Revision to National Flood Insurance Program Maps

The purpose of this page is to define revisions to National Flood Insurance Program (NFIP) Maps, a commonly used term in floodplain management.

Definition/Description

FEMA has established administrative procedures for changing effective Flood Insurance Rate Maps (FIRMs) and Flood Insurance Study (FIS) reports based on new or revised scientific or technical data. A physical change to the affected FIRM panels and portions of the FIS is referred to as a ''physical map revision.'' When FEMA revises a community's FIRM, the community is required to amend its floodplain management regulations within 6 months of being notified to incorporate the new data.Changes can also be made by a Letter of Map Change (LOMC).

There are several categories of LOMCs, depending on the complexity of the changes.

A Conditional Letter of Map Revision (CLOMR) is not a revision to an NFIP map.

All requests for changes to effective maps, other than those initiated by FEMA, must be made in writing by the Chief Executive Officer (CEO) of the community or an official designated by the CEO.

NFIP Requirement

• Part 65 - Identification and mapping of special hazard areas

Guidance

• IS-9 Managing Floodplain Development Through The National Flood Insurance Program (NFIP) (pages 4-21 to 4-27)

Related Keywords

• Conditional Letter of Map Revision (CLOMR)
• Flood Insurance Rate Map (FIRM)
• Flood Insurance Study (FIS)
• Flood Map
• Letter of Map Change (LOMC)
• Letter of Map Revision (LOMR)
• Letter of Map Revision Based on Fill (LOMR-F)

Special Topic Resources

• Flood Hazard Mapping Website
• Application/Certification Forms for Conditional Letters of Map Revision, Letters of Map Revision, and Physical Map Revisions (MT-1)
• Application/Certification Forms for Conditional Letters of Map Revision, Letters of Map Revision, and Physical Map Revisions (MT-2)