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World Bank Commission Evaluates Impact of Dams by Staff Columbia Basin Bulletin - December 1, 2000

Dams provide electricity, water, flood control and irrigation. But they have also wreaked havoc on people, ecosystems and animals, and have seldom delivered on promises, according to a report by the World Commission on Dams released Nov. 16.

The 12-member Commission included representatives from industry, dam owners, government and environmentalists, with two members from the United States. It was established by the World Bank and the World Conservation Union and began its work in 1998.

In its research on the impact of dams, the Commission focused mostly on nine large dams, including Grand Coulee Dam on the Columbia River in Washington, as being representative of the world's 45,000 large dams. In addition to the benefits dams were meant to provide, the Commission found that they also caused significant negative social and environmental effects that developers never assessed before construction.

"Rivers, watersheds and aquatic ecosystems are the biological engines of the planet," the Commission wrote. "They are the basis for life and the livelihoods of local communities. Dams transform landscapes and create risks of irreversible impacts. Understanding, protecting and restoring ecosystems at river basin level is essential to foster equitable human development and the welfare of all species."

Among the Commission's findings are dams generate 19 percent of electricity worldwide and 24 countries generate more than 90 percent of their energy with dams. Half of the world's dams were built to provide water for irrigation and those account for 12 percent to 16 percent of the world's food production. Twelve percent of large dams supply domestic and industrial water, and large dams provide flood control services in more than 70 countries.

However, in general dams have not delivered all of the predicted water and electricity services or the social benefits claimed by developers ahead of construction. Even dams built for flood control have had a negative effect on protecting property. That's not because the dam failed in its flood control design, but because it "led to greater vulnerability to flood hazards due to increased settlement in areas still at risk from floods," according to the Commission. In addition, the building of large dams has tended to take longer and cost more than predicted.

Dams have had a huge negative impact on people, most of who had little say in whether a dam should be built or in how it would effect them. The report said dams "have fragmented and transformed the world's rivers, while global estimates suggest that 40-80 million people have been displaced by reservoirs." The most recent example of this displacement is the 10,000 villagers in China that were moved to make way for the Three Gorges Dam. They were the first of a predicted 1 million people that will be displaced as that dam is built.

Dams have also affected the livelihoods of many more people who live downstream from dams, particularly those that "rely on natural floodplain functions and fisheries," the report said. It is this aspect -- the inequitable sharing of the costs and benefits of dams -- which the Commission attempts to address in its guidelines for future dam development.

The report concluded:

"the 'end' that any project achieves must be the sustainable improvement of human welfare. This means a significant advance of human development on a basis that is economically viable, socially equitable and environmentally sustainable. If a large dam is the best way to achieve this goal, it deserves support. Where other options offer better solutions, they should be favoured over large dams. Thus the debate around dams challenges views of how societies develop and manage water resources in the broader context of development choices."

Some of those other options could produce energy or provide water at a lower cost and with fewer negative impacts, according to the Commission. Some are small-scale, decentralized water supplies, renewable energy resources, such as wind generation, or conservation of both energy and water.

On the environmental side, it would surprise no one in the Northwest who has followed the decline of salmon that the Commission also found large dams to have caused the loss of forests, wildlife habitat, species and aquatic biodiversity in both upstream and downstream fisheries. The best example in the report of disrupted fish migrations is in the Columbia River where 5 percent to 14 percent of adults die as they pass each of eight dams while swimming upriver to spawn.

In addition, dams have degraded upstream areas due to inundation of the reservoir area. There have also been cumulative impacts on water quality, natural flooding and species composition on rivers where a number of dams are located.

"On balance, the ecosystem impacts are more negative than positive and they have led, in many cases, to significant and irreversible loss of species and ecosystems," the report said.

After assessing all the benefits and costs of dams, the Commission concluded that "the true economic profitability of large dam projects remains elusive, as the environmental and social costs of large dams were poorly accounted for in economic terms." It further concluded that there was "a failure to recognise affected people as partners in the planning process, with rights, and to empower them to participate in the process."

There are 6,375 large dams -- dams higher than 45 feet -- in the U.S. One of those studied was Grand Coulee Dam. In its assessment of the impacts on people and the environment for Grand Coulee, the Commission found that about 2,000 members of the Colville tribe and between 100 and 250 members of the Spokane tribe were displaced as a result of building Grand Coulee. Also, 3,000 to 4,000 non-indigenous people were displaced. The creation of Lake Roosevelt flooded at least eight towns of non-indigenous peoples and two Native American towns.

The dam also completely eliminated salmon runs upstream from the dam. However, by the time the dam was built, those runs had already dropped to 25,000 from an estimated natural run of between 500,000 and 1.3 million fish. Grand Coulee, according to the report, exacerbated the difficulties the mid-Columbia Treaty tribes had to maintain their traditional livelihood by fishing.

Grand Coulee also fostered the development of a strong farming community that contributes significantly to the state's economy, according to the report. In addition, tourism has risen and made significant contributions to the prosperity of the area.

Did Coulee deliver on the promises made by its promoters? Yes and no.
• only about half of the acres proposed receive irrigation water;
• The construction cost to bring irrigation water to the area was estimated at $1.25 billion, but the actual cost was $3.6 billion;
• the original goal of having farmers repay 50 percent of the irrigation construction costs are actually between 10percent and 15percent;
• The estimated cost for two power houses was set at about $2 billion, but cost $2.67 billion, or about one-third more;
• the influence of Grand Coulee on Canadian Treaty projects upstream resulted in further habitat destruction and disruption of the livelihood of Canadian indigenous peoples.

On the other hand, the low-cost power from Grand Coulee and other dams on the Columbia River helped fuel the economy of the Northwest. And, after the third powerhouse came online in 1975, the original predictions of generating capacity and generation were exceeded by an enormous margin, according to the report.

The report said influencing the final outcome of whether to build a dam or not, or how to mitigate a dam's impacts, can best be achieved by gaining public approval through focusing on the key stages in decision-making and in complying with regulators, by making in-depth environmental impact studies mandatory and by taking a hard look at alternatives to dams.

The report closed with this:

"We have conducted the first comprehensive and global review of the performance of dams and their contribution to development. We have done this through an inclusive process that has brought all significant players into the debate. And we believe we have shifted the centre of gravity in the dams debate to one focused on options assessment and participatory decision-making. The rights-and-risks approach we propose will raise the importance of social and environmental dimensions of dams to a level once reserved for the economic dimension."

The World Commission on Dam will meet again in February 2001 to determine its next steps.

Link information:
World Commission on Dams: www.dams.org