ABSTRACT
ABSTRACT: The paper considers the effects of climate change and reservoir sedimentation on water supply reliability and sustainability. From a global fresh water supply perspective it is argued that river water has the greatest potential for sustainable development. The known fact that reservoir storage is required to reliably supply water from rivers leads to the conclusion that provision of such space will become even more important in the future due to the uncertainties of increased hydrologic variability associated with climate change. The limited availability of dam sites emphasizes the need to indefinitely maintain reservoir storage space for use by future generations, thereby ensuring sustainable development. The current undesirable situation that is characterized by more reservoir storage space being lost to sedimentation than is added through construction of new facilities points to the importance of implementing reservoir sedimentation management techniques. Historically, its implementation has been hampered by an incorrect perception that reservoir sedimentation management is not economically viable. To transform this view it is necessary to acknowledge the dual nature of reservoir storage, i.e., it can be either renewable or exhaustible depending on design and operating decisions. Correct characterization of reservoir storage space and implementation of principles of the economics of exhaustible resources quantifies the value to reservoir sedimentation management, previously ignored. Sustainable and reliable supply of fresh water in the future demands changes in engineering and operating paradigms and changes in the ways dams and their reservoirs are economically evaluated.
