Michael C. Blumm has posted “Reserved Water Rights as a Rule of Law” on SSRN. Here is the abstract:

The reserved water rights doctrine is — and always has been — a controversial doctrine in Western water law circles because it provides a federal trump over state systems of water allocation. First articulated by the U.S. Supreme Court over a century ago, states and their water rights holders have always resisted implementation of federal water rights because the federal government and its trustee Indian tribes often have different water priorities than the states, long committed to diversionary rights largely for irrigated agriculture.

In Idaho, opposition to federal water rights largely succeeded in defeating water for wilderness, national forests, national recreational areas, and other federal conservation lands in the decisions by state courts in the massive Snake River Basin Adjudication (SRBA). Now, in an Idaho Law Review article, two advocates for state water rights who helped defeat federal water rights in the SRBA proffer a theory that, if accepted by other Western states, would export their Idaho victories.

This response to their effort explains why their theory is flawed and should be rejected by Western state courts. Their argument was in fact not adopted by the Idaho Supreme Court, which employed other reasoning for rejecting federal reserved water rights. This essay maintains that, although Congress certainly has the power either to affirm or reject water rights for federal lands, the idea that water rights may be lost by mere congressional discussion of the doctrine followed by a decision not to take action cannot be interpreted as a rejection of a legal doctrine over a century old. There is no support for interpreting congressional inaction to reverse a long settled legal doctrine like federal reserved water rights — and the costs imposed on federal interests, especially in terms of instream flows, would be significant.