SANDAG Regional Sea-Level Rise Adaptation Guidance for Transportation Infrastructure



SB1 Adaptation Planning Grant: Initial Case Study

Challenge: Developing plans and strategies



Over a two-year project period (spring 2018-spring 2020), the San Diego Association of Governments (SANDAG) will:

  1. Provide recommended updates for existing shoreline management policies;
  2. Examine potential sea-level rise impacts to regional transportation infrastructure in San Diego County; and
  3. Create a suite of adaptation strategies and best practices for local jurisdictions to consider when updating or preparing relevant local policies, plans, or vulnerability assessments. Adaptation strategies will include relevant policies, potential projects (with an emphasis on natural infrastructure), and funding mechanisms.

The final deliverable will be the Regional Sea-Level Rise Adaptation Guidance for Transportation Infrastructure (Adaptation Guidance). Included in this guidance will be shoreline policies to advance natural infrastructure approaches, for instance approaches like the Cardiff Living Shorelines project.

SANDAG is the Metropolitan Planning Organization (MPO) for the San Diego region and therefore aligns its Regional Transportation Plan (RTP) with the State's guidance. The RTP Guidelines (most recently adopted in 2017) and the California Transportation Plan 2040 both include policies that focus on adaptation of the transportation system and transportation infrastructure.

Lead Agency and Partnerships

SANDAG will serve as the lead agency for this project and will be responsible for preparation of the final Adaptation Guidance and reporting. Key information for this project will be obtained from vulnerability assessments and adaptation plans currently in process or planned for by a number of coastal jurisdictions in the San Diego region, as well as information from the Port of San Diego, Caltrans District 11, and the San Diego Regional Climate Collaborative.


This project has three main drivers:
(1) the State’s RTP Guidelines and the California Transportation Plan 2040, which both include policies that focus on adaptation of the transportation system and transportation infrastructure;
(2) SANDAG’s commitment to develop strategies that will enhance the region's ability to adapt to the consequences of climate change which was identified as a continuing action in San Diego Forward: The Regional Plan; and
(3) the need to elevate work done at a local level to a regional decision-making body to promote sound and coordinated adaptation efforts, and to best protect vulnerable portions of the regional transportation network.

Funding from SB1’s Caltrans adaptation planning grant program provided the funding to support this work-effort.

Engagement Process

Three public workshops will be held to support this project. The first workshop will be hosted by the Shoreline Preservation Working Group at SANDAG, allowing elected officials from coastal communities to participate in a dialogue on coastal adaptation and to gain any preliminary feedback on the proposed content of the Adaptation Guidance. After the initial draft of the Adaptation Guidance is completed, two additional public workshops will be held to gather feedback on the draft document from local staff members and members of the public. This feedback will be incorporated into the final guidance document.

The preliminary planning for this project includes one public outreach meeting in the northern part of the region and one in the southern part of the region, allowing vulnerable coastal community members from throughout the San Diego region to engage with this work effort. 

Climate Impact Area

A number of transportation assets exist in or near the coastal areas of the San Diego region including highways, bikeways, roadways, and both light and heavy rail infrastructure. These transportation assets could be impacted by flooding under future sea-level rise scenarios. The final Adaptation Guidance will examine potential sea-level rise impacts to regional transportation infrastructure in San Diego County and create a suite of adaptation strategies and best practices for consideration by local jurisdictions, thereby helping the region plan for and become more resilient to future sea-level rise impacts.  

Funding Source

This project is funded by a Caltrans adaptation planning grant that was awarded to SANDAG in December 2017. $180,000 was awarded from Caltrans, and SANDAG is providing an additional $23,321 in staff time to assist with this project. The total project budget is $203,321.

Research and Data

This project builds upon work conducted by a number of local jurisdictions and agencies. In preparing individual vulnerability assessments, most of these entities utilized modeling information from the USGS’s Coastal Storm Modeling System (COSMOS 3.0), which provides a suite of sea-level rise scenarios with four possible coastal storm conditions. Please see additional resources for links to this information.


Vulnerability assessments that have been prepared by local jurisdictions and agencies have used different sea-level rise projections in their analysis. As such, one of the challenges presented in creating the Adaptation Guidance is not having “apples to apples” analyses that can be directly compared to one another. SANDAG plans to address this by providing a summary table at the beginning of the document outlining which scenarios were used by each jurisdiction and also providing an explanation of evolving sea-level rise science.


The main outcome from this project will be preparation of the Adaptation Guidance. This document will address future vulnerabilities to the regional transportation system, as well as possible local and regional adaptation strategies that can be utilized in the future. Possible next steps include benefit-cost analyses of specific strategies and/or planning and permit activities necessary to implement adaptation strategies.


Preparation of the final Adaptation Guidance requires coordination and collaboration with local jurisdictions and agencies. This type of project could be replicated by another metropolitan planning organization or department of transportation if there is enough information on sea-level rise vulnerability and adaptation available at the local level that could be combined into a single document and elevated to a regional decision-making body.

Additional Resources

A number of local work efforts will contribute to the Adaptation Guidance. An overview of these individual projects can be found here.

CoSMoS 3.0

Further Information

Please contact Sarah Pierce at 619-699-7312 or via email at for additional information on this project.