greenhouse gas effects diagram

The changing climate is leading to rising seas. American researchers project that sea levels in San Mateo County could rise by 6 inches by 2030 and 1-2 feet by 2050. The many places we all love and key community services and network of roadways, levees, energy and wastewater infrastructure, that are essential to day-to-day community and economic functions could be impacted.

Whether you live close to the shore or inland, sea level rise could affect all of us in San Mateo County, which is why we are working collaboratively to meet this challenge. We are working together to ensure the safety and wellbeing of our community and safeguard the places we all depend on.


At the “Meeting the Challenge of Sea Level Rise in San Mateo County” conference in December 2013, U.S. Congresswoman Jackie Speier, California Assemblyman Rich Gordon and County Supervisor Dave Pine initiated the efforts to address the countywide challenge of sea level rise. The conference was a success and drew hundreds of stakeholders from all different sectors and organizations, all interested in the same goal of proactively protecting our communities against the impacts of sea level rise. Through that process it became clear that more specific information was needed about the impact of sea level rise in San Mateo County communities.

From these initial efforts, the County’s newly created Office of Sustainability, along with leadership from the County’s Board of Supervisors, launched the “Sea Change SMC” initiative in 2015. The first two tasks under Sea Change SMC included commencement of the San Mateo County Sea Level Rise Vulnerability Assessment and initiating a community engagement process to build support for cross jurisdictional collaboration.

The Assessment, which was supported and funded by the County and the California State Coastal Conservancy, began in 2015 and covers the entire County except the area south of Half Moon Bay. The goals of this effort were to assess vulnerability, identify impacts of flooding and erosion on people, places, and critical infrastructure, and provide a menu of actionable solutions to protect people and places.

Sea Change SMC continues to address the challenge of sea level rise by working together with and providing resources to local governments, stakeholder agencies and communities groups to create a prepared and stronger County.

The Sea Change SMC initiative is spearheaded and staffed by the County’s Office of Sustainability and the Offices of Supervisors Dave Pine and Don Horsley.

Program Partners

List of program stakeholders

Thank you to all the organizations that have and continue to engage in the Sea Change SMC efforts.