On January 27, the US Supreme Court agreed to allow Texas to file suit against New Mexico and Colorado seeking apportionment of the waters of the Rio Grande River. The Texas suit now marks the 100th exercise of the Supreme Court’s Article III, Section 2 original jurisdiction over “controversies between two or more states.” It is the fifth dispute between Texas and New Mexico before the US Supreme Court. As we previously reported, Texas claims that New Mexico is permitting excessive withdrawal of surface water and hydrologically connected underground water between the Elephant Butte Reservoir and the Texas-New Mexico border in violation of the terms of the Rio Grande Compact. Colorado is named as a defendant solely because it is a signatory to the Rio Grande Compact. The Court’s Order granting Texas leave to file against New Mexico and Colorado also set the schedule for the first phase of the litigation: New Mexico has 60 days to move to dismiss the suit. Squire Sanders will continue to monitor this case as it moves forward.