Challenges of reservoir planning and management in a changing world

Possible shifts of the rainfall regime in the next decades may have important implications for reservoir planning and management. Also, land use change may alter the inflow regime to reservoirs, including the water and sediment dynamics. This paper reviews challenges to reservoir planning and management, and emerging approaches to address these issues in a changing world. Changing persistence of stream flow may increases the uncertainties of sizing reservoir storage, and changing floods may increase the uncertainties associated with spillway design. Short term reservoir operation can be supported by ensemble forecasts and robust operation models to assess the uncertainties of management alternatives. Reservoir sedimentation is a major issue in many parts of the world which may be exacerbated by changes in catchment land use. It is argued that robust bottom-up approaches are needed that are vulnerability or resilience centred to complement the traditional top-down (scenario) approaches to reservoir planning and management.