Among the upcoming cases to be heard by the U.S. Supreme Court will be Arizona v. Navajo Nation, No. 21-1484. 

The case focuses on two issues:

  1. Whether the opinion of the U.S. Court of Appeals for the 9th Circuit, allowing the Navajo Nation to proceed with a claim to enjoin the secretary of the U.S. Department of the Interior to develop a plan to meet the Navajo Nation’s water needs and manage the mainstream of the Colorado River in the Lower Basin so as not to interfere with that plan, infringes upon the Supreme Court’s retained and exclusive jurisdiction over the allocation of water from the LBCR mainstream in Arizona v. California
  2. Whether the Navajo Nation can state a cognizable claim for breach of trust consistent with the Supreme Court’s holding in United States v. Jicarilla Apache Nationbased solely on unquantified implied rights to water under the doctrine of Winters v. United States.

Please describe the case Arizona v. Navajo Nation. 

The Navajo Nation has long been pursuing a lawsuit against the United States government on the theory that the U.S. had breached its trust responsibilities to secure water for the Tribe’s use on its reservation lands. The Navajo Nation has been opposed in its efforts both the federal government, which denies that the specific claimed duty exists, and by western states and water users, who fear that the ultimate end of any such suit will be their loss of water allocated from the Colorado River under prior interstate agreements and a Supreme Court decision. 

Both the U.S. and the western water users and states - Arizona, Nevada, and Colorado - seek the Supreme Court’s review of a 9th Circuit decision that a duty exists sufficient to support the Navajo Nation’s lawsuit. The states also argue that regardless of whether such a duty exists all claims to enforce it are barred by the Supreme Court’s prior reservation of jurisdiction over claims related to Colorado River water allocation, while the U.S. takes the position that it is premature to consider this question. 

What is the chief legal question in the case? 

Whether tribal water rights the Supreme Court has previously found to be implied by tribal treaties (“Winters” rights) are enforceable in a suit for breach of trust given prior Supreme Court precedent indicating such enforcement requires a right expressly accepted by the U.S. 

To what extent a suit on this basis, which would require the U.S. to develop a plan to secure water for the Navajo Nation consistent with its rights (which would probably mean taking water from the Colorado River), would be inconsistent with the Supreme Court’s retention of jurisdiction over all claims related to the allocation of waters from the Colorado River.  

What are the possible impacts of the case? Why do they matter? 

Western water is over-allocated and something of a zero-sum problem under current law. Interests holding rights under the current system would lose water if the Navajo Nation’s rights were interposed into the current allocation framework.  Meanwhile, the Navajo Nation suffers from water scarcity and poverty in part attributable to a long history of unfair treatment under these systems. 

What do you think will be the likely ruling in Arizona v. Navajo Nation? 

It is very difficult to predict. The Court has long attempted to protect tribal interests - and a ruling on this issue for the Navajo Nation would be most consistent with the Court’s prior water law decisions that attempt to achieve that result. 

Whatever the ruling, the most likely outcome is more litigation while the western states continue to manage their water resources unsustainably and in a manner that prioritizes agriculture and urban growth over environmental protection and tribal wellbeing.