On March 5, 2018, the Supreme Court of the United States decided Texas v. New Mexico, No. 141 Orig., holding that the United States may pursue the Rio Grande Compact claims it has pleaded as an intervenor in a water rights dispute between Texas and New Mexico.

With Congress’s approval, Texas, New Mexico, and Colorado signed the Rio Grande Compact (the Compact) to resolve disputes over water rights in the Rio Grande. The Compact requires Colorado to deliver a specified amount of water to New Mexico annually at the state line. It also requires New Mexico to deliver a specified amount of water annually to the Elephant Butte Reservoir (the Reservoir). A set of agreements negotiated simultaneously (the Downstream Contracts) promised Texas water districts a certain amount of water every year from the Reservoir’s resources.

Texas filed suit under the Supreme Court’s original jurisdiction, alleging that New Mexico violated its duty to deliver water to the Reservoir under the Compact by allowing downstream New Mexico users to siphon off water below the Reservoir.  After the Supreme Court permitted the United States to intervene in the action, the United States filed a complaint raising parallel allegations to those made by Texas. New Mexico moved to dismiss the complaint. The Court referred the matter to a Special Master, who recommended that the Court dismiss in part the United States’ complaint on the ground that the Compact does not confer on the United States the power to enforce its terms. The United States filed an exception to the Master’s report, arguing that it may pursue claims for violations of the Compact.

The Court agreed and held that the United States may pursue the Compact claims it has pleaded in this original action. Recognizing its unique authority to mold original actions, the Court stated that several considerations, taken collectively, led to the conclusion that the United States may pursue its claims in this action. First, the Compact is inextricably intertwined with the Rio Grande Project, an infrastructure project in which the United States was involved. Second, New Mexico admitted that the United States plays a key role in the Compact’s operation. Third, a breach of the Compact could jeopardize the United States’ ability to satisfy its treaty obligation to ensure a regular release of water from the Rio Grande to Mexico. Finally, the United States asserted the claims in an existing action brought by Texas, sought the same relief as Texas, and did so without objection by Texas. Although the Court held that United States may pursue its claims in this action, it cautioned that “[n]othing in [its] opinion should be taken to suggest whether a different result would obtain in the absence of any of the considerations [the Court] outlined or in the presence of additional, countervailing considerations.”

The Court sustained the United States’ exception to the Master’s recommendation, overruled all other exceptions, and remanded the case to the Master for further proceedings.

Justice Gorsuch delivered the opinion for a unanimous Court.

Download Opinion of the Court.