The multi-year research effort in this volume has demonstrated that (1) similar challenges are faced by all SERIDAS rivers, (2) problem recognition varies widely across basins, and (3) response strategies are not sufficiently grounded in the long-term goal of river sustainability. We recommend that river managers and stakeholders follow these guidelines: Determine the river’s dependable yield – the water supply, averaged over the period of the most severe drought experienced in the historical record. Use the dependable yield to define and implement a river management strategy that carefully balances human and ecological needs in the basin. To meet human needs, do more with less – practice water conservation. This is the best obtainable strategy for redefining and maintaining river sustainability.

A reservoir is a replacement of a segment of the river with a watercourse that is quite different, a larger, more quiescent water body with different water quality and capable of stratification. This chapter describes design and functions of river reservoirs. The main challenges faced by SERIDAS reservoirs are highlighted. Special attention is given to a reservoir’s dependable yield, which can be maintained constantly without failure throughout the time history of reservoir storage. All reservoirs act as sediment traps and will eventually silt up unless special actions are taken to manage sediment. Reservoirs significantly alter the hydrology of the river downstream from the dam and can affect its water quality and its ecosystem. With increases in population and agriculture, water demands will increase, exacerbated by climate changes. Skillful management will be needed to temper conflicts that arise over how reservoirs will be operated under situations of incompatible objectives.