An Overview of the Law of Groundwater Management

Abstract

Groundwater management law has evolved in this century from a simple rule of capture to a variety of rules that require sharing among claimants, both within and outside of groundwater basins. Courts and legislatures have modified the law of groundwater in response to aquifer depletion. Most of the change has occurred in the Far West, but eastern states are now modifying their law as shortages and use conflicts intensify. Arizona, Colorado, and New Mexico have developed the most sophisticated conservation regimes that attempt to limit groundwater use to improve methods of extraction and to move water to higher valued uses. Other large groundwater using states are also implementing or considering similar conservation regimes. Groundwater conservation is encouraged by a recent Supreme Court decision that holds that groundwater is subject to the negative commerce clause. The decision has the effect of forcing states to justify conservation regimes that block out‐of‐state and perhaps in‐state access to the resource.