FEMAs Letter of Map Revision Confusion

by | Mar 30, 2024 | Elevation Certificate, Flood Zones, Land Surveying

In our 20 years in business, we came across a brand new “thing” that we have never seen before. It had us questioning our results regarding an elevation certificate that on a property that was in the floodplain. What we learned is that sometimes the devil is in the details.

Here’s what happened-we had a homeowner contact us to perform an elevation certificate as they were informed that they were in the floodplain and were going to be required to carry flood insurance. The homeowner was in disbelief and had conversations with the neighboring properties. One of the neighbors advised that they had a letter from FEMA and that they were no longer required to carry flood insurance.

The homeowner reached out to us and had us perform an elevation certificate. The purpose of an elevation certificate is to determine the lowest adjacent grade around the structure on the property. That number is then compared to the base flood elevation that is set by FEMA based on calculations and studies performed. If the lowest adjacent grade is higher than the base flood elevation, then it is assumed that the water will not rise high enough to damage the property.

When we performed the field work necessary to obtain the data for the elevation certificate our findings indicated that the property was located within the flood plain by almost two feet. This of course was very upsetting to the homeowner.

We were stunned and baffled to learn that the neighboring property who had similar elevations had somehow been issued a Letter Of Map Revision on their property. We pulled a copy of the letter that was issued for the neighboring property and saw something we had never seen before. Someone had taken the information from the elevation certificate and filed a Letter Of Map Revision even though the numbers showed that the property was still in the floodplain.

What that neighboring property owner had failed to mention when telling the homeowner about the letter they received was that it was a Letter Of Map Revision was based on fill, a determination document with a result of a non-removal, meaning their property had not been removed from the floodplain.

Unfortunately, the results that we provided only further confirmed that our homeowner was located within the floodplain. However, the homeowner was able to use the elevation certificate to lower their flood insurance rate. This is a good reminder to double check the details on important information such as this example as a homeowner.


Cardinal Surveying would like the opportunity to earn your business. They service the greater St Louis Metro area, have been rated A+ with the Better Business Bureau since 2003, have surveyed over 35,000 properties and are a family-owned company who prides themselves on producing accurate results with exceptional customer service. They can be contacted via email at [email protected] or phone at 636.922.1001. They look forward to working with you for all your land surveying needs.