A Path Forward for Water-Secure Growth in Arizona

Last week, Governor Katie Hobbs signed a proclamation recognizing EPCOR, a water provider in the West Phoenix metropolitan area, for obtaining the first 100-year Assured Water Supply designation under the new Alternative Designation of Assured Water Supply Program, known as ADAWS. This is a new path forward for building new homes while upholding the consumer protection Arizona has committed to homeowners in the Phoenix Valley since 1980. 

ADAWS was created in response to the Arizona Department of Water Resources’ (ADWR) 2023 groundwater model for the greater Phoenix area, which projected that there would not be enough groundwater to meet expected demands over the next 100 years. As a result, the construction of new subdivisions that rely solely on groundwater on the outskirts of the Valley was paused. However, new housing projects could still move forward if they are within a water provider's service area that has a 100-year Assured Water Supply Designation, which is a voluntary standard a water provider can achieve if it demonstrates enough water supplies to satisfy projected demands for the next 100 years. Achieving this requires water providers to invest in renewable sources and the infrastructure needed to reduce dependence on finite groundwater. For nearly 30 years, the ten AMWUA municipalities have demonstrated a 100-year Assured Water Supply for all residents and businesses within their communities.

The new ADAWS rules offer an opportunity for additional water providers to earn a Designation. Like the existing Designation framework, ADAWS requires careful planning, but it also introduces new safeguards in response to the projected groundwater shortfall. For example, when a provider acquires renewable water, they must reduce groundwater pumping by at least 25% of that renewable volume—an essential step to ensure that participation in ADAWS results in real, measurable reductions in groundwater use over time.

Now, EPCOR has achieved the first 100-year Assured Water Supply designation in the Phoenix Active Management Area in 25 years. This designation will extend 100-year water supply protections within EPCOR’s Sun City, Sun City West, and Aqua Fria service areas, with the potential to provide enough water for 60,000 new homes.  

Arizona’s requirement to demonstrate water availability before development has long been a cornerstone of protecting consumers and maintaining economic stability. While this halt on new subdivisions outside of designated water providers’ service areas has posed challenges for the homebuilding industry, the state’s focus on water security guarantees that growth remains sustainable for future generations. There can be no affordable housing without a dependable water supply.

The ADAWS Program marks a positive step forward in how we manage and protect our state’s most vital resource. It resulted from a challenging public stakeholder process that prioritized protecting Arizona’s groundwater supplies while ensuring water resources are secured before new development starts. Over the past 40 years, this approach has allowed Arizona to protect consumers, especially homeowners, and maintain stability for our growing economy. 

For 56 years, the 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 www.amwua.org .