The purpose of this page is to define Zone A99, a commonly used term in floodplain management.
Areas subject to inundation by the 1-percent-annual-chance flood event, but which will ultimately be protected upon completion of an under-construction Federal flood protection system. These are areas of special flood hazard where enough progress has been made on the construction of a protection system, such as dikes, dams, and levees, to consider it complete for insurance rating purposes. Zone A99 may only be used when the flood protection system has reached specified statutory progress toward completion. No Base Flood Elevations (BFEs) or depths are shown. Mandatory flood insurance purchase requirements and floodplain management standards apply.
- Answers to Questions About the National Flood Insurance Program - Flood Hazard Assessments and Mapping Requirements (page 29)
- IS-9 Managing Floodplain Development Through The National Flood Insurance Program (NFIP) (page 3-33)