FEMA Floodplain Mapping and Revisions
Correcting the flood maps when they don't match reality
FEMA's flood maps drive insurance and building requirements, but they don't always reflect a property's actual conditions. Colman Engineering prepares FEMA floodplain mapping and revisions for property owners across Virginia, including Letters of Map Amendment and Revision. When the effective mapping does not reflect actual site conditions, we build the technical case for a correction.
Benefits
FEMA Floodplain Mapping and Revisions
A path to correcting the maps
When a flood map doesn't match your property's real conditions, a revision can set the record straight. We prepare the technical submittals FEMA's process requires.
Potential relief from requirements
A successful revision can affect flood insurance obligations and building requirements, providing relief when the effective mapping genuinely overstates the risk.
The analysis to back the case
FEMA revisions rest on solid hydrologic, hydraulic, and elevation data. We bring the water resources analysis needed to make a defensible case.
Building the technical case for a map correction
We evaluate your property against the effective flood mapping to determine whether a revision is supportable and which type fits, such as a Letter of Map Amendment or Revision. We develop the elevation, hydrologic, and hydraulic data the case requires and prepare the submittal to FEMA. We support the process through FEMA's review and any requests for additional information. The aim is a well-documented case for mapping that reflects your property's actual conditions.
Use Cases
A floodplain revision fits when you believe the effective flood map overstates the hazard on your property.
01
You think your property is mapped in error
The flood map shows your structure or land in a zone that doesn't match the ground. A revision can seek to correct it.
02
You want relief from flood requirements
Mapping is driving insurance or building requirements you believe are unwarranted. A supportable revision may address that.
03
Site conditions have changed
Fill, grading, or other changes have altered the flood picture. A revision can reflect the updated conditions in the mapping.
Tips and FAQs
Map revisions come in different forms, and the appropriate one depends on your situation and whether it is based on existing conditions or physical changes to the site. The process rests on technical data and FEMA review, so the analysis determines what can be supported. We can assess the likely path before you commit to the full effort.
What's the difference between a LOMA and a LOMR?
A Letter of Map Amendment generally addresses mapping errors based on existing conditions, while a Letter of Map Revision reflects changes such as fill or new analysis. We help identify which fits your case.
Can you tell me if a revision will succeed?
We can evaluate your situation and explain whether the available data appear likely to support a revision before you invest in the full submittal.
Will a revision lower my flood insurance?
It can, if it removes or reduces the mapped flood hazard for your structure. The revision changes the mapping basis; insurers then apply the result.
How long does the FEMA process take?
It varies with the type of revision and FEMA's review. We give you a realistic expectation once we understand your specific case.
