U Of A-Led Project Presents Solutions For Arizona's Water Worries

A University of Arizona-led team of collaborators at Arizona's three state universities today released a detailed report and associated products describing possible solutions to the state's concerns about future water resource availability.

"Given the current concerns about the reliability of Colorado River deliveries to Arizona, this is a critical time to be thoroughly exploring our water supply options," said Katharine Jacobs, a recently retired U of A professor of environmental science and the project's principal investigator.

The Arizona Tri-University Recharge and Water Reliability Project is led by the Center for Climate Adaptation Science and Solutions within the U of A's Arizona Institute for Resilience in collaboration with researchers from Arizona State University and Northern Arizona University.

The project team modeled the water budget for each of Arizona's 51 groundwater basins and described management strategies that can increase water capture and recharge.

The report's key findings include:

• There is an overall reduction in total water storage across the state, which is correlated with hotter and drier weather.
• More than 95% of Arizona's precipitation is lost through evaporation. Reducing these losses by even small percentages could significantly increase water supply.
• The Mogollon Rim has the highest potential for generating large volumes of water for capture and storage because of higher precipitation volumes.
• Improving water recharge through land management practices such as in land development, forest thinning, and flood and fire management could substantially increase water supply in some areas.

The report includes a Decision Support Framework intended to help water managers navigate the new sources of information, as well as a Recharge Opportunities Matrix providing more than 50 approaches to collecting and recharging water. A complete literature review also is included, with links to evidence supporting the report's 24 key findings.

The team also made detailed projections of future water supply for the whole state through the end of the century.

"We have taken a major step forward in understanding water supply conditions in Arizona with a level of precision never before available," said Giuseppe Mascaro, the lead ATUR researcher for ASU. "This project has given the team an opportunity to demonstrate how accurately we can model both current and future water supply conditions."

"The water supply information that is provided in the Basin Profiles section of this report provides a great starting point for more detailed water supply and demand planning activities," said Marlana Hinkley, a U of A master's student who integrated multiple sources of information from ATUR researchers to produce the profiles.

One product of the ATUR project is a framework to augment existing land and water management practices to enhance groundwater recharge into aquifers. The framework, recently published in the journal Groundwater, describes opportunities to improve groundwater recharge across diverse landscapes, by considering recharge within management activities associated with forest and flood management, and thus enhancing water resources for the state.

"Getting water underground before it has a chance to evaporate is an important path towards enhancing recharge," said Abe Springer, the lead ATUR researcher for NAU.

"This project has built a solid scientific foundation for maximizing water supplies that are currently lost to the atmosphere, in order to support communities and natural habitats across the state," Jacobs said.

Fifteen faculty members across the three universities, along with more than 25 students and post-doctoral researchers, have worked together on this research since January 2023.

The ATUR project was begun under the direction of Thomas Meixner, then department head of hydrology and atmospheric sciences at the U of A.

"Our team made a decision early on to continue this work, both motivated by, and in honor of Dr. Meixner's legacy as a groundbreaking scientist whose work continues to inform and benefit all of Arizona," said Neha Gupta, ATUR project manager at the U of A. "This project is a wonderful demonstration of how academics can work together with stakeholders and external partners to develop information to support water resources across the state, while also taking a leap forward on behalf of science."

The ATUR report was prepared at the request of the Arizona Department of Water Resources and funded by the Arizona Board of Regents Technology and Research Initiative Fund supporting academic research in areas of greatest need to Arizonans.

About The University of Arizona
Established in 1885, the University of Arizona is the state's flagship, land-grant institution. The U of A ranks among America's top institutions, focusing on student access and success while driving a $1B research enterprise and engaging communities throughout the state, nation and world. As a leading Research 1 institution and member of the Association of American Universities, the U of A advances the frontiers of interdisciplinary scholarship and entrepreneurial partnerships. With two accredited medical schools, designation as a Hispanic-Serving Institution by the U.S. Department of Education, recognition as a premier university for service members, distinguished programs in management information systems, planetary sciences, dance, photography, and public and applied humanities, the U of A offers the world to its students while uplifting Arizona.