By: Katryn Hurtado, Associate
Interstate compacts regarding water allocation could face increasing scrutiny since the Supreme Court issued its decision in Tarrant Regional Water District v. Hermann this June. Tarrant resolved a longstanding dispute between Texas and Oklahoma over cross-border rights to the Red River and its tributaries under the Red River Compact of 1980. Drought and rapid population growth in the Dallas-Forth Worth area has led to increased water scarcity, and has caused Texas to intensify its efforts to purchase water from neighboring states like Oklahoma. Despite having an abundance of water, Oklahoma enacted a moratorium on selling or exporting ground or surface water outside its borders. After unsuccessful attempts to gain a permit to purchase water, the Texas state agency, Tarrant Regional Water District, filed a suit in federal court, claiming that the Oklahoma moratorium is pre-empted by the Red River Compact and violates the Commerce Clause.
The Compact resolved over 20 twenty years of disagreements regarding the allocation of water in the Red River Basin among Arkansas, Louisiana, Oklahoma, and Texas, through which the Red River and its tributaries flow. Under the Compact, Texas claimed rights to billions of gallons of water located in one of the Red River subbasins, relying in part on a provision of the compact stating: “Signatory States shall have equal rights to the use of runoff originating in subbasin 5 and undesignated water flowing into subbasin 5.” The Court, however, upheld the Oklahoma statute citing the Compact’s silence on cross-border rights, the strong presumption against defeating State statute, customary practices in interstate compacts, and the parties’ previous conduct under the Compact.
More than thirty interstate water compacts could be affected by the Court’s interpretation of water apportionment and its emphasis on state sovereignty. In particular, compacts with similar language to that of the Red River Compact may be approached by states with greater uncertainty, leading to an increase in litigation. States may also begin to enact statutes similar to the Oklahoma moratorium, further inflaming the already mounting water crisis in many Western states. Protectionist policies enjoy popular support despite the threat of climate change and urban growth, which will likely continue to destabilize interstate water agreements over future decades. While the Court’s decision in Tarrant secured a victory for states seeking to assert dominion over their own natural resources, it may only be a matter of time before the need for cooperation and resource sharing amid a rapidly changing environmental landscape defeats the “strong presumption” against striking down state legislation.
 Tarrant Reg’l Water Dist. v. Herrmann, 133 S. Ct. 2120 (2013).
 Id. at 2125 (“The Red River Compact . . . allocates water rights among the States within the Red River basin as it winds through Texas, Oklahoma, Arkansas, and Louisiana.”).
 See Nicholas Andrew, Interstate Water Transfers and the Red River Shootout, 41 Tex. Envtl. L.J. 181, 181-82 (2011).
 See Mark A. Willingham, The Oklahoma Water Sale Moratorium: How Fear and Misunderstanding Led to an Unconstitutional Law, 12 U. Denv. Water L. Rev. 357, 357-58 (2009). See also okla. stat. tit. 74, § 1221.A (2008).
 See Wyatt Cox, A Reserved Right Does Not Make a Wrong, 48 Tulsa L. Rev. 373, 389 (2012) (noting Tarrant was initially filed in the Western District Court of Oklahoma which held in Oklahoma’s favor, later affirmed by the Tenth Circuit prior to the Supreme Court’s grant of certiorari).
 Tarrant, 133 S. Ct. at 2125. See generally Sporhase v. Nebraska, 458 U.S. 941, 959-60 (1982) (holding a Nebraska statutory restriction on withdrawal of groundwater for use outside the state to be unconstitutionally facially discriminatory legislation in violation of the Commerce Clause).
 Tarrant, 133 S. Ct. at 2125.
 Id. at 2126-28.
 Tarrant, 133 S.Ct. at 2132-37.
 See Jim Malewitz, Red River Showdown: Texas-Oklahoma Water War Could Reverberate Across the US, Stateline: The Pew Charitable trusts (Apr. 24, 2013), http://www.pewstates.org/projects/stateline/headlines/red-river-showdown-texas-oklahoma-water-war-could-reverberate-across-us-85899470724.
 See Jeremy P. Jacobs, Supreme Court Wades into Bitter Texas-Oklahoma Feud Ahead of Expected ‘Flood of Litigation’, Greenwire (Mar. 12, 2013), http://www.eenews.net/greenwire/stories/1059977696.
 Id.; See also April Reese, Stakes High as Supreme Court Weighs Intervention in N.M.-Texas Dispute, Greenwire (Mar. 12, 2013), http://www.eenews.net/greenwire/2013/03/12/stories/1059977697 (discussing Texas’ pending suit against New Mexico and Colorado claiming illegal diversion of water for agricultural use in violation of the Rio Grande Compact).
 See Megan Herzog, Supreme Court Agrees to Hear TX-OK Water Dispute: Tarrant Regional Water District v. Herrmann, Legal Planet: Environmental law and policy (Jan. 8, 2013), http://legal-planet.org/2013/01/08/supreme-court-agrees-to-hear-tx-ok-water-dispute-tarrant-regional-water-district-v-herrmann/.
 Tarrant, 133 S.Ct. at 2132.