Richardson, Jesse J., Jr.2024-05-162024-05-162024-05-0139 J. Env't L. & Litig. 351049-0280https://hdl.handle.net/1794/2944556 pagesThis Article offers a short primer on water rights in the United States, contrasting eastern riparian water rights and western prior appropriation rights. Summaries of the Supreme Court’s opinions on equitable apportionment provide a concise history of the doctrine. The Article then attempts to glean a coherent test for determining equitable apportionment from the case law. Given the dramatic differences between the riparian and prior appropriation doctrines, the cases are then categorized and discussed based on the water rights regimes used by the contesting states. Finally, the Article draws conclusions from the cases and offers recommendations to improve the process.en-USAll Rights Reserved.Water lawUnited States lawWater rightsUnited States Supreme Court decisionsResource managementArticle