SAN LUIS OBISPO, Calif., June 29 (San Luis Obispo Online) — San Luis Obispo County is asking residents to weigh in on a question with long-term consequences: could ocean desalination become part of the region’s future water supply?
The effort, called the Desalination Executable Solution and Logistics Plan, or DESAL Plan, is a regional planning project led by the San Luis Obispo County Flood Control and Water Conservation District and the county Public Works Department with 16 partners. County materials say the work is still in a feasibility-study phase, which means officials are comparing options and gathering input rather than choosing a final site or design.
What is the DESAL Plan?
County project materials describe the DESAL Plan as a five-phase effort. The current phase is focused on feasibility, with the goal of identifying possible desalination locations, conceptual pipeline and conveyance setups, needed infrastructure, likely impacts, partnership issues and estimated costs.
The county says the study is being supported by a WaterSMART grant from the U.S. Bureau of Reclamation.
That matters because desalination projects can take years to plan, permit and build. County Public Works Deputy Director Courtney Howard said the county wanted to start now because the region depends heavily on rainfall for existing supplies. “We are so heavily dependent on rainfall for existing water supplies, and it takes a long time to implement any kind of a project to create this new water supply using the ocean and removing the salt from it, we feel it’s really important to get the planning process started now to be ready for when communities say they need it,” Howard said.
Why is the county looking at desalination?
At its simplest, desalination is the process of removing salt from seawater to make water usable. San Luis Obispo County says it wants to study whether that kind of source could help create a more reliable, resilient, drought-proof supply for the future.
The county’s planning effort is regional, not just local to one city or utility. County materials say public and stakeholder outreach is part of the process, including updates for the public, partner agencies, the Water Resources Advisory Committee and the Board of Supervisors.
A City of San Luis Obispo staff report said joining the regional DESAL Plan would fit the city’s General Plan water and wastewater policies. The city also said it wanted to be evaluated as a possible partner in a future regional desalination project.
What options are being studied?
The county has said it is looking at a range of possibilities, including onshore and offshore options, facilities built next to existing infrastructure or at new sites, and the possible reuse of existing outfalls or other infrastructure.
County presentations have also discussed several geographic areas under consideration, including Cambria, Cayucos, Morro Bay, South County near the South SLO Wastewater Treatment Plant and the former Nipomo Mesa Refinery area. Those locations are being studied as possibilities, not as final selections.
What has the county decided so far?
Not much beyond the planning process itself.
A county project page says the Board of Supervisors authorized staff to proceed with the DESAL Plan on Oct. 18, 2022. County materials later described the work as Phase 1 of a five-phase effort.
The county says no final decisions are being made during the feasibility-study phase. The final technology, final site, final partner list and any permit path have not yet been set out in the materials reviewed so far.
Why does public input matter?
Because the county says the project is still being shaped.
The point of the current phase is to gather information from residents, agencies and other partners before anything is built. The county has said it planned two identical in-person community engagement sessions on April 20 and April 21, 2026, and earlier outreach included online and virtual participation opportunities.
For now, the main question is not whether a desalination plant will be built. It is whether desalination should remain one of the region’s options as San Luis Obispo County plans for a future with less certainty in its traditional water supply.
What should readers watch next?
The next major milestones are likely to come from the county’s feasibility work: which sites rise to the top, what the estimated costs look like, how water would move from the plant to users, and whether the project can fit the needs of multiple local agencies.
Until then, the DESAL Plan remains a planning effort — a way for county leaders and the public to test whether desalination could work for the Central Coast before anyone commits to building it.