ADWR has completed work on a new, basin-scale model of groundwater conditions in the Phoenix AMA, which covers an area of 5,646 square miles and includes 4.6 million residents. This is the most comprehensive groundwater model ever developed for an AMA in the state of Arizona.
The model projects 4.86 million acre-feet (maf) of “unmet demand” in groundwater supplies over the next 100 years, under current conditions. This shortfall is attributable to decades of groundwater overdraft and the continued reliance on groundwater resources.
In light of these findings, the State will no longer approve new determinations of Assured Water Supply (AWS) within the Phoenix AMA based on groundwater supplies. Developments within existing AWS Certificates or Designations may continue, but communities or developers seeking new determinations must now do so based on alternative water sources.
The model shows that the primary goal of Arizona’s Groundwater Management Act of 1980 is largely being met: existing homeowners are protected and will continue to receive their water deliveries into the future. According to ADWR, the AWS program “is working as intended — as a consumer-protection program — to ensure water supplies are available in advance of growth.”
To learn more, read ADWR’s official statement, download the model FAQs, or check out this PowerPoint presentation, which summarizes the modeling results.