ABSTRACT
This chapter argues that why freshwater is a unique type of resource, with characteristics that are notably different from other resources. The relation between the quantity and quality of freshwater flows and ecosystem functioning is the domain of ecologists. Water is for free, so there is no way in which economies account for the scarcity of freshwater resources or the vulnerability of ecosystems to overexploitation or pollution. Water is a local resource because it naturally moves within the boundaries of river basins, without crossing these boundaries. Governments may have programmes to combat pollution and promote efficient use of freshwater resources, but by facilitating economic growth that is based on the ignorance of the fragility of freshwater systems, they effectively do more harm than good if it comes to sustainable water use. Freshwater availability varies strongly within the year and over the years and from place to place, so that scarcity fluctuates over time and space as well.
