Floodplain data
- FEMA National Flood Hazard Layer (NFHL): geospatial database of current effective flood hazard data, built from effective flood maps and LOMCs. You can view it in the NFHL Viewer or download county/state data from the Map Service Center.
- Hawaiʻi DLNR Flood Hazard Assessment Tool (FHAT): informational viewer showing FEMA DFIRM flood zones. It does not identify all areas subject to flooding.
- DLNR Engineering Division – NFIP: the State's National Flood Insurance Program page.
Oʻahu's updated FIRMs became effective June 10, 2026 (Honolulu DPP).
Sources
- https://www.fema.gov/flood-maps/national-flood-hazard-layer — checked Oct 22, 2026 (HST)
- https://msc.fema.gov/portal/home — checked Oct 22, 2026 (HST)
- https://fhat.hawaii.gov/ — checked Oct 22, 2026 (HST)
- https://dlnreng.hawaii.gov/nfip/ — checked Oct 22, 2026 (HST)
- https://www.honolulu.gov/dpp/resources/fema-flood-insurance-rate-maps-information/ — checked Oct 22, 2026 (HST)