Author(s): De Cesare Giovanni; Lafitte Raymond
Linked Author(s):
Keywords: Reservoir sedimentation management; Sustainable development; Historical overview; Reservoir design and operation; Life cycle assessment
Abstract: An analysis of the evolution of the reservoir sedimentation technology during the 20th century was carried out based more particularly on statistics of some 400 publications related to the subject. The situation appears as follows: in the first half of the century, the theoretical aspects of sediment transport and silting of reservoirs were generally known. The removal processes of deposited sediment by flushing and dredging, and the routing by sluicing and venting were also known and applied in some particular cases. Only after 1970 these curative processes became more generally studied, developed and applied. It was only in the 1980s, that the concept of an integrated reservoir sedimentation management began to be clear and coherent and the phenomenon of reservoir sedimentation recognized to its full degree of significance. The problems of reservoir sedimentation and its countermeasures are clearly set out in the 1999 ICOLD Bulletin 115 "Dealing with reservoir sedimentation", and more recently, 2003, in RESCON (Reservoir Conservation) published under the auspices of the World Bank. This development has a key impact on how to choose the most economically feasible and technically sound method of prolonging the useful life of artificial reservoirs. It is expected to help provide economic and conservation benefits for the years to come. With somehow common practice in reservoir design and operation, neglecting the impact of reservoir sedimentation and not providing countermeasures where needed, hydropower with storage may be considered as non-sustainable. The simple principle for reservoir sediment management, if there is enough water available, was announced succinctly by Chinese engineers in 1976 "Store the clear water and discharge the muddy water". But despite that knowledge, large reservoirs have been created to be ultimately filled with sediment. In 1987, Mahmood summarized the situation of worldwide reservoir sedimentation as follows: …the average age of man made storage reservoirs in the world is estimated to be around 22 years. This is simply too short for structures that, in best conditions, may be technically available for at least hundred years. Life cycle assessment of a reservoir project designed to be sustainable regarding it storage volume would lead to a long term economic solution, which is in addition more environmentally friendly and easier accepted by the general public.
Year: 2007