December 15, 2020

Supreme Court rules in favor of NM in water evaporation case

The U.S. Supreme Court ruled Monday morning in favor of New Mexico in a water dispute case with Texas involving the Pecos River Compact. The court denied a motion to review the Pecos River Master’s decision regarding evaporative losses that occurred while New Mexico was storing water upstream for Texas. 

After a tropical storm hit the area in September 2014, the state of Texas asked New Mexico to store water it would normally deliver to Texas under the compact in the Brantley Reservoir while Texas grappled with flooding issues related to the storm.

Texas finally asked for the water to be released in August 2015, but by then, roughly 20,000 acre-feet of water had evaporated. Under the compact’s River Master’s Manual, New Mexico is not responsible for making up evaporative water losses when the state is holding water at the request of Texas. In 2017, the river master determined that New Mexico’s delivery obligation would be reduced by 16,000 acre feet as a result of the evaporation. 

But Texas petitioned the Supreme Court to review the decision. 

In a 7-1 ruling, the court determined that New Mexico was entitled to a delivery “credit” for the evaporated water, with Judge Samuel Alito dissenting in part.