Flood Insurance Rate Maps

A Flood Insurance Rate Map (FIRM) is the official map of a community on which the Federal Emergency Management Agency (FEMA) has delineated both the Special Flood Hazard Areas and the flood risk premium zones. Communities are mapped by their respective flood control agencies or the U.S. Army Corps of Engineers. The Flood Control District is responsible for mapping and delineating Maricopa County.

FEMA Adoption Process


Once floodplain delineation studies are completed on a local level, they are sent to FEMA for approval. This FEMA adoption process takes approximately six to nine months. In the interim period, the District uses this data as the "best available information" for floodplain management. Some delineation studies are not sent immediately to FEMA, during which time the District looks at options for reducing the floodplain.

Special Flood Hazard Area


On a FIRM, a Special Flood Hazard Area (SFHA) is noted with shading. An SFHA is an area with a one percent chance of being flooded in any given year, hence the property is in the 100-year floodplain. Any land area susceptible to being inundated by flood waters from any source is identified as a floodplain.

View current and pending 100-year FEMA Effective Floodplain Maps.

Newly Mapped Areas


If you are in a newly mapped area and required to purchase flood insurance FEMA’s website can provide information to help you work with your agent on the best rate. If you have an Elevation Certificate for a single family home that indicates your lowest adjacent grade is above the BFE you can use the FEMA MT-EZ form to submit a Letter of Map Amendment (LOMA) application to have FEMA determine if your home can be considered above/out of the floodplain.