fldzone = 'A'

Risk tier: High — inside the Special Flood Hazard Area (SFHA).

Zone A is the baseline high-risk inland flood zone: land subject to inundation by the 1%-annual-chance flood (the "100-year floodplain") where FEMA performed an approximate study rather than a detailed hydraulic analysis. Because the study was approximate, no Base Flood Elevation (BFE) was computed — this is the defining characteristic that separates A from AE.

How to read it

Zone A is extremely common in rural and less-developed areas, where the cost of a detailed engineering study has not been justified. The flood risk is real and equal in magnitude to AE — the only difference is that FEMA did not publish a specific flood elevation, which makes compliance and insurance rating harder because there is no official number to build to.

• staticbfe is NULL for Zone A — there is no determined BFE.
• Where a project needs an elevation, the community, a surveyor, or an engineer must develop a BFE using best available data.

Building and insurance implications

• Flood insurance is federally required for buildings with a mortgage from a federally regulated or insured lender.
• New construction and substantial improvements must comply with the community's floodplain-management ordinance.
• Because there is no published BFE, rating and elevation-certificate requirements are more involved than in AE.

zonesubty values

Zone A polygons usually carry no subtype. When present, subtypes typically flag administrative qualifiers rather than changing the hazard.

In the data

-- Parcels in the approximate 1%-annual-chance floodplain
SELECT lrid, parceladdr, fldzone, firmdate
FROM   lr_parcel_us
WHERE  fldzone = 'A';

See also: Zone AE (the detailed-study equivalent with a BFE), and the flood-zone overview.