Amerika menghancurkan 850 Bendungan untuk merestorasi Sungai dan mengembalikan jalur migrasi Ikan Salmon. Kita dipropaganda bahwa bendungan seolah satu2nya opsi untuk pengairan dan sumber energi terbarukan. Sementara negara2 maju sudah faham dampak buruknya lebih intens dibanding dampak baiknya, sehingga beranjak meninggalkan konsep bendungan -yang man made- kita malah membangunnya. Sementara negara2 maju makin memilih opsi rehabilitasi daerah tangkapan air dan reklamasi aliran sungai, negeri ini malah meninggalkan kearifan tradisional merawat daerah aliran sungai dan menegasikan nilai-nilai dan fungsi-fungsi alam yg demikian canggih dan memberikan kemanfaatan jangka panjang yg tak tergantikan. Mari terus kampanyekan perbaikan ekosistem daerah aliran sungai daripada membangun bendungan: mahal, jangka pendek, memutus aliran fungsi ekosistem, membuang emisi gas rumah kaca, dst.

lemahsagandu

Foto dari atas Bendungan Jatigede Kabupaten Sumedang Jawa Barat, 1389Ha Hutan akan ditenggelamkan, 2041 Sawah Subur akan ditenggelamkan, 28 Kampung Buhun, dan 25 Situs Cagar Budaya Sunda akan dihancurkan, 11.000 KK akan dimiskinkan.

Dari National Geographic: American Rivers reports that in the United States, nearly 850 dams have been removed in the last 20 years, with more than a hundred removed in 2012 and 2013 alone. “We’re at the end of the large dam-building era in this country and the beginning of the river restoration era,” says Irvin.

The Glines Canyon Dam, however, is the largest dam to be demolished so far and will likely remain so for some time. The Elwha’s location in a national park fueled unusually broad support—and federal funding—for its restoration and simplified the logistics of dam removal. With climate change rendering much of the American West increasingly vulnerable to drought, the region cannot easily give up large dams that provide not only electricity but also water storage.

Meanwhile, hundreds of large dams are planned or under construction in developing countries. Demand for electrical power in urban Thailand, for example, is driving the construction of two large dams on the mainstem of the Mekong River, and nine more large dams are proposed—a cascade that threatens the productivity of the largest freshwater fishery in the world. A recent op-ed in the New York Times calls such large dams “brute-force, Industrial Age artifacts,” arguing that they not only are environmentally and socially costly but also place huge financial burdens on the countries that build them.

In this photo taken June 3, 2014, the Elwha River flows into the Strait of Juan de Fuca near Port Angeles, Wash.

The Elwha River flows into the Strait of Juan de Fuca, carrying sediment once trapped behind dams. The gradual release has rebuilt riverbanks and created estuary habitat for Dungeness crabs, clams, and other species.

Photograph by Elaine Thompson, Associated Press

Michelle Nijhuis

for National Geographic

Published August 26, 2014

Today, on a remote stretch of the Elwha River in northwestern Washington state, a demolition crew hired by the National Park Service plans to detonate a battery of explosives within the remaining section of the Glines Canyon Dam. If all goes well, the blasts will destroy the last 30 feet of the 210-foot-high dam and will signal the culmination of the largest dam-removal project in the world.

In Asia, Africa, and South America, large hydroelectric dams are still being built, as they once were in the United States, to power economic development, with the added argument now that the electricity they provide is free of greenhouse gas emissions. But while the U.S. still benefits from the large dams it built in the 20th century, there’s a growing recognition that in some cases, at least, dambuilding went too far—and the Elwha River is a symbol of that.

The removal of the Glines Canyon Dam and the Elwha Dam, a smaller downstream dam, began in late 2011. Three years later, salmon are migrating past the former dam sites, trees and shrubs are sprouting in the drained reservoir beds, and sediment once trapped behind the dams is rebuilding beaches at the Elwha’s outlet to the sea. For many, the recovery is the realization of what once seemed a far-fetched fantasy.

“Thirty years ago, when I was in law school in the Pacific Northwest, removing the dams from the Elwha River was seen as a crazy, wild-eyed idea,” says Bob Irvin, president and CEO of the conservation group American Rivers. “Now dam removal is an accepted way to restore a river. It’s become a mainstream idea.”

(Related: “Spectacular Time-Lapse Video of Historic Dam Removal.”)

Before the Park There Was the River

The Elwha runs for 45 miles, from the Olympic Mountains to the Strait of Juan de Fuca, and all but its final five miles lies within what is now Olympic National Park. Long before the park was established in 1938, the river was regionally famous as the richest salmon river on the Olympic Peninsula. For generations, the Lower Elwha Klallam Tribe, whose members live at the mouth of the Elwha, depended on the river’s fish and shellfish for survival. But the peninsula was also famous for its massive trees, and in the early 1900s, the local timber industry needed power for its mills and its growing ranks of workers.

Fish were no match for finance, and the 108-foot-high Elwha Dam, located five miles upstream from the river’s outlet, started generating power in 1914. “There is no question but that the Elwha is harnessed at last and forever,” a local newspaper reporter crowed at the time. The larger Glines Canyon Dam, eight miles further upstream and inside what is now Olympic National Park, began operations in 1927.

News map of the Elwha river and its former dams.

NG MAPS. SOURCES: Washington State Department of Ecology; Washington State Department of Natural Resources

For almost half a century, the two dams were widely applauded for powering the growth of the peninsula and its primary industry. But the dams blocked salmon migration up the Elwha, devastating its fish and shellfish—and the livelihood of the Lower Elwha Klallam tribe. As the tribe slowly gained political power—it won federal recognition in 1968—it and other tribes began to protest the loss of the fishing rights promised to them by federal treaty in the mid-1800s. In 1979, the U.S. Supreme Court ruled that Washington tribes, including the Elwha Klallam, were entitled to half the salmon catch in the state.

With this court victory behind them, the tribes began to fight for the protection and restoration of salmon runs. In the mid-1980s, the Elwha Klallam and environmental groups started to push for dam removal in earnest, arguing that their environmental costs and safety risks outweighed their benefits—especially because the Olympic Peninsula had long since been connected to the regional power grid, and the dams now provided only a small fraction of the power used by its residents and mills. In 1992 Congress authorized federal purchase of the two dams on the Elwha from the timber companies that owned them and ordered a study of the idea of removing them.

A Slow Demolition

It would take nearly two decades more for dam demolition to begin—much longer than it took to build the dams in the first place. The timber industry and some local communities opposed the idea, and U.S. Senator Slade Gorton of Washington blocked federal funding until he was voted out of office in 2000.

Though a few smaller dams had been removed from U.S. rivers, no one one had attempted a dam removal as large as the one proposed for the Elwha. The unknowns were daunting: What would happen to the estimated 27 million cubic yards of sediment (21 million cubic meters)—enough to fill the Seahawks’ CenturyLink Field nine times over—trapped behind the dams? How would salmon and other wildlife respond to a free-flowing river? How would tribal members and other nearby residents be affected?

In 2004, the tribe, the National Park Service, and the city of Port Angeles reached an agreement on dam removal. The dams would be taken down in several stages, allowing for a relatively gradual release of sediment. Two water-treatment facilities would be built to protect local water supplies, and the tribe would receive federal funds for a new, larger fish hatchery.

Finally, on September 15, 2011, a barge-mounted excavator began chipping concrete off the upstream face of Glines Canyon Dam. Removal of the Elwha Dam began later that week. At a ceremony by the river, former Senator Bill Bradley of New Jersey praised the demolition of the dams in terms that wouldn’t have sounded out of place at their inauguration. “The reflection you see in Elwha is an image of what our country is capable of,” he told the crowd.

Six months later, the Elwha Dam was gone, and the river flowed in its original channel for the first time in more than a century. Steelhead and coho salmon transplanted above the dam site spawned in the river’s tributaries, and juvenile coho were spotted. In the summer of 2012, Chinook salmon began migrating up the river, and by the following fall, they too had spawned in tributaries and in the Elwha mainstem.

“We had heard there would be all these positive changes,” says Robert Elofson, river restoration director for the Lower Elwha Klallam Tribe and an early advocate of dam removal. “But to actually watch it in action—well, it’s very, very impressive.”

In this June 3, 2014 aerial photo, the Elwha River flows freely through what was Lake Mills and past the old Glines Canyon Dam, bottom, in the Olympic National Park near Port Angeles, Wash.

In the world’s largest dam removal project, the Elwha River now flows past the old Glines Canyon Dam (at bottom) in Olympic National Park.
Photograph by Elaine Thompson, Associated Press

The River Returns

Over the past three years, the sediment trapped behind the dams has washed downstream, rebuilding riverbanks and gravel bars and, in and around the river’s mouth, creating some 70 acres of new beach and riverside estuary habitat for Dungeness crabs, sand lance, surf smelt, clams, and other species. On the ocean bottom just offshore, what used to be a kelp-covered expanse of cobbles is now blanketed with mud and sand, also good habitat for crabs and sand lance. “We’re seeing all sorts of different creatures. It’s fantastic,” says U.S. Geological Survey researcher Jonathan Warrick. The Elwha Klallam tribe hopes that eventually, its members will once again be able to harvest shellfish near the mouth of the Elwha.

As salmon populations recover, researchers expect the whole food web—from invertebrates to birds to otters and bears—to benefit. Smithsonian research fellow Christopher Tonra, who is studying American dippers on the Elwha, says that almost as soon as salmon returned to the river, the birds began to follow the fish and to eat salmon eggs and fry. “To see these birds that had never been exposed to spawning salmon before immediately respond to the resource—that’s been really exciting,” he says. Analysis of nitrogen isotopes in dipper blood, feathers, and toenail clippings suggests that the birds are indeed benefiting from the nutrients salmon provide.

Other animals have been slower to adapt to the changes on the Elwha. The reservoirs behind the Elwha and Glines Canyon dams have been drained and revegetated, and the young trees and shrubs are attractive food for deer, elk and other species. But the area’s Roosevelt elk, known to be creatures of habit, have yet to discover the tasty vegetation growing behind the Elwha dam site.

“The buffet table has been set, and the elk are sometimes just a couple of hundred yards away,” says Elwha Klallam tribe wildlife biologist Kim Sager-Fradkin. “But the elk haven’t crossed the highway and discovered that the reservoir is gone. Once they find out, I don’t know if they’re ever going to leave.”

The Elwha’s recovery is not without controversy. The tribal fish hatchery has been criticized by some environmental groups for initially stocking a population of steelhead trout that’s not native to the river. And though the river and its denizens appear to be thriving, both the dams and their removal have wrought great and lasting changes that won’t readily be undone.

Rebecca Brown, a professor at Eastern Washington University who is studying the effects of the dam removal on riverside vegetation, says that the release of so much sediment in such a short time has created an ecosystem that’s distinctive and likely to stay that way. “A thousand years from now, we’re still going to be able to see the effects of this sediment dump,” she says.

Dam Bust, Dam Boom

American Rivers reports that in the United States, nearly 850 dams have been removed in the last 20 years, with more than a hundred removed in 2012 and 2013 alone. “We’re at the end of the large dam-building era in this country and the beginning of the river restoration era,” says Irvin.

The Glines Canyon Dam, however, is the largest dam to be demolished so far and will likely remain so for some time. The Elwha’s location in a national park fueled unusually broad support—and federal funding—for its restoration and simplified the logistics of dam removal. With climate change rendering much of the American West increasingly vulnerable to drought, the region cannot easily give up large dams that provide not only electricity but also water storage.

http://player.d.nationalgeographic.com/players/ngsvideo/share/?feed=http://feed.theplatform.com/f/ngs/dCCn2isYZ9N9&guid=00000148-134a-d1e0-a1fe-d3df81e70001&link=http://video.nationalgeographic.com/video/

This video by the National Park Service, produced last year as part of a series, shows how the dam removal is restoring the Elwha River.
Video by Wings Over Watersheds

Meanwhile, hundreds of large dams are planned or under construction in developing countries. Demand for electrical power in urban Thailand, for example, is driving the construction of two large dams on the mainstem of the Mekong River, and nine more large dams are proposed—a cascade that threatens the productivity of the largest freshwater fishery in the world. A recent op-ed in the New York Times calls such large dams “brute-force, Industrial Age artifacts,”  arguing that they not only are environmentally and socially costly but also place huge financial burdens on the countries that build them.

Once the final section of the Glines Canyon Dam is removed this week, the remaining sediment behind it will begin to move downstream. Because of several years of low precipitation in the Pacific Northwest, sediment has so far moved more slowly than expected, and researchers hope a hearty flood or two will help move the rest. No matter the weather, however, the demolition means that salmon will regain access to the 75 miles of river habitat blocked by the dams.

Brian Winter, who has worked on Elwha River restoration for the National Park Service since 1993, is looking forward to seeing Chinook salmon swimming above the dam site, within the park’s designated wilderness. The season’s Chinook run has already started, so chances are slim that any fish will make it that far this year. But whether they return this year or next, he plans to hike in and see them arrive.

“I’ll be there,” he says. “I just want to sit on the bank and watch that happen.”

Info dari World Commission on Dams, www.internationalrivers.org tentang 10 hal yang harus diketahui tentang bendungan… Bendungan tidak seindah yang dikampanyekan oleh pemerintah tentang segala manfaatnya… masalah utama adalah AIR. Apakah kita perlu bendungan atau kita perlu air… Sumber air tidak harus dari bendungan… dengan hutan kita terjaga, aliran sungai tetap terjaga, mata air dipelihara, situ, embung, atau telaga alami terpelihara maka kita tidak perlu Bendungan.

10 Things You Should Know About Dams

By: Peter Bosshard,Date: Tuesday, May 27, 2014


1. 50,000 Large Dams Are Clogging the World’s Rivers:

About 50,000 dams with a height of 15 meters or more and millions of smaller dams have been built on the world’s rivers. Some of them date back centuries, but most were built after World War II. About 5,000 dams have a height of 60 meters or more; another 350 such giants are currently under construction.

2. Dams Are Changing the Face of the Earth:

Dams have fragmented two thirds of the world’s large rivers and flooded a land area the size of Spain. Their reservoirs contain three times as much water as all the world’s rivers, and constantly lose close to four Niagara Falls to evaporation. Dams trap 40 cubic kilometers of sediments every year, and starve deltas of the silt that protects them against the intruding sea.

3. Dams Provide Important Services:

Dams generate 16% of the world’s electricity and irrigate food crops for 12-15% of the world’s population. To a lesser extent, dams have also been built for water supply, flood protection, navigation and tourism purposes. Most dams have been built for irrigation, but 80% of the water they store is used for hydropower.

4. Dams Kill Fish:

Dams block the migration of fish, deplete rivers of oxygen, and interfere with the biological triggers that guide fish. They also reduce the ability of rivers to clean themselves. Due to dam building and other factors, the population of freshwater species declined by 37% between 1970-2008 – more than the populations of any other ecosystems. Tropical freshwater populations declined by a stunning 70%.

5. Dams Are Changing the Climate:

Dams are not climate-neutral. Particularly in the tropics, organic matter rotting in their reservoirs emits methane, an aggressive greenhouse gas. Scientists have estimated that reservoirs account for 4% of all human-made climate change, equivalent to the climate impact of aviation. The floods and droughts caused by climate change in turn make dams less safe and less economic.

6. Dams Displace People:

Dams have displaced an estimated 80 million people, with 23 million alone in China. Displacement robs people who are already poor and marginalized of their resources, skills and cultural identity, and impoverishes them further. Dams have also negatively impacted about 500 million people living downstream. The benefits of dams often bypass the people who sacrifice their livelihoods for them.

7. Dams Can Put Human Rights at Risk:

Most dams that displace large populations are being built by authoritarian governments. In Burma, China, Colombia, Ethiopia, Guatemala, Sudan and other countries, dam builders have often responded to opposition with serious human rights violations. In the worst dam-related massacre, more than 440 indigenous people were killed to make way for Guatemala’s Chixoy Dam in 1982.

8. Dams Are Expensive:

Large dams belong to the most expensive investments many governments have ever made. An estimated 2000 billion dollars has been spent on dams since 1950. Due to planning errors, technical problems and corruption, dams experience average delays of 44% and cost overruns of 96%. Such massive overruns make them uneconomic.

9. Dams Don’t Last Forever:

Sooner or later reservoirs silt up, and the cost of maintaining dams becomes bigger than their benefits. In the United States, more than 1000 dams have been removed at great cost. When dams are not properly built or maintained, they can break. In the world’s biggest dam disaster, the failure of China’s Banqiao Dam killed an estimated 171,000 people in 1975.

10. Better Solutions Are Usually Available:

In 2012, governments and businesses installed 75 gigawatt of wind and solar power, compared with 30 gigawatt of hydropower. Such alternatives fare even better when social and environmental impacts and transmission costs are included. The International Energy Agency has proposed that 60% of the funds needed to achieve energy access for all should go to local renewable energy projects.

Sumber: http://www.internationalrivers.org/node/8326

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