Jan 31 2023Share

100-Year Assured Water Supply Designation Better Positions Communities to Face Challenges

By Warren Tenney

Many headlines claim that Arizona is running out of water. While some specific areas within our state are facing challenges, such as wells running dry or aquifers not being able to sustain new development, it is vital to look at what created these problems. It’s even more important to clarify that not all communities are in a water crisis and to understand why that is.

Firstly, the communities serviced by municipal water providers in the Phoenix and Tucson metropolitan areas that have a 100-year assured water supply designation are not experiencing water emergencies. This is because the ten AMWUA cities and other designated providers have built resiliency by complying with the regulations tied to the 1980 Groundwater Management Act and the 100-Year Assured Water Supply Program. Based on the guiding principle of “water first, then development,” the 100-year assured water supply designation is the platinum standard that no other state can match for consumer protection that ensures sustainable growth.

In addition to managing their water through those regulations, these communities, under the leadership and direct accountability of elected city councils, are responsible for meeting the water demands of their residents and businesses throughout their service areas. This direct stewardship has led the AMWUA municipalities to pursue the sustainable use of surface and recycled water, invest billions of dollars in infrastructure, and embrace innovation to find new ways to conserve and manage resources to meet the water demands of their residents and commercial customers. This approach has helped ensure that the AMWUA cities planned and invested to meet today's water demands of 3.7 million residents and the Valley’s thriving high-tech manufacturing, defense, financial services, health care, higher education institutions, and other services that support regional and national economies. 

The reality is the communities or areas of the state that have not been held to the same regulatory requirements, including Rio Verde, are now struggling with major water predicaments. Each crisis is the inevitable consequence of loopholes used to circumvent the requirement to have a 100-year assured water supply or be exempt from the Groundwater Management Act. These gaps in our state water management must be addressed to ensure communities have the necessary water supplies to be resilient and prevent water quandaries from happening anywhere else.

Arizona has over a century of experience developing creative solutions to water problems. Our test today is to acknowledge the issues, develop resolutions to manage and safeguard water resources effectively, and continually invest in those resources and the necessary infrastructure.

The ten AMWUA cities remain resilient because of their compliance with the 100-Year Assured Water Supply, in addition to the extensive planning and investments they have made in amassing reliable water supplies for their communities. They are well aware that they will face a future with less Colorado River water. Yet, because of the planning and investing to be able to have a 100-year assured water supply designation has better positioned the AMWUA cities to prepare for Colorado River shortages and other challenges.

Water is the lifeline of all our communities, and we are in this together as a state. Modernizing and expanding the Groundwater Management Act and closing loopholes in the Assured Water Supply Program sends a positive message to Arizona residents, businesses, and the nation that Arizona is confronting its water challenges and preventing new ones from happening. We have seen the benefit of those forward-thinking policies; we just need to address the gaps before more crises come from them.

For over 50 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe, and sustainable water supplies to their communities. For more water information, visit

To print or save this week's blog, a PDF version is available HERE.

Additional perspectives:
Arizona is not out of water, despite all those headlines you might read - Joanna Allhands, Arizona Republic
Tucson will not be another Rio Verde, thanks to our water utility - Juliet McKenna, Ariziona Daily Star

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