fldzone = 'AE' (formerly A1–A30)

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

Zone AE is the 1%-annual-chance inland floodplain in areas where FEMA performed a detailed hydraulic study and published Base Flood Elevations (BFEs). It is the most consequential high-risk zone for development because there is an official elevation to build to.

Relationship to A1–A30

Before the FIRM modernization program, detailed-study riverine zones were numbered A1 through A30, each corresponding to a BFE range. FEMA consolidated all of them into the single label AE. On older or un-modernized panels you may still encounter the numbered forms; treat A1–A30 as equivalent to AE.

Base Flood Elevation

The BFE is the water-surface elevation of the base (1%-annual-chance) flood. In AE areas it is the central regulatory number:

• Where a single elevation applies to the polygon, it is published in staticbfe (feet, NAVD 88).
• Along rivers and streams the BFE changes continuously downstream, so many AE reaches have staticbfe = NULL; the applicable elevation must be read from the FIRM/Flood Insurance Study profile at the site.

zonesubty values

The floodway subtype is the most restrictive land within AE: encroachment is generally prohibited unless an engineering analysis proves no rise in the base flood.

Building and insurance implications

• Flood insurance is federally required for mortgaged structures.
• New and substantially improved buildings must have the lowest floor elevated to or above the BFE (communities often add freeboard).
• An Elevation Certificate documents the structure's elevation relative to the BFE.

In the data

-- AE parcels in the regulatory floodway
SELECT lrid, parceladdr, staticbfe
FROM   lr_parcel_us
WHERE  fldzone = 'AE'
  AND  zonesubty = 'FLOODWAY';

See also: Zone A (approximate study, no BFE), Zone AH and Zone AO (shallow-flooding variants).