What are flood hazard zones and what do they mean?

The Flood Insurance Rate Map (FIRM) is used in regular-program communities by lenders to determine the flood insurance requirements and by insurance agents to determine flood insurance premium rates for specific properties. The map includes areas within the 100-year flood boundary, which are termed "Special Flood Hazard Areas" (SFHAs). A "100-year flood" does not refer to a flood that occurs every 100 years, but refers to a flood level with a 1 percent or greater chance of being equaled or exceeded in any given year.