Zone A Coastal

Portion of a community’s coastal floodplain that is subject to wave heights between 1.5 and 3 feet during a 100-year flood event associated with a storm. The main source of flooding must be astronomical tides, storm surges, seiches, or tsunamis rather than riverine flooding. This zone is within the Special Flood Hazard Area on a community’s flood map, landward of a V Zone or open coast without mapped V Zones. Waves are capable of damaging many structures on shallow or solid wall foundations in the Coastal A Zone, and this zone is often referenced in building codes and standards. Note that Coastal A zones are not shown on present day Flood Insurance Rate Maps or mentioned in a community’s Flood Insurance Study.