According to Justice Sotomayor writing for a unanimous US Supreme Court on June 13, 2013 in Tarrant Regional Water District v. Herrmann et al., No. 11-889 (U.S. June 13, 2013), state statutes that regulate surface water permitting in a manner that disfavors out-of-state permit applicants are not pre-empted by an interstate water compact when the compact is silent on cross-border rights. There are likely many state water managers relieved by this ruling, but there are certainly others who may be frustrated by yet another roadblock to obtaining new water supplies for growing populations.

The Red River Compact of 1978 (Compact) equitably apportioned water of the Red River and its tributaries among four states: Arkansas, Louisiana, Oklahoma, and Texas. The Compact created a system where the three upper basin states (Oklahoma, Texas, and Arkansas) must allow a certain amount of water (3,000 cubic-feet per second (CFS)) to flow downstream to the lower basin state (Louisiana). When there is more than 3,000 CFS flowing at the Arkansas-Louisiana state border, each of the four states is entitled to 25% of the excess. When there is less than 3,000 CFS flowing, the upper basin states must allow more water to flow.

In an attempt to secure new water supplies for its increasing population, the Tarrant Regional Water District (Tarrant) in Texas sought to utilize Oklahoma’s water permitting system to obtain 310,000 acre feet per year (AFY) from a tributary of the Red River in Oklahoma that falls under the Compact. Concurrent with filing its application in Oklahoma, Tarrant also sued in Federal District Court to enjoin enforcement of Oklahoma’s water laws, which were written in a manner that disfavored it as an out-of-state water user. Tarrant argued two points: (1) that the Compact’s provision ensuring each state an “equal right” to 25% of the excess at the Arkansas-Louisiana border created a “borderless common” where each of the four states could access the water; and (2) that the Oklahoma water statutes were unconstitutional under the dormant Commerce Clause.

In advocating for the “borderless common” theory, Tarrant argued that the Compact’s silence on the idea of one of the states being allowed to cross state lines must have meant that a state can cross state lines to obtain it’s 25% share of the excess water. The Court disagreed. “Three things persuade us that cross-border rights were not granted by the Compact: the well-established principle that states do not easily cede their sovereign powers, including their control over waters within their own territories; the fact that other interstate water compacts have treated cross-border rights explicitly; and the parties’ course of dealing.” Terrant, slip op. at 14. Further, brushing aside the constitutional argument, Justice Sotomayor noted that under the Compact, the water in dispute had already been allocated to Oklahoma until such time that a call on the river is made, and therefore is not available for interstate commerce.

States that are parties to water compacts should be encouraged that the US Supreme Court recognizes and has upheld their rights to restrict water exports from within their borders; but, states must recognize the difficulties that such restrictions place on the state’s water users, managers, and utilities as they seek out new water sources. Going forward, the key to securing new water supplies in inter-boundary areas may lay in careful negotiation of new compacts or amendments of existing ones.