New Mexico and Texas file settlement in decade-long lawsuit

New Mexico and Texas are close to resolving a 12-year lawsuit about Rio Grande water use in the Lower Rio Grande region.

“This settlement brings an end to more than a decade of costly and contentious litigation and provides a clear path forward for New Mexico,” New Mexico Attorney General Raúl Torrez said in a statement.

Along with Colorado, New Mexico and Texas filed a package of settlement agreements Friday that set new limits on groundwater pumping in southern New Mexico, but may give New Mexico water users south of Elephant Butte more surface water.

Long-term, the agreement probably means less farmland in southern New Mexico, but the Office of the State Engineer does not expect it to constrain the growth of southern cities, like Las Cruces.

“Climate change is going to mean less surface water decade in, decade out, going forward,” said Nat Chakeres, general counsel for the Office of the State Engineer. “We’ve tried, as part of the settlement, to also keep that in mind … and make sure that everything we are committing to doing, we can actually do.”

Texas sued New Mexico in 2013 for excessive groundwater pumping, and the states reached a deal in 2022. But the federal government objected to the deal, and in 2024 the Supreme Court ruled 5-4 the agreement needed the federal government’s support.

The new settlement has that federal support, as well as support from affected irrigation districts, Chakeres said.

Signed in 1938, the Rio Grande Compact is an agreement about how to share the river’s water between Colorado, New Mexico and Texas. Under the original compact, New Mexico was obligated to deliver a certain amount of water to Elephant Butte Reservoir, but the compact did not specify how much water the Lower Rio Grande region south of the reservoir could use before the river reached the state border. Instead, the Bureau of Reclamation managed that water distribution through agreements with irrigation districts.

The settlement agreement does not change Rio Grande Compact requirements north of Elephant Butte. It does set out specific amounts of surface water that need to make it from Elephant Butte to Texas, giving a clear water allocation for New Mexico users south of Elephant Butte. It also sets specific limits on how much groundwater pumping New Mexico is allowed to do south of Elephant Butte.

New Mexico’s overall water usage south of Elephant Butte is estimated at 300,000 to 350,000 acre-feet per year, Chakeres said. That includes surface and groundwater. New Mexico has committed to reducing groundwater pumping by 18,200 feet annually.

A significant majority of those reductions will likely come from purchasing water rights connected to farmland, Chakeres said. The Office of the State Engineer is going to work on a plan to meet those goals with water users and managers in the Lower Rio Grande region, said Deputy State Engineer Tanya Trujillo.

The Office of the State Engineer has already enrolled a number of water rights holders in a temporary water conservation program.

“In that program, we think we have already got about two thirds of the reductions we need to meet the settlement, but we need to make those permanent, and we need to retire the rest,” Chakeres said. “So, we have 10 years to do this depletion reduction. We’re hoping we can do it faster.”

The second-largest city in the state, Las Cruces, is in the Lower Rio Grande region south of Elephant Butte. But Chakeres does not expect the new groundwater and surface water requirements to constrain the city’s growth.

The State Engineer’s Office plans to work with municipalities and commercial water providers to ensure water supply is available to “keep their economies thriving,” he said.

“The city of Las Cruces has been pretty active in implementing conservation measures,” Chakeres said. “It’s grown a lot in the past 30 years, and its water use has actually not grown since the mid-90s.”

When it comes to surface water, New Mexico could come out ahead under the settlement.

In 2008, the federal government made an agreement with two irrigation districts, one in New Mexico and one in Texas, about how surface water south of Elephant Butte would be distributed. The state of New Mexico disagreed with some of the surface water calculations and changes have been made to those calculations as part of the settlement.

“We believe that under most situations, the new way that the districts are agreeing to operate the project will result in more surface water for New Mexico,” Chakeres said.

The settlement also includes remedies for delivering too much or not enough water to Texas, which could avert the need for future lawsuits.

The U.S. Supreme Court’s Special Master, a judge based in Pennsylvania, still has to consider the settlement agreement and provide a recommendation to the U.S. Supreme Court, something he’s scheduled to do in a hearing on Sept. 29. Assuming there are no objections, the Supreme Court will likely decide whether to accept the settlement in early 2026.

This is not the first time New Mexico and Texas have reached a settlement setting limits on groundwater pumping. In 2003, the states got a Supreme Court decree after a lawsuit from Texas alleged New Mexico’s groundwater pumping was undermining Pecos River water deliveries.

“It’s a similar concept that we needed to collectively limit our groundwater use so that we can make a delivery under the compact and that was called the 2003 Pecos settlement agreement, and it’s been working for over 20 years,” Chakeres said. “We now meet our compact deliveries quite reliably on the Pecos River when before we were not.”

Cathy Cook covers the federal government for the Albuquerque Journal. Reach her via email at ccook@abqjournal.com.