Unanimous US Supreme Court: United States Can Participate as Party in Texas v. New Mexico

The United States will be allowed to participate as a party in the Texas v. New Mexico lawsuit before the United Stated Supreme Court, wrote Justice Gorsuch last week on behalf of a unanimous bench.


We’ve been following Texas v. New Mexico for years.  To read a more detailed explanation of the merits of the lawsuit, click here.

There are multiple agreements at issue in this litigation.

First, what we will refer to as “the Treaty.”  In 1906, the United States entered into a treaty with Mexico, requiring the US to deliver 60,000 acre feet of water per year to Mexico.  In order to do this, the United States constructed a dam, completed in 1916, as part of an infrastructure system at Elephant Butte called the Rio Grande Project.  The Elephant Butte Reservoir is located in New Mexico about 105 miles north of the Texas state line.

Second, there are various “Downstream Contracts.”  In these agreements, the federal government agreed to supply water from Elephant Butte Reservoir to downstream water districts in New Mexico and Texas.

Third, the “Rio Grande Compact” was signed in 1939 between the states of Colorado, New Mexico, and Texas.  The Compact was approved by Congress as Constitutionally required.  Under this Compact, Colorado is required to deliver a certain amount of water to New Mexico at the CO/NM state line and New Mexico is required to deliver a certain amount of water to Texas not at the state line, but at the Elephant Butte Reservoir.


In 2003, Texas filed suit against New Mexico before the US Supreme Court claiming that New Mexico violated the Compact.  Essentially, Texas claims that New Mexico is illegally depleting the Rio Grande’s flow before it reaches the New Mexico/Texas state line.  Specifically, Texas claims that New Mexico allows impermissible diversion of surface water from the river and that increased groundwater pumping also depletes the river by causing the surface water to leave the river to recharge connected underground aquifers.  As to the groundwater pumping, Texas points to wells–approximately 2,500 of these wells have been drilled below the Reservoir since the Compact was signed– and claims that these wells are depleting the amount of water coming to Texas pursuant to the Compact.  Although Texas does not point to a specific term of the Compact that was violated and does not dispute that New Mexico is delivering the correct amount of water into the Elephant Butte Reservoir, it claims that the “purpose and intent” of the Compact is violated when New Mexico allows water to be diverted prior to delivery into Texas.

In response, New Mexico claims that its only obligation under the Compact is to deliver a certain amount of water into the Elephant Butte Reservoir.  The Compact does not require any specific amount of water be delivered to the Texas/New Mexico state line.  New Mexico claims that what happens between the Reservoir and the Texas state line is governed by New Mexico law and not by the Compact.  New Mexico claims that the wells drilled below the Reservoir are proper as they were drilled based upon water rights that were granted under New Mexico law.

After the lawsuit was filed, the United States sought to intervene as a party and essentially make the same claims as Texas.

The case was referred to a Special Master, who recommended that New Mexico’s Motion to Dismiss be denied and that the United States be allowed to intervene, but only on a narrow set of issues. [Read full Special Master Report here.]  The US Supreme Court agreed and denied New Mexico’s Motion to Dismiss and agreed to  hear oral argument on whether the United States was a proper party to this litigation.  Oral argument occurred back in January 2018.

Supreme Court Opinion

Last week, the US Supreme Court issued its opinion, finding that the US is allowed to intervene as a party in this case and to assert the claims it has set forth.  [Read full opinion here.]

The Supreme Court explained that the United States does not have some automatic or blanket authority to intervene as a party to a lawsuit involving a Compact between states, but that it may be allowed to do so in situations where there are “distinctively federal interests” at stake.  In this case, the Court listed four reasons that it believes allowing the US to intervene was appropriate.

First, the Compact between the states is “inextricably intertwined” with the Rio Grande Project and the Downstream Contracts.  Essentially, the Court explained, the US serves as a sort-of agent for the Compact to ensure that required deliveries are made.

Second, New Mexico conceded–both during pleadings and in oral argument, that the United States is an integral party to the Compact and could even be sued if the federal government were interfering with the Compact.

Third, a breach of the Compact could affect the US ability to meet its treaty obligations to Mexico.

Finally, the Court noted that the US did not initiate this litigation, nor does it seek so expand or change the claims already at issue.  Instead, it seeks the same relief as Texas already sought when it filed suit in the first place.

What Happens Next?

This was only one battle in what could certainly be a lengthy war.  Now that the United States will be a party to the case and New Mexico’s Motion to Dismiss has been denied, litigation will proceed to discovery, motions, and eventually a hearing before the Special Master, who would then make recommendations the US Supreme Court on the merits of the case.

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