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Water Rights/Case Library

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Arizona v. Navajo Nation, 599 U.S. 555 (2023)

Why this matters: The Navajo Nation has a paper right to Colorado River water and roughly a third of its households have no running water. In 2023 the Supreme Court said the 1868 treaty gives them the right but no promise of a pipe. Background for a Wisconsin reader, and a sharp lesson in the gap between having a water right and having water.

Doctrine: Federal and tribal reserved rightsreserved rightsWater the federal government implicitly set aside when it created a reservation, park, or forest. These claims date to the 1800s, outrank almost everyone else, and never expire from non-use., trust responsibility

Case name and citation

Arizona v. Navajo Nation, 599 U.S. 555 (2023). Consolidated with Department of the Interior v. Navajo Nation, No. 22-51. Docket No. 21-1484.

Court and year

Supreme Court of the United States. Decided June 22, 2023. 5 to 4. Opinion by Justice Kavanaugh, joined by Chief Justice Roberts and Justices Thomas, Alito, and Barrett. Thomas concurred. Gorsuch dissented, joined by Sotomayor, Kagan, and Jackson.

One-line holding

The 1868 treaty reserved the water necessary to accomplish the purpose of the Navajo Reservation, and it did not require the United States to take affirmative steps to secure that water for the Tribe.

Facts

The 1868 treaty of Bosque Redondo ended the Navajo people’s forced internment and established a reservation, now about 17 million acres, almost entirely within the Colorado River Basin.

Under Winters v. United States, that reservation implicitly reserved the water needed to fulfill its purpose. See 1908-winters-v-united-states.md.

The practical situation on the reservation is severe. Roughly 30 percent of Navajo households lack running water, and per-capita use is a small fraction of the American average.

The Nation’s mainstem Colorado River rights in the Lower Basin have never been quantified. Arizona v. California allocated the Lower Basin and adjudicatedadjudicationA court proceeding that sorts out every water claim on a river system at once. Arizona's has been running since 1974 and still is not finished. some tribal rights, and the Navajo Nation’s claims to mainstem water were not settled there. See 1963-arizona-v-california.md.

The Nation sued the federal government, arguing the treaty and the trust relationship required the United States to take affirmative steps: assess the Nation’s water needs, develop a plan to meet them, and potentially build the pipelines, wells, and pumps to deliver water.

Arizona, Nevada, and Colorado intervened against the Nation to protect their own Colorado River allocations.

The district court dismissed. The Ninth Circuit reversed, holding the United States did have a duty under the treaty to take affirmative steps.

Does the 1868 treaty impose a judicially enforceable duty on the United States to take affirmative steps to secure water for the Navajo Nation?

Holding and reasoning

No, 5 to 4. Ninth Circuit reversed.

The majority separated 2 things. The treaty reserved the water necessary to accomplish the reservation’s purpose, and the Court did not disturb that. What the treaty did not do was promise federal action to obtain or deliver it.

The reasoning rested on text. The treaty says what it says, and it says plenty: build a schoolhouse, provide a teacher, supply seeds and farm implements, furnish clothing. It says nothing about securing water.

The controlling standard: the federal government owes judicially enforceable duties to a tribe “only to the extent it expressly accepts those responsibilities” through a treaty, statute, or regulation. A general trust relationship is not enough, because the United States “is a sovereign, not a private trustee.”

Kavanaugh framed the Nation’s claim narrowly. The Navajos didn’t allege the United States had interfered with their water access. They asked for affirmative action, and “it is not the Judiciary’s role to rewrite and update this 155-year-old treaty.”

The Court pointed to Congress and the President as the appropriate source of relief.

Gorsuch’s dissent is worth reading in full. He argued the canons of Indian treaty construction, which require reading treaties as the tribe would have understood them, and the historical context of a people promised a permanent home compel some affirmative obligation.

His line about the delay: the government has been avoiding these promises since “Elvis was still making his rounds on The Ed Sullivan Show.”

He closed constructively, sketching how the Nation might pursue its Colorado River claims through other routes, including intervention in existing adjudicationsadjudicationA court proceeding that sorts out every water claim on a river system at once. Arizona's has been running since 1974 and still is not finished..

Why it matters

Winters (1908) established that a reservation carries water. Arizona v. Navajo Nation (2023) established that Winters does not carry a delivery truck.

The distinction is legally coherent and practically brutal. A senior priority datepriority dateThe date your water right got in line. In a western drought, older dates get their full amount and newer dates get nothing. It is the single most valuable number in a western water deal. on a river you cannot physically reach, with no infrastructure and no money to build it, is a right in the abstract.

Roughly a third of Navajo households haul their water. They hold what is arguably the most senior water right in the Lower Colorado Basin.

The case also tightens the general rule about federal trust obligations. Courts will enforce specific promises in specific instruments. Diffuse trust language gets you sympathy and not a remedy.

There is a Colorado River angle that explains why 3 states intervened. Every acre-footacre-footEnough water to cover 1 acre a foot deep: 325,851 gallons. Roughly what 2 or 3 suburban households use in a year. eventually decreeddecreeThe court order at the end of an adjudication, spelling out exactly who gets how much water and in what order. to the Navajo Nation comes out of an already over-allocated river, most painfully from Arizona, which holds the junior priority in the Lower Basin.

The Nation’s claims are not extinguished. Quantification through negotiated settlement, which is how most modern tribal water rights get resolved, remains available and active.

What it means for a landowner today

No Wisconsin application. Read this for the concept, which does transfer.

  • A water right is a legal entitlement. Access to water is a physical and financial problem. They are different, and owning the first doesn’t guarantee the second.
  • Translated to a parcel purchase: confirming that you may legally draw water is step 1. Step 2 is confirming a well can actually produce usable water at reasonable depth and quality.
  • If your parcel abuts a lake or stream in Wisconsin, riparian rightsriparianThe eastern US rule, and Wisconsin's rule. If your land touches a lake or stream, you get reasonable use of that water, shared with everyone else whose land touches it. The rights come with the land and generally cannot be sold separately from it. and public trustpublic trust doctrineThe state holds navigable waters and the land beneath them for everyone, and cannot sign that away. Wisconsin's version is written into the state constitution and is among the strongest in the country. access rules govern use. Federal reserved rightsreserved rightsWater the federal government implicitly set aside when it created a reservation, park, or forest. These claims date to the 1800s, outrank almost everyone else, and never expire from non-use. are almost never in play, though tribal reserved rights and treaty rights do exist in Wisconsin, particularly Ojibwe off-reservation usufructuary rightsusufructuary rightsIn treaty law, the reserved right to hunt, fish, and gather on land that was ceded. Wisconsin Ojibwe bands hold these under the 1837 and 1842 treaties. recognized in the Voigt line of cases. [UNVERIFIED] as to any specific application near Lake Michigan; confirm with counsel if it comes up.

Who verifies: a licensed well driller and hydrogeologisthydrogeologistA geologist who specializes in groundwater. Worth hiring for acreage, tricky geology, or any large planned withdrawal. for actual water availability, a real estate attorney for the rights themselves.

Subsequent history / is it still good law

Good law as of July 2026.

The decision reversed the Ninth Circuit and left the Navajo Nation’s underlying reserved water rights intact while foreclosing the affirmative-duty theory.

Efforts to quantify Navajo rights continue through negotiated settlements and state adjudications rather than breach-of-trust litigation. The Nation has pursued settlement processes in Arizona and Utah. Verify the current status of any specific settlement before relying on it.

Sources

Research demo, not legal advice. Facts current as of July 2026. Water law is state-specific and moves quickly, so confirm anything you plan to act on with a licensed attorney and the relevant state agency.