On January 27, 2014, the Supreme Court of the United States granted a motion by the State of Texas for leave to file a complaint to enforce its rights under the Rio Grande Compact, which apportions the water of the Rio Grande Basin among the states of Colorado, New Mexico and Texas. State of Texas v. State of New Mexico and State of Colorado, No. 220141. The motion was preceded by over a decade of unsuccessful efforts to resolve the matter through more informal means and litigation in lower court proceedings.

In March 2013, the defendant States of New Mexico and Colorado filed briefs in opposition to Texas’ motion for leave and Texas replied. Several cities and water districts also weighed in on either side of the question. Earlier this month, in response to a request from the Supreme Court, the United States Solicitor General filed an amicus curiae brief on the issues presented.

In granting Texas’ motion for leave to file the complaint, the Supreme Court also granted the State’s motion for leave to file a supplemental brief. New Mexico is allowed 60 days within which to file a motion to dismiss, in the nature of a motion under Rule 12(b)(6) of the Federal Rules of Civil Procedure. Texas is allowed 45 days to file a response to the motion. A reply, if any, by New Mexico must be filed within 15 days after Texas’ response is filed.


The Compact states that it is intended to apportion the water of the Rio Grande Basin from its headwaters in Colorado to Fort Quitman, Texas. Under the Compact, Colorado is required to deliver a specified quantity of water to Elephant Butte Reservoir, a federal Bureau of Reclamation project that distributes water pursuant to contracts with irrigation districts in southern New Mexico and western Texas. The Reservoir is in southwestern New Mexico, roughly 105 miles north of the Texas state line.

Texas complains that New Mexico has depleted its equitable apportionment under the Compact by allowing diversion of surface water and pumping of groundwater that is hydrologically connected to the Rio Grande Basin below the Reservoir, thus diminishing the amount of water that flows into Texas. Texas requests declaratory relief, a decree requiring New Mexico to deliver water to Texas in accordance with the Compact, and damages.

New Mexico contends that the Compact does not require it to deliver any specific amount of water to the Texas state line, and that Texas therefore fails to allege a violation of the Compact. Colorado takes no position on Texas’ allegations, and states that it cannot support Texas’ motion until it better understands the alleged Compact violations at issue. The Supreme Court will have the option of referring the matter to a Special Master to resolve any factual issues in the first instance once briefing is completed.


Litigation and administrative challenges involving water rights have increased in recent years as growing populations meet decreasing water availability. Fresh water will remain one of the scarcest natural resources and a source of contentious battles in the upcoming years as states and private interests fight for their fair shares. Many of these water rights, especially in the western United States, are governed by centuries-old interstate water compacts. Courts have been reluctant to take up disputes involving these compacts and reinterpret the agreements, preferring instead that states look to cooperative study, conference, and mutual concessions before beginning judicial proceedings.1 Thus, careful drafting of new compacts or amendments to existing compacts may be one of the few avenues left for acquiring water sources for thirsty states.