Floodplain Information

Are you in a floodplain?

View our GIS Floodplain Viewer map to see current designated floodplains within Maricopa County.

  1. Identifying a Floodplain
  2. Challenging a Floodplain Determination
  3. Flood Insurance Rate Maps

How a Floodplain is Identified

Floodplain Delineation Studies identify land areas (floodplains) subject to inundation by a flood that has a one-percent probability of being equaled or exceeded in any given year, also known as a 100-year flood. The results of a Floodplain Delineation Study are submitted to the Federal Emergency Management Agency (FEMA) in order for the study to be incorporated onto the Flood Insurance Rate Maps (FIRM).

Any development in an area that is determined to be a floodplain must meet the requirements of local, state and federal regulations. One of these requirements is to build the structure so the lowest floor is above the base flood elevation. The Base Flood Elevation (BFE) is the predicted highest flood water elevation expected to occur at a location during a 100-year flood. New habitable construction must be built above the BFE, habitable means floors with living areas on them.


Unidentified Floodplains

It is important to understand that floodplains and flood hazards exist in areas that have not yet been documented by a Floodplain Delineation Study. Although your property may not have been in a floodplain when you moved in, that could change in the future. Your area may not have been studied yet, or the floodplain limits might be modified because of changes that occurred during flooding events, or development in the area caused some change. Also, the District may use new technology that it believes will result in a more accurate identification of the floodplain limits.

Flood Hazard Information

Fill out the Flood Hazard Information Request Form. A District representative will complete a Flood Hazard - Flood Insurance Rate MAP (FIRM) Information form with the zone and map information and email or fax it back to you. There is no fee for floodplain determinations from the Flood Control District.

Sunset Dam

Floodplain Management

The District is responsible for floodplain management and regulation in unincorporated Maricopa County, as well as in the following communities:

  • Buckeye
  • Carefree
  • Cave Creek
  • Chandler
  • El Mirage
  • Gila Bend
  • Guadalupe
  • Litchfield Park
  • Mesa
  • Queen Creek
  • Surprise
  • Tolleson
  • Wickenburg
  • Youngtown

The following cities/towns conduct their own floodplain management. Contact the appropriate floodplain agency regarding floodplain questions using the phone numbers listed: