Many people hear the term “100-year flood” and are confused about what this actually means and how it affects their property as well as their flood insurance coverage.

The 100-year flood is synonymous with several other terms that you may have heard, including “Base Flood”, “1% annual Chance Flood”, “High Risk Flood Zone” and “Special Flood Hazard Area” (SFHA). The 100 year-flood zone is any zone containing the letters “A” or “V”.

The 500-year flood zone is used to designate base floodplains of lesser hazards, such as areas protected by levees from 100 year flood, or shallow flooding areas with average depths of less than one foot or drainage areas less than 1 square mile.
Learn about the 500-year flood zone.