SACRAMENTO – Caltrans has finalized the last two of 12 district-based Climate Change Vulnerability Assessment Reports designed to provide the department with a comprehensive database that will help in evaluating, mitigating and adapting to the effects of increasing extreme weather events on the state transportation system.

The final two reports cover Caltrans’ coastal districts 1 (Eureka) and 5 (Salinas south to Santa Barbara). The climate effects examined include rising average temperatures, higher sea levels, storm surge, and precipitation. These in turn increase the incidence of flooding, drought, wildfires, coastal erosion and mudslides.

“The completed assessments cover all 58 counties in the state and give California a comprehensive evaluation of climate change effects on the State Highway system,” said Caltrans Director Toks Omishakin. “We are now integrating the findings into our planning process to better protect California’s citizens, economy and transportation investments.”

Caltrans is also sharing the reports and statewide data in the form of interactive online maps with local, regional, state and federal agencies to facilitate use of the information for their own analysis towards achieving a more resilient transportation system.

The 12 reports examine various expected impacts due to climate change. Understanding these impacts helps Caltrans assess physical climate risk to the transportation system and work towards adapting our infrastructure to be more resilient to these impacts. For example, the reports project that by the year 2085:

Over this century, sea levels will rise 5.5 feet along the California coast—affecting 130 miles of State Highway by accelerating soil erosion and cliff retreat.

Increased severity and frequency of wildfires could threaten more than 7,000 miles of state highway.

High temperatures on the central coast and in the northwest part of the state could rise by 6 to 12 degrees, increasing drought and wildfire potential.

Each Climate Change Vulnerability Assessment Report includes a high-level summary of potential climate impacts to each district’s portion of the State Highway System and the Technical Reports detail the processes utilized to identify these impacts.

All 12 summaries, their technical reports and interactive maps may be viewed online.