Comparison
LOMA vs LOMR
Understand the difference between a Letter of Map Amendment and a Letter of Map Revision before choosing the wrong path.
A LOMA amends the map for a specific property that was incorrectly included in the flood zone. A LOMR revises the map itself, usually because of new hydrology, hydraulic modeling, or physical changes like levees or channel improvements. Most individual property owners need a LOMA, not a LOMR.
Key takeaways
Comparison
LOMA versus LOMR
These two letter types serve very different purposes despite the similar names.
| Topic | LOMA | LOMR |
|---|---|---|
| What it changes | Amends the map for a specific structure or parcel | Revises the published flood map for an area |
| Who typically requests it | Property owner, buyer, or their professional | Community, developer, or engineering firm |
| Evidence required | Elevation Certificate or survey for the property | Engineering study with updated hydrology or hydraulics |
| Typical timeline | Weeks to a few months | Months to over a year |
| Cost | Hundreds to low four figures | Tens of thousands or more |
Frequently asked questions
What is the difference between a LOMA and a LOMR?
A LOMA is a property-specific amendment that says a particular structure or parcel should not have been included in the flood zone because it sits above the Base Flood Elevation. A LOMR is a revision to the flood map itself, usually driven by new engineering data or physical changes to the floodplain.
Which one do most homeowners need?
Most homeowners need a LOMA or LOMR-F, not a LOMR. A LOMR is typically pursued by communities, developers, or engineering firms when the underlying flood data has changed for an entire area.
Can a homeowner request a LOMR?
Technically yes, but LOMRs require detailed engineering studies, updated flood models, and often community coordination. The cost and complexity make them impractical for individual homeowners in most cases.
Does a LOMR take longer than a LOMA?
Yes, significantly. A LOMA with clean evidence can process in weeks, while a LOMR typically takes months to over a year because of the engineering review and community involvement required.
If my area had a levee built, is that a LOMA or LOMR?
Levee construction that changes the flood risk for an area is a LOMR scenario, not a LOMA. The community or levee sponsor would typically pursue the LOMR to update the map for the protected area.
Can a LOMA and LOMR affect the same property?
Yes. A property might have an existing LOMA that gets superseded when a LOMR revises the map for the broader area. When the new map takes effect, the LOMA may need to be revalidated against the updated flood data.