Project Details

Wickenburg Area Drainage Master Study/Plan

Public Meetings

Currently there are no public meetings scheduled for this project.

Past Public Meetings

• 8/15/2013
• 8/30/2012
• 2/3/2011
• 9/30/2010
Project Contact: Douglas Williams
Region: NW
District: 4 - Clint L. Hickman

The purpose of the Wickenburg Area Drainage Master Study (ADMS) was to identify known and potential flooding and erosion hazards in the Wickenburg Area. The study is an update of the Wickenburg ADMS completed in 1994. The study is a joint effort between the Flood Control District of Maricopa County (District), the Town of Wickenburg, and a variety of key stakeholders. The study area and its watershed encompass 145 square miles in Maricopa County surrounding the Town of Wickenburg.

Due to growth, development and other factors, previous drainage patterns may have been altered in a way that could cause new flooding hazards or actually reduce the flooding hazard. In this light, the District is using recent topographic data, new rainfall data, and updated modeling techniques to provide a more accurate picture of the area's flooding potential. New data and advancements in technology will also help to identify where future flood control measures should be focused.

The study was completed in three phases, with the first phase identifying the current floodplain and flood hazards for Sunset Wash and Sunnycove Wash. Initial results of Phase 1 were presented to the public on February 3, 2011. The study results were approved by the Federal Emergency Management Agency (FEMA) in 2012 and revisions to the official FEMA flood hazard map (known as Flood Insurance Rate Maps or FIRMs) will become effective on August 24, 2012. Phase 2 commenced in February 2011 with a Public Meeting held on August 30, 2012 to present the preliminary results. The District performed floodplain delineations and flood hazard assessments along approximately 80 linear miles of washes and within the Town of Wickenburg as well as drainage areas in the surrounding areas that contribute to washes in town. When the Phase 2 results are finalized, they will be submitted to FEMA for approval which will then result in an updated flood hazard map.

Other areas around the Town of Wickenburg were studied in Phase 3, which was completed by Dec., 2013.



A Public Meeting was held on September 30, 2010 at the Wickenburg Community Center to introduce the project and gather information from residents regarding flooding issues and concerns. A brief presentation was given which explained the purpose of the study, and District and Project Team staff members were present to answer questions.

On February 3, 2011 the District and Town of Wickenburg hosted a Public Meeting to provide the results of Phase 1 and an introduction to Phase 2. Information presented at the Public Meeting included the updated proposed floodplain boundaries for the contributing drainage area to Sunset Wash and Sunnycove Wash, and an introduction to the next project phase to update floodplain boundaries along nearly 80 linear miles of washes in the Town as well as drainage areas in the surrounding areas that contribute to washes in town. District staff at the Public Meeting answered questions about how the proposed changes in floodplain boundaries may affect building and flood insurance requirements.

In July 2011, the District submitted the final data and results from Phase 1 to the FEMA for their review and use in future updating of the current flood hazard maps. The study results were approved by FEMA in a Letter of Map Revision (LOMR) for the studied area. This LOMR became effective on August 24, 2012 and provides the most up-to-date picture of the flood risks along Sunset Wash and Sunnycove Wash. The area affected by the LOMR primarily includes the main town area, and some of the drainage area contributing to the Sunnycove and Sunset dams and downstream to the Hassayampa River. Interested parties may view the updated floodplains via the “Current 100-Year FEMA Effective and Preliminary Floodplain Maps” link on the Maps page of the District’s Web site. Note that changes in floodplain boundaries can affect local building and federal flood insurance requirements. Changes in flood insurance rating and federal mandatory purchase requirements due to the remapping become effective on August 24, 2012. For more information on flood insurance, contact your insurance agent or visit

Phase 1 has been completed and the floodplains have been approved by FEMA.


In Phase 2, which commenced in February 2011, the District performed floodplain/floodway delineations which resulted in revising the existing floodplain/floodway boundaries within the drainage areas contributing to the various washes within and surrounding the Town of Wickenburg. The revised delineations include the establishment of 16.6 linear miles of new Zone AE floodplains with Base Flood Elevations; the revision of 8.8 linear miles of Zone A floodplains to Zone AE floodplains with Base Flood Elevations; and the revision of 52 linear miles of floodplain and floodway widths and Base Flood Elevations (increases and decreases) for areas with previously delineated Zone AE floodplains and floodways. A Public Meeting was held on August 30, 2012 presented these floodplain delineations for review and comment by area residents and other interested parties. A follow-up open house was held August 15, 2013 where the final floodplains, which were submitted to FEMA, were presented.


The washes for determining the floodplain boundaries for phase 3 have been determined. The District presented draft floodplain boundaries at a public open house August 15, 2013 and has since submitted them to FEMA.

For more information about this project or to share knowledge of flooding in and around Wickenburg, please e-mail the Project Contact listed at the top of this page.

Available Documents

Document Name Type Size
Existing and Proposed Study Limits PDF 1.47 MB
Phase 1 Approved Floodplain Boundaries PDF 1.64 MB
Phase 1 Proposed Floodplain Boundaries PDF 5.4 MB
Phase 2 Floodplains Index Map PDF 149.20
Phase 2 Floodplains - Area 1 PDF 417.63 KB
Phase 2 Floodplains - Area 2 PDF 464 KB
Phase 2 Floodplains - Area 3 PDF 399.28 KB
Phase 2 Floodplains - Area 4 PDF 445.99 KB
Phase 3 Floodplains PDF 973 KB
Project Fact Sheet PDF 1.1 MB
Project Survey PDF 175 KB
Public Meeting Brochure - August 15, 2013 PDF 2.75 MB
Public Meeting Brochure - August 30, 2012 PDF 3.5 MB
Public Meeting Brochure - February 3, 2011 PDF 2.08 MB
Public Meeting Brochure - September 30, 2010 PDF 1.48 MB
Public Meeting Presentation - August 30, 2012 PDF 6.10 MB
Public Meeting Presentation - February 3, 2011 PDF 1.5 MB
Public Meeting Presentation - September 30, 2010 PDF 1.85 MB

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