Wildfire seasons are getting longer and hotter, threatening forests and the water supplies they protect. Forest restoration, especially thinning dense stands of trees, can reduce wildfire risk and improve water availability — but measuring the water benefits of forest management has been challenging.

That’s why Arizona State University Professor Enrique Vivoni founded the startup company Tributary. Its mission is to give utilities, governments, nonprofits and companies better tools to measure the real water outcomes of forest restoration projects.

Drying soils in northern Mexico can trigger simultaneous drought and heat wave episodes in the southwestern United States, including Arizona and states like Texas and New Mexico, according to a new study involving an Arizona State University professor.

Co-authored by Enrique Vivoni, a senior global futures scientist with the Julie Ann Wrigley Global Futures Laboratory, the research underscores the increasing persistence of "hot droughts," which extend across consecutive days and nights, hindering recovery and posing significant risks to the region.

A little more than two years ago, the state Department of Water Resources announced a moratorium on building new homes in some parts of the Valley that rely on groundwater. That came after the agency determined that there wasn’t an assured hundred-year water supply in those areas, as required under state law.

Kathleen Ferris is a senior fellow at the Kyl Center for Water Policy at Arizona State University and one of the crafters of the original Groundwater Management Act of 1980.

Cora Tso, who is Navajo and a senior research fellow specializing in tribal issues at ASU’s Kyl Center for Water Policy, stated “about 10 tribes are excluded from that conversation because we don't have our water rights resolved” — yet “we have some golf courses that are located on tribal lands that have the same water consumption use as some small AI data centers.”

Another contributor is that different-sized utilities also have different sampling frequencies, Paul Westerhoff, a professor of sustainable engineering and the built environment at Arizona State University, told Newsweek.

He said that, for example, there are nine compounds of haloacetic acids. While the EPA currently regulates only five of them, some utilities and states report all nine, whereas others only report the five on which the EPA has implemented regulations.

In its proposed plan of operations, the groundwater replenishment district expresses strong confidence in its ability to keep acquiring new supplies to meet its replenishment obligations, noting the wide availability of credits and the broad array of potential supplies.

Outside experts such as Ferris and Sarah Porter, the Kyl Center’s director, are more skeptical, citing the growing competition for all future supplies, including credits, their increasing costs, and the enormous number of legal and environmental uncertainties involved in bringing in new supplies.

“Lawsuits are cumbersome, and they don’t necessarily achieve the kind of sophisticated results that people would like,” Kathleen Ferris, former ADWR director and senior research fellow at the Kyl Center for Water Policy said. “But again, if you can’t get anything done any other way, then people are tempted to go to court.” 

“Hot droughts will propagate to other parts of the country and have detrimental effects on health, on infrastructure, on daily life,” said Enrique Vivoni, a hydrologist at Arizona State University and senior author on the study. As climate change continues, the authors said, more places will likely experience the dry soil conditions that spur and spread hot drought. “We need systems to alert us to hot drought just like we have systems that alert us to hurricanes.”

In rural Arizona, access to safe and affordable drinking water is not guaranteed. Households in rural communities often rely on private wells, small treatment systems or hauled water, all of which can be unreliable and expensive.

Arizona Water for All, or AW4A, a pillar of Arizona State University’s Arizona Water Innovation Initiative, is addressing water insecurity through a new project that identifies unsafe water sources and engages rural communities in sustainable water practices. 

Kathleen Ferris, a former state water director who is now a senior researcher studying water supply issues at Arizona State University, takes a particularly cynical view of the local attitude toward development — the “god of growth,” as she calls it. 

An architect of the 1980 law that, years later, would halt North Star Ranch and the hundreds of thousands of other new suburban homes, she sees the restrictions as a protection against the worst of Arizona’s past excesses. “We are not going to have growth without water,” she said. “We will have water in hand before growth is allowed.”