LOMA & LOMR: Letters of Map Change Explained

A Letter of Map Amendment (LOMA) is an official determination by FEMA that a specific property or structure has been incorrectly included in a Special Flood Hazard Area (SFHA) as shown on the Flood Insurance Rate Map (FIRM). A LOMA is issued when FEMA confirms that the property's natural ground elevation, or the structure's lowest floor elevation, is at or above the Base Flood Elevation (BFE).

The key word in LOMA is "amendment," meaning FEMA is amending its map to acknowledge that the property should not have been in the SFHA in the first place. This is not a change to the flood map itself; rather, it is an official recognition that the existing topography naturally protects the property from the base flood. LOMAs apply to individual properties or structures, not to larger areas.

There are two types of LOMAs. A LOMA-OAS (Letter of Map Amendment based on Lowest Adjacent Grade) is issued when the lowest ground adjacent to the structure is at or above the BFE. A LOMA based on structure elevation is issued when the lowest floor of the structure itself is at or above the BFE, even if the surrounding ground is below the BFE (typically for elevated structures).

A Letter of Map Revision (LOMR) is FEMA's modification to an effective FIRM. Unlike a LOMA, which addresses individual properties, a LOMR officially changes the flood zone boundaries, BFE values, or floodway delineations for a larger area on the map. LOMRs are issued when physical changes to the floodplain (such as construction of levees, channels, or fill) alter flood risk for an area, or when better technical data becomes available that shows the current map is inaccurate.

LOMRs are typically requested by communities, developers, or property owners who have completed flood mitigation projects that change flood conditions in an area. For example, a developer who fills a portion of a floodplain to elevate a subdivision above the BFE may apply for a LOMR to have the newly elevated area removed from the SFHA.

A Conditional Letter of Map Revision (CLOMR) is FEMA's formal review and comment on a proposed project that would, upon completion, affect the hydrologic or hydraulic characteristics of a flooding source. Essentially, a CLOMR is a preliminary review that tells you whether FEMA would approve a LOMR after the proposed work is completed.

CLOMRs are not required by FEMA but are strongly recommended before beginning any project that could change flood hazard boundaries. Obtaining a CLOMR before construction provides assurance that the project design will be acceptable to FEMA, reducing the risk of costly redesigns after the fact. Many communities require a CLOMR as part of their local permitting process.

After the project is built according to the approved CLOMR plans, the applicant submits as-built certifications and applies for a LOMR. If the construction matches the approved plans, FEMA issues the LOMR to officially revise the map.

Applying for a LOMA is a straightforward process for property owners whose natural ground elevation is above the BFE. Here is a step-by-step overview of what is involved.

One of the advantages of a LOMA over other map change requests is that FEMA does not charge a processing fee. However, there are costs associated with preparing the required documentation.

While the upfront cost may seem significant, consider that removing your property from the SFHA can save you $1,000 to $3,000 or more per year in flood insurance premiums. For most property owners, the LOMA pays for itself within the first year of premium savings.

You may qualify for a LOMA if your property meets the following criteria. The fundamental requirement is that the property is above the BFE due to natural conditions, not because of man-made fill or grading.

Once FEMA approves your LOMA, several important changes take effect for your property. Understanding these changes helps you take full advantage of the new designation.