Tarrant Regional Water District v. Hermann

It is a rare occurrence that the United State Supreme Court hears a case involving water rights.  But when the Court does hear a water case, it is generally a large case involving a dispute between two or more states regarding a shared water source.  Such is the case in Tarrant Regional Water District v. Herrman, which pits the State of Oklahoma against the State of Texas.

The case focuses on the Red River Compact, which was signed in 1978 by Arkansas, Louisiana, Oklahoma, and Texas following more than 20 years of negotiation.  The purpose of the Compact was to equitably apportion the water of the Red River and its tributaries between the states.  The area covered by the Compact was divided into five subdivisions (called "Reaches"), which were further divided into "Subbasins."  This case centered on Subbasin 5 of Reach II. 

Due to the large population growth in north Texas in recent years, public water suppliers in north Texas began searching for new sources of water to meet the growing demand.  Tarrant Regional Water District and other water districts in north Texas tried to purchase water from Oklahoma, but were unsuccessful. Tarrant then filed a permit with the Oklahoma Water Resources Board to take 310,000 acre-feet of water from the Kiamichi River, which is a tributary to the Red River located in Oklahoma. 

Because Tarrant knew that the permit would be denied based on Oklahoma laws prohibiting out-of-state applicants from diverting water in Oklahoma, Tarrant filed a lawsuit to enjoin enforcement of these laws.  Tarrant claimed that the Oklahoma laws were pre-empted by the Compact and violated the federal commerce clause.  The district court ruled in favor of Oklahoma, and that decision was upheld by the Tenth Circuit Court of Appeals.  The case was then sent to the United States Supreme Court.

The section of the Compact at issue gave the states "equal rights to the use of runoff water originating in subbasin 5 [of Reach II] and undesignated water following into subbasin 5," but was silent regarding state boundary limitations. Tarrant asserted that the Compact therefore allowed them to divert water from Subbasin 5 of Reach II, even if the diversion occurred within Oklahoma.  Oklahoma, on the other hand, argued that because the Compact did not explicitly allow diversions by one state in another state, Texas was prohibited from diverting water in Oklahoma. 

Ultimately, the Court sided with Oklahoma, and held that the Compact did not create any cross-border rights and that the water located within Oklahoma's portion of Subbasin 5 remained under the control of Oklahoma and its laws.  The Court also concluded--in very brief and summary analysis--that Oklahoma's laws did not violate the federal commerce clause.