and that the county would consult the BMC and the Department of Groundwater Sustainability when making annual growth-rate recommendations.

Public comment was split. Supporters — including housing advocates, the Home Builders Association and several residents — urged the board to end a cycle of delay and provide predictability and infill opportunities. Opponents, including several professional hydrologists and residents, urged postponing adoption until completion and peer review of a newer transient groundwater model and raised concerns about continuing local seawater intrusion, chloride and nitrate trends.

After deliberation the board approved staff’s recommendations to accept the Coastal Commission’s suggested modifications and to introduce the GMO amendments that implement the phased approach. The board also directed staff to return by December with a LOHCP implementation package that includes: a proposed mitigation-fee ordinance for public notice and introduction; justification and recommended amount for an initial internal county loan to ‘jump-start’ mitigation credit accrual (staff discussed a preliminary $2 million figure); detailed costing and fee examples (for instance, what the recommended per‑square‑foot mitigation fee would mean for a typical 2,000‑square‑foot house); a recommendation on an implementing entity MOU (staff proposed the Land Conservancy of San Luis Obispo County as a likely partner); staffing needs (staff recommended 0.5 FTE principal environmental specialist for phase‑1 implementation); and endowment parameters for long‑term habitat maintenance.

Staff emphasized the implementation process is adaptive: the GMO includes an annual board review of the allowable growth rate for Los Osos, and the county pledged to lower or pause allocations if the basin-yield metric or new data indicate unacceptable risk.

What happens next: Staff will prepare the LOHCP implementation materials and a mitigation-fee ordinance for the board’s consideration in December; if the Board adopts the fee ordinance, it would be noticed and considered for adoption at a subsequent hearing. The Coastal Commission must still certify the LCP amendment for the planning changes to take effect. The county’s direction aims to create a predictable, programmatic path for property owners while retaining annual oversight tied to groundwater indicators.