Dams should not be designed by laws and computers; they should be designed by the experience and judgment of Engineers.Possible laws or regulations for dams safety should preferably focus on safety targets, not on design methods. Laws for workers safety may be efficient and easily adapted to all dams.
For thousands of years, dams have been used to store water and to create energy. However, 90 percent of global dam investments have been made after 1950, both in terms of the millions of small or medium sized dams and the thousands of dams higher than 50m. The characteristics of these dams vary greatly.
This report, prepared recently for ICOLD’s Committee on Governance of Dams, analyses the roles of dams in the past, present trends in construction and upgrading, the future purposes of dams and their likely development during the XXI Century to maintain sustainable development. It represents a comprehensive study of the sustainability of dams from the technical, economic environmental and social points of view.
The installed worldwide capacity is close to 1000 GW, supplying up to 3.500 TWh/year. A part of the energy may be stored seasonally (20%?) and a large part daily. This production may be adapted to needs or associated with intermittent renewable energies. In many countries the full capacity generation may be permanent during the rainy season (when solar energy is reduced) and mainly used for peak hours during the long dry season.