While some communities in Marin County have initiated sea level adaptation projects on their own, the county itself is still deciding what governance structure is needed to consider broader approaches.
On Tuesday, the county Board of Supervisors approved their responses to recommendations in a Marin County Civil Grand Jury report on the county’s preparedness for sea level rise. That report, “Sea Level Rise: The Water is Upon Us, We Cannot Run – We Cannot Hide,” concluded that too many communities are currently exposed to the growing risk of flooding. It recommended that Marin create a single countywide entity to address sea level rise planning, and that it do so as soon as possible.
The grand jury, a group of citizens that oversees government practices, highlighted One Shoreline in San Mateo County, a single organization formed in 2020 by the City/County Association of Governments of San Mateo County from a water management district.
One Shoreline works across jurisdictions to share expertise, benefit disadvantaged communities, and provide a single entity to secure state, federal, and private funding. The website lists nine current adaptation projects underway in creeks, shorelines, and floodplains.
“The complexity of addressing sea level rise could delay critical adaptation measures, such as building barriers to protect shoreline properties and strengthening underground electricity and sewer infrastructure,” the grand jury report said.
In a response Tuesday, Ariel Espiritu Santo, deputy county administrator, told supervisors that the county has hired a firm to help them determine what governance structure would be best. They can expect a report next summer.
“We are currently in the process of analyzing possible governance structures,” she said, referring to a council-approved $500,000 contract to hire Los Angeles-based AECOM Technical Services Inc., a firm that specializes in infrastructure consulting.
“They’re going to do a pretty involved engagement process. They’re going to get the feedback. And then they’re going to come up with some ideas on what possible structures could be, and then they’re going to go back to the engagement process and get feedback on some options and ask how this works. And then from that, mixed with external research, they can come to our board and make some options and a recommendation,” Santo said.
Meanwhile, individual entities are taking action here and there. The community of Stinson Beach, for example, is already shopping around from a list of engineering options presented in June by the Marin County Community Development Agency.
The grand jury estimates that the cost of adapting in Marin County will be about $17 billion. If the county takes no adaptive action, that cost could rise to more than $34 billion.
According to the report, much of the city of Corte Madera currently lies within the floodplain, which has been designated as a Special Flood Hazard Area by the Federal Emergency Management Agency.
The city of Larkspur has a mitigation action plan, but it focuses on reducing greenhouse gas emissions and has yet to address sea level rise adaptation. Mill Valley has a 2040 climate action plan, but by 2050, daily tides are predicted to flood the same area that currently experiences flooding from a 1-in-100-year rainfall event.
Novato cited funding as a critical element, as the 101 and 37 freeways are at risk from sea level rise. Additionally, the city of San Rafael has requested funding for adaptation services in a low-lying canal neighborhood.
A 2023 state law, Senate Bill 272, requires all local governments along California’s coast to develop sea level rise plans that must be completed by 2034.
“But the water is already here. Marin residents have experienced sea level rise and related tidal flooding in Corte Madera, Marin City, Mill Valley and Sausalito, among other cities,” the civil grand jury report said. “The grand jury concludes that Marin cannot wait 10 years to complete such a plan because sea level rise is already impacting communities and flood risks will only increase over time.”
