Completed: December 2024.

Funding: Federal Emergency Management Agency.

Committee Overlap: Mapping & Engineering Standards.

As 2D modeling becomes more prevalent, there is an interest in mapping SFHAs and floodways using 2D modeling technology. FEMA Guidance for Flood Risk Analysis and Mapping: Floodway Analysis and Mapping (December 2020) includes provisions related to 2D modeling. This project focused on two issues associated with floodways - surcharge averaging and appropriately representing the impact of floodway surcharge.

Related projects:

2D Modeling Guidance - 2025

Floodway Outreach Project - 2023

Floodway Encroachment Standard: Minimizing Cumulative Adverse Impact - 2013