Interpreting Flood Insurance Rate Maps and Flood Insurance Study Reports

As a part of the National Flood Insurance Program (NFIP), the Federal Emergency Management Agency (FEMA) periodically conducts Flood Insurance Studies (FISs) and uses the results of these studies to produce FIS reports and Flood Insurance Rate Maps (FIRMs). FIRMs show the estimated extent of flooding during a hypothetical “100-year storm” (also called a 1% storm)—a storm that has an estimated 1% chance of being equaled or exceeded during any given year. (Note: A 100-year storm can occur more than once a century.)

Correctly interpreting FIRMs and FIS reports can be complicated. Following are some resources to help.

• The Massachusetts Office of Coastal Zone Management article, The Art and Science of Identifying Flood Zones.
• The FEMA introductory fact sheet, Using a Flood Insurance Rate Map (FIRM).
• An animated FEMA tutorial on FIRMs.
• The FEMA Map Services Center, which maintains copies of all FIRMs and FIS reports.
• FEMA’s FIRMette tutorial, which provides instructions for determining the flood designation for an individual parcel by creating a “FIRMette” (a section of a FIRM for a specific address or location).
• The National Flood Insurance Program website, which has information on FISs, FIRMs, and other floodplain management issues.
• Richard Zingarelli, Massachusetts NFIP Coordinator, who can be contacted at Richard.Zingarelli@state.ma.us or (617) 626-1406 for more information on these and other NFIP topics.

Also see: understanding the limitations of FIRMs and FIS reports.