Texas v. New Mexico and Colorado (Argument January 8, 2018)
Supreme Court hears a second "original jurisdiction" case on opening day of 2018.
On January 8, 2018, the Court will be hearing arguments in Texas v. New Mexico and Colorado. Just like Florida v. Georgia, it is an "original jurisdiction" case - meaning the case starts directly in the Supreme Court (more on "original jurisdiction" here).
Texas, New Mexico and Colorado made an agreement in 1938 (the Rio Grande Compact) to share the water of the Rio Grande River fairly. Now, Texas argues New Mexico is cheating. The Compact says to "deliver" the water to a reservoir so it will get to Texas. New Mexico is delivering the water to the reservoir and then taking some water back out - before it gets to Texas. New Mexico claims the Rio Grande Compact allows it.
The Special Master
The Supreme Court will be reviewing the recommendations of a "Special Master" - a person the Court appointed to review all the evidence on its behalf. A. Gregory Grimsal submitted his report (with recommendations) to the Court on Feb. 13, 2017.
The Special Master has told the Court that Texas's case is valid. Although the case has not been fully tried, New Mexico made a preliminary attempt to get the case dismissed, and it is this attempt to dismiss that the Special Master says the Court should deny.
The United States federal government is trying to get involved in the case so it can ensure that it can abide by its treaty with Mexico. The U.S. has an agreement with Mexico to share certain amounts of Rio Grande water, so the federal government argues it should be allowed to intervene.
Where is Colorado?
Colorado is involved in the case too, but at this stage of the case the Supreme Court will be hearing arguments related to New Mexico's attempt to dismiss the case. So Colorado is submitting briefs, but the issues being heard on Jan. 8 primarily relate to New Mexico and Texas.