Hazard Mitigation Assistance Program and Policy Guide
Part 12, B.6. Floodproofing 416
Application of wet floodproofing as a flood protection technique under the NFIP is limited to specific
situations in Zone A (A, AE, A1-30, AH, AO and AR). For certain uses and types of structures,
communities may allow wet floodproofing only through the issuance of a variance from certain
floodplain management requirements. The situations and conditions in which a community may
allow wet floodproofing are described in detail in NFIP Technical Bulletin 7
, Wet Floodproofing
Requirements and Limitations for Buildings and Structures Located in Special Flood Hazard Areas in
Accordance with the National Flood Insurance Program (May 2022).
For structures in Zone V (V, VE and V1-30), more stringent design and construction requirements
have been established for the portion of the structure below the Base Flood Elevation. For
information on V-zone design and construction requirements, refer to the NFIP regulations under
44
CFR § 60.3; FEMA P-55, Coastal Construction Manual: Principles and Practices of Planning, Siting,
Designing, Constructing, and Maintaining Residential Buildings in Coastal Areas, Fourth Edition,
Volume I (Aug. 2011); and the FEMA “
National Flood Insurance Technical Bulletins” webpage. For
more information on NFIP's general requirements for wet floodproofing, refer to 44 CFR § 60.3, NFIP
Technical Bulletin 7, FEMA Policy #104-008-3 and Floodplain Management Bulletin P-2140.
B.6.2.6.2. Dry Floodproofing in Special Flood Hazard Areas
An important objective of the NFIP is to protect structures constructed in floodplains from flood-
induced damage. In support of this objective, the NFIP regulations include building design and
construction criteria that apply to new construction and substantial improvements (including
structures that have incurred substantial damage) of existing structures in SFHAs. Residential
structures in Zone A (A, AE, A1-30, AR, AO or AH) must be constructed with their lowest floors
elevated to or above the Base Flood Elevation. Non-residential structures constructed in Zone A (A,
AE, A1-30, AR, AO or AH) must either have their lowest floors elevated to or above the Base Flood
Elevation or be dry floodproofed to or above the Base Flood Elevation. Measures to accomplish dry
floodproofing of non-residential structures must provide watertight protection and be designed to
withstand hydrostatic, hydrodynamic and impact forces produced by flooding. The intent is to provide
complete protection at least up to the floodproofing design level, which must, at a minimum, be at
the Base Flood Elevation.
Dry floodproofing can be used to fulfill the requirements for non-residential buildings in SFHAs that
are not subject to high-velocity wave action. Some requirements apply to existing buildings when the
cost of repairing or improving a building in an SFHA equals or exceeds 50% of the building’s market
value. NFIP requires new and substantially improved buildings be constructed in ways that minimize
or prevent flood damage. As with new non-residential buildings, existing non-residential buildings
may be brought into compliance by elevating them on compliant foundations or, if determined to be
feasible, by implementing dry floodproofing measures. For more information on NFIP's general
requirements for dry floodproofing, refer to 44 CFR § 60.3(c) and NFIP Technical Bulletin 3.
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456
Requirements for the Design and Certification of Dry Floodproofed Non-Residential and Mixed-Use Buildings Located in
Special Flood Hazard Areas in Accordance with the National Flood Insurance Program (Jan. 2021)