Magazine article UNESCO Courier

Large Dams-The End of an Era?

Magazine article UNESCO Courier

Large Dams-The End of an Era?

Article excerpt

Peter [*] Coles

Growing debate about the rights and wrongs of large-scale dam construction focuses on the very meaning of development

At the last count, there were around 40,000 large dams on the world's rivers, according to the International Commission on Large Dams (ICOLD). [1] Most of them were built in the last 35 years. A further 1,600 are under construction in over 40 countries. But is the era of building very large dams coming to an end? Pressure groups of displaced rural communities and ecology organizations have already disrupted dam building in the United States and India.

This coming August the independent World Commission on Dams (WCD), set up in 1998 by the World Bank and IUCN (the World Conservation Union) to look at the long term developmental effectiveness of dams, will publish its conclusions after two years of fact-finding. Preliminary reports to the Commission, whose 12 commissioners span most groups of stakeholders, are already suggesting that the development benefits may not be all they promised. And that the people who gain least from dams are those already at the bottom of the socio-economic pile.

"Dams are both a technology option and a development choice," said South African Minister of Education and WCD Chair Professor Kader Asmal last December. By focusing on dams as a reflection of societal needs, he said, WCD is inevitably confronting the very meaning of "development". "We are tackling the question of how knowledge, interests, and values determine the context within which dams are either chosen or rejected as the preferred option, and how such decisions can best be negotiated between competing interests." Part of WCD's remit is to find out what these interests are. They might, for example, include the needs of industry and urban residents versus agriculture and rural populations, or, more cynically, the dam industry versus those interested in intermediate technology or traditional solutions to development challenges.

For ICOLD, the links between dam building and development are obvious.Two prerequisites for the development of a nation are energy and water, says one ICOLD paper. But since these resources are most scarce precisely where demand is rising most rapidly, dams have become almost synonymous with development. So, while dam building in developed countries has slowed to a trickle in the last decade, major constructions are underway in industrializing countries, like China's massive Three Gorges project and India's Narmada Valley Development project (see article below). Over half of all large dams (more than 22,000) are in China, while India has become the third largest dam constructor in the world, with over 3,000 large dams.

Smoothing the flood-and-drought cycle

Although dams produce power without contributing to the greenhouse effect- about 20 per cent of world electricity and seven per cent of all energy, according to ICOLD--their primary purpose is water control. Reservoirs can provide drinking water, while smoothing out the "boom and bust" cycles of flooding and drought brought about by monsoons. They do this by storing excess water in reservoirs during the rainy season and releasing it in times of scarcity. But by far the greatest use of dams is to supply irrigation water for agriculture. In developing countries, according to the United Nations Environment Programme (UNEP), irrigation accounts for over 75 per cent of water consumption. In some countries, the figure is over 90 per cent.

At present, according to ICOLD, one third of all food produced already comes from irrigated land. And the organization sees irrigation as the only way to meet the future increase in demand, expecting 80 per cent of food production to come from irrigated land by 2025. …

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