Interstate Water Rights: Take No Drop for Granted

Abstract

During the past 100 years, water rights have been equitably apportioned among states by the Supreme Court and, increasingly, divvied up by interstate water compacts. Despite these rulings and interstate agreements, when water flows across state lines, individual upstream users may nonetheless draw on waters allocated to downstream users on the other side of the border, thus satisfying their needs out of the lower state’s water allocation. And upstream states that lack a rightful claim to sufficient water — as they increasingly do in modern drought conditions — have every incentive to let their citizens do just that.State plaintiffs have sought to deter such behavior via litigation. The Supreme Court — most recently in its decision in Kansas v. Nebraska — has embraced that deterrent goal, notwithstanding potential efficiency gains deriving from the breach of interstate water apportionments. At the same time, the Court’s favored tools of deterrence are of little help to water users on the losing end of a breach.This paper proposes a new framework for resolving interstate water disputes: By applying the law of eminent domain to interstate water takings, the Court could promote more efficient interstate water use during a time of widespread drought, while vindicating the usufructory rights of downstream states’ citizens.