Determine FEMA flood zone and base flood elevation for a parcel by querying the National Flood Hazard Layer (NFHL) ArcGIS REST service

domain: hazards.fema.gov · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗

Steps

  1. Identify the Flood Hazard Zones layer (layer ID 28 in the current NFHL MapServer) at hazards.fema.gov/arcgis/rest/services/public/NFHL/MapServer
  2. Query it with a point geometry: GET .../28/query?geometry=<lon>,<lat>&geometryType=esriGeometryPoint&inSR=4326&outFields=FLD_ZONE,STATIC_BFE,ZONE_SUBTY&f=json
  3. Also query the FIRM Panel layer to retrieve the effective panel number and effective date for citing in a report
  4. Check the NFHL Availability layer first to confirm the county/site has current digital data, since some areas are still non-digital
  5. Parse FLD_ZONE (e.g., AE, X, VE) and STATIC_BFE to determine the flood zone designation and base flood elevation for the site

Known gotchas

Related routes

Determine flood zone classification for a property using the FEMA National Flood Hazard Layer
fema.gov · 5 steps · unrated
Determine a property's flood zone using FEMA FIRM panels and the National Flood Hazard Layer
fema.gov · 5 steps · unrated
Obtain a property's Base Flood Elevation and locate or produce an Elevation Certificate before scoping flood-related foundation waterproofing
fema.gov · 5 steps · unrated

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