Caltrans releases first Climate Change Vulnerability Assessment

Sacramento, Calif. — Caltrans released its first Climate Change Vulnerability Assessment, an effort by the department to understand how and where the future effects of climate change may impact the State Highway System and its users. This assessment specifically evaluates the vulnerability of the San Francisco Bay Area region’s (Caltrans District 4’s) infrastructure, and is the first of 12 such studies that will eventually cover each Caltrans region of the state.

“Climate change poses an immediate and growing threat to California, and Caltrans is being proactive in determining what this means for the state’s transportation system. This study and those that will follow intend to provide data to support the discussion about how climate change impacts the way we plan, design, build, operate and maintain the state highway system,” said Malcolm Dougherty, Director, Caltrans.

Caltrans’ District 4 Climate Change Vulnerability Assessment identifies specific locations along the State Highway System in the Bay Area that may be impacted by rising sea levels and larger storm surge, more frequent wildfires, changing precipitation patterns and increasing temperatures associated with climate change. These state highways are critically important not only for the San Francisco Bay Area, but also for intra-state travel and commerce. By identifying the possible risks and implications of climate change, the reports seek to guide future planning processes and investments to ensure the long-term future of California’s transportation system.

The past storm season in California caused severe flooding, landslides and coastal erosion totaling over $1.2 billion in highway damages statewide. Nearly $390 million of those damages occurred in Caltrans District 4. Extreme events like these and associated costs are expected to become more pronounced and more frequent in the future as a result of climate change.

The Summary Report (www.dot.ca.gov/transplanning/ocp/docs/D4_Caltrans_Vulnerability_Assessment_v49.pdf) for the Bay Area assessment provides an overview of the extent and locations of possible climate impacts.

The more in-depth Technical Report (www.dot.ca.gov/transplanning/ocp/docs/rCT_D4_Technical_Report_VerAL.pdf) provides technical information and the methods of analysis used to determine the potential exposure of Caltrans District 4’s State Highway System. The report is supported by an extensive GIS database and Caltrans has developed an interactive mapping application (https://caltrans.maps.arcgis.com/apps/webappviewer/index.html?id=517eecf1b5a542e5b0e25f337f87f5bb) for public use, which shows impacted locations and the climate model results.

Both reports and the interactive mapping application, as well as more information, can be accessed on Caltrans’ Office of Smart Mobility and Climate Change Vulnerability Assessment page (www.dot.ca.gov/transplanning/ocp/vulnerability-assessment.html).

Using the data from the study, Caltrans intends to help evaluate the vulnerability of other modes of the transportation system through partnerships and data sharing with local and regional agencies. As Caltrans moves towards a resilient transportation system, the department will continue to enhance its climate effort and close partnerships with local, regional, state and federal agencies in order to create coordinated adaptation solutions for the state transportation system.

Caltrans has been considering the impact of climatic changes on the state transportation system and developed guidance and studies on how climate change can be incorporated into planning and project design. This also aligns with Governor Edmund Brown Jr’s call to integrate climate change into transportation investment decisions through Executive Order B-30-15.

Caltrans’ current policy and guidance documents can be found on Caltrans’ Climate Change Branch’s Policy & Guidance page (www.dot.ca.gov/transplanning/ocp/cc-policyguidance.html).