The Colorado River is critical for Arizona. Its water comes out of kitchen faucets amid the suburban sprawl of the Phoenix area and is used to grow crops under the desert sun. But it starts hundreds of miles away, as snow in the Rocky Mountains.
For years, a major Arizona water agency has been part of efforts to boost that snow through cloud seeding. Now, leaders of that agency are considering pulling funding from the program amid high tensions between states that share the Colorado River.
Cloud seeding is a technology that can help add snow in critical high-mountain watersheds by releasing particles into the air that cannot create snow, but can essentially tell it where to fall.
The Central Arizona Project runs a 336-mile-long canal system that carries water from the Colorado River across the desert and into the Phoenix and Tucson areas. Since 2007, it has been part of a collaborative effort to run cloud seeding equipment in the Rocky Mountains. The program brings together water users that benefit from faraway snowmelt — like CAP, water agencies in Las Vegas and Los Angeles and major farming districts in Southern California — and agencies that manage water near the snowy mountains themselves.
Now, the future of CAP’s participation in that collaboration is in question.
At a meeting of the CAP board of directors on Thursday, the cloud seeding program got caught in the middle of bigger water politics.
“I know we've been funding this for almost 20 years, and now everybody's trying to cut us off,” said Barbara Seago, a CAP board member representing Maricopa County. “So my take is, why would we keep funding anything that benefits Colorado if they're willing to cut us off?”
Right now, Arizona is in a particularly heated chapter of a multi-state feud over sharing water from the Colorado River. Its shrinking water supply is divided between seven Western states. For more than a century, those states have been split into two camps. The Upper Basin states of Colorado, Utah, Wyoming and New Mexico on one side, and the Lower Basin states of Arizona, California and Nevada on the other.
After years of negotiations, those two groups failed to agree on a plan about cutting back on demand in the face of drought and climate change. The result has been a messy scramble to keep the river flowing normally before the old plan expires this fall.
The federal government recently announced a plan to cut back on water use that would allow it to reduce up to 40% of the Colorado River water that flows to Arizona, California and Nevada, with the sharpest cuts likely to come for the Central Arizona Project. Meanwhile, the upstream states would not face any mandatory federal cutbacks.
Those states did not volunteer new mandatory cutbacks during negotiations, while Arizona and its allies did.
Amid the fallout of those negotiations and the new federal plan for water reductions, CAP leaders were reluctant to help fund a program that might help rival states.
“The Upper Basin has shown a willingness to take our money and our water,” said April Tornquist, a CAP board member representing Maricopa County. “So what can we put into an agreement that is beneficial for Arizona?”
Scientific research on the efficacy of cloud seeding is limited, but those who implement the technology in the Rocky Mountains are confident that it can meaningfully bring snow to places it is needed.
In recent years, water agencies in Arizona, California and Nevada have sent about $1.5 million per year to upstream cloud seeding work. Those agencies say it is a small part of the solution to the complicated, politically fraught issue of supply-demand imbalance along the Colorado River, but it is still worthwhile.
Technical experts on CAP’s staff explained the program to the board as a way to benefit the Colorado River system overall, even if it is difficult to draw a straight line between dollars spent on cloud seeding and water that physically flows into Arizona’s reservoirs and canals.
“If we have more water on the ground in the watershed,” said Nolie Templeton, CAP’s Colorado River policy and analysis manager, “Then I think everybody in the watershed is going to benefit because more of that water will make it into our rivers and streams.”
Templeton said there is no minimum contribution required for CAP to be part of the collaboration going forward, but each agency’s funding for cloud seeding work would be capped at $525,000 per year in 2027 and gradually climb to $750,000 per year in 2036. Costs would be shared equally between the Upper and Lower basins.
Karen Cesare, the CAP board secretary representing Pima County, used a metaphor to explain how the cloud seeding program could exist outside of larger inter-state water feuds.
“This is the International Space Station of the Colorado River Basin, whereby parties that are otherwise at odds with each other hang out together at the space station for the advancement of science,” Cesare said. “We get along great with our Russian cosmonaut buddies up in the space station. Nobody has a problem with that, while we recognize that maybe we have other issues with Russia.”
CAP expects to make a decision about participating in the cloud seeding collaboration at its next board meeting, in September.
