Texas v. New Mexico
The Supreme Court blocked Texas and New Mexico from finalizing their Rio Grande water-sharing settlement, ruling that the two states cannot approve a deal that eliminates the federal government's independent legal claims without Washington's consent.
The decision keeps alive the federal government's push for stricter limits on New Mexico's groundwater pumping than the two states were willing to accept, and forces a decade-long water dispute to continue before the Supreme Court's specially appointed trial officer.
“we cannot now allow Texas and New Mexico to leave the United States up the river without a paddle.”
The majority's closing line explaining why the United States' settled claims block approval of the consent decree.
How it got here: Texas filed an original action in the Supreme Court; the US intervened; after a partial trial, Texas and New Mexico agreed on a consent decree; the Special Master recommended approval; the US filed an exception and the Supreme Court set the case for argument.
The Case in Depth
What happened
Texas, New Mexico, and Colorado share the waters of the Rio Grande under a 1938 interstate compact. In 2013 Texas sued New Mexico, arguing that excessive groundwater pumping by New Mexico entities was diverting water bound for Texas. The federal government's Bureau of Reclamation also joined the lawsuit, asserting its own interests: it has contractual duties to deliver water to two irrigation districts and must supply Mexico with 60,000 acre-feet per year under a 1906 treaty. After years of proceedings before a court-appointed Special Master, Texas and New Mexico negotiated a proposed settlement that would create a new formula for measuring water deliveries — but the federal government refused to go along.
The question before the Court
Can Texas and New Mexico settle their decade-long Rio Grande water dispute through a consent decree if the federal government — which has its own legal claims in the case — refuses to agree to it?
The Court's answer
No — Texas and New Mexico cannot finalize their settlement over the United States' objection. The Court held that the federal government has its own valid legal claims under the Rio Grande Compact, grounded in three independent interests: its contractual duty under the Downstream Contracts to deliver water to two irrigation districts, its integral role in operating the Rio Grande Project (the irrigation system the Compact depends on), and its treaty obligation to deliver water to Mexico. Because those claims belong distinctly to the federal government — not merely as a stand-in for the states — a settlement between the states cannot lawfully extinguish them.
The proposed settlement would have done exactly that. By adopting a new water-measurement formula tied to groundwater-pumping levels from 1951–1978, the decree would have treated those pumping levels as Compact-compliant, making it legally impossible for the government to continue arguing that New Mexico is breaching its Compact duty. A court may not enter a consent decree that cuts off a non-consenting party's valid claims, so the Court refused to approve it.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Farmers, irrigation districts, and water managers in Texas and New Mexico face continued legal uncertainty about how Rio Grande water will be divided. New Mexico has warned that tighter pumping limits could cost tens of thousands of jobs and a large share of its economy. The ruling also signals that whenever the federal government intervenes in a state water dispute, it can block a negotiated settlement — making future interstate water agreements harder to finalize.
What changes now
The States' proposed consent decree is rejected, and the case returns to the Special Master for further proceedings. The federal government will continue to litigate its claim that New Mexico's groundwater pumping violates the Compact and seek an injunction requiring New Mexico to stop that interference. The underlying merits — including what groundwater-pumping level the Compact actually requires — remain to be decided. The Court noted that its ruling says nothing about whether the US could have initiated its own Compact lawsuit independently.
What this does not decide
The Court explicitly declined to decide whether the federal government could have filed its own Rio Grande Compact lawsuit without a pending State action, whether the government's 1938-baseline pumping theory is correct on the merits, or how any state water law is affected. The ruling also does not resolve the underlying water allocation dispute.
Concurrences and dissents
Dissent — Justice Gorsuch
Justice Gorsuch argued that the Special Master's recommendation to approve the consent decree and dismiss the government's remaining claims without prejudice was correct and should have been followed. He maintained that the 2018 Texas I ruling did not hold that the US has independent Compact claims — it merely permitted intervention to protect the government's operational interests, which the consent decree already satisfies. He accused the majority of ignoring a century of water law precedent giving states authority over their water rights and requiring federal reclamation projects to follow state compacts and decrees. In his view, the US could pursue any independent claims in lower courts and return to seek decree modification if it prevailed, making the Court's veto of the settlement both unnecessary and harmful to state sovereignty.
How the Court got there
The legal reasoning, step by step
- The Court started from the rule, drawn from Firefighters v. Cleveland (1986), that parties who resolve a lawsuit through settlement cannot use that deal to dispose of a non-consenting intervenor's valid claims. The threshold questions are therefore whether the United States has valid Compact claims of its own and, if so, whether the proposed decree would extinguish them.
- On the first question, the Court relied heavily on its own 2018 ruling (Texas v. New Mexico, 'Texas I') that allowed the federal government to intervene. That decision had identified three 'distinctively federal interests' giving the government its own stake: (1) the Compact is inextricably tied to the Rio Grande Project and the Downstream Contracts — agreements by which the United States assumed a legal duty to deliver water to the irrigation districts; (2) New Mexico itself had conceded the government plays an integral role in the Compact's operation; and (3) the government's treaty obligation to deliver water to Mexico depends on New Mexico honoring its Compact duties. Those interests, the Court said, compel the same conclusion today: the US has valid Compact claims.
- The Court rejected the states' argument that the government has no valid claims because the Compact doesn't give it a personal water allocation. That was equally true in 2018. The government's claims arise from the Compact's entanglement with the Downstream Contracts and the risk that New Mexico's pumping leaves the Bureau of Reclamation unable to meet its contractual and treaty obligations — not from any right to water for itself.
- The Court also rejected the states' argument that the government's interests are purely derivative of the states'. The 2018 ruling had already found those interests to be 'distinctively federal' and independent of Texas's. And the Court distinguished Hinderlider v. La Plata River (1938), which gave states conclusive authority over their citizens' water shares under that compact, because that compact gave states sole authority over apportionment — whereas the Rio Grande Compact explicitly relies on the federal government's operation of the Rio Grande Project to effectuate the water split.
- On the second question — whether the decree would dispose of the US's claims — the Court pointed to the states' own concessions before the Special Master that the decree would resolve 'all of the Compact claims stated by any party.' More substantively, the proposed decree's new measurement formula (the EEPI) is built on 1951–1978 pumping data, the very period of elevated groundwater pumping the government says violates the Compact. Entering the decree would legally settle that issue in New Mexico's favor and bar the government from ever arguing otherwise, cutting it off from the injunctive relief it seeks.
Doctrinal impact
Cases affected by this decision
Reaffirms Texas v. New Mexico (583 U. S. 407)
The 2018 ruling allowing US intervention is confirmed as establishing valid, independent federal Compact claims.
Reaffirms Firefighters v. Cleveland (478 U. S. 501)
Rule that a consent decree cannot dispose of non-consenting intervenors' valid claims is reaffirmed and applied.
Distinguishes Hinderlider v. La Plata River & Cherry Creek Ditch Co. (304 U. S. 92)
That compact gave states sole apportionment authority; the Rio Grande Compact explicitly relies on federal operation, so Hinderlider's reasoning does not apply.
Distinguishes California v. United States (438 U. S. 645)
That case required federal compliance with state water-permit laws; here the US claims the Compact itself — federal law — bars New Mexico's pumping.