Recipients of irrigation water from the Bureau of Reclamation (BuRec) face a future of water conservation. By modelling surface water as a fixed input to a multioutput firm, this paper accurately represents the institutional constraints governing western water allocation and, simultaneously, establishes a cohesive analytical approach to BuRec water conservation. General results are developed on the multioutput agricultural firm, and a tractable empirical model is derived and then estimated using data on agricultural production with BuRec-supplied water. Applying water-constraint elasticities from the econometric results, a simulation finds that, with a 10- percent reduction in BuRec water supply, production adjustments would cause prices 9f three major crops to change between 0.8 and 4.6 percent, but would not significantly affect prices of the remaining seven major crops produced by BuRec-served farms.