Reata Wash Flood Control Project

DC Ranch Engagement Plan for Reata Wash Flood Control Project – View here

[Latest Update click here]

What is the Reata Wash Flood Control Project?

The Reata Wash Flood Control Project is a capital improvement that if built, would construct channels, culverts, levees, floodwalls and bank stabilization improvements to provide 100-year flood protection.

In the early 1990s, the Federal Emergency Management Agency (FEMA) identified the 100-year Reata Wash floodplain for its potential flood hazards. The Reata Wash floodplain encompasses a large area in north Scottsdale primarily between Pinnacle Peak Road and the Central Arizona Project Canal, see map. There are more than 4,600 residential homes, public facilities and commercial structures located within the floodplain; more than 2,000 of the structures are in DC Ranch.

After FEMA established the Reata Wash floodplain, bridges, drainage and flood control structures were built to reduce the risk of flooding. Despite these measures, “gaps” remain in the existing flood control infrastructure. Within DC Ranch, the developer, DMB, constructed approximately 70% of the flood measures needed.

In the mid-1990s, and as part of the City of Scottsdale’s Desert Greenbelt project, a special tax district was conceived for property owners within the Reata Wash floodplain to generate a portion of the funds necessary to construct improvements to provide 100-year flood protection to property owners within the floodplain. However, no funds were collected, and the Scottsdale City Council canceled the Desert Greenbelt project in January 2001.

In 2014, the City of Scottsdale initiated a Reata Wash Flood Control Study to identify and recommend flood control measures that will reduce flood risks to residents, property and public infrastructure in the Reata Wash floodplain.

The study showed that a major flood in the Reata Wash would have a city-wide impact. Thus, the Scottsdale City Council initially considered the Reata Wash Flood Control project for inclusion in the 2019 City of Scottsdale Bond. City council members removed it in part due to City concerns that the project faced some opposition and therefore inclusion would jeopardize the passage of the bond.

A major flood in the Reata Wash would have a significant impact:

Emergency responders would temporarily lose vehicular mobility
70% of Scottsdale may lose access to tap water
50% of Scottsdale may lose sanitary sewer service
4,600 residential, commercial and public structures may experience flood damage
A police and fire station could be closed indefinitely
City-wide trash pick-up may be delayed and generate extensive overtime pay
At least 68,000 cars per day would be displaced due to temporary closures on Pima, Hayden, Bell, and other roads
24 Scottsdale golf courses could lose access to their irrigation water

In April 2019, Scottsdale’s mayor, several city council members, and the city manager stated their commitment to finding a way to get the Reata Wash improvements constructed. The City has issued a contract that will result in preliminary design and a firm cost estimate and allow the City to seek FEMA approval. This work is expected to be completed in spring of 2020.

Once the design and cost analysis are complete, The Scottsdale City Council will consider funding options to build this crucial regional flood control project.

The completion of the Reata Wash Flood Control Project would provide 100-year flood protection, eliminating or minimizing damage throughout Scottsdale from a significant flood event. In addition, it would remove or reduce the size of the existing FEMA-designated floodplain thereby reducing the requirement for many property owners to purchase flood insurance.

How can residents engage?

The Community Council will keep residents informed of opportunities to weigh in with the City as the public process unfolds in the coming months.

At any time, residents may offer comment to the Community Council by emailing: Christine.Irish@dcranchinc.com.

How will DC Ranch be involved?

The DC Ranch Community Council will stay engaged with the City throughout this process. If deemed appropriate, the Community Council may develop a position on the Reata Wash Flood Control Project on behalf of the DC Ranch community-at-large.

Latest Updates

August 2023

On July 25, the City of Scottsdale submitted a 30% design plan for the Reata Wash Flood Control Project to FEMA. FEMA has 90 days to review; the city then has 90 days to respond to the review. Once the 30% design plan is approved by FEMA, the city will finish the design and make plans for implementation. This will include securing funds from the Maricopa County Flood Control District and in the city’s Capital Improvement Budget, along with seeking construction bids and contracts. The city states that construction will be done in phases, stretching over 4-5 years. Completion of the project is currently projected for 2028, with an additional year needed for final FEMA approval which should result in flood insurance requirement changes and/or elimination.

April 2022

The City of Scottsdale’s engineering consultant, Wood/Patel, experienced health issues that have delayed their work on the Reata Wash project. It is now expected that August 2022 will be when the City’s 30% plans and Conditional Letter of Map Revision application to FEMA will be submitted.

Dec. 30, 2020

The City of Scottsdale has advised DC Ranch that FEMA has approved the new hydrology study for Reata Wash and its tributaries. The City’s next step is to proceed with 30% design and a Conditional Letter of Map Revision (CLOMR) application to FEMA. A CLOMR is an official document, and if approved by FEMA, indicates that FEMA will adopt a revised floodplain delineation if the Reata Wash flood control project is built. The city anticipates this next step to take 12-18 months. If the city builds the Reata Wash flood control project, 4600 homes/business would no longer be designated as in a floodplain. Many of these properties are in DC Ranch.

Sept. 1, 2020

The City of Scottsdale submitted the latest hydrology analysis of the Reata wash watershed to FEMA. The study found that the 100-year peak discharge rates for the watershed are significantly lower than originally calculated. FEMA has 90 days to review. If it is approved by FEMA, the City can design a less-expensive project.

Jan. 29, 2020

The City of Scottsdale embarked on a 2-dimensional hydrology analysis of the Reata wash watershed that goes through DC Ranch using state-of-the-art software and methods. While substantial flood threat remains, the study found that the 100-year peak discharge rates for the watershed are significantly lower than originally calculated. This new information (outlined in a document called a LOMR) needs sign-off by the City’s Floodplain Administrator; it will then go to FEMA for their review and approval. If it is approved by FEMA, the City can design a less-expensive project based on these lower flows.

The City will still need to decide how this flood abatement project will be funded. Some options include:

City can apply for some Maricopa County “flood funds”
City could allocate funding in their Capital budget
City could form a taxingdistrict where residents within the flood plain would be assessed taxes to fund the project

This project is important for many reasons, including safety. Up to 70 % of the City’s drinking water could be affected by a major flood. In addition, the flood plain impacts home building and requires mandatory flood insurance for mortgage holders. Council staff will continue to monitor the project and engage on behalf of DC Ranch when appropriate.

May 23, 2019

The Community Council voted to approve a Reata Wash Engagement Plan. Chris Irish, Director of Public Affairs, will represent DC Ranch in interactions with the City on this matter.

May 2, 2019

The Reata Wash flood control project will not be part of the city of Scottsdale’s November 2019 bond package. While the DC Ranch Community Council and many residents lobbied for its inclusion, two Scottsdale citizen groups threatened to boycott the bond if the Reata Wash project was included.

Scottsdale’s mayor, several city council members and the city manager have stated their commitment to finding a way to get the Reata Wash improvements completed. The city has issued a contract that will result in preliminary design, a firm cost estimate and allow the city to seek approval from the Federal Emergency Management Agency. This work is expected to take 12 months to complete.

Once complete, funding options to build this important regional flood control project will be brought back for consideration by the community and the City Council.

The DC Ranch Community Council will stay engaged with the City throughout this process and continue to inform residents of opportunities for input.