As historic drought rages, SLO County turns to desalination to help bring water to cities

San Luis Obispo County officials have begun the lengthy planning process for a regional, large-scale desalination project to bring another source of water to drought-parched cities and towns.

In the desalination process, salty water — usually from the ocean — is purified into drinking or irrigation water. The technology is considered controversial because of its typically high costs, energy requirements and environmental impacts.

The county Board of Supervisors directed public works staff to make planning for a regional desalination project one of their priorities during the 2022-23 fiscal year.

By this fall, supervisors expect to vote on a resolution that would officially authorize the San Luis Obispo County Public Works Department to work with local agencies and the public in identifying a feasible desalination project.

That will officially kickstart an undertaking that could span nearly two decades before construction possibly begins sometime between 2041 and 2045. It’s a massive endeavor, one that could outlast the tenure of the employees working on the project now, but that county staff feel is vital.

“With the drought and with critical housing needs, we all recognize — water managers, (elected officials) and the public — recognize that a drought-proof water source as part of the county’s water portfolio would really be a benefit,” said Kate Ballantyne, the county’s deputy director of public works, in an interview with The Tribune.

“And we’re seeing a lot of competition for watersheds and groundwater basins,” added Courtney Howard, the county’s water resources division manager. “It’s important, too, to recognize the environmental impact we’re having on our existing resources.”

Local cities open to new sources of water

The county officials stressed that they have only just started one of the preliminary steps in the process: figuring out if the county even wants desalination. They’ve held meetings with local government leaders and water purveyors from cities and towns across the region and down to Santa Barbara County.

In interviews with The Tribune, local government leaders have indicated mixed levels of interest in the desalination project.

Leaders in Los Osos, Morro Bay and Cambria, for example, say they’re certainly interested, but have to bring the idea to their respective governing boards before they can give a solid thumbs-up to the county.

Officials in Pismo Beach and Grover Beach said that, while desalination is something they could possibly consider, they have their sights set on a project much closer to fruition: Central Coast Blue.

That wastewater recycling plant is currently in the design phase and set to be in operation by 2025. It’ll likely provide 900 to 1,000 acre-feet per year of fresh water for Pismo Beach, Grover Beach, Arroyo Grande, Oceano and the county.

Those South County cities’ investment in Central Coast Blue doesn’t mean they are turning down the opportunity to be involved in a desalination project.

“In this day and age, I don’t think you can say no to another source of water,” said Ben Fine, Pismo Beach’s public works director.

The cities of San Luis Obispo and Paso Robles, which both have some of the most diverse and substantial supplies of water in the county, have said they’re not expecting they’ll need the desalination project. But they aren’t turning their backs on the project, either.

“We’re waiting to hear more how we could be involved,” Mychal Boerman, San Luis Obispo’s deputy director of utilities, told The Tribune. “We’re limited for sure. These days, we can conserve, use recycled water or use desal. And we want to be smart how we go forward.”

Paso Robles water resources manager Kirk Gonzalez told the Tribune that the city “has secured sufficient water supply to serve our existing community now and through buildout.”

“It’s unlikely that Paso Robles would be able to directly benefit from desalination by receiving water from the project,” Gonzalez wrote in an email.

However, he said, the city is looking forward to working with the county “to determine how a desalination project may benefit our coastal communities and ... somehow indirectly benefit inland communities like Atascadero, Templeton and the city of Paso Robles.”

Ballantyne and Howard noted that they’ll need to engage cities and towns from the get-go and ensure they have financial commitments before embarking on the next steps in the desalination project process.

Regional desalination ‘very big’ project for SLO County

Desalination projects aren’t necessarily new to San Luis Obispo County.

Morro Bay’s desalination plant, built in 1992, has sat idle since 2000 due to expired permits

PG&E has operated a large desalination plant at Diablo Canyon Power Plant for decades.

The county drafted rough plans to bring some of that water to drought-stricken South County residents in 2015. However, the announcement that the power plant would be decommissioned in 2025 effectively killed those plans, county and PG&E officials said in 2016.

What’s unique about the county’s new desalination project is its scope.

County and local officials compared the project to the $176-million Nacimiento Water Project or work to bring state water to the region.

“This is big, it’s very big,” San Luis Obispo County Supervisor Bruce Gibson said. “And it’s going to be a very complicated project.”

Top of mind for Ballantyne and Howard are the financial and environmental impacts the project could have on the region.

They kept a close eye on the California Coastal Commission’s consideration, and then denial, of the proposed Poseidon Water desalination plant in Huntington Beach.

Among the commissioners’ reasons for rejecting the massive, $1.4 billion project were the costs to ratepayers, and environmental impacts both onshore and offshore.

“It’s an opportunity for lessons learned,” Howard said. “We are going to benefit from those that have come before us by just gaining an understanding of what were deal breakers for certain projects, and what were the successful elements for the other projects that do go forward?”

Ballantyne and Howard both said public engagement will be a key proponent of the desalination project — and there will be plenty of opportunities for the community to weigh in.

Additionally, the project will require a certain mix of patience and urgency, they said.

“It is kind of hard to wrap your head around getting from here to a successful project,” Ballantyne said. “But we do know that waiting to initiate a regional desal project is just going to continue to push that timeline out. So we have recognized ... that we need to start now for the future.”

“It just seems like not doing anything would be worse,” Howard added. “Given the way we depend on rainfall for existing supplies, if that’s changing, we need to change as well.”