Tribal Water Rights Settlement Acts Involving Arizona and Their Impacts on Water Security

In the western part of the United States, surface water rights follow the prior appropriation doctrine, while tribal water rights are governed by the reserved water rights doctrine. States and Tribal Nations share borders, but water knows no boundaries, and water-related conflicts emerged by the late 19th Century. The United States Supreme Court recognized the reserved water rights doctrine through Winters v. United States in 1908. Over a century later, many tribal water rights claims remain unresolved. Since 1978, congressionally approved tribal water rights settlement acts have emerged as a way to resolve pending tribal water rights claims in the United States. As of March 2026, Tribal Nations, Arizona, the United States, and other interested parties have negotiated 11 congressionally approved tribal water rights settlement acts. This article qualitatively analyzes these 11 congressionally approved tribal water rights settlement acts. The historical and legal analysis highlights the importance of water sharing through water rights settlement acts to ensure water security for Arizona, Tribal Nations, and other interested parties.