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Surface Water


Glossary

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

Elevated Building - A building that has no basement and has its lowest elevated floor raised above the ground level by foundation walls, shear walls, posts, piers, pilings, or columns.

Elevation Certificate - A certificate that verifies the elevation data of a structure on a given property relative to the ground level.  The Elevation Certificate is used by local communities and builders to ensure compliance with local floodplain management ordinances and is also used by insurance agents and companies in the rating of flood insurance policies.

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 Hazard Boundary Map (FHBM) - Official map of a community issued by the Federal Insurance 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 severity or type 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.

Grandfathering - An exemption based on circumstances previously existing. Under the NFIP, buildings located in Emergency Program communities and Pre-FIRM buildings in the Regular Program are eligible for subsidized flood insurance rates.  Post-FIRM 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 FIRM revisions.

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.

Lowest Floor - The lowest floor of the lowest enclosed area (including a basement).  An unfinished or flood-resistant enclosure, usable solely for parking of vehicles, building access, or storage in an area other than a basement area, is not considered a building's lowest floor provided that such enclosure is not built so as to render the structure in violation of requirements.

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.

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.

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).

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.

 

See more definitions here www.fema.gov/business/nfip/19def2.shtm   Off site

 






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