Step 1: Know the rules

Most communities have adopted building codes that require reconstruction to meet certain standards, including standards that protect from wind, water, earthquakes, and other natural forces. These codes cannot be ignored and must be enforced to protect people from the next disaster.

Most flood-prone communities in Louisiana participate in the National Flood Insurance Program. As a condition of receiving Federally-backed flood insurance, these communities are committed to properly regulate reconstruction in floodplains. The most important regulation is that if a building in the floodplain is substantially damaged by whatever cause (flood, wind, fire, etc.), it must be rebuilt and protected from flooding to the same standards as a new building in the floodplain. “Substantially damaged” means that the cost to repair is 50% or more than the value of the building before it was damaged.

The substantial damage rule means that every damaged building in the floodplain must be assessed before it can be rebuilt. It also means that some mitigation measures will be implemented during reconstruction.


Administering the substantial damage rule is discussed in Step 8.


  • The basic requirements of the National Flood Insurance Program are reviewed in the Louisiana Floodplain Management Desk Reference. Section 14 introduces the rules for substantially damaged buildings.
  • Since the Desk Reference was written, FEMA has refined the substantial damage software.
  • FEMA will likely hold training classes and provide technical assistance to communities using the substantial damage software. Check with your state’s Joint Field Office (JFO) to see if this is in the works.
  • The City of Conway realized its obligation to FEMA as a participant in the National Flood Insurance Program. Meeting these rules was both a priority of the City and a helpful tool to motivate people to think about mitigating and rebuilding differently. See Section 1 in Conway’s Mitigation Commitment Resolution.
Next→ Step 2. Adopt higher redevelopment standards