While water is the origin and sine qua non of all life on Earth and, perhaps, of all possible life in the universe, Adam Smith was, in 1776, able to note the paradox that while water is invaluable, its ubiquity and plenitude make it essentially valueless in the marketplace. While water has been taken for granted in the past, retrospect allows us to see the essential and irreplaceable role that water plays in both the development of civilizations and the functioning of natural processes. In the twenty-first century, looming water scarcity, degradation, and emerging ideas about the management and value of water allow us to reassess the nature and value of water from a variety of perspectives and disciplines. In this global seminar we will broadly investigate the nature of the local, regional and international water systems, and we will examine the roles that water plays in sustaining life on Earth. By understanding the interconnections between the ecological, economic, agricultural, scientific, ethical and life-sustaining aspects of water, students will develop their ability to engage in interdisciplinary analysis of hydrological issues that are of both contemporary and perennial importance.