The following essay by Professor Rhett Larson is a summary of his recently published monograph (under the same title), which appears in Vol. 2.3, 2017, pp. 1-82, of Brill Research Perspectives in International Water Law. Professor Larson is a Professor of Law at the Arizona State University School of Law. He can be reached at Rhett.Larson [at] asu.edu.
John Wesley Powell was an 19th Century explorer of the western United States. In a report to the U.S. Congress, Powell recommended that the borders of future western states be based on watersheds and warned of the risks associated with political subdivisions sharing transboundary waters. Congress ignored Powell’s advice, and established western state boundaries with many inter-state waters traversing and, in some cases forming, sub-national borders. As a result, and as I discuss in my recent monograph published in Brill Research Perspectives on International Water Law, the United States has a long and colorful history of transboundary water management that provides both encouraging lessons and cautionary tales for international water law.
For example, the common law doctrine of “equitable apportionment” developed by the U.S. Supreme Court in cases involving its original jurisdiction over inter-state water disputes is similar in many respects to the principle of equitable and reasonable utilization embodied in Articles 5 and 6 of the U.N. Convention on the Law of the Non-Navigational Uses of International Watercourses ( “Watercourse Convention”).
Beyond the obvious use of the word “equitable” in the articulation of both the inter-state doctrine and the international doctrine, the factors set forth by the U.S. Supreme Court in determining equitable apportionment are similar to the factors laid out in Article 6 of the Watercourse Convention in determining equitable utilization. The U.S. Supreme Court considers “physical and climatic conditions,” and international law considers “[g]eographic, hydrographic, hydrological, climatic, ecological and other factors of a natural character.” The U.S. Supreme Court considers consumptive uses, while the Watercourse Convention includes considerations of the “effects of the use or uses of watercourses.” The U.S. Supreme Court considers wasteful uses, and the Watercourse Convention includes considerations of conservation options.
Despite these similarities, the U.S. doctrine of equitable apportionment and the factors included in determining reasonable and equitable utilization under the Watercourse Convention have differences that are important to note for what each doctrine may learn from the other. The Watercourse Convention expressly includes consideration of population, which seems an obvious factor missing from inter-state water law. The Watercourse Convention also considers both existing and potential uses of the watercourse, while the U.S. doctrine of equitable apportionment considers only “consumptive uses,” not necessarily potential future uses. It might also be helpful for the U.S. doctrine of equitable apportionment to expressly factor in ecological considerations in a way similar to the Watercourse Convention, because those considerations may not always be adequately captured by the concept of waste embodied in the U.S. law.
On the other hand, the U.S. equitable apportionment doctrine includes a cost-benefit analysis consideration that could be a helpful factor to evaluate equitable utilization in international water law. Additionally, the consideration of the character and rate of return flows under U.S. inter-state water law may also be a helpful factor to include in determining equitable utilization in international water law.
In Bean v. Morris, an early equitable apportionment case before the U.S. Supreme Court, the Court identified an important factor when evaluating inter-state water allocations that could be incorporated into international equitable and reasonable utilization analysis. States in the U.S. typically rely on one of two legal regimes for allocation rights to water. The approach to water rights in eastern states is generally common law riparian rights based on English and Roman laws, under which rights are apportioned to owners of property abutting water bodies based on the requirement that uses be reasonable. The approach to water rights in western states is generally prior appropriation, with water rights based on a first-in-time, first-in-right scheme, subject to beneficial use requirements and the prohibition against waste.
Neighboring U.S. states sharing transboundary waters can therefore have dramatically different approaches to allocating water rights and different policy aims in water management. These differences have aggravated inter-state water disputes over transboundary waters. The U.S. Supreme Court, in an early equitable apportionment case, sought to mitigate the impact of, if not reconcile, these different approaches to water rights. In Bean v. Morris, the Supreme Court held that it would apply principles of prior appropriation when allocating water between states that recognize prior appropriation as their own internal water rights system.
International water law could similarly look to using domestic water law principles held in common between two nations sharing a watercourse as a factor in the evaluation of reasonable and equitable utilization. Such an approach would be a more targeted application of Article 38(1)(c) of the International Court of Justice’s statute authorizing reliance on “general principles of law recognized by civilized nations” in resolving international disputes. Nations are perhaps more likely to view such a factor as reasonable and equitable if based on domestic laws already accepted and legitimized under their respective domestic laws.
Other potentially helpful lessons from U.S. inter-state water law for international water law may include the use of special masters to facilitate dispute resolution and the recognition and quantification of water rights held by indigenous peoples. Cautionary tales for international water law from U.S. inter-state water law include the inter-state problems created by the bifurcation of groundwater and surface water rights, and the over- or under-empowerment of basin-level, inter-jurisdictional commissions. Many countries with federal structures, like the United States, have been dealing with inter-jurisdictional water disputes for generations, and therefore could be fertile ground for cultivating ideas for reform in international water law.
The entire article is available here.