The US Supreme Court [official website] heard oral arguments on Monday in two original jurisdiction cases concerning state disputes over water rights and allocation.

In the first case, the court heard arguments concerning water rights to the Rio Grande River. Texas filed the original complaint against New Mexico and Colorado, alleging [SCOTUSblog report] the states were violating the water allocation provisions of the 1938 Rio Grande compact. The US filed a complaint as an intervening party under authority from the constitution and federal law. The federal government’s position as an intervening party was the primary challenge raised in oral arguments.

In its argument [transcript, PDF], the US asserted its authority to file a complaint as an intervening party, arguing that New Mexico did not have full responsibility to apportion the water, but that the Bureau of Reclamation had a significant role in the equitable allocation framework. Thus, to reach a full resolution, the US must be a party to the case, rather than simply as an amicus.

The second case the court heard was Florida v. Georgia, concerning a dispute over the Apalachicola-Chattahoochee-Flint River basin.

The case arose from a dispute [SCOTUSblog report] dated back to 1980 from a series of droughts in the river basin, which depleted Florida’s water supply. The US Army Corp. of Engineers maintain several dams to allocate the water supply to achieve various objectives, including municipal and industrial water supply. Florida filed the lawsuit in 2012 seeking injunctive relief to limit Georgia’s depleted water usage.

During argument [transcript, PDF] before the Supreme Court, Florida argued that the Special Master committed a legal error in his previous ruling, which held that Florida failed to show by “clear and convincing evidence” that limiting Georgia’s water consumption would then increase Florida’s water supply. The special master found that Florida did indeed suffer injury resultant from Georgia’s water consumption, but that Florida did not show injunctive relief was the appropriate remedy to increase Florida’s water supply.

In response to Florida’s opening argument, Justice Ginsburg pointed out that the special master denied relief because Florida failed to even address the benefits it would receive from increased water-flow and only focused on the harm the depleted water supply caused. The US submitted an amicus brief to the court but refused to join as a party to the dispute, despite the Army Corps.’s role in maintaining the waterway.