Preliminary Maricopa County Physical Map Revision FIRM Update
The Federal Emergency Management Agency (FEMA) is revising certain Flood Insurance Rate Maps (FIRMs) for Maricopa County. The purpose of this map revision is to incorporate several large floodplain delineation studies onto the FIRMs that were too large to be incorporated under FEMA's traditional Letter of Map Revision (LOMR) process. In addition to incorporating these larger studies, the FIRM panels included in the revision will be updated for local LOMRs, updated community limits, and in certain locations, the FIRM panels will have new identification numbers and be printed at a closer scale. FEMA's formal Appeal and Protest Period is scheduled to run from September 4, 2014 through December 4, 2014. More information regarding this project can be found on Region IX's website. The updated individual map panels and Flood Insurance Study volumes can also be viewed on FEMA's Map Service Center website.
To view your property and affected floodplains, follow the link above to open a map application where you can view and compare the preliminary Physical Map Revision FIRM panels with the October 2013 FIRM panels.
If you have questions about the proposed floodplain delineation changes, use the "Submit Inquiry" button at the top of the map. All questions submitted will be responded to, and if necessary, District staff will provide guidance on how to submit a formal Appeal or Protest to FEMA regarding the new delineations being incorporated on the preliminary Countywide DFIRM panels. Submitting an inquiry through the District's online map is not considered as submitting an official appeal or protest to FEMA. Please note, the "Submit Inquiry" button will only be available until the end of the Appeal and Protest Period.
Appeals submitted to FEMA must include scientific or technical data that show base flood elevations (BFEs) are incorrect. Only new BFEs can be appealed. Protests submitted to FEMA must include scientific, technical, or other data to show that other flood hazard information is incorrect (e.g., flood boundary limits, floodway information, flood zone call out, etc.). Comments may also be submitted to FEMA to correct non-technical information (e.g., road names, community limits, etc.).
Flood Hazard Identification Studies
This map contains active and complete flood hazard identification studies by the Flood
Control District of Maricopa County. Click on a study to obtain more
Current & Pending 100-Year FEMA Effective Floodplain Maps
These maps are designed to assist in determining if a particular piece of property is located in a 100-year floodplain as designated by the Federal Emergency Management Agency (FEMA). The map, however, is not an official document that may be used for floodplain determination.
The Flood Control District provides information on Special Flood Hazard Areas (commonly known as 100-year floodplains, or areas with a one-percent (1%) or greater chance of flooding in any given year). To obtain this information in written form, please fill out the Request for Special Flood Hazard Area Information Form. You may fax or e-mail this request form to the following:
FAX: (602) 372-6232
Once you have sent in your request, District staff will complete the form with the floodplain zone and map information and fax or email it back to you. There is no fee for the official floodplain determination service.
NOTE: Some cities and towns perform their own floodplain management. A list of those cities and towns is found in the Floodplain Management section of this Web site.
Updated Countywide FIRM Panels (Effective October 16, 2013)
- View October 16, 2013 effective FIRMs
The Countywide FIRM panel update being conducted by the Federal Emergency Management Agency has been completed. The updated panels became effective on October 16, 2013.
Information on who to contact for floodplain and flood insurance rate map questions for a specific parcel or property may be found on the Information Sources page.
Each green triangle represents the location of an elevation certificate that has been issued for a particular structure. An elevation certificate may be viewed and printed by clicking on a green triangle on the map.
This map is intended for use by experienced engineers as a design aid for preparing site drainage and grading plans, and for establishing building lowest floor elevations for new structures. Users are strongly encouraged to consult with District staff prior to applying this information for the first time to obtain a clear understanding of the basis for the information and for guidance in its application. The map, however, is not an official document that may be used for floodplain determination.
This map is designed to assist in obtaining the results of hydrologic and hydraulic modeling for a portion of the Rio Verde Area Drainage Master Plan (ADMP). A 25.1-square-mile portion of the 40-square-mile ADMP study area was analyzed using a grid-based 2-dimensional computer model. Information is available for each 25-foot by 25-foot square grid for the entire 25.1-square-mile detailed study area. The information available is an estimate of the 100-year 24-hour storm peak discharge in cubic feet per second, the dominate direction of that discharge, and the resulting peak water surface elevation on the NAVD 1988 vertical datum. The results are the average for each grid element. The preliminary floodplain boundaries also shown on the map are based on this data.
Current & Historical Aerial Photography
Aerial photography is available for many areas within Maricopa County from various years ranging from 1930-present. All aerial photography is available for free online viewing using this web application, and is also for sale if desired.
10-Foot Countywide Elevation Contour and Digital Terrain Model (DTM) Data
The 10-foot elevation contours and spot elevations cover most of the County. The data are from 2001 with a positional accuracy of approximately +/- 5 feet. The DTM data, based on 15,000-foot x 15,000-foot tiles, may be purchased in Arc/Info Generate, AutoCAD DWG and Microstation In-Roads formats.
Geodetic Densification and Cadastral Survey (GDACS) Data
These maps have GDACS data produced by the Maricopa County Department of Transportation (MCDOT), and display National Geodetic Survey (NGS), Continuously Operating Reference Station (CORS) and Continuously Operating Base Station (COBS).
Report a Flood enables residents of Maricopa County to view and share images and videos of current and past flooding incidents. The information submitted will be used by the Flood Control District of Maricopa County to better protect residents from flooding.