Economics of reservoir sedimentation and sustainable management of dams

Accepted practice has been to design and operate reservoirs to fill with se diment, generating benefits from remaining storage over a finite period of time. The consequences of sedimentation and project abandonment are left to the future. This 'future' has already arrived for many existing reservoirs and most others will eventually experience a similar fate, thereby imposin g substantial costs on society. Such costs could be avoided if sedimentatio n was minimized and dams were allowed to live forever. The fact that the wo rld's inventory of suitable reservoir sites is limited provides an addition al reason for encouraging the sustainable management of dams. This paper pr ovides a framework for assessing the economic feasibility of sediment manag ement strategies that would allow the life of dams to be prolonged indefini tely. Even if reduced accumulation or removal of sediment is technically po ssible, its economic viability is likely to depend on physical, hydrologica l and financial parameters. The model presented incorporates such factors a nd allows a characterization of conditions under which sustainable manageme nt would be desirable. The empirical implementation of the model draws upon the substantial amount of technical information available. We analyze the sustainability of reservoirs, with a focus on the trade-off between such su stainability and the short to medium term benefits which a reservoir is exp ected to produce. The results show that, for a very wide range of realistic parameter values, sustainable management of reservoirs is economically mor e desirable than the prevailing practice of forcing a finite reservoir life through excessive sediment accumulation. (C) 2001 Academic Press.