Flood · Glossary
Letter of Map Revision (LOMR)
Updated 2026-07-20
A LOMR officially revises an effective FEMA flood map based on new study or fill. Always check Letters of Map Change when screening flood risk.
What it means
A LOMR officially revises an effective FEMA flood map based on new study or fill. Always check Letters of Map Change when screening flood risk.
Why it matters for land decisions
Confirm how the concept applies to your specific parcel with the city or county planning department and the controlling agency map or ordinance.
- Treat online GIS as a first-pass screen.
- Verify before design, escrow, or lending decisions.
People also ask
What is Letter of Map Revision (LOMR)?
A LOMR officially revises an effective FEMA flood map based on new study or fill. Always check Letters of Map Change when screening flood risk.
Is a GIS overlay enough to decide?
No. Public GIS is a screening tool. Official determinations come from the governing agency, recorded documents, and licensed professionals when required.
Official sources
Related terms
Check this on a California parcel
Parcel View screens zoning, flood, fire, soils, and planning layers for any California lot — every finding linked to the official source.