For the better part of a century, the Arizona Supreme Court played a dominant role in shaping Arizona’s approach to groundwater. From the adoption of the first territorial water code in 1864 to the enactment of the Groundwater Management Act (“GMA”) in 1980, the Arizona legislature was content to remain largely in the background, leaving some of the most important decisions about groundwater regulation to the courts. Those decisions witnessed Arizona’s transformation from a state dependent on agriculture and mining to one of the fastest-growing, most water-limited states in the West.
Although the GMA has done much to shift control of groundwater regulation to the legislature, the courts continue to affect the development of legal principles applicable to groundwater, though on a much more limited scale. In particular, since the passage of the GMA, the Arizona Supreme Court has increasingly deferred to the legislature when confronted with important decisions about the state’s limited water resources. As the court itself has remarked:
Regulation of water use, . . . especially in a desert state, does not lend itself to case-by-case definition. In this field, we not only confer private rights and interests but deal in the very survival of our society and its economy. Simply put, there is not enough water to go around. All must compromise and some must sacrifice. Definition of those boundaries is peculiarly a function for the legislature. It is plainly not a judicial task. Accordingly, we must look to the legislature to enact the laws they deem appropriate for wise use and management of what may be a valuable water resource for Arizona.