Go to the FEMA website and use their mapping tool (Map Viewer) to help you determine whether your project is in Zone A (the 100-year floodplain). See the example of FEMA 100-year floodplain research in the Documentation Toolkit. Use the following steps:
The 100-year floodplain, defined by FEMA, is the elevation to which a flood has a 1% chance of reaching or exceeding in a given year. (It is not the level of the most significant flood within a 100-year period.) So-called 100-year floods can occur many times within a 100-year period.
Avoid using carpet near entryways or areas where water and dirt may be tracked into the building. Installing permanent entryways helps to limit the amount of moisture that gets into the building and can contribute to earning IEQc5: Indoor Chemical and Pollutant Source Control.
Remember that any material can collect dust and thus provide a medium for mold growth, so keep both dust and moisture away from all materials as much as possible.