Caltrans
As sea levels rise, the Marin 101 corridor will face increasing risks of high tide flooding, coastal erosion, and wave hazards. This project builds on the Caltrans District 4 Vulnerability Assessment (2019), the Transportation Authority of Marin Sea Level Rise Adaptation Planning Study (2025) and Caltrans Statewide Climate Vulnerability and Risk Assessment (2026) completed by Arup and Pathways Climate Institute.
Pathways Climate Institute, as a subconsultant to Arup, is leading the coastal hazards assessment. Pathways recommended sea level rise scenarios to inform analysis, planning, and design, based on best-available science and relevant guidance. The coastal hazards assessment includes characterization of existing and future conditions for coastal flooding, groundwater rise, waves and overtopping, and erosion.
Pathways staff will support communication of the hazards analysis results and what they mean for Caltrans and the community throughout the engagement process. Pathways will also develop coastal engineering design criteria, and co-lead development of adaptation strategies and preliminary conceptual designs. The project includes coordination with the surrounding jurisdictions to identify adaptation projects outside of Caltrans right-of-way that can provide flood risk reduction benefits to Caltrans and the adjacent communities.