Too Simple Rules for a Complex World? Prior Appropriation Water Rights as Natural Rights

This Article assesses the fit of Professor Claeys’s theory of Natural Property Rights to traditional prior appropriation, the regime that allocates water in the West, and its capacity to fit the future of the regime. Natural Property Rights does not offer clear answers to the conflicts under the prior appropriation doctrine of water when there is scarcity. This Article explores the lack of determinacy of Claeys’s theory and the maladjustment between the theory and some of the foundational prior appropriation principles, which cannot be ignored even in the most stylized form of the regime. In particular, the Article analyzes the interaction between the definition of the right and the type of use, the necessity proviso in a market context, the role of greed in prior appropriation trades, and the public trust doctrine.