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dam-l E Mag: Are Dams Obsolete/LS
>>www.emagazine.com
>>E Magazine, January-February 1999 issue:
>>
>>Damning Dams:
>>Is One Of The Greatest Engineering Marvels Of The Industrial Age
>>Becoming Obsolete?
>>
>>By Elaine Robbins
>>
>
>> An inevitable part of many 1950s science documentaries was an
>>awestruck tribute to our ability to "tame nature"--by building huge dams
>>and controlling the flow of mighty rivers. There are an estimated
>>800,000 dams on the planet and 40,000 large dams--an incredible 20,000 in
>>China alone.
>>
>> The really big dams are the largest structures ever built by man,
>>engineering marvels as awe-inspiring as the great pyramids of Egypt. And
>>they rival the pyramids for the sheer magnitude of construction: It took
>>5,000 workers on 24-hour shifts for five years to build the colossal
>>Hoover Dam.
>>
>> Dams have also brought great benefits to society. In the 1930s, the
>>great era of dam building in the United States, they brought electricity
>>to rural areas. They helped control flooding and brought irrigation to
>>the arid West. Says Marc Reisner, author of Cadillac Desert, the classic
>>account of dam-building in the American West, the Hoover Dam's "turbines
>>would power the aircraft industry that helped defeat Hitler, would light
>>up downtown Los Angeles and 100 other cities....Hoover Dam proved it
>>could be done."
>>
>> But 50 years later, there are signs that these monuments to the
>>industrial age may not be as permanent as their builders planned. In a
>>proposal that would have been unthinkable 10 years ago, a range of groups
>>are calling for the dismantling of Arizona's Glen Canyon Dam, to restore
>>the Colorado River's original flow. Even Daniel Beard, former
>>commissioner of the Federal Bureau of Reclamation and once a staunch dam
>>defender, has called for Glen Canyon to be dismantled.
>>
>> Glen Canyon isn't the only target of the new dam
>>deconstructionists. Last December, the Quaker Neck Dam in North Carolina
>>became the first big dam to come down. The Edwards Dam in Maine will be
>>removed next summer, and a dam on the Elwha River in Washington will
>>likely be next. As many as a dozen dams are now slated to be dismantled
>>in the U.S., American Rivers reports.
>>
>> Why the seemingly sudden shift? In many cases, the benefits don't
>>justify the damage to fisheries and river ecoystems. Studies in
>>Cambodia, Canada, Laos, Thailand, Brazil and many other countries
>>concluded that dams have a significant effect on fisheries--disrupting
>>migratory fish patterns and spawning habits. On the Columbia River in
>>the American west, for example, the estimated cost of losses to salmon
>>fisheries between 1960 and 1980 was $6.5 billion, according to the
>>National Marine Fisheries Service. The World Bank, the largest single
>>international financier of large dam projects, admits that the results of
>>these studies could mean that the bank's "assumptions about the
>>environmental impact of dams are wrong."
>>
>> Steve Glazer, chair of the Sierra Club's Colorado River task force,
>>sees the effects on western river basins. "Dams have a tremendous impact
>>on natural function in ecosystems," he says. "Because of the changes in
>>temperature and in water quality, the native fish in the Colorado River
>>are all threatened by the construction of dams."
>>
>> New dam construction fragments river habitat the same way a
>>six-lane freeway breaks up land habitat. Juvenile fish are often
>>stranded trying to make the journey to the sea. As reservoirs are
>>filled, severe and immediate flooding leaves river ecosystems
>>significantly altered, and sometimes devastated. But it's not just the
>>species directly affected that are in danger. Dams prevent the seasonal
>>flooding that create species-rich flood plains. And native species
>>downstream often can't survive the colder waters released beneath a dam.
>>Estuaries at the mouth of rivers, deprived of freshwater flow, are often
>>devastated as well.
>>
>> As dam builders move into developing nations, large dams threaten
>>some of the world's greatest remaining stores of biodiversity. According
>>to Philip Williams, president of the California-based International
>>Rivers Network (IRN), existing plans for six major hydroelectric dams
>>threaten the Mekong, "whose biodiversity is second only to the Amazon and
>>whose fishery and floodplains support much of the population of
>>Cambodia." The $1.5 billion San Roque Dam in the Philippines, partially
>>financed by the Export-Import Bank of Japan, is the largest private
>>hydroelectric project in Asia, and is expected to cause considerable
>>erosionand damage local fisheries.
>>
>> And dams are part of a plan to build a 2,000-mile shipping channel
>>into the Pantanal region of Brazil, one of the world's largest tropical
>>wetlands. In Sarawak, on the island of Borneo in Malaysia, preparations
>>were made for "Operation Noah"--an attempt to relocate some of the 220
>>mammal and bird species, 104 fish species, and 1,230 plant species, many
>>unique to Borneo--that were threatened by the planned $5.4 billion Bakun
>>Dam. Fortunately, the project was indefinitely postponed in September
>>1997.
>>
>> Dams also have incalculable human costs, as people are displaced
>>and archaeological treasures inundated. (Since human civilizations often
>>rise along rivers, riparian areas harbor a disproportionate share of the
>>world's archaeological sites.) When China finishes its Three Gorges Dam
>>on the Yangtze in 2009, for example, the project will flood an area with
>>1,208 known historic sites, and displace nearly two million people.
>>
>> In Silenced Rivers: The Ecology and Politics of Large Dams, IRN's
>>Patrick McCully estimates that 30 to 60 million people have been
>>displaced by large dams. "The available evidence suggests very few of
>>these people ever recover from the ordeal, either economically or
>>psychologically," he writes.
>>
>> "We're beginning to understand that we need to put ecosystems back
>>into the equation," says Sandra Postel, director of the Global Water
>>Policy Project. "Even if dams aren't decommissioned or breached, I think
>>there will be more of an effort to manage them in a way that restores
>>some of the ecological functions that have been lost."
>>
>> Even in poor regions like the African Sahel, hard-hit by drought
>>and famine, there is evidence that the benefits dams bring may not
>>outweigh the environmental and human costs. According to a World
>>Resources Institute analysis of a major regional dam project on the
>>Senegal River, many hoped-for economic benefits still hadn't materialized
>>more than 10 years later. But valley fisheries were devastated, forcing
>>people to truck in fish from the coast. Incidents of bilharzia, diarrheal
>>diseases and malaria increased and surprisingly, nutrition has not
>>improved as expected.
>>
>> As the true costs of large dams are better understood, governments
>>may learn the value of small-scale solutions. Environmentalists and
>>river advocacy groups urge a better planning process for large dams.
>>They argue that more efficient energy use and water distribution can go a
>>long way toward making new dam projects unnecessary.
>>
>> Our mighty dams might have been built to last through the ages, but
>>there's nothing that says we can't shorten their lifespans.
>>
>> CONTACT:
>>
>> International Rivers Network
>> 1847 Berkeley Way
>> Berkeley, CA 94703
>> Tel: (510) 848-1155
>>
>>
>>(C) 1999, Earth Action Network
>>Updated by webmaster@emagazine.com
>>http://www.emagazine.com
>>
>
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Lori Pottinger, Director, Southern Africa Program,
and Editor, World Rivers Review
International Rivers Network
1847 Berkeley Way, Berkeley, California 94703, USA
Tel. (510) 848 1155 Fax (510) 848 1008
http://www.irn.org
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