State v. State

Background

This case is a dispute between the State of Montana and the State of Wyoming about water in the Tongue River at the Stateline between the two States. The Court exercised original jurisdiction over this controversy among sovereign States. The issues were tried before a Special Master, and the Court considered briefs on the parties’ exceptions to the Special Master’s Second Interim Report. The dispute centers on whether Wyoming reduced the volume of water available and whether notice requirements for damages were met in certain years.

Reasoning

The central questions were whether Wyoming was liable for reductions in river volume at the Stateline and whether Montana had satisfied notice requirements tied to damages for specific years. The Court granted Wyoming’s motion for partial summary judgment on the notice requirement for damages for 1982, 1985, 1992, 1994, and 1998. The Court also found Wyoming not liable for 1981, 1987, 1988, 1989, 2000, 2001, 2002, and 2003. The Court determined that Wyoming was liable to Montana for a reduction of 1,300 acre-feet in 2004 and for a reduction of 56 acre-feet in 2006, and entered an order and judgment reflecting those findings.

Real world impact

The order resolves which specific years Wyoming is liable and which years it is not, and it sends the case back to the Special Master to calculate monetary damages and any other appropriate relief. Montana will have the Court’s liability findings and the measured reductions (2004 and 2006) as the factual basis for damage calculations. The Special Master will determine the amount and form of relief consistent with the Court’s judgment.