No Base Flood Elevations (BFEs) or depths are shown. Zone A99 may only be used when the flood protection system has reached specified statutory progress toward completion. 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. Mandatory flood insurance purchase requirements and floodplain management standards apply.Ī99: Areas are subject to inundation by the 1-percent-annual-chance flood event, but will ultimately be protected upon completion of an under-construction Federal flood protection system. Mandatory flood insurance purchase requirements and floodplain management standards apply.ĪR: Areas that result from the decertification of a previously accredited flood protection system that is determined to be in the process of being restored to provide base flood protection. Average flood depths derived from detailed hydraulic analyses are shown in this zone.

Mandatory flood insurance purchase requirements and floodplain management standards apply.ĪO: Areas subject to inundation by 1-percent-annual-chance shallow flooding, usually sheet flow on sloping terrain, where average depths are between one and three feet. Base Flood Elevations (BFEs) derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance purchase requirements and floodplain management standards apply.ĪH: Areas subject to inundation by 1-percent-annual-chance shallow flooding, typically areas of ponding, where average depths are between one and three feet. Mandatory flood insurance purchase requirements and floodplain management standards apply.ĪE, A1-A30: Areas subject to inundation by the 1-percent-annual-chance flood event determined by detailed methods. Because detailed hydraulic analyses have not been performed, no Base Flood Elevations (BFEs), or flood depths are shown. FEMA Flood ZonesĪ: Areas subject to inundation by the 1-percent-annual-chance flood event are generally determined using approximate methodologies. Definitions for all FEMA flood zones are provided in the table below. These zones could still have flood risk as historically more than 20% of NFIP claims are made by policyholders in an X, B, or C zone. FEMA’s low and moderate-risk flood zones – those outside the SFHA – are those that begin with the letters “X,” “B,” or “C.” Flood insurance is not required within these zones. The SFHA designation is important because it is the basis for floodplain management regulations for communities across the country and because it decides whether a home is required to have flood insurance or not.įEMA’s high-risk flood zones – those that make up the SFHA – are those that begin with the letters “A” or “V.” Homeowners located in A or V zones are required to purchase flood insurance if they have a mortgage from a federally-backed or federally-regulated lender. As a result, FEMA maps the areas with a 1% annual chance of flooding. In developing zone maps, FEMA focuses primarily on identifying the 1-percent annual chance floodplain (also known as the 100-year floodplain, Special Flood Hazard Area, or SFHA). Search your address to learn how flood zones might impact you. FEMA creates FIRMs to inform flood insurance pricing in the National Flood Insurance Program (NFIP) and to guide floodplain management regulations for NFIP-participating communities. Learn about the definitions of FEMA Flood Zones and the differences between them.įederal Emergency Management Agency (FEMA) Flood MapsįEMA maps flood zones in communities across the US, identifying areas of varying flood risk on Flood Insurance Rate Maps (FIRMs).

Fema flood zone memphis