Texas v. New Mexico

Summary

The Supreme Court held that New Mexico is entitled to delivery credit for water that evaporated while stored in New Mexico at Texas’s request under §C.5 of the River Master’s Manual, which implements the 1949 Pecos River Compact. The Court rejected Texas’s timeliness objection, finding both states agreed to postpone resolution of the evaporated-water issue. The decision affirms that when Texas requests storage of its allocation in New Mexico, reservoir losses (including evaporation) reduce New Mexico’s delivery obligation. The case addresses interstate water compacts, equitable apportionment, and the interpretation of the River Master’s Manual.

Holdings

1. New Mexico's motion was not untimely because both parties agreed to postpone resolution of the evaporated-water issue, and the time limits are not jurisdictional.
2. Under §C.5 of the River Master's Manual, when water is stored in New Mexico at Texas's request, New Mexico's delivery obligation is reduced by the amount of reservoir losses attributable to storage. Since Texas requested storage, New Mexico is entitled to credit for the evaporated water.

Questions Presented

1. Whether New Mexico's motion for credit was untimely
2. Whether New Mexico is entitled to delivery credit for evaporated water stored at Texas's request

Disposition

denied