A Prescription for Reducing the Damage Caused by Dams

Posted: 01-Mar-2001; Updated: 15-Sep-2003

There was a time when no achievement could evoke national pride like a major dam. More than 45,000 large dams (45 feet or higher) were built in the past century, supplying 19% of the world's energy and nurturing almost half the irrigated farmland. But in recent years, the environmental and social harm caused by large dams has become obvious. And as the need for water grows, dams could become a source of international strife.

Now a landmark study has analyzed the performance of large dams. Produced by the World Commission on Dams and unveiled by Nelson Mandela, the study found a landscape of "mostly negative" impacts. Environmental Defense scientist Deborah Moore, as one of the 11 supervising commissioners, played a central role in ensuring that the study stood firm on environmental principles.

"For the first time, dam builders, affected communities and environmentalists have endorsed a common policy for building and managing dams," said Moore, who spent 14 years at Environmental Defense protecting rivers. "Now, avoiding the negative environmental and social impacts of a dam is the priority."

Harming people and wildlife

As many as 80 million people have been displaced by dams worldwide. The projects have often been unprofitable, dogged by corruption or slow to deliver energy or water. In many poor countries, residents who lose their lands and livelihoods receive the fewest benefits from dams.

Dam building has also led to massive loss of wildlife habitat. Rotting vegetation trapped in reservoirs emits methane, contributing to global warming. Large dams have altered river flows downstream, killing plants and fish and causing some species to become extinct.

Moore succeeded in placing recommendations in the final report for alternatives to dams such as water conservation, water trading and other market incentives. Also included is an "intact rivers" policy similar to the U.S. Wild and Scenic Rivers Act, as well as provisions for environmental restoration and reparations to affected communities. The report could help resolve Western U.S. water conflicts, Moore predicted, with its focus on constructive alternatives and on improving operations of existing dams.

"Deborah Moore's participation meant that the Commission had a member with a strong regard for the environment and a high degree of scientific precision," said Commission chair Professor Kader Asmal.

Will the report actually improve how dams are managed? Environmental Defense is leading efforts to ensure adoption of the recommendations by the agencies that bankroll dams. The U.S. Export-Import Bank has already incorporated the recommendations in its new draft environmental guidelines, and we are pressing the World Bank and lenders in Brazil, India and South Africa.

"For the first time, people agree that the environmental and human costs of big dams can outweigh their benefits," says Moore. "This is an opening to reform the entire decision-making process around development projects."