LIBERATING THE RIVERS: All the Wild Rivers.

• Author: Runyan, Curtis
• Position: Three articles included; environmental effects of dams - Statistical Data Included

In the United States, the number of dams being torn down now outnumbers those being built. Elsewhere as well, people are having second thoughts about the great 20th-century enthusiasm for controlling arid harnessing rivers.

In 1966, Floyd Dominy, the commissioner of the U.S. Bureau of Reclamation, gave a speech lambasting environmentalists for their opposition to damming up the Grand Canyon national park. If the dams were not built, he told the audience, the Colorado River would be "useless to anyone." Dominy, head of the agency that led the charge in the United States' rush to dam up its rivers, concluded: "I've seen all the wild rivers I ever want to see."

Thirty years later, in 1998, Bruce Babbitt, the U.S. Secretary of the Interior, traveled across the country to several rivers on a "Sledgehammer tour"--not to break ground on new construction, but to tear four dams down. "America overshot the mark in our dam building frenzy," he said in a speech to the Ecological Society of America. "For most of this century, politicians have eagerly rushed in, amidst cheering crowds, to claim credit for the construction of 75,000 dams all across America. Think about that number. That means we have been building, on average, one large dam a day, every single day, since the Declaration of Independence. Many of these dams have become monuments, expected to last forever. You could say forever just got a lot shorter."

One of the world leaders in building new dams, the United States, is now leading the world in tearing them down. The country is now decommissioning more large dams than it builds each year, and has removed at least 465 of them, according to a study by American Rivers, Friends of the Earth, and Trout Unlimited. France and other countries are following suit. "It's striking how, in just two or three decades, the U.S. has gone from building dams to not building dams to taking some of them down," wrote Marc Reisner, author of Cadillac Desert, in the Earth Day 2000 edition of Time magazine. "What we're just beginning to understand is how water development has, like nuclear energy, amounted to a Faustian bargain between civilization and the natural world."

Ecologically, rivers are under siege. They are being drained, diverted, polluted, and blocked at a rate that has degraded freshwater ecosystems worldwide. With more than half of the world's rivers stopped up by at least one large dam (over 15 meters high), dams have played a significant role in destabilizing riverine ecology. For example, at least one fifth of the world's freshwater fish are now endangered or extinct. In addition, reservoirs behind dams have flooded vast amounts of the world's most fertile agricultural and forest land. Reservoirs also trap the sediment loads of rivers, reduce the supply of nutrients flowing downstream, release water at cooler temperatures, and disrupt healthy river ecosystems.

The ill-effects of dams are not confined to river valleys. Half of the world's dams were built to irrigate the farmland that now provides about 12 to 16 percent of the human food supply. However, channeling water to irrigate basins without good drainage has led to extensive salinization and waterlogging of soils. Bad drainage and poorly planned irrigation--including groundwater pumping--have reduced or ended the productivity of nearly one-fifth of the world's irrigated land.

The impact of dam building on communities has also been substantial. An estimated 40 to 80 million people have been physically displaced by the construction of dams. They have been flooded our, forced to move. One of the world's most massive engineering projects, the Three Gorges Dam in China, if completed could force the relocation of nearly 2 million people. Most frequently, the people affected are not those who receive the irrigation, electricity, or other benefits provided by dams. In fact, those who are resettled have rarely ever seen their livelihoods restored. "The poor, other vulnerable groups, and future generations are likely to bear a disproportionate share the social and environmental costs of large dam projects without gaining a commensurate share of the economic benefits," finds the World Commission on Dams (WCD), an independent, collaborative body consisting of dam construction industry representatives, anti-dam activists, and government officials, among others. The commission released its land mark report in November 2000, providing one of the first global surveys of dams with input from both supporters and critics.

The U.S. effort to consider dam removal or breaching is only part of a worldwide shift in thinking about dams. (See "Stream of Consciousness," page 36.) In almost every country in the world, the number of new dams being built is plummeting. Ninety-one large dams were built in the 1970s in Brazil, for instance. The number built dropped to 60 in the 1980s, and to 28 in the first six years of the 1990s (see graph below). Even where dams continue to be built, public acceptance is waning, says Owen Lammers of the Glen Canyon Action Network, an ambitious U.S. activist group pushing to tear down the massive Glen Canyon Dam in Arizona. "The number of dams being constructed is going down," says Lammers, "while the number facing resistance and severe criticism is going up."

Evoking the almost religious fervor with which dams have been built in the past, Prime Minister Jawaharlal Nehru called the massive concrete and earthen structures being put up around his country "the temples of modern India." But after a half-century of being regarded as technological marvels, many of these structures are being re inspected and rejected as boondoggles.

Still, the number of dams and dam projects that have been stopped or removed is only a tiny fraction of those that have been built in the past half century. And projects that face strong opposition may also be getting strong support from urban residents, large-scale farmers, or other groups that stand to benefit from a dam's construction. The Sardar Sarovar Dam on India's Narmada River, for example, is at the center of the country's debate over how development should occur. The Narmada Bachao Andolan (NBA), the local movement opposed to the damming, has rallied international attention against the project, which includes plans to construct 3,200 dams on the river. But despite the opposition, in October 2000 the Indian Supreme Court lifted its four-year stay on the project.

When the global rush to build dams reached its peak in the 1970s, on average two or three large dams were commissioned around the world every day. International lenders, governments, development agencies all felt they had found in dams a solution to many of the world's development dilemmas. Dams have played an important role in addressing hunger, drought, and lack of access to clean water and electricity. They generate 19 percent of the world's electricity supply, provide water for 30 to 40 percent of the world's irrigated land, and in some places help to reduce floods. But the benefits of controlling unruly waterways--building dams and creating reservoirs with the aim of halting floods, expanding irrigation, providing drinking water, and supplying hydroelectric energy--have always been assumed to overwhelmingly outweigh the costs, even though little was known about what these costs were. However, as researchers conduct more studies on the effects of dams and as more of the local people who are affected are consulted, the assumption that the benefits outweigh the costs has become less certain.

Now that more than 45,000 large dams (over 15 meters high) have been built around the world, a growing body of research indicates that their costs may be higher than many ever imagined. The World Commission on Dams report finds that "In too many cases an unacceptable and often unnecessary price has been paid [to secure the benefits of dams], especially in social and environmental terms, by people displaced, by communities downstream, by taxpayers, and by the natural environment." Irrigation schemes haven't supplied projected revenues, hydropower dams have not met electricity-generation projections, drinking water supplies have been costly and often unreliable, and reservoirs have lost their usefulness as they fill with sediment. Recent studies have shown that the organic debris washed into reservoirs releases large amounts of greenhouse gases, raising questions as to whether hydroelectric dams really do produce clean, renewable energy. "Considering the enormous capital invested in large dams, it is surprisin g that substantive evaluations of project performance are few in...