What Is Flood Zone A99? Levee-Protected Areas Explained

Flood Zone A99 is a FEMA flood zone designation for areas expected to be protected from the 1% annual chance flood by a federal flood protection system — such as a levee, dike, or dam — that is still under construction but has reached a level of progress FEMA recognizes as adequate. Zone A99 remains part of the Special Flood Hazard Area, so the federal mandatory flood insurance purchase requirement still applies the same way it would in any other high-risk zone. Unlike most Special Flood Hazard Area zones, Zone A99 flood maps do not show a Base Flood Elevation or flood depth for the area, because the zone is treated as a transitional classification until the protection system is finished.

If you own property in Zone A99, or you are looking at a flood map that shows it, here is what the designation means, how it compares with other high-risk zones, and what it means for your flood insurance requirement.

What Zone A99 Means on a Flood Map

Zone A99 sits inside the Special Flood Hazard Area, the area FEMA has identified as having at least a 1% annual chance of flooding — sometimes described as roughly a 26% chance over the life of a 30-year mortgage. What sets A99 apart from other high-risk zones is the reason the area is mapped as high-risk in the first place.

In a typical A or AE zone, the flood risk comes from the surrounding terrain and waterways. In Zone A99, FEMA has determined that a federal flood protection system — a levee, floodwall, or dam being built by a federal agency — will protect the area from the 1% annual chance flood once construction is complete. Because that protection is not finished yet, FEMA still maps the area as part of the Special Flood Hazard Area.

Why Zone A99 Has No Base Flood Elevation Shown

Most zones within the Special Flood Hazard Area, such as AE or VE, show a Base Flood Elevation or flood depth on the map. Zone A99 does not. FEMA does not publish a BFE or depth for A99 areas because the zone represents a transitional status tied to the progress of the protection system, not a final floodplain analysis of the area as it will exist once construction is finished.

This is one of the more practical ways to recognize Zone A99 on a map: if a property sits inside a shaded high-risk area but the map shows no BFE or depth number attached to it, A99 is often the reason.

How Zone A99 Differs from Other High-Risk Zones Like AE

The clearest way to understand Zone A99 is by comparison with a standard high-risk zone:

• Zone AE shows a Base Flood Elevation because FEMA has completed detailed flood modeling for that area as it exists today.
• Zone A99 shows no BFE because the area's flood risk is expected to change once a federal flood protection system now under construction is finished.
• Both zones are part of the Special Flood Hazard Area, and both carry the same mandatory flood insurance purchase requirement for federally backed mortgages.

In other words, A99 is not a lower-risk version of AE. It is a placeholder classification for an area whose risk picture depends on a construction project that has not yet been completed.

Does Zone A99 Affect Your Mandatory Flood Insurance Requirement

No. Because Zone A99 is part of the Special Flood Hazard Area, federally regulated lenders still require flood insurance as a condition of a mortgage on a building in that zone, just as they would in an AE, A, or VE zone. The fact that a federal flood protection system is under construction, and is expected to eventually protect the area, does not remove the requirement while that system remains unfinished.

This surprises some property owners, who assume that a levee or floodwall already provides protection simply because it exists on the ground. Until FEMA completes its review of the finished system and the map is updated, the property is treated as being in the Special Flood Hazard Area for insurance purposes.

What Happens When the Flood Protection System Is Finished

Once a federal flood protection system reaches completion and is certified, the area's flood risk can be reassessed. At that point, FEMA may review the flood map for that area and determine whether the zone designation should be updated based on the completed system and current data. Until that review happens and a map update takes effect, Zone A99 and its mandatory insurance requirement remain in place.

Property owners in a Zone A99 area who want to know where a specific flood control project stands should check with the federal agency responsible for construction or with the local floodplain administrator, since progress on these systems varies by community.

Common Mistakes with Zone A99

• Assuming the levee or dam already protects the property. The flood protection system has to be finished and recognized by FEMA, not just under construction, before the area's risk status can change.
• Expecting a Base Flood Elevation number on the map. A99 areas intentionally show no BFE or depth, which can look like missing data rather than a deliberate part of the designation.
• Dropping flood insurance because a protection project is underway. The mandatory purchase requirement stays in place until the map itself is updated, regardless of construction progress.
• Confusing A99 with a standard A or AE zone. The underlying reason for the classification, and what would need to happen for it to change, are different.

Pro Tips from Sterling Flood Underwriters

Send the flood map panel, not just the zone letter. Seeing the A99 designation on the actual map helps confirm there's no published BFE to account for.

Ask what federal project is tied to the designation. Knowing which levee, dike, or dam system applies to your property can help explain why the zone exists and what would need to happen for it to be reviewed.

Get a Quote

Properties in Zone A99 remain in the Special Flood Hazard Area, and Sterling can quote flood coverage for them without requiring an elevation certificate. Get a flood insurance quote from Sterling Flood.

Frequently Asked Questions

What does Zone A99 mean?

Zone A99 is a FEMA flood zone for areas expected to be protected from the 1% annual chance flood by a federal flood protection system, such as a levee or dam, that is under construction but not yet finished.

Does Zone A99 have a Base Flood Elevation?

No. FEMA does not publish a Base Flood Elevation or flood depth for Zone A99 areas, since the zone reflects a transitional status tied to an unfinished flood protection project.

Is flood insurance required in Zone A99?

Yes. Zone A99 is part of the Special Flood Hazard Area, so federally regulated lenders still require flood insurance on mortgaged buildings in that zone.

Will my zone change once the levee or dam is finished?

It can. Once a federal flood protection system is completed and certified, FEMA may review the area and update the flood map, but the current zone and its insurance requirement remain in effect until that happens.