Glossary of Terms

100-year Flood

A flood event having 1-percent chance of being equaled or exceeded in any given year; also referred to as the 1-percent annual chance flood and the Base Flood.

100-year Floodplain

Boundary of the flood that has a 1-percent chance of being equaled or exceeded in any given year. Officially termed the 1-percent annual chance floodplain. Also see Special Flood Hazard Area.

500-year Floodplain

Boundary of the flood that has between 0.2 and 1-percent chance of being equaled or exceeded in any given year. Officially termed the 0.2-percent annual chance floodplain.

Act

See National Flood Insurance Reform Act (NFIRA)

Base Flood

The flood having a 1-percent chance of being equaled or exceeded in any given year.

Base Flood Elevation (BFE)

The elevation shown on the Flood Insurance Rate Map (FIRM) for Zones AE, AH, A1-A30, AR, AR/A, AR/AE, AR/A1-A30, AR/AH, AR/AO, V1-V30, and VE that indicates the water surface elevation resulting from a flood that has a 1-percent chance of equaling or exceeding that level in any given year.

Coastal Barrier

A naturally occurring island, sandbar, or other strip of land, including coastal mainland, that protects the coast from severe wave wash.

Coastal Barrier Improvement Act of 1990 (CBIA)

Enacted on November 16, 1990, the Act greatly expanded the identified land in the Coastal Barrier Resources System established pursuant to the Coastal Barrier Resources Act of 1982.

Coastal Barrier Resources Act of 1982 (CBRA)

For the purposes of the NFIP, the Coastal Barrier Resources Act of 1982 designated certain portions of the Gulf and East Coasts as undeveloped coastal barriers. These areas are shown on appropriate flood insurance map panels and have certain coverage restrictions.

Coastal Barrier Resources System (CBRS)

Communities, coastal barriers, and other protected areas identified by the Department of the Interior legislation defined above.

Coastal High Hazard Areas

Special Flood Hazard Areas along the coasts that have additional hazards due to wind and wave action. These areas are identified on Flood Insurance Rate Maps as Zones V, V1-V30, and VE.

Community

Defined by the NFIP as any State, area, or political subdivision; any Indian tribe, authorized tribal organization, or Alaska native village; or authorized native organization that has the authority to adopt and enforce floodplain management ordinances for the area under its jurisdiction. In most cases, a community is an incorporated city, town, township, borough, or village, or an unincorporated area of a county or parish. However, some States have statutory authorities that vary from this description.

Community Number

A six-digit designation identifying each NFIP community. The first two numbers are the state code, and the next four are the FEMA-assigned community number. An alphabetical suffix is added to a community number to identify revisions in the Flood Insurance Rate Map for that community.

Community Rating System (CRS)

A program developed by FEMA’s Mitigation Division to provide incentives for those communities in the Regular Program that have gone beyond the minimum floodplain management requirements to develop extra measures to provide protection from flooding.

Elevation Certificate

A certificate that verifies the elevation data of a structure on a given property relative to the ground level; must be issued by a professional surveyor.

Emergency Program

The initial phase of a community's participation in the National Flood Insurance Program. During this phase, only limited amounts of insurance are available under the Act.

Federal Emergency Management Agency (FEMA)

The federal agency within the Department of Homeland Security that is tasked with responding to, planning for, recovering from and mitigating against man-made and natural disasters.

FHBM

See Flood Hazard Boundary Map

FIRM

See Flood Insurance Rate Map

Flood

A general and temporary condition of partial or complete inundation of two or more acres of normally dry land area or of two or more properties (at least one of which is the policyholder's property) from one of the following:
  • Overflow of inland or tidal waters

    Unusual and rapid accumulation or runoff of surface waters from any source
  • Mudflow

    Collapse or subsidence of land along the shore of a lake or similar body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels that result in a flood as defined above

Flood Disaster Protection Act (FDPA)

Act that made the purchase of flood insurance mandatory for the protection of property located in Special Flood Hazard Areas.

Flood Hazard Boundary Map (FHBM)

Official map of a community issued by the Administrator, where the boundaries of the flood, mudflow, and related erosion areas having special hazards have been designated.

Flood Insurance Rate Map (FIRM)

Official map of a community on which the Mitigation Division Administrator has delineated both the special hazard areas and the risk premium zones applicable to the community.

Flood Zone (Zone)

A geographical area shown on a Flood Hazard Boundary Map or a Flood Insurance Rate Map that reflects the risk of flooding in the area.

Floodplain

Any land area susceptible to being inundated by floodwaters from any source.

Floodplain Management

The operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to, emergency preparedness plans, flood control works, and floodplain management regulations.

Floodway

Channel of a stream plus any adjacent floodplain areas that must be kept free of encroachment so that the 100-year flood discharge can be conveyed without increasing the elevation of the 100-year flood by more than a specified amount (1 foot in most states).

Grandfathering

An exemption based on circumstances previously existing. Under the NFIP, buildings located in Emergency Program communities and Pre-Flood Insurance Rate Map buildings in the Regular Program are eligible for subsidized flood insurance rates. Post-Flood Insurance Rate Map buildings in the Regular Program built in compliance with the floodplain management regulations in effect at the start of construction will continue to have favorable rate treatment even though higher base flood elevations or more restrictive, greater risk zone designations result from Flood Insurance Rate Map revisions.

Letter of Determination Review (LODR)

FEMA's ruling on the determination made by a lender or third party that a borrower's building is in a Special Flood Hazard Area(SFHA). A LODR deals only with the location of a building relative to the SFHA boundary shown on the Flood Insurance Rate Map.

Letter of Map Amendment (LOMA)

An amendment to the currently effective FEMA map which establishes that a property is not located in a Special Flood Hazard Area. A LOMA is issued only by FEMA.

Letter of Map Revision (LOMR)

An official amendment to the currently effective FEMA map. It is issued by FEMA and changes flood zones, delineations, and elevations.

LOMA

See Letter of Map Amendment

LOMR

See Letter of Map Revision

Mandatory Purchase

Under the provisions of the Flood Disaster Protection Act of 1973, individuals, businesses, and others buying, building, or improving property located in identified areas of special flood hazards within participating communities are required to purchase flood insurance as a prerequisite for receiving any type of direct or indirect federal financial assistance (e.g., any loan, grant, guaranty, insurance, payment, subsidy, or disaster assistance) when the building or personal property is the subject of or security for such assistance.

Map Revision

A change in the FHBM or FIRM for a community which reflects revised zone, base flood, or other information.

National Flood Insurance Program (NFIP)

A federal program enabling property owners in participating communities to purchase insurance protection against losses from flooding. This insurance is designed to provide an insurance alternative to disaster assistance to meet the escalating costs of repairing damage to buildings and their contents caused by floods.

National Flood Insurance Reform Act (NFIRA)

The purpose of the National Flood Insurance Reform Act of 1994 is to improve the financial condition of the NFIP and reduce federal expenditures for disaster assistance to flood-damaged properties. The act affects every part of NFIP, insurance, mapping and floodplain management. NFIRA also gives lenders tools with which to enforce requirements for flood insurance coverage mandated under the Flood Disaster Protection Act of 1973. Also referred to as the Reform Act and The Act.

Non-Participating Community

Community that is not participating in the NFIP. Non-participation may be the result of suspension, withdrawal or failure to join the program initially. NFIP flood insurance is not available in non-participating communities.

Non-Special Flood Hazard Area (NSFHA)

An area in a low to moderate risk flood zone (Zones B, C, X) that is not in any immediate danger from flooding caused by overflowing rivers or hard rains. However, it's important to note that structures within a NSFHA are still at risk.

Participating Community

A community for which the Mitigation Division Administrator has authorized the sale of flood insurance under the NFIP.

Ponding Hazard

A flood hazard that occurs in flat areas when there are depressions in the ground that collect "ponds" of water. The ponding hazard is represented by the zone designation AH on the FIRM.

Post-FIRM Building

A building for which construction or substantial improvement occurred after December 31, 1974, or on or after the effective date of an initial Flood Insurance Rate Map (FIRM), whichever is later.

Pre-FIRM Building

A building for which construction or substantial improvement occurred on or before December 31, 1974, or before the effective date of an initial Flood Insurance Rate Map (FIRM).

Preferred Risk Policy (PRP)

A policy that offers fixed combinations of building/contents coverage or contents-only coverage at modest, fixed premiums. The PRP is available for property located in B, C, and X zones in Regular Program communities that meet eligibility requirements based on the property's flood loss history.

Reform Act

See National Flood Insurance Reform Act (NFIRA)

Regular Program

The final phase of a community's participation in the National Flood Insurance Program. In this phase, a Flood Insurance Rate Map is in effect and full limits of coverage are available under the Act.

Sheet Flow Hazard

A type of flood hazard with flooding depths of 1 to 3 feet that occurs in areas of sloping land. The sheet flow hazard is represented by the zone designation AO on the FIRM.

Special Flood Hazard Area (SFHA)

A FEMA-identified high-risk flood area where flood insurance is mandatory for properties. An area having special flood, mudflow, or flood-related erosion hazards, and shown on a Flood Hazard Boundary Map or a Flood Insurance Rate Map as Zone A, AO, A1-A30, AE, A99, AH, AR, AR/A, AR/AE, AR/AH, AR/AO, AR/A1-A30, V1-V30, VE, or V.

Zone

A geographical area shown on a Flood Hazard Boundary Map or a Flood Insurance Rate Map that reflects the risk of flooding in the area. Also see Flood Zone.
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