These data represent a subset of the data available on the paper Flood Insurance Rate Maps (FIRM) as provided by the Federal Emergency Management Agency (FEMA). The Q3 flood data were developed to support floodplain management and planning activities but do not replace the official paper FIRMs. These data are not suitable for engineering applications or site work nor can the data be used to determine absolute delineations of flood boundaries. Instead the data should be used to portray zones of uncertainty and possible risks associated with flooding. All counties except Franklin are available for Massachusetts. In ArcSDE the layer is named Q3FLOOD_POLY_NO_NFHL. The datalayer is managed by MassGIS but no effort has been or will be made to correct data discrepancies. FEMA does not recommend the alteration of the data. As a final reminder, these data do not replace the paper FIRMs which remain the official documents.

Note that the dataset FEMA_NFHL_POLY, FEMA's National Flood Hazard Layer, represents newer flood zone data which is meant to replace the older data derived from the FIRMs and is available for much of Massachusetts. The data in this layer (Q3FLOOD_POLY_NO_NFHL) contains only the data in the older Q3FLOOD_POLY in areas where the NFHL data are not available.