Confusion where ground and surface waters meet : Gila River General Adjudication, Arizona, and the search for subflow

Abstract

Arizona is presently in the midst of a general adjudication for the Gila River system -- the watershed which comprises the southern two-thirds of the state. The purpose of the adjudication is to prioritize all water claims in the river system: both state-established and federally reserved rights. Arizona adheres to a bifurcated (or divided) system of water law which only recognizes a component of ground water -- called subflow -- to be appropriable. Wells which pump non-appropriable water -- called tributary flow -- are not to be included in the adjudication. The problem is that federal laws do not recognize this artificial bifurcation. The challenge lies in identifying a subflow zone which satisfies the hydrologic fiction of existing state precedents and the hydrologic reality of federal statutes. At the core of the problem lies the fate of Arizona's perennial stream water and the fulfillment of federally reserved tribal water rights. Thus, larger questions loom: can Arizona law reconcile its glutinous past with a water-scarce future, will the adjudication ever reach a finality, and even if it does, will it be a finality that all sides can live with?