100-year flood: The term "100-year flood" is misleading. It is not the flood that will occur once every 100 years. Rather, it is the flood elevation that has a 1 percent chance of being equaled or exceeded each year. Thus, the 100-year flood could occur more than once in a relatively short period of time.

The 100-year flood, which is the standard used by most federal and state agencies, is used by the National Flood Insurance Program (NFIP) as the standard for floodplain management and to determine the need for flood insurance. A structure located within a special flood hazard area shown on an NFIP map has a 26 percent chance of suffering flood damage during the term of a 30-year mortgage.

Actual cash value: The cost to replace an insured item of property at the time of loss, less the value of physical depreciation.

Base flood: The flood having a one percent chance of being equaled or exceeded in any given year.

Base flood elevation: The elevation shown on Flood Insurance Rate Maps (FIRMs) for 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.

Community Rating System: A program developed by 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.

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.

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: 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:

• Overflow of inland or tidal waters; or
• Unusual and rapid accumulation or runoff of surface waters from any source; or
• Mudflow; or
• 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): 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: A standard homeowners policy will not cover damages caused by flooding. You must have flood insurance from an insurer that writes for the National Flood Insurance Program. If your community participates in NFIP's floodplain-management program, you are eligible to buy coverage no matter if your flood risk is low, medium or high. Flood insurance is also available to renters, condominium owners and business owners.

You may have trouble finding flood coverage if you are a resident of "coastal barrier resource system" area or a community that does not participate in NFIP's programs.

Flood plain: 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.

Mandatory flood insurance: 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.

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.

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

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.

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.

Replacement value: The cost to replace property with the same kind of material and construction without deduction for depreciation.

Special Flood Hazard Area: 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.

Standard Flood Insurance Policy (SFIP): A policy issued to insure a building and/or contents.

Write Your Own (WYO) program/companies: A cooperative undertaking of the insurance industry and FEMA begun in October 1983. The WYO Program operates within the context of the NFIP and involves private insurance carriers who issue and service NFIP policies.

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

For more terms, see the NFIP's glossary of flood insurance terms.

Flood insurance acronyms

ACV -- Actual Cash Value

BFD -- Base Flood Depth
BFE -- Base Flood Elevation
CBRA -- Coastal Barrier Resources Act of 1982
CBIA -- Coastal Barrier Improvement Act of 1990
CBRA -- Coastal Barrier Resources Act of 1982
CBRS -- Coastal Barrier Resources System
COLMA -- Conditional Letter of Map Amendment
COLMR -- Conditional Letter of Map Revision

Source: FEMA