Damming evidence

Nehru, India's first prime minister, called large dams "the new temples of India, where I worship". In the post-independence world, when hopes for rapid industrial advance in former colonial territories were high, the giant gleaming dam holding back a mighty river became a potent icon of modernity. Seeing what the Hoover Dam and its successors had done for the American west, every nation wanted one. Or in India's case dozens. They would generate hydroelectricity, provide irrigation for parched soils and control floods as well as supplying cities and industry.

In the past 50 years, India has built more large dams than any nation bar the United States. Now the time has come for appraisal: for balancing the benefits against our growing awareness of the social and environmental costs of this new technology. Earlier this year the World Bank, which has invested more money in large dams than any other body, launched a World Commission on Dams. Its members are not just engineers, but politicians, economists and social and environmental activists. And this book is a valuable contribution from the front line of the dams debate.

The central question Satyajit Singh asks is, on whose behalf have the waters of India's great rivers been tamed? In particular he looks at dams built to provide irrigation. Who gains the water? Who loses it? Who controls the sluice gates and irrigation pumps? He argues that the sheer scale of large dams and their attendant works concentrate both water and power into the hands of elites.

Opposition to large dams in India is intense. The construction of the Sardar Sarovar dam on the River Narmada in Madhya Pradesh has taken place against a constant backdrop of picket lines, hunger strikes and attempts by distraught villagers to drown themselves in the rising flood waters. And there has been a crescendo of international opposition that forced the World Bank to withdraw its own funding.

This is not surprising. By the time its reservoir is full, the Sardar Sarovar dam will have displaced more than 150,000 people, half of them from tribal communities. In theory its waters will irrigate the land of poor farmers in the drought-prone neighbouring state of Gujarat. In practice, because of the nature of Indian politics and the economic imperative to recoup the cost of the dam, the water will go largely to rich plantation owners in that state.

And while Sardar Sarovar grabs the headlines, dozens of other dam projects linked to irrigation schemes go ahead with protests that do not extend beyond the valleys of the rivers to be tamed. An estimated 16 million people have lost their land to large dams in India in the past 50 years.

In the early days of Indian dam building there was little if any compensation for displaced people in money or land. Now things are a little better. At the Tehri dam site in the Himalayas the state authorities have built a new town to replace the one to be flooded. But, as Singh scrupulously relates, it is not so easy to find suitable land on which to relocate a rural community. Most have been hugely impoverished by the process. And, in a densely inhabited country, surely there is an economic cost to the loss of such much land beneath reservoirs that has not been captured in conventional cost-benefit analysis?

Singh is effective in showing how large dams and irrigation projects generally provide a poor economic as well as social return. They continue to be built because they are efficient means of using state cash to divert water resources from rich to poor and from the subsistence to the cash economy. His historical perspective is illuminating. Singh traces the decline of traditional systems of water management back to colonial times and argues against a prevailing view, first propounded 40 years ago by Karl Wittfogel, that the taming of water was a necessarily despotic activity.

In conclusion, Singh joins with many Indian environmental and social campaigners who call for a return to smaller, decentralised and democratic water technologies. Not just because they suit his political and social agenda, which of course they do, but because they work well in engineering and economic terms. It is the fusing of arguments about efficiency and equity that is this book's greatest strength.

Fred Pearce is author of The Dammed.