Freeboard

NFIP Policy Index

Definition/Description

Freeboard is a factor of safety usually expressed in feet above a flood level for purposes of floodplain management. "Freeboard" tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, bridge openings, and the hydrological effect of urbanization of the watershed. Freeboard is not required by NFIP standards, but communities are encouraged to adopt at least a one-foot freeboard to account for the one-foot rise built into the concept of designating a floodway and the encroachment requirements where floodways have not been designated. Freeboard results in significantly lower flood insurance rates due to lower flood risk.

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NFIP Requirement

IS-9 Managing Floodplain Development Through The National Flood Insurance Program (NFIP)

Technical Bulletin 10, Ensuring That Structures Built on Fill In or Near Special Flood Hazard Areas Are Reasonably Safe From Flooding (FIA-TB-10)

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Related Keywords

Elevation
Encroachments
Floodway
Higher Standard Elevation

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Special Topic Resources

CRS Credit for Higher Regulatory Standards

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Last Modified: Saturday, 19-May-2007 12:08:21 EDT