The National Flood Zones are used to determine flood insurance rates in designated flood prone areas within communities that voluntarily participate in the National Flood Insurance Program (NFIP). The National Flood Zones are controlled by the Risk Insurance Division of the Mitigation Directorate of the Federal Emergency Management Agency (FEMA), a component of the Department of Homeland Security (DHS).
The National Flood Zones are designated using a combination of Flood Elevation Determination Maps, Flood Insurance Rate Maps, Flood Hazard Boundary Maps, and Flood Boundary and Floodway Maps.
Flood Zone Laws
The U.S. Congress created NFIP through the National Flood Insurance Act of 1968, the Flood Disaster Protection Act of 1973, and the National Flood Insurance Reform Act of 1994. All three of these acts are codified as Title 42 USC §§ 4001 et seq.
The Code of Federal Regulation authorizes FEMA to administer NFIP at Subchapter B (Insurance and Hazard Mitigation) of Title 44 (Emergency Management and Assistance).
Flood insurance is only available to property owners and renters that are located within a participating community within a National Flood Zone area. The participating communities are listed in the NFIP Community Status Book.
Moderate to Low Risk Areas
Moderate to low risk flood zone areas are designated as Zone B, Zone C and Zone X.
Zone B is a moderate hazard that is protected by 100-year flood levees. It is said to get major flooding every 100 to 500 years.
Zone C is a minimal hazard that is above the 500-year flood level.
Zone X is a low hazard that is outside of the 500-year flood level and may be protected by a 100-year flood levee.
High Risk Areas
High risk flood zone areas are designated as Zone A, Zone AE, Zone AH, Zone AO, Zone AR and Zone A99.
Zone A has a one percent chance of flooding each year and a 26 percent chance of flooding during the life of a 30-year mortgage.
Zone AE is known as the base floodplain.
Zone AH has a one percent chance of flooding one to three feet every year and a 26 percent chance of flooding during the life of a 30-year mortgage.
Zone AO has the same hazard as Zone AH, in addition to being located near a stream or river.
Zone AR has an increased flooding hazard due to the building of a dam. Mandatory flood insurance purchase requirements apply in this zone.
Zone A99 has the same hazard as Zone AR, except that the dam is part of a federal government construction project.
High Risk Coastal Areas
High risk coastal flood zone areas are designated as Zone V and Zone VE.
Zone V has a 1 percent chance of flooding each year with the possibility of storm waves and a 26 percent chance of flooding during the life of a 30-year mortgage.
Zone VE has has a greater than 1 percent chance of flooding each year with the possibility of storm waves and a greater than 26 percent chance of flooding during the life of a 30-year mortgage.
Undetermined Risk Areas
Undetermined risk flood zone areas are designated as Zone D and have a possible, but undetermined, hazard.
Tags: chance flooding, National Flood, percent chance, percent chance flooding, Zone Zone Zone
