· Hawaii Statewide GIS Program (geoportal.hawaii.gov)
· USGS National Map (elevation/hydro)
· NWS Honolulu & Hawaii Mesonet (precipitation)
· NASA Earth Observatory (satellite imagery)
· Hawaii DLNR (watersheds, OSDS, environmental data)
· FEMA & Esri GIS Hub (response mapping)
· CW3E/UCSD (Atmospheric rivers & IVT)
· NLCD/MRLC (Impervious surface)
· 2020 Census (Population)
· USDA/NRCS Soil Survey (Soils)
Contamination & environmental catalysts: OSDS, landfills, industrial facilities, agricultural runoff, USTs, Pineapple soils with high iron oxide content, atmospheric river data from CW3E, population exposure analysis.
Aging infrastructure: The Wahiawa Dam was built in 1906. North Shore drainage systems were not designed for this volume.
Radar gap: The Molokai WSR-88D radar was offline, removing a key tool for real-time forecasting during the event.
Climate signal: Kona lows are a normal feature of Hawaii's winter, but this back-to-back sequence with tropical moisture at this intensity is consistent with climate-change-driven intensification of Pacific weather systems.
Hawaii Statewide GIS Program — Hazards MapServer
LIVE FEMA DFIRM flood hazard areas (Dec 2025), sea level rise coastal flood zones (1% annual + 3.2ft SLR), FIRM panels. Served via geodata.hawaii.gov/arcgis/rest/services/Hazards/MapServer.
NWS Honolulu (HFO) — Rainfall Summaries
NWS Official rainfall totals for March 10–16 and March 19–24 events. Station-by-station data for Oahu, Maui, Molokai, Lanai, Kauai, and Hawaii Island. Flash flood warnings and watches.
weather.gov/hfo — March 2026 Event SummaryUniversity of Hawaii Mesonet / Hawaii Climate Data Portal
UH 77-station statewide network recording precipitation every 5 minutes. Documented 2 trillion gallons statewide and 3,000% above-normal totals. Filled the gap left by the Molokai radar outage.
UH Mānoa — Mesonet March 2026 summaryNASA Earth Observatory / Disasters Mapping Portal
NASA Landsat 8/9 and Sentinel-2 satellite imagery showing before/after flood extent in Waialua and Mokuleia (January 25 vs March 14, 2026). NASA Disasters Response Coordination System activated.
NASA Earth Observatory — Kona Storms Flood O'ahuUSGS National Map — Elevation & Hydrography
USGS 1/3 arc-second DEM for Hawaii elevation. National Hydrography Dataset (NHD) stream networks. Used for watershed delineation and flood routing context.
apps.nationalmap.gov/downloaderHawaii DLNR — Watersheds & Streams
DLNR Division of Aquatic Resources watershed boundaries and stream network for all main Hawaiian Islands. Used for identifying drainage basins that overflowed during the Kona low events.
geoportal.hawaii.gov — Watersheds | StreamsFEMA / Esri — Incident Response Mapping
FEMA FEMA Geospatial Resource Center activated for the Hawaii flooding incident. Provides situational awareness layers, shelter locations, damage assessments.
FEMA GIS — Hawaii Flooding March 2026Hawaii Emergency Management Agency
Official situation reports, evacuation orders, rescue counts, and recovery updates. Disaster relief period in effect through April 13, 2026 per Governor Green's proclamation.
dod.hawaii.gov/hiema