A Letter of Map Revision (LOMR) is a document that officially revises a portion of the current Flood Insurance Rate Map (FIRM) and/or Flood Insurance Study (FIS) according to requirements and procedures outlined in Part 65 of the NFIP regulations. The LOMR allows the Federal Emergency Management Agency (FEMA) to revise flood hazard information on the FIRM and/or FIS via letter without physically revising and reprinting the map or report itself, in less time and at less expense than a Physical Map Revision.
LOMRs are generally based on physical changes within the floodplain that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the effective Base Flood Elevations (BFEs), base flood depths, Special Flood Hazard Area (SFHA), or regulatory floodway. A LOMR is accompanied by an annotated copy of the affected portions of the FIRM and/or FIS report. Additional information regarding LOMRs is provided on FEMA’s website. In most instances, prior to a LOMR becoming effective, stakeholders are provided a 90-day period in which they can appeal the flood hazard information contained within the LOMR. An appeal is a formal objection to the flood hazard data that has been submitted for inclusion approval. This could include appealing addition or modification of proposed BFEs, base flood depths, SFHA boundaries or zone designations, or regulatory floodway boundaries. Appeals must be supported by scientific and/or technical data.
To learn more about what constitutes scientific and technical data, please refer to the Resources listed below. All appeals must be submitted to the community’s Chief Executive Officer (mayor, county supervisor, etc.) for official submittal to FEMA, as outlined in Part 67 of the National Flood Insurance Program regulations.
Effective FIRMs and FIS reports can be found at the FEMA Map Service Center (MSC) website. In addition, LOMRs are posted to the MSC website once they become effective and can be found along with the FIRM they revised.
Procedure Memorandum 57: The Expanded Appeals Process
More information of FEMA’s Appeals Process at FEMA’s Flood Hazard Determination Notices Homepage
Appeal resolution process information can be found at Scientific Resolution Panels
General information can be obtain at the FEMA Map Information eXchange (FMIX): 877.336.2627