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A Zone A

1% annual chance flood zone without base flood elevations

Where A sits

Cross-section of a river floodplainDiagram: a river valley. The floodway is the channel and the land beside it; the 1%-annual-chance flood surface (the base flood elevation) covers the valley floor as zone A or AE; a narrow band higher up is shaded X, the 0.2% floodplain; higher ground is X.0.2% CHANCE A YEAR (500-YEAR)BASE FLOOD ELEVATION · 1% A YEARXAEFloodwayAEX
  1. A / AE Inside the 1%-a-year floodplain: about a 26% chance of flooding over a 30-year mortgage. AE has a mapped base flood elevation; plain A does not.
  2. Floodway The channel and the land beside it that has to be kept clear enough to carry the flood. Building here is tightly limited.
  3. X shaded The 0.2% (500-year) floodplain, plus some levee-protected and very shallow flood areas.
  4. X Outside both lines. No federal requirement to insure, which is not the same as no risk.

What Is Zone A?

Zone A is a high-risk flood zone where FEMA has determined there is a 1% annual chance of flooding, but has not conducted detailed hydraulic analysis to determine Base Flood Elevations.

Zone A areas are typically in less-developed regions where detailed flood studies have not been performed. The risk is the same as Zone AE, but without the precision of established flood depths.

Without a BFE, building requirements may be more conservative, and insurance rating may use different methods.

Flood Insurance Requirements

Flood insurance is required if you have a mortgage from a federally regulated or insured lender, or a federally backed loan such as FHA, VA, Fannie Mae or Freddie Mac. This is a Special Flood Hazard Area (SFHA).

How the National Flood Insurance Program works →

Base Flood Elevation (BFE)

No — Base Flood Elevations have not been determined for Zone A. An Elevation Certificate can help establish your property's flood risk more precisely.

What base flood elevation means and how to read it →

Check Your Property's Flood Zone

Enter your address to see if your property is in Zone A