Resource managers, economists, and legal scholars consider water a natural resource. The fundamental tensions raised by the concept of international water management are legal, such as sharing water in international watercourses, conserving permanent sovereignty over natural resources, and trading water in international watercourses actively or shielding it from world market interference. Contemporary natural resource management’s fidelity to historic legal baselines, protecting preexisting national ownership, and shielding water in international watercourses from watercourse states’ interference is increasingly untenable, particularly in light of international watercourse law. Water in its natural state is neither a good nor a natural resource, and the institutions and goals of a natural resource concept must be changed to better reflect a dynamic, integrated world. Dwindling water resources force a radical reconsideration of the aims, features, and criteria of the natural resource concept.