How private interests benefit from tribal water settlements

When power players like mining and agriculture are involved, tribal nations, usually the senior-most water-rights holders, often must fight obstruction.

First, the Santa Cruz River stopped flowing into the San Xavier District of the Tohono O’odham Nation. Then wells began to dry up across the reservation, and farming became nearly impossible for tribal members. Fissures and sinkholes opened up across the landscape where the ground had sunk as much as 15 feet.

The collapsing, cracking earth was the result of decades of agriculture and mining companies and cities overusing groundwater — a finite resource — in a desert. Those responsible included the Anamax Mining Company, Cyprus-Pima Mining Company and Duval Corporation (now all part of the global mining company Freeport-McMoRan), as well as the copper-mining giant Asarco and the agribusiness Farmers Investment Company. All were operating near the San Xavier District, pumping water from underneath land the Tohono O’odham had farmed for thousands of years.


This story is the fourth story in our Water for Water series about the Colorado River. Get this and other great reporting from High Country News by signing up for our newsletter.

Alarmed, the nation sued to protect its water rights in 1975. Although water rights are tied to reservations as part of the treaty-based relationship between tribes and the federal government, state courts have the power to oversee and enforce them. Given the history and impacts of forced removal and rapid colonial expansion in the Southwest, tribal water rights have taken decades to resolve. Companies, cities and farms moved in, becoming large water-users near reservations. As a result, they become part of the settlement process and, in some cases, “have to give something or restrict something on their part,” said Sharon Megdal, director of the University of Arizona Water Resources Research Center.  By the time the Tohono O’odham settled in 1982, they had negotiated with all five business entities, plus the city of Tucson and the state of Arizona.

At the outset of settlement discussions, tribal leaders felt animosity toward the idea of being forced to negotiate with the companies and the city at all, said San Xavier District Chairman Austin Nunez, who joined the water discussions when he was elected in 1987. As the first people of the region, they felt their claims should be accepted. It was their homeland, after all, that was bearing the brunt of extraction and expansion. “This is the only land that we will ever have,” said Nunez. “We cannot relocate to anywhere else in the United States.”

The San Xavier del Bac Mission in the San Xavier District of the Tohono O’odham Reservation, with mines in the distance.

In Arizona, tribes face a state system that often aligns with business interests over Indigenous water rights. Arizona has regularly assisted in the pursuit of water for agriculture, farms and utilities in the state, building dams and the Central Arizona Project. But it has taken the opposite approach when tribes seek water. “Any time water is involved and any time a tribe is trying to lay claim to some water, the historical approach has been to immediately obstruct that effort,” said Dylan Hedden-Nicely (Cherokee), professor of law at the University of Idaho.

 “Any time water is involved and any time a tribe is trying to lay claim to some water, the historical approach has been to immediately obstruct that effort.”

Given the complexity of water settlements — which can include multiple amendments, litigation and side deals — the full scope of corporate involvement is difficult to track. But a review of decades of settlements by High Country News and ProPublica found that mining companies benefited from at least six out of 14 tribes’ water settlements in Arizona. Other settlements forced tribes to contend with corporations, utilities and other nongovernmental entities to acquire the water they’re legally entitled to, creating protracted negotiations that delayed their ability to secure their share. They also had to make concessions — including dropping objections against mining companies and giving up the right to future litigation.

Lucas Waldron/ProPublica

THAT RELATIONSHIP between the state of Arizona and business interests was recently on display in Arizona v. Navajo Nation, which went in front of the Supreme Court in March. The case focused on the Navajo Nation’s claims that the federal government has a treaty-based responsibility to protect its future water interests, since the nation still does not have settled water rights in Arizona. The state opposed the Navajo Nation, arguing that water from the Lower Colorado River is “already fully allocated.”

Courts can be a risky venue for tribal water claims, and they force people to choose sides. In the Navajo Nation’s case, business interests have sided with the state of Arizona, creating a united front of 27 trade groups, mining associations, farm groups and irrigation districts from Colorado River Basin states and across the West. These businesses and organizations have filed a brief in support of Arizona’s position, arguing that a ruling favoring the Navajo Nation “would have severe negative consequences for Arizona, its residents, its businesses, and its agricultural and industrial sectors.” The court sided with the state, saying the federal government did not have to secure water rights for the tribe.


The Asarco Mission Complex copper mines.


“A big piece of all of this is just how unethical it is to make tribes give up something in order to fulfill a basic human right like water access, and how water has been over-appropriated in the basin at the expense of tribes,” said Heather Tanana (Diné), assistant professor at the University of Utah’s law school.  While tribal nations have rights to about 25% of the Colorado River Basin’s annual water supply, it’s taken years of negotiations to secure those rights; many tribal citizens still don’t have access to actual water. Historically, when it comes to shaping water policy in the basin, Tanana said that “(tribes) haven’t been involved, and the federal government has done a poor job of protecting those interests.”

And, if the companies and corporations do give up water, they want something in return: A review of every water settlement in the Colorado River Basin showed that settlement terms often guarantee water contracts for the companies, as well as some protection from future litigation. In the Hualapai Tribe’s settlement of 2022, Freeport-McMoRan negotiated the ability to sever its water rights from one parcel of land and transfer them to another in order to supply its Bagdad Mine — an open-pit copper and molybdenum mining complex — a concession that the U.S. Department of Interior had previously objected to. In the San Carlos Apache Tribe’s settlement, mining company Phelps Dodge received right-of-way permit extensions through 2090.

“A big piece of all of this is just how unethical it is to make tribes give up something in order to fulfill a basic human right like water access, and how water has been over-appropriated in the basin at the expense of tribes.”

By the end of the Tohono O’odham’s settlement, which became law in 1982, the San Xavier and Schuk Toak Districts were awarded 66,000 acre-feet of water per year via the Central Arizona Project. That system, built to distribute Colorado River water, didn’t deliver water for 18 years, after the cost and a lack of demand by agricultural users in the region delayed construction.

In an update to the settlement in 2004, Asarco and Farmers Investment Company agreed to reduce their groundwater use. Up to a quarter of a million dollars was made available for Asarco to conduct a land exchange study. In addition, Tucson agreed to pay for sinkhole repairs on the reservation.

But the nation was denied a buffer zone around its land, where it wanted pumping curtailed, and the San Xavier District was allowed to pump just 10,000 acre-feet for its own use. (One acre-foot per year can support up to three single-family households in the West.) In order to get Asarco to use Colorado River water instead of cheaper groundwater, the nation had to drop all groundwater litigation against the company.

“We certainly did not get everything we set out for in those negotiations,” Nunez said. But, “we believe we got the best we could.”

Water settlements also play a part in the extraction of coal from tribal lands to fuel non-Native economic and population growth. In Arizona, the Salt River Project — a public utility that manages water and power for most of Phoenix — has had a central role in that dynamic. In a settlement between the Pueblo of Zuni, the Salt River Project and others that was passed by Congress in 2003, Zuni was able to guarantee 10,000 acre-feet for wetland restoration on their reservation lands in Arizona. The Salt River Project, meanwhile, emerged from the settlement with rights to up to 21,000 acre-feet of groundwater to fuel its coal-powered generating station.

The Asarco Mission Complex copper mines at the southern border of the San Xavier District of the Tohono O’odham Nation.

WHEN TRIBES AND COMPANIES reach an impasse, it can stall or sink negotiations, as happened with a Navajo-Hopi settlement in 2012, ultimately delaying access to water. That settlement tied reservation drinking-water access to renewing land and operational leases for a Peabody Western Coal Company mine and the Salt River Project’s power plant. The settlement failed, in part because it included the demands made by the corporation and utility, and the two tribal nations are still working to quantify their water rights. But as more time passes, less water becomes available: The amount of water in the Colorado River is shrinking due to drought and aridification linked to climate change.

“Every second that passes, it’s harder and harder for tribes to get water that’s already over-allocated and in shorter and shorter supply,” said Andrew Curley (Diné), assistant professor of geography at the University of Arizona.

“Every second that passes, it’s harder and harder for tribes to get water that’s already over-allocated and in shorter and shorter supply.”

Tribes have gained at least some concessions from the corporations in return. In the San Xavier Reservation case, Asarco — which opened its first smelter in Arizona in 1912, the same year as statehood — agreed to buy some water from the tribe as part of the settlement. The five companies involved in the settlement also contributed a combined $1 million to a fund for the nation. For decades, Asarco and other companies used water that belonged to the Tohono O’odham Nation without compensating the tribe — a demonstration of the financial and political power nongovernmental entities have long held over access to water in the region.  (Grupo México, Asarco’s parent company, did not respond to requests for comment. Neither did Freeport-McMoRan.)

When the Tohono O’odham first asserted their water rights in the San Xavier District in the 1970s, businesses pushed back. Agribusinesses said that a settlement favorable to the senior-most water-rights holder in the region — one protected by treaties and federal law — would cost them water and money. “This is a raid on a portion of water for agriculture,” a representative of the Arizona Farm Bureau told the Arizona Republic at the time. Today, the Farm Bureau is one of the organizations opposing the Navajo Nation in the Supreme Court case. The Tohono O’odham, meanwhile, argued that maintaining the status quo would cost them their homeland.

Nearly five decades later, agriculture is the largest water user in the Colorado River; in Arizona, it uses about 74% of the water supply. Meanwhile, the rest of the Tohono O’odham Nation still does not have settled water rights. Instead, it remains tied up in a nearly 50-year-long water adjudication with over 30,000 other parties, including the Salt River Project, Freeport and Asarco. 

Anna V. Smith is an associate editor of High Country News. She writes and edits stories on tribal sovereignty and environmental
justice for the Indigenous Affairs desk from Colorado. @annavtoriasmith

Mark Olalde is an environment reporter with ProPublica, where he investigates issues concerning oil, mining, water and other topics around the Southwest.

Umar Farooq is an Ancil Payne Fellow with ProPublica, where he reports on national issues. @UmarFarooq_

We welcome reader letters. Email High Country News at [email protected] or submit a letter to the editor. See our letters to the editor policy.



Hi there, reader.

We hope you found value in the article, above.

Before you go, I’d like to ask you for a few dollars of support.

For more than 50 years, High Country News has been funded by readers just like you: citizens of the world who are curious and passionate about the West.

I’m guessing you are the kind of person who stays abreast of news and takes time to keep informed about issues that matter to you. As such, I’m sure you’re well aware that journalism around the globe is in real trouble.

You can help our team of independent writers, editors, illustrators and photojournalists stay focused on the important stories with your tax-deductible donation today. Even $4 – or the cost of a small latte – makes a difference to us.


We hope you’ll return to this website again, and read as much as your tough or tender heart can consume. And you’ll feel better knowing you’ve invested in fair-minded, in-depth journalism.

We need you now, more than ever.

Onward, with courage and resolve!
Greg Hanscom
Executive Director/Publisher