In Texas’ long-running fight with New Mexico over Rio Grande water rights, the U.S. Supreme Court ruled Monday that the federal government has a right to intervene in the dispute — a position backed by Texas officials.
The legal dispute began in 2014, when a Texas complaint argued that New Mexico was violating terms of the 1938 Rio Grande Compact, a Congress-approved agreement that divided the river’s water rights for users in the two states and Colorado.
Lone Star officials claimed that New Mexico violated the compact by allowing water allocated to Texas to instead be pumped from an area below the Elephant Butte reservoir, about 125 miles northwest of El Paso.
Monday’s Supreme Court ruling focused on a move to intervene in the dispute by the U.S. Interior Department, which essentially backed Texas’ complaint and sought to preserve the federal government’s interests in the region, particularly its treaty obligations to provide Rio Grande water to Mexico.
In a unanimous ruling written by Justice Neil Gorsuch, the Supreme Court rejected arguments by New Mexico and Colorado, which said the U.S. government lacked the authority to intervene in a dispute among states under federal law or the compact.
Gorsuch noted that although the Rio Grande Compact does not include the federal government, the Interior Department did not initiate the action against New Mexico but instead sought to join a complaint filed by Texas — a move that Texas officials did not oppose.
The U.S. government also had substantial interests to protect, the court said, noting that “a breach of the Compact could jeopardize the federal government’s ability to satisfy its treaty obligations to Mexico.”
During oral arguments in January, Texas Solicitor General Scott Keller argued that the federal government should be allowed to intervene in the dispute because it owns the Rio Grande Project, which regulates the river’s flow and water rights in the three states in addition to ensuring that Mexico gets the water it deserves by treaty.
Monday’s ruling was the latest step in the long-running dispute. Last October, the Supreme Court rejected New Mexico’s bid to have the Texas complaint dismissed.
A spokesman for New Mexico Attorney General Hector Balderas said the state will continue “to vigorously defend the rights of New Mexico water users” as part of legal actions begun by Gary King, the former attorney general.
“Today’s ruling was a preliminary matter clarifying the United States’ role in the case,” spokesman James Hallinan said.