This chapter presents water as a complex resource with a diversity of uses, broadly defined, and considers the values that may be associated with water and why they are important. It provides how societies can, and do, make decisions about water resources where different values systems intersect and overlap. The chapter identifies water as a resource whose allocation and use among diverse users is a fundamental requirement of societies. It traces the efforts to introduce universal principles that establish water allocation as subject to technical criteria that draw legitimacy from economic valuation and environmental economics but also from conservationist perspectives on environmental management. The chapter argues that universalising technical approaches tend, in practice, to be heavily conditioned by local political relationships that expose the incommensurability of systems of value encountered among those who use water. The ‘scarcity’ narrative framing water generates ‘universal’ criteria for management.