Flood Zone Definitions

100 Year Flood:     As determined by the Federal Emergency Management Agency, a flood event of a magnitude expected to be equaled or exceeded once on the average during any 100-year period.   The term "100-year flood" is misleading. It is not the flood that will occur once every 100 years. Rather, it is the flood elevation that has a 1- percent chance of being equaled or exceeded each year. Thus, the 100-year flood could occur more than once in a relatively short period of time. The 100-year flood, which is the standard used by most Federal and state agencies, is used by the National Flood Insurance Program (NFIP) as the standard for floodplain management and to determine the need for flood insurance.

 

500 Year Flood:  The flood having a 0.2% or greater annual probability of occurring.

 

  

Base Flood Elevation:   The expected flood height measured in feet above mean sea level

(NGVD 1929 Datum)

 

Zone A:   Flood hazard areas inundated by the 100 Year Flood, no base flood elevations determined.

 

Zone AE: Flood hazard areas inundated by the 100 Year Flood, with base flood elevations determined.

 

Zone VE: Areas of coastal flooding with velocity hazard (wave action), base flood elevations have been determined.

 

Zone X:   Areas determined to be outside the 100 year flood plain.

 

Zone X500:  Areas determined to be outside the 500 year flood plain.