The central theme of the paper is that rivers are the most desirable natural resources ensuring sustainable supply of fresh water. To reliably supply water from rivers, it is necessary to create reservoir storage, emphasizing the importance of dams. It is further shown that climate change will lead to more frequent occurrence of multiple-year droughts and that resilience to the effects of climate change will require hydrologically large reservoir storage volumes to reliably supply fresh water. Review of current conditions indicate that reservoir storage volumes are reducing because of reservoir sedimentation, and that more reservoir storage is lost to sedimentation than what it gained by construction of new dams. It is demonstrated that current engineering design philosophy and current approaches to economic evaluation of projects do not support the requirements of sustainable development, most importantly creation of intergenerational equity. The current assumption that reservoir storage is an exhaustible resource, subject to storage loss by reservoir sedimentation, is addressed. It is demonstrated that reservoir storage has a dual nature; it can be either renewable or exhaustible depending on actions of planners, designers, and operators. If dams are planned, designed, and operated with the intent to preserve storage, then reservoirs are classified as renewable resources. If planners, designers, and operators act in a manner 424allowing continued loss of storage to sedimentation, then reservoirs are classified as exhaustible. Classification of whether a reservoir is either renewable or exhaustible is therefore solely dependent on decisions by planners, designers, and operators. It is argued that it is possible to sustainably develop reservoir storage space by changing engineering design philosophy from a design life to a life cycle management concept and to change how projects are economically evaluated. To assist in planning sustainable development of reservoirs, the RESCON 2 approach is introduced, which assists in pre-feasibility assessment of the technical and economic viability of implementing reservoir sedimentation management approaches. In addition, it provides a means of preliminarily assessing the impacts of climate change or reservoir sustainability and selection of reservoir sedimentation management approaches.