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Louisiana Flood Zone Classification

Louisiana flood zones are classified mainly through the Flood Insurance Rate Map (FIRM) to determine insurance policies. It relies on historical evidence and hydrologic studies. Areas in the Special Flood Hazard Areas (SFHA), where flood classifications begin with an "A" or a "V," have a 26 percent chance of being inundated by flood waters within the 30-year mortgage period. Classifications and restrictions vary in different Louisiana communities.

  1. SFHA and FIRM

    • All insurance rates are determined by FIRM maps, though other more extensive regulatory maps may be adopted in a community. Building and remodeling in the SFHA zone is more restrictive and these regulations may not be insisted upon in other zones. New homes in these areas must be built above the flood hazard level. One-fourth of the claims paid by the National Flood Insurance Program are for properties outside of the SFHA zone. The Louisiana Mapping Project advises residents to check with their local floodplain administrator to get a definite determination of flood risk.

    Numbered "A" Zones

    • There are both numbered and unnumbered "A" zones or approximated (method of measurement) zones. Base flood elevation (BFE) is not determined in the unnumbered A zones. Zones A1 through 30, known as numbered zones, are base floodplains that show a BFE. In areas where the BFE is determined, the number in parenthesis is the zone's depth of flooding measured from ground level and not from sea level.

    A and V Zones

    • Zones AE, AH and AO have BFEs. AE zones have recently been moved from the numbered zones and are now under the Flood Insurance Rate Map. AH and AO zones are subject to shallow flooding. A99 zones are protected by levees whereas AR zones are in an area that was protected by a levee or flood system that has been decertified. A V zone is one of those near the ocean that have velocity hazards from wave action. In VE V zones, BFE is not determined; in VE zones, the BFE is provided by the Flood Insurance Rate Map.

    Zones B, C and D

    • B zones have moderate flood hazards that are protected by levees or are within the 100-year to 500-year flood limits. These zones may also have shallow flooding with an average depth of less than 1 foot or drainage areas of less than 1 square mile.

      Flooding in C zones is minimal. These areas are above the 500-year flood limit. C zones may have local problems, such as ponding or poor drainage, but the problems found have not merited a study or a base floodplain designation. Zone D may have flood hazards, but these hazards have not been determined.

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