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Project Name: Mesa Zone D Flood Delineation Study


Project Manager: Kathryn Gross
Contact by phone at (602) 506-4837 or by email

Project is in Supervisor District:

  • District 1: False
  • District 2: True
  • District 3: False
  • District 4: False
  • District 5: False

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Project Type: Study

Project Description:

The study identifies current Special Flood Hazard Areas for a portion of the previously unstudied FEMA Zone D area in the City of Mesa. 

The study area is approximately 26.1 square miles and is roughly bounded by The Central Arizona Project (CAP) Canal to the east, US 60 to the north, Ellsworth Road to the west and Williams Filed Road alignment to the south. 

This area has been divided into 3 phases. Most of the area is listed as Zone D floodplains, and Flood Insurance Rate Map panels have not been printed for it. 

Phase 1 

Phase 1 studied the portion north of Elliot Road to the US 60, from Meridian Road on the east to Ellsworth Road on the west. The study area covers approximately 8.1 square miles. 

FEMA recently approved the technical data for floodplain management purposes and will update the related FIS with new FIRM panels for the area of all three phases.  This is expected to occur over the next two years.

Detailed information for study results can be viewed on the Proposed FEMA Floodplain Map for Mesa Zone D Phase 1.

Phase 2

The Phase 2 study area extends from Elliot Road on the north to Williams Field Road on the south and from the CAP Canal on the east to Signal Butte Road on the west, approximately 13.4 square miles. 

The compilation of technical data for Phase 2 is currently underway and will soon be submitted to FEMA for review. Like Phase 1, there are no printed FIRM panels for the area, and after technical review and approval by FEMA, new FIRM panels for the area will be printed. This is expected to occur over the next two years. 

Phase 3

Phase 3 covers the area from Signal Butte Road on the east to Ellsworth Road on the west, which is approximately 4.6 square miles. Data Collection for this phase is in progress. The study technical documentation will be compiled and provided to FEMA by the fall of 2024. The results will also propose eliminating Zone D designations and any currently listed Zone X (shaded) designations and ultimately printing FIRM panels in areas currently without them. This is expected to occur over the next three years.

Last Updated: 1/30/2024 8:03:25 AM

Project Updates

Preliminary Results Available for Review
Posted On: 3/8/2022 3:21:12 PM

There are proposed changes to the current flood maps. They will be submitted to FEMA for review in March 2022.

Review these changes here:

The new mapping will include the following flood hazard zones:

  • Zone AE: An area with a detailed delineation of a floodplain and in which Base Flood Elevations have been determined. A Regulatory Floodway may be part of the delineation. 
  • Zone AO: An area with Flood depths of one to three feet (usually sheet flow on sloping terrain); average flood depths have been determined. For areas of alluvial fan flooding, velocities may have also been determined.
  • Zone X (shaded): Areas of 500-year flood; areas of 100-year flood with average depths of less than one foot or with drainage areas less than one square mile; and areas protected by levees from the 100-year flood. 
  • Zone X (unshaded): Areas to be determined outside the 500-year floodplain.

Public Meetings

There are no public meetings scheduled.

Project Documents

Document Name Description Document Type Filesize Posted On  
Proposed FEMA Floodplain Map for Phase 1 Proposed FEMA Floodplain Map for Mesa Zone D Phase 1 PDF 7 3/3/2022 4:08:59 PM View