This is a very interesting article about the legal ongoings between Oklahoma and Texas about this issue

Water: Supreme Court wades into bitter Texas-Okla. feud ahead of expected 'flood of litigation' -- 03/12/2013 -- www.eenews.net (http://eenews.net/public/Greenwire/2013/03/12/1)

This will be resolved shortly and it looks like the Supreme is a little confused by it.

U.S. Supreme Court justices grapple with Oklahoma-Texas water dispute | News OK (http://newsok.com/u.s.-supreme-court-justices-grapple-with-oklahoma-texas-water-dispute/article/3801410?custom_click=pod_headline_politics)

Here's the transcripts.

Transcript of Arguments in Oklahoma?s Supreme Court Water Case | StateImpact Oklahoma (http://stateimpact.npr.org/oklahoma/2013/04/23/transcript-of-arguments-in-oklahomas-supreme-court-water-case/)