Oklahoma v. New Mexico

Syllabus The Canadian River flows through New Mexico and the Texas Panhandle before entering Oklahoma. Its waters are apportioned among these States by the Canadian River Compact. Article IV(a) of the Compact gives New Mexico free and unrestricted use of all waters "originating" in the river's drainage basin above Conchas Dam-a structure that predates the Compact and provides water to the Tucumcari Project, a federal reclamation project-and IV(b) gives it free and unrestricted use of waters "originating" in the river's drainage basin below that dam, limiting the "conservation storage" for impounding those waters to 200,000 acre-feet. In 1963, New Mexico constructed Ute Dam and Reservoir downstream from Conchas Dam. In 1984, Ute Reservoir was enlarged, giving it a storage capacity of 272,800 acre-feet, which has been reduced to about 237,900 feet because of silting. Oklahoma and Texas filed this litigation, contending that Article IV(b)'s limitation is imposed on reservoir capacity available for conservation, and that capacity for the so-called "desilting pool" portion of Ute Reservoir was not exempt from that limitation because it was not allocated solely to "sediment control." In 1987, while the case was pending, the river above Conchas Dam flooded, spilling over that dam, and Ute Reservoir caught a sufficient amount of spill waters to exceed 200,000 acre-feet. When New Mexico refused to count the spill waters for purposes of the limitation, Texas and Oklahoma filed a supplemental complaint, claiming that if the limitation applies to actual stored water, then water spilling over Conchas Dam or seeping back from Tucumcari Project constitutes waters originating below Conchas Dam under Article IV(b). As relevant here, the Special Master's Report recommended that (1) Article IV(b) imposes a limitation on stored water, not physical reservoir capacity (Part VI of the Report); (2) water originating in the river basin above Conchas Dam but reaching the river's mainstream below that dam as a result of spills or releases from the dam or seepage and return flow from Tucumcari Project are subject to the Article IV(b) limitation (Part VII); (3) the issue whether and to what extent the water in Ute Reservoir's "desilting pool" should be exempt from the Article IV(b) limitation should be referred to the Canadian River Compact Commission for negotiations and possible resolution (Part VIII); and (4) if the recommendations are approved, New Mexico will have been in violation of Article IV(b) since 1987, and the case should be returned to the Special Master for determination of any injury to Oklahoma and Texas and recommendations for appropriate relief. The States have filed exceptions.

Held: 1. Oklahoma's exception to the recommendation in Part VI of the Master's Report is overruled. Nothing on the Compact's face indicates a clear intention to base New Mexico's limitation on available reservoir capacity when Texas' limitation is based on stored water. Early drafts uniformly referred to stored water, and the contemporaneous memoranda and statements of compact commissioners and their staffs do not explain why a change to "storage capacity" was made in the final draft, although it is most probable the terms were being used loosely and interchangeably. Pp. 229-231. 2. Also overruled are New Mexico's exceptions to the recommendation in Part VII of the Report. New Mexico errs in arguing that the term "originating" is unambiguous, and that there are no restrictions on the impoundment of the spill waters, since they are waters originating above Conchas Dam, to which the State has free and unrestricted use under Article IV(a). Rather, the Special Master correctly concluded that the Compact's drafters intended in Article IV(a) to give New Mexico free and unrestricted use of waters "originating" in the river's drainage basin above Conchas Dam only if the waters were stored, used, or diverted for use at or above Conchas Dam. There is substantial evidence that, in drafting the Compact, Texas and Oklahoma agreed that storage limits were not necessary for waters above Conchas Dam because the waters in that basin had been fully developed, that any future water development would necessarily occur below that dam, and that 200,000 acre-feet of storage rights would satisfy all of New Mexico's future needs below the dam. The Compact's ambiguous use of the term "originating" can be harmonized with the drafters' apparent intent only if it is interpreted so that waters spilling over or released from Conchas Dam, or returned from Tucumcari Project, are considered waters originating below Conchas Dam. Thus, any water stored in excess of the 200,000 acre-feet limit should have been allowed to flow through Ute Dam for use by the downstream States, rather than being impounded by New Mexico. Pp. 231-240. 3. Texas' and Oklahoma's exception to the recommendation in Part VIII of the Report is sustained insofar as those States argue that the "desilting pool" issue should not be referred to the Commission. There was no legal basis for the Master's refusing to decide whether the water in the desilting pool should be counted towards the Article IV(b) limitation, since a dispute clearly exists in this case, and since there is no claim that the issue has not been properly presented. Arizona v. California, 373 U.S. 546, 83 S.Ct. 1468, 10 L.Ed.2d 542. Thus, the matter must be remanded to the Master for such further proceedings as may be necessary and a recommendation on the merits. Pp. 240-241. Exceptions sustained in part and overruled in part, and case remanded.