Facing increasingly dire challenges, many south-western cities are taking increasingly bold action to guarantee alternate water supplies for the future, said Sarah Porter, the director of the Kyl Center for Water Policy at Arizona State University.

“Cities have a whole lot of tools that they’re going to deploy,” Porter said. “Because cities are going to be differentially impacted by the Colorado River shortage, they’ve developed a voluntary framework for helping each other out.”

“Cities have the ultimate responsibility to make sure there’s tap water,” said Kathryn Sorensen of Arizona State University and the former director of the Phoenix water utility. “And that means they have to be constantly vigilant and constantly innovate and constantly find new arrangements and new supplies.”

These arrangements, while not a new development, have taken on greater significance as the American West struggles through record heat and aridity this year that is an indicator of worsening water supply challenges in the drying region. Based on a decades-long track record, these arrangements also illustrate that neighbors helping neighbors can be a cost-effective form of climate adaptation.

The federal forecast for Lake Mead got worse again last month. The newest study has the reservoir dropping to 1,015.77 feet by July 2027 and 1,011.74 feet by May 2028 nearly 29 feet under the record low set in 2022, and lower than anything since the lake first filled in the 1930s. The projection fell about 5 feet in a single month. A group of the basin’s own experts now says the system is one dry winter from collapse.

“We can’t conserve enough to save this system,” Sarah Porter of Arizona State University’s Kyl Center for Water Policy told the Review-Journal. She is right, and it is worth considering how much that sentence gives away.

From an academic and logistical standpoint, water infrastructure expert and Arizona State University sustainable engineering professor Margaret Garcia agrees — though she initially focused in on possible risks to the pipelines.

"I like the idea, it's creative," she said of Holley's suggestion. "And I would say that reusing assets is always good to think about. But when we change what kind of materials we move through a pipeline, we do need to be very cognizant about what that means for the integrity of the pipeline. What is appropriate for one substance may not be for another."

Sarah Porter, an Arizona State University water researcher, said, "There’s no question that there is a risk that if the next couple of years are bad, that even with these cuts the system will still crash. Even if they are mediocre years, the system could still crash.

"If next year is very good, it just buys us a year or two. To have a string of very good years is very unusual," said Porter, director of ASU's Kyl Center for Water Policy.

“It is literally a lifeboat,” Kathryn Sorensen, the director of research at ASU’s Kyl Center for Water Policy, told the Agenda. “It is a means to decide not to take water in one year when you don’t really need it, save it in your own name, and then use it in some other year when you really do need it.”

Sarah Porter, the director of the Kyl Center for Water Policy, says an example of how this could work is a city may have access to a supply of water, when another city doesn’t. According to Porter, there’s also a part of the program that calls for developing an emergency pool of water that would be available under certain conditions.

“It really has potential in the future to change the way cities in the Phoenix to Tucson area are managing water,” Porter said. “So you know time will tell, but it’s one of those necessity is the mother of invention kind of moments.”

Imperial Valley's economy has long relied on Colorado River agriculture. If it weren't for that part of the country around Imperial and Yuma, Arizona, "no one in America could afford a salad in February," Rhett Larson, a water-law expert at Arizona State University, said.

Larson said that while farmers may make money selling land or water rights, the people who are often hurt are the fertilizer salesmen, tractor repairmen, teachers, dry cleaners, or anyone in these rural communities who doesn't have land or water rights to sell.

“I don't think that they understand how big the risk is right now,” Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, said. “We're really on the edge of a very, very deep, disruptive cut in Colorado River supplies. We have to plan for that possibility.”

"The projections for water demand are not eyebrow-raising," said Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University.

Concerns about water are largely a "substitute for concerns people have for this fast-developing industry."

Yes, but: Experts, including both Gleick and Porter, caution that aggregate water-use figures can obscure local impacts, particularly in drought-prone regions where even modest demand can become contentious.