SCOTUS Sides With New Mexico in Interstate Dispute Over Pecos River

In Texas v. New Mexico, 592 U. S. ____ (2020), the U.S. Supreme Court denied a motion by the State of Texas to review the Pecos River Master’s determination that New Mexico was entitled to a delivery credit for evaporated water stored at Texas’ request under the Pecos River Compact. By a vote of 7-1, the justices agreed that New Mexico should receive delivery credit for the evaporated water even though that water was not delivered to Texas

Facts of the Case

The 1949 interstate Pecos River Compact provides for equitable apportionment of the use of the Pecos River’s water by New Mexico and Texas. In a 1988 amended decree in the same case, the Supreme Court appointed a River Master to annually calculate New Mexico’s obligations to Texas under the Compact. The Court also adopted the River Master’s Manual, which elaborates on how to make the necessary calculations to determine whether New Mexico is complying with its obligations under the Compact. As relevant, §C.5 of the Manual provides that when water is stored “at the request of Texas” in a facility in New Mexico, then New Mexico’s delivery obligation “will be reduced by the amount of reservoir losses attributable to its storage.”

In 2014, a tropical storm caused heavy rainfall in the Pecos River Basin. To prevent flooding, Texas’s Pecos River Commissioner requested that some of the River’s water be stored in New Mexico. New Mexico’s Commissioner agreed. Several months later, the water was released; however, a significant amount of water evaporated while the water was held in New Mexico.

For years thereafter, the States sought to reach an agreement on how the evaporated water should be accounted for under the Compact. To permit those negotiations to continue, the River Master outlined a procedure in 2015 that called for the future resolution of the issue. Neither State objected. When negotiations eventually broke down, however, New Mexico filed a motion with the River Master that sought delivery credit for the evaporated water. The River Master agreed, rejecting Texas’s argument that the motion was untimely and concluding that the evaporated water was water stored “at the request of Texas” under §C.5 of the River Master’s Manual.

Supreme Court’s Decision

The Supreme Court rejected Texas’ motion, agreeing with the River Master’s decision. “We agree with the River Master’s determination, and we deny Texas’s motion for review,” Justice Brett Kavanaugh wrote on behalf of the majority.

The Court first rejected Texas’ argument that New Mexico’s motion for credit for the evaporated water was untimely. As Justice Kavanaugh emphasized, both parties agreed to postpone the River Master’s resolution of the evaporated-water issue. Accordingly, neither party could now object to the negotiation procedure outlined by the River Master for resolving the dispute.

The Court further found that New Mexico is entitled to delivery credit for the evaporated water. In support, the Court point to Section C.5 of the River Master’s Manual. As Justice Kavanaugh explained:

The River Master’s Manual, which was approved by this Court in 1988, implements the Compact and speaks directly to this question: When water is stored in New Mexico “at the request of Texas,” then New Mexico’s delivery obligation “will be reduced by the amount of reservoir losses attributable to its storage.” Here, the water was stored in New Mexico at the request of Texas, so New Mexico’s delivery obligation must be reduced by the amount of water that evaporated during its storage.

Finally, the Court found that Texas’s counterarguments—that the stored water was not actually part of the “Texas allocation” referred to in §C.5, that New Mexico did not “store” the water for §C.5 purposes, and that Texas should not be charged for any evaporation occurring from March 15 until the water was released in August 2015—were unpersuasive.