Large dams - a contribution to sustainable water and energy development?

Looking back on 5000 years of history, dams are still a decisive technology to balance the uneven distribution of water in space and time, raise the water head for hydropower generation, and reduce or increase downstream runoff, thus delivering flood protection or low flow augmentation. Because strong negative impacts on both humans and nature were experienced through large dams, especially during the second half of the twentieth century, new projects were hampered during the 1980s and 1990s. Both governance and economy systems play a decisive role in these developments. The World Commission on Dams was founded in 1998 to carry out a global review on the effectiveness of dams, and to develop criteria and guidelines to make new dam building projects more sustainable. For future planning, special attention has to be given to a participatory approach as well as to the impacts of global change and uncertainty aspects. To cope with these requirements it is suggested that multi-criteria decision support should be implemented as a planning method.