Environmental Flows: Striking the Balance between Development and Resource Protection

Management of scarce water resources through the use of environmental flows, particularly in developing countries in data-poor arid areas, raises many scientific challenges. These include transforming hydrological data into an ecologically relevant format, providing quantified predictions of river responses to flow change, describing the impacts of river change on common-property users of the rivers, providing the information in a format that decision makers can use, and guiding monitoring and adaptive management. Each of these challenges emerged in South Africa during the last two decades, when rivers and other aquatic ecosystems were enhanced in stature from having no rights to their own water to being one of only two sectors with a right to water; the other sector is for basic human needs. This paper outlines the challenges, how they are being addressed in South Africa, and perceptions of what remains to be done.