This chapter outlines the ways in which fresh water is crucial to all of us in myriad ways, and the challenges we face when disrupting natural hydrodynamic systems. Since improvements made in sanitation in the nineteenth century, wealthy countries have largely alleviated the effects of water-borne disease and lack of safe drinking water. However, it is precisely modern, urbanized society that has caused the most damage to marine systems, through pollution, eutrophication (introduction of nutrients) and hydro-electric dams, in service of its industrial development. For developing countries, the UN’s Sustainable Development Goals (SDGs) recognized, in 2015, the increasing need for access to safe drinking water. The chapter emphasizes that the past models of water management in industrialized nations, which have come at huge ecological and social costs, should be regarded critically by developing regions, desperate to utilize water systems for growing urban populations. Hering advocates learning from the successes and failures of wealthy countries; developing sustainable, balanced approaches to agriculture (particularly the use of fertilizer) and waste management; and implementing decentralized, locally-appropriate methods of water-management.