If you are in the Community Floodplain (Future Floodplain), you could rebuild on the current footprint if you brought the structure into compliance with the new Future 100-Year Floodplain elevations. Any development inside the FEMA floodplain carries additional restrictions and requirements.
If the value of the addition or improvement to the house is less than 50 percent of the market value of the existing structure, you need only make sure that the improvement meets the requirements described in the current local floodplain regulations. Additions or other improvements valued at 50 percent or more of the market value of the existing structure are considered substantial improvements. In such cases, the entire structure must be brought into compliance with the elevations shown on the current flood map.
If my floodplain property is severely damaged by a flood, would I be able to make repairs?
If your house receives "substantial damage" within a ten-year period (meaning any damage where the cost to restore the structure to how it was before it flooded equals or exceeds 50 percent of the structure's market value), then you will not be able to rebuild. For a property valued at $150,000 this would mean if you sustained $75,000 worth of damage, you could not repair any wall, ceiling, floor or other structural part of the house.
"Substantial improvement" means any repair, reconstruction, or improvement of a structure, where the cost equals or exceeds fifty percent of the market value of the structure, either (1) before the improvement or repair is started, or (2) if the structure has been damaged and is being restored, before the damage occurred.
"Substantial improvement" also means any repair, reconstruction, or improvement to a structure on two separate occasions during a 10 year period beginning after September 8, 1999, for which the cost of repairs, reconstruction, or improvement at the time of each alteration equals or exceeds 25 percent of the market value of the structure before the alteration occurred.
For the purposes of this definition, "substantial improvement" is considered to occur when the first alteration of any wall, ceiling, floor, or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure. The term does not, however, include either (1) any project for improvement of a structure to comply with existing state and local health, sanitary, or safety code specifications which are solely necessary to assure safe living conditions, or (2) any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places. However, should your house be substantially damaged (damage is 50 percent or more of the pre-damage market value) and you wish to repair it, you be required to bring the entire structure into compliance with the zone designation and flood elevations in effect at the time the repairs take effect.
Charlotte-Mecklenburg Storm Water Services Floodplain Permitting Office