Summary

The purpose of this assessment is to complement previous inland flood analyses by updating the inland flooding component of TPB’s 2024 Transportation System Climate Vulnerability Assessment using forward-looking datasets that explicitly capture the potential for expanded future floodplains in the region. This addendum presents updated risk scores for inland flooding using the Fathom U.S. Flood Map dataset, which models future pluvial and fluvial flooding at a high spatial resolution using best-in-class elevation information. The TPB is committed to building system-wide resilience in the face of natural hazards and extreme weather and recognizes the need for improving understanding of potential future flooding impacts on the region’s transportation system, and this analysis is the next step in doing so.