Tarrant Regional Water Dist. v. Herrmann
The Court ruled that a four-state agreement dividing up the Red River's water does not give Texas the right to cross into Oklahoma to take water, so Oklahoma's laws blocking out-of-state water permits stand.
The decision resolves a fight over a fast-growing Texas region's search for new water supplies, confirming that states generally keep control over water within their own borders unless a compact says otherwise in clear terms.
“States rarely relinquish their sovereign powers, so when they do we would expect a clear indication of such devolution, not inscrutable silence.”
The Court's core reason for reading the compact's silence against cross-border water rights.
How it got here: The Texas agency sued in federal district court, which ruled for Oklahoma's water board; the Tenth Circuit affirmed, and the Supreme Court agreed to hear the case.
The Case in Depth
What happened
A Texas water agency serving the fast-growing Dallas-Fort Worth area wanted to draw water from a river in Oklahoma that feeds into a shared basin governed by a four-state water-sharing agreement. After failing to buy water from Oklahoma, the agency applied for a permit to take Oklahoma water, but Oklahoma laws effectively block out-of-state entities from receiving such permits.
The question before the Court
Could a Texas water agency cross into Oklahoma to take water from a shared river basin under an interstate water-sharing agreement, despite Oklahoma laws blocking out-of-state water permits?
The Court's answer
No — the Court ruled that the water-sharing agreement does not let Texas cross into Oklahoma to take water, so Oklahoma's laws blocking out-of-state permits are not overridden by federal law. Reading the agreement like a contract, the Court found its silence about crossing state lines was ambiguous at best, and looked to other clues to figure out what the four states intended.
Those clues — the general rule that states rarely give up control over their own water, the fact that other interstate water agreements spell out cross-border rights explicitly when they exist, and the fact that no state tried to claim cross-border rights for nearly thirty years — all pointed the same way. The Court also rejected the argument that Oklahoma's laws unlawfully block interstate commerce, because the water in question isn't left unclaimed under the agreement; it belongs to Oklahoma unless another state formally challenges that.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Texas cities that hoped to tap Oklahoma's water to serve a booming population must find other sources, since Oklahoma can keep enforcing laws that block out-of-state water permits. The ruling also guides how courts will read other multistate water-sharing agreements when they are silent about crossing state lines.
What changes now
This is a final merits decision resolving the legal question of whether the water-sharing agreement grants cross-border rights; it does not. The Texas agency's pending water permit application, which the parties agreed to leave on hold during this litigation, can now be resolved by Oklahoma's water board under its existing laws. No further proceedings on the legal question are expected, though Texas retains the option to seek an accounting under the compact if it believes Oklahoma is taking more than its allotted share.
What this does not decide
The Court noted it was not deciding whether Oklahoma's control over its water could still face limits under other doctrines, such as the Commerce Clause, in situations the Texas agency did not raise here. It also left open how much of the disputed water Texas can access within its own borders.
How the Court got there
The legal reasoning, step by step
- Because the agreement is a congressionally approved compact among states, the Court treated it as a contract and started with its actual wording, since that is normally the clearest evidence of what the states intended when they signed it.
- The Court found the agreement's silence about crossing state lines to permit water use was genuinely unclear — it could mean either that borders don't matter in that section, or that the drafters simply assumed borders would still apply. Because the text alone couldn't resolve this, the Court turned to background principles and other evidence of intent.
- The Court applied a longstanding presumption that when a state doesn't clearly say it is giving up control over its own water, courts should assume it kept that control, since states rarely surrender core sovereign powers by accident.
- The Court compared this agreement to other multistate water-sharing agreements, finding that agreements which actually grant cross-border rights say so in explicit, detailed language — including who can cross, who pays, and how it's administered. The absence of any such language here suggested the drafters never meant to create cross-border rights.
- The Court also looked at how the states had behaved since the agreement took effect: no state tried to claim cross-border rights for almost thirty years, and the Texas agency itself had earlier tried to buy water from Oklahoma rather than claim a right to take it — behavior inconsistent with believing it already had that right.
- Having concluded the agreement created no cross-border rights, the Court also rejected the argument that Oklahoma's permitting laws illegally blocked interstate commerce, since the water at issue is not unclaimed under the agreement — it remains Oklahoma's unless another state formally disputes that allocation.