Climate Change and Water Law

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Climate Change and Water Law


Climate change continues to have detrimental effects on the environment, especially water resources. The Intermountain West faces record-breaking droughts and increased water scarcity. Water law in the Intermountain West was not developed to confront the unstable environment that climate change creates. This article addresses the ways in which western water law in the Intermountain West may inevitably adapt to climate change.

Development of Western Water Law and the Law of Prior Appropriation

The legal doctrine governing water law varies in the United States of America, depending broadly on whether a state is located to the east or to the west of the 100th meridian (Craig, 2020 at 3-4, see References). The western United States, inclusive of the Intermountain West, is predominantly governed by the law of prior appropriation, whereas the Eastern states are generally governed by the riparian doctrine.  Id . at 3. Under the riparian doctrine, water rights are allocated between real property owners adjacent to a body of water and water is allocated under the theory of reasonable use wherein each riparian water user has an equal right to make a reasonable use of the water source, subject to the equal right of the other riparian water users' reasonable use of the same source.  U.S. v. Willow River Power Co ., 324 U.S. 499, 505 (1945). In other words, "[r]iparian law gives equal and correlative rights to those owning land along the stream, while the law of appropriation recognizes that the person who has found available water and put it to beneficial uses has a right to continue his use." (Trelease at 24). Although the eastern riparian system of water law also faces challenges with climate change, such as flooding, this article addresses only the challenges to western water law, and specifically how the prior appropriation systems adapt to climate change impacts.