Gila River Indian Community blasts federal Colorado River cutback plan

"The community has forcefully made its case to the federal government throughout this process that it cannot simply take our water without our consent," tribal Gov. Stephen Roe Lewis said.

At the time, Lewis' statement at times took a more upbeat tone, citing recent, “encouraging” discussions among tribes, Lower Basin states' water officials and the federal government. Those discussions make him optimistic “that we may be on a path that will prove successful for the next two years,” Lewis wrote in his statement about the U.S. Bureau of Reclamation’s proposed cuts of river water to Arizona.

Lewis was reacting to last Friday’s bureau release of its final environmental impact statement on the river. It called for cuts of up to 3 million acre-feet of water a year over the next decade to water users in the Lower Colorado River Basin, which includes Arizona, California and Nevada. That’s about 40% of the Lower Basin’s legal water rights to the river.

Arizona Department of Water Resources officials have said cuts on that scale would be "devastating" to Arizona’s economy. But the bureau has also said it will impose such severe cuts only if current conditions on the river, which included its second lowest spring-summer runoff on record, don’t improve or continue to deteriorate. It says it will set formal plans for cutting water use every two years in releasing operating plans for the river.

The final environmental report "proposes actions that deviate substantially from the requirements of the Law of the River, and on its face fails to adequately address its trust responsibility to tribes in the basin who are seriously affected by cuts to critical water supplies," Lewis said in his statement.

The Law of the River is a series of laws, regulations, court cases and other legal requirements that have historically been used by states and the federal government to determine how they should manage the Colorado River.

The Gila River Indian Community provides more than one-third of its total annual CAP supply, or about 121,000 acre-feet, to other water users such as cities through leases or exchanges. For example, the tribe trades some of its CAP supplies for treated sewage effluent from cities including Mesa and Chandler.

It splits the rest of its water between its tribal farms and for use on off-reservation farms, on which the Gila River Indian Community puts CAP water and in return gets long-term storage credits it can sell to raise revenue, and directly recharges some into the aquifer for environmental restoration purposes.

Summing up his view of the strength of the community’s legal position, Arizona State University law professor Rhett Larson said, “It’s a reasonable claim, but no guarantee."

The tribe “has a reasonable claim that reductions to its CAP supply imposed without the community’s agreement could violate the federal government’s trust obligation,” said Larson, who specializes in water issues.

In 2023, the U.S. Supreme Court ruled against the Navajo Tribe’s legal efforts to force the state of Arizona to secure water or pay for infrastructure to deliver its Colorado River supplies to cities and farms on its reservation, he noted.

That seemed to interpret the federal tribal trust obligation narrowly as it applies to water, Larson said. But that was a different case involving the interpretation of older and more general treaties, than to more recent water rights settlement agreements such as the one the Gila River Indian Community has “that are explicitly connected to CAP water rights,” he said. 

“But that Supreme Court decision is still evidence that the scope of the trust obligation is often contested. Context and facts matter in predicting court outcomes, and even with that context and those facts, court outcomes can be unpredictable,” Larson said.

In his statement, tribal Gov. Lewis said the Gila Community “has been deeply engaged with both the federal government and the Lower Basin states to ensure that the first round of federal operating guidelines for the river represent a path forward that we can all support as an interim measure that will give us time to continue discussions to develop long-term, basin-wide solutions.”

Besides an agreement that would balance water use cuts between Upper Basin and Lower Basin states, “an essential element” is a federal commitment to offset cuts it will impose on tribal water use, “and whether such offset or other funding meets the federal trust obligation,” Lewis said.

If the federal government's final river operating guidelines for 2027 and 2028 don't meet the tribe's reasonable expectations of its federal trustee, "we will stand ready to challenge the (final statement) and the operating guidelines in every forum available to protect our community's interests in this difficult time,” Lewis said.