BY: Warren Tenney

Arizona’s Future Is Dependent on Water Security

Published Apr 09, 2024

This year, Arizona lawmakers have introduced over 90 water bills, far surpassing the number seen in previous legislative sessions. Unfortunately, the vast majority of these bills would chip away at the foundation of Arizona’s economy - the 100-year Assured Water Supply Program - instead of addressing our long-term water security as we confront reduced Colorado River water and stresses to our aquifers. The introduced bills also highlight the tension between short-term profits and long-term water management for continued economic sustainability.

This friction intensified last June when the Arizona Department of Water Resources (ADWR) released its updated groundwater model for most of Maricopa County and projected that the demand would exceed the groundwater available for the next 100 years. This projection halted the construction of new subdivisions solely dependent on groundwater located outside the service areas of water providers with a Designation of Assured Water Supply.

Advancing solutions to better secure our water future should have been a primary focus of this legislative session. Instead, significant time has been misspent trying to tweak or discount ADWR’s groundwater model to revive groundwater-dependent homebuilding in the Valley’s far west and southeast sides without considering the long-term implications of increased pumping. This was most evident last week when Arizona House and Senate committees held two hearings about groundwater challenges and affordable housing in the Valley.

These hearings did not have ADWR explain the complexity of its state-of-the-art, peer-reviewed groundwater model, nor were water experts asked to provide proposed solutions to current challenges. Instead, a paid consultant hired by a group of far West Valley developers was given the floor to present revisions to the groundwater model that resolve some, but not all, of its unmet demand by deepening and redistributing wells and reducing the projected water use for the developments. The consultant, their clients, and the Home Builders Association of Central Arizona (HBACA) argued that these revisions, which ADWR is still reviewing, show it is okay to build more groundwater-dependent housing in the far West Valley.

Unfortunately, no water experts were invited to these hearings to debate or explain the implications of the consultant’s revisions. There was no discussion about which water provider would be responsible for serving these proposed homes, how much these homeowners would pay for water service, or the required cost for the Central Arizona Groundwater Replenishment District (CAGRD) to replenish the groundwater pumped. There was no discussion on what it would mean for the CAGRD to be required to annually replenish over 75,000 acre-feet of groundwater pumped for these new developments (that is more water than Peoria, Avondale, and Goodyear delivered last year). Also absent was any mention of what water supplies, such as groundwater from rural Arizona, Colorado River water from on-river users, or from elsewhere, CAGRD would need to acquire over time to meet this extremely large obligation, which would effectively triple its current 35,000 acre-foot replenishment obligation. 

Even more unfortunate, the HBACA used the hearings to promote the unsubstantiated claim that the 100-year Assured Water Supply Program is incompatible with housing affordability. As housing experts have explained, housing costs are influenced by numerous factors, including interest rates, inflation, supply chain interruptions, labor markets, and governmental regulations. Water is not the driver of housing affordability; water security drives our whole economy. One does not need to be an economist to know that a home without water is worthless. Since, for many, a home is the most important investment they will ever make, the 100-year assured water supply requirement provides critical consumer protection to the 4.55 million people who call Maricopa County their home.

What should have been clarified at last week’s hearings is that ADWR’s groundwater model confirmed what other recent studies have projected - increased groundwater pumping is not sustainable, and future growth requires new water supplies.

What also should have been explained is that water security, above everything else, determines if our desert communities and economy can thrive in this century. The thriving and robust economy in the Valley and Arizona has been built on the foundation of safe, reliable water systems constructed, operated, and maintained by the ten AMWUA municipalities , all of which have been granted a Designation of 100-year Assured Water Supply by ADWR. Workers, entrepreneurs, small business owners, major companies, and high-tech industries have the confidence to invest in Arizona as a direct result of its major cities proving that they have the water necessary to prosper and make Arizona their home.

Rearranging a few wells and entertaining unrealistic replenishment assumptions to justify building groundwater-dependent houses in the far West Valley sends the message that Arizona is not serious about grappling with its water challenges. While the current halt on new subdivisions on the edges of the Valley is undeniably difficult for the homebuilding industry, the shortsighted arguments made at last week’s hearings only jeopardize the water security of existing Valley homeowners, other industries, and our entire economy.

We cannot continue pushing the status quo of shortsighted and magical thinking about groundwater availability, which keeps us from facing the sobering reality of our challenges today. Effectively managing our groundwater will become even more critical as we confront the certainty of receiving significantly less Colorado River water after 2026. Solutions are possible, such as adopting Advanced Water Purification and expanding Bartlett Dam , but they will require tough decisions and major investments that will be kicked down the road if we keep pretending that we can continue to grow on increasingly strained groundwater supplies.

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

For 55 years, the Arizona Municipal Water Users Association has helped protect our member cities' ability to provide their communities with assured, safe, and sustainable water supplies. For more information, visit .