Potential deal to end SCOTUS Rio Grande case becomes public

A proposed agreement between Texas, New Mexico and Colorado was unsealed Monday, months after the states announced a deal to end a nearly decade-old Supreme Court case over the waters of the Rio Grande.

The deal would change the 83-year-old legal basis for how the three states share water from the river — the so-called Rio Grande Compact. If the Supreme Court allows it, the decree would end the lawsuit that has been invoked Original No. 141 Texas vs. New Mexico and Colorado. The case has extended over nine years and cost taxpayers in New Mexico and Texas tens of millions of dollars.

Map showing new point for delivery of Rio Grande water between Texas and New Mexico at an existing stream gauge in East El Paso. (Courtesy of Margaret “Peggy” Barroll in the joint application)

Under the changes, Texas’ share of the Rio Grande water would be measured at a point on the state line at an El Paso gauge, rather than NM’s current requirement to deliver Texas’ water more than 100 miles upstream at Elephant Butte Reservoir.

The agreement provides a new set of calculations to determine what is owed to farmers in southern New Mexico and farwestern Texans, and incorporates groundwater pumping into the formulas.

Finally, it also provides terms for New Mexico and Texas to settle disputes over over- or under-delivery of Rio Grande water.

To provide water for these shipments, the New Mexico Office of the State Engineer could close wells or apply other restrictions, such as.

In affidavits accompanying the proposed agreement, senior New Mexico and Texas water officials urged the Supreme Court to accept the proposal.

Bobby Skov, the Rio Grande Compact Commissioner for Texas, called the deal “fair” and “consistent with the Compact.”

State Engineer Mike Hamman, who is also New Mexico’s Compact Commissioner, said the agreement resolves longstanding issues between the two states and provides clear guidance on how to honor the accords.

“I anticipate that the consent decree will help states avoid future conflicts,” Hamman wrote.

A key change in the document includes water transfers between the New Mexico and Texas Irrigation Districts to compensate for years when pumps or diversions in New Mexico result in not enough water from the Rio Grande reaching the state line.

Courtesy photo showing the two Elephant Butte Reservoirs where water from the Texas Rio Grande is currently being stored at a new location to measure whether New Mexico maintains water supplies at the existing El Paso Gage just over 100 miles downstream. (Courtesy of Willian Hutchison’s explanation).

If the state fails to meet the new supply requirements for three consecutive years, the agreement requires the state to send additional water from the New Mexico Irrigation District to the Texas Irrigation District.

To provide water to make up any shortfall, Hamman offered seven bullet points his letter support agreement.

Hamman said the state engineer’s NM office could curb groundwater pumping; Monitor groundwater pumps, buy water rights to shut down groundwater wells; temporarily fallow farmland; increasing conservation in both municipal and agricultural uses; or try to import water into the Lower Rio Grande.

Hamman warned that the state agency will enforce well closures if voluntary or compensated measures don’t work.

New Mexico is still embroiled in the lengthy court process that began in 1996 to determine the jurisdiction of water rights between the Caballo Reservoir and the state line for farmers, local authorities, corporations and the federal government.

As for the next steps, a hearing on the proposed decree is tentatively scheduled for February 2023.


The Supreme Court case was sparked by decades of litigation over the Lower Rio Grande — the region between Caballo Reservoir and where the river frequently evaporates above Fort Quitman, about 90 miles along the Texas-Mexico border.

In 2014, Texas filed a lawsuit in the Supreme Court alleging that New Mexico groundwater pumped below Elephant Butte illegally drew water from the Rio Grande that Texas had been promised.

The proposed agreement is the result of months of confidential negotiations between the parties to the case – New Mexico, Texas, Colorado and the federal government. Discussions included input from concerned organizations such as agricultural associations, the two regional irrigation districts, the cities of Las Cruces and El Paso, New Mexico State University, and water utilities in Albuquerque and El Paso.

In earlier actsThe federal government and the Greater Irrigation District of El Paso have asked the special master overseeing the case to overturn the proposed decree because it was the result of an incomplete agreement and makes concessions that states have legal acts that states cannot enforce.

Last week, Judge Michael Melloy refuted the federal government’s arguments that the proposed agreement must be kept secret and ordered most of the documents released.

The United States’ objections to the proposed decree remain classified and not public at this time.