WASHINGTON — Oklahoma won a major victory Thursday in defense of the state's water supply, as the U.S. Supreme Court ruled unanimously that Texas can't reach across the border to claim a share of the Kiamichi River.
Oklahoma Attorney General Scott Pruitt said the decision protected Oklahoma's right to manage its water for generations to come, though the state is still in negotiations with the Chickasaw and Choctaw tribes about water rights in southeastern Oklahoma.
The high court's decision ended a six-year legal battle with the Tarrant Regional Water District, a Texas state agency that claimed a water compact among Texas, Oklahoma, Arkansas and Louisiana gave Texas the right to reach into Oklahoma to get its share of allotted water.
The Red River Compact — approved by Congress in 1980 — gives each of the four states an equal share of excess water from the Kiamichi River. But the compact doesn't explicitly say whether one state can cross a border without permission to get its share.
The Supreme Court on Thursday agreed with Oklahoma's position — which was supported in the case by Arkansas and Louisiana — that the compact would have spelled out the terms if cross-border access was permitted.
“Many compacts feature unambiguous language permitting signatory States to cross each other's borders to fulfill obligations under the compacts, and many provide for the terms and mechanics of how such relationships will operate,” the opinion written by Justice Sonia Sotomayor says.
“The absence of comparable provisions in the Red River Compact strongly suggests that cross-border rights were never intended to be part of the agreement.”
Moreover, the court held that states rarely relinquish their sovereign powers. If Oklahoma had intended to give up its rights to the water within its borders, there would have been a clear indication in the compact, “not inscrutable silence,” the court held.
The court also noted that the Texas agency waited a long time after the compact's approval to claim the right to get water in Oklahoma.
“Once the Compact was approved in 1980, no signatory State pressed for a cross-border diversion until Tarrant filed suit in 2007,” the court opinion states.
“And Tarrant's earlier offer to purchase water from Oklahoma was a strange decision if Tarrant believed the Compact entitled it to demand water without payment.”
The Supreme Court also held Thursday that Oklahoma's laws allocating water — and essentially barring out-of-state sales — do not violate the Commerce Clause of the U.S. Constitution.