THE COUNTY OF SAN MATEO HAS INITIATED A SEA LEVEL RISE VULNERABILITY ASSESSMENT. The Assessment is part of a long-term resilience strategy to ensure our communities, ecosystems, and economy are prepared for climate change. The effort, which is spearheaded by Supervisor Pine, is funded by the California State Coastal Conservancy and conducted through a collaborative, multi-stakeholder effort.

The County and its partners are currently working on completing the vulnerability assessment, and anticipate finalizing the report in late spring 2017.

Program Overview

Program Overview

The goal of the assessment is to identify vulnerable assets on the bay and coast side of the San Mateo County peninsula, determine types of impacts, issue initial recommendations on adaptation measures, and improve flooding and sea level rise mapping. Arcadis, a design and consulting firm, is conducting the technical study. For details, see the project schedule. The County of San Mateo will manage and oversee the collaboration of many organizations working together to plan and adapt for sea level rise, in partnership with the California State Coastal Conservancy.

Sea Change San Mateo
El Granada, CA

Using the best available science, information from existing relevant efforts, and guidance from stakeholders, the assessment will identify key assets at risk from multiple scenarios of sea level rise and storm events. The Vulnerability Assessment is being developed through an inclusive process with maximum participation from San Mateo County cities and relevant agencies, businesses, organizations, and community groups. This effort includes a focus on nature-based solutions and reducing impacts to underserved communities.
Our objective is to set the stage for future efforts to increase resiliency by identifying and prioritizing near, mid-, and long-term actions for key assets, identifying potential funding sources for actions, and increasing the County’s staff capacity to address sea level rise challenges.

Vulnerability assessment deliverables include:

  • An inventory of key assets throughout the County at risk from multiple scenarios of sea level rise and storm events.
  • An understanding of the types of sea level rise and storm related impacts that San Mateo County will experience.
  • A road map for taking actions to increase resiliency that includes initial recommended adaptation measures and improved flood and sea level rise mapping and data.
  • A replicable methodology available for use by others in San Mateo County
  • A collaborative network through which to plan future efforts.

Program Stakeholders

Program Stakeholders

The project will be informed by a Technical Working Group, Policy Advisory Committee, and by community input through public meetings.

Technical Working Group (TWG) is comprised of individuals with a working knowledge and familiarity with the physical location, surrounding environment, proximity to sea level rise-associated risks, and the operation of key assets in San Mateo County. Those assets may include, but are not limited to water treatment and pumping facilities, civil infrastructure (e.g. water, power, and sewer), communications and power stations, hospitals, schools, population centers, and natural resources.

  • TWG members will help provide data, information on vulnerable assets, and details on any existing sea level rise efforts. Members will also review work products.
  • The TWG will meet 3 times throughout the project in September, December, February
Sea Change San Mateo
Mirada Surf Park, El Granada, CA

Policy Advisory Committee (PAC), made up of individuals who are familiar with and/or have some experience with the formation and/or implementation of regulations, policies and/or programs related to land uses including but not limited to transportation, real estate development, disaster planning and wildlife management as they may be impacted by change in sea level, storm surge, high tides and salt water intrusion. The Policy Advisory Committee will also include individuals who represent special interest groups in the County whose members share this expertise and familiarity.

  • PAC members will help provide high level input into the project
  • The PAC will meet two times throughout the project in September and March


sea change san mateo county project timeline graphic



The vulnerability assessment will be conducted using existing sea level rise modeling completed by United States Geological Survey (USGS) as part of the Our Coast Our Future tool. Arcadis will use a range of scenarios to evaluate how different amounts of sea level rise, combined with the 1% annual chance storm will affect the County. Using the results of the sea level rise mapping, Arcadis, in coordination with the Technical Working Group, will evaluate which assets are at risk over the near and long term. A detailed evaluation of vulnerability will be completed for approximately 30 representative assets, including natural resources such as wetlands and other habitat areas. The results of the vulnerability assessment will be used to inform development of near and long-term adaptation strategies for the County.

We will provide multiple and substantive options for stakeholder input into the project and will provide a forum for collaboration across cities and stakeholders throughout the County. The project will draw from the steps used in Bay Conservation and Development Commission’s Adapting to Rising Tides project, and experience gained through projects funded by the Conservancy’s Climate Ready Grant Program, the Ocean Protection Council’s Local Coastal Program Sea-Level Rise Grant Program, and the Coastal Commission’s Local Coastal Program Planning Grant Program.