A Robust and Diverse Water Portfolio Enables Arizona To Meet the Challenges Ahead

By L. William Staudenmaier, John D. Burnside, Fred Breedlove and John Habib

Over the past five weeks, we have described the wide range of water resources available to meet Arizona’s current and future needs. These resources include groundwater, in-state surface water, Colorado River water, long-term storage credits, and reclaimed water. We also discussed the latest developments on groundwater availability in the Phoenix Active Management Area (Phoenix AMA). As these previous articles demonstrate, Arizona has abundant and diverse water supplies. 

Despite this robust water portfolio, Arizona faces multiple water-related challenges. Some of these challenges are tied to drought and climate change, such as the current depleted state of the Colorado River. Others are tied to continued growth in Arizona, the very thing that drives our vibrant economy. The latest example of this kind of challenge is the recently issued revised groundwater model for the Phoenix AMA, which shows a projected deficit of 4% in legally and physically available groundwater at the end of the 100-year model projection period.

But the diversity of our supplies helps us meet these challenges. For decades, Arizona has been storing Colorado River water and reclaimed water in our aquifers, to the point where we have multiple years of water supply in storage to cover our needs during droughts on the Colorado River. Arizona municipalities and others have also invested extensively in infrastructure to treat and use reclaimed water, including potentially direct potable reuse in the near future. 

At the same time, as competition for available water increases, so has our collective efficiency in using water. The laws of supply and demand have worked well in this regard – as competition for water increases, so does the price of water, and higher prices prompt purchasers to use it wisely. This reality has resulted in the seemingly anomalous fact that Arizona collectively uses no more water today, with a population over seven million people, than we used in the 1950s when our population was less than one million. Increased efficiency and wiser choices about how we use water will undoubtedly continue as we face the challenges noted above. 

Finally, we are preparing to face the future by augmenting our collective water supplies. In the 2022 legislative session Arizona dedicated $1 billion to the Water Infrastructure Finance Authority over three years with the specific instruction to use these funds to augment Arizona’s water supplies (although the legislature later diverted a portion of those funds for other water projects). One frequently discussed potential opportunity is to work with other states and Mexico on ocean desalination facilities to provide additional supplies to water users in Arizona and potentially throughout the Colorado River Basin. Locally, numerous parties are collaborating to evaluate the possibility of raising the height of Horseshoe Dam to enable greater impoundment and use of floodwaters from the Verde River. This water can augment supplies in parts of the Phoenix metropolitan area as we described in our article on in-state surface water. These, and other projects, will contribute to our ability to meet the challenges ahead. 

In sum, despite its desert climate, long-term drought, and rapid population growth, Arizona remains in an enviably strong position regarding water. We have abundant and diverse supplies, well-developed legal systems, and a collective will to continue thriving in the desert.