- City Departments
- Building Department
- Floodplain Management (FEMA)
- Flood Maps
- Map Changes On-File
Map Changes On-File
About Flood Map Changes
When FEMA creates flood maps, it does so with a rather broad brush, knowing there will be areas where the elevation of the ground will be higher than estimated. The most accurate measurements are made on site by land surveyors, usually with their production of an Elevation Certificate.
When a surveyor finds the lowest ground level is higher than the flood level, FEMA will issue a Letter of Map Change (LOMC), that will reclassify that building as being in a less-restrictive flood zone.
If you have an Elevation Certificate, the following is how to tell if your building would qualify for a LOMC:
- Look in block B9 for the Base Flood Elevation (BFE)
- Look for the ground measurement on line C2(f) for Lowest Adjacent Grade Next to Building
- If the Lowest Adjacent Grade Next to Building is equal to, or higher than, the Base Flood Elevation, your building is eligible
If the flood level in Block B9 is 6 feet, and the measurement on line C2(f) is 6.3 feet, then the ground is higher than the flood level and a LOMC would likely be approved. In Key West, most LOMC’s come in the form of a Letter of Map Amendment (LOMA)
Types of Letter of Map Changes (LOMCs)
While there are several types of possible maps changes, all are considered Letter of Map Changes (LOMC):
Letter of Map Amendment (LOMA)
LOMA usually applies to a single building or lot. LOMA requests involving one or more structures. For a LOMA to be issued by FEMA to remove one or more structures from the Special Flood Hazard Area (SFHA), the National Flood Insurance Program (NFIP) regulations require that the lowest adjacent grade (the lowest ground adjacent to the structure) be at or above the BFE. For LOMA Requests involving one or more lots, a LOMA to be issued by FEMA to remove one or more entire lots from the Special Flood Hazard Area (SFHA,) the National Flood Insurance Program (NFIP) regulations require that the lowest point on the lot(s) must be at or above the BFE.
Letter of Map Amendment based on Fill (LOMA-F)
LOMA-F usually applies to a single building or lot. For a LOMR-F requests involving one or more structures to be issued by FEMA to remove the structure from the SFHA, the NFIP regulations require that the lowest adjacent grade of the structure be at or above the BFE. The participating community must also determine that the land and any existing or proposed structures to be removed from the SFHA are "reasonably safe from flooding." For LOMR-F requests involving one or more lots, a LOMR-F to be issued by FEMA to remove the entire lot and structure, both the lowest point on the lot and the lowest floor of the structure must be at or above the 1-%-annual-chance flood elevation.
Conditional Letter of Map Amendment (CLOMA)
CLOMA is a letter from Department of Human Services (DHS)-FEMA stating that a proposed structure that is not to be elevated by fill natural ground) would not be inundated by the base flood if built as proposed.
Conditional Letter of Map Amendment based on Fill (CLOMA-F)
A letter from DHS-FEMA stating that a parcel of land or Revision Based on Fill proposed structure that will be elevated by fill would not be (CLOMR-Friday) inundated by the base flood if fill is placed on the parcel as proposed or the structure is built as proposed.
Letter of Map Revision (LOMR)
While the above map change documents usually refer to specific buildings, sometimes FEMA will approve changes to an area within multiple flood zones that may cover multiple buildings or lots. On their effective date, these become official changes to the flood maps.
Revision of Maps
When FEMA issues a Letter of Map Change (LOMC/A/R etc.), the initial flood maps aren’t revised until new flood maps are issued. Thus, during this interim, the Flood Insurance Rate Maps (FIRMs) will likely continue to indicate the old rating, yet the LOMC would be the controlling document.
With FEMA’s proposed new flood maps, only two of the 76 map changes will be retained. FEMA has issued a preliminary Summary of Map Actions (SOMA) detailing these changes. (New flood maps likely won’t take affect before the summer of 2021.)