Trial and Error: How Courts Have Shaped Prior Appropriation in New Mexico

This systematic review of New Mexico prior appropriation case law from 1883 to the present employs a thematic chronology in four parts spanning approximately three decades each, including the following topics. Part One covers the initial conflict between prior appropriation and riparian common law and early interpretations of the 1907 Water Act. In Part Two, courts contrast the 1907 Act with the old arid region doctrine and justify the integration of groundwater into prior appropriation. Diminishing supplies and increasing usage drive Part Three’s concentration on proceedings to change places of use and points of diversion, at times deferring issues of priority or subordinating prior appropriation to other systems of allocation. Part Four explores progress of general stream adjudications, affirmation of prior appropriation against equitable apportionment and common use, and the expansion of power for priority enforcement subject to political barriers. The conclusion distinguishes between prior appropriation’s vitality in principle and in practice, with a call to the New Mexico Legislature to enact statutes and provide adequate funding to meet New Mexico’s present and future water needs