Which of the following problems with the three gorges dam is of greatest concern to experts?

First in a three-part series.

Carpenter Ran Yunnong (behind his home) fixes his boat by the side of the river. He says the river is easier to navigate now, since the dam has been built. Anthony Kuhn, NPR hide caption

toggle caption

Anthony Kuhn, NPR

Carpenter Ran Yunnong (behind his home) fixes his boat by the side of the river. He says the river is easier to navigate now, since the dam has been built.

Anthony Kuhn, NPR

As a massive Chinese reservoir is filled to capacity, concerns resurface about the project's impact on the environment, resettled residents and the region's cultural heritage. Read a series overview.

Rocky cliffs loom over the waters of the Little Three Gorges in Wushan County. Anthony Kuhn, NPR hide caption

toggle caption

Anthony Kuhn, NPR

Rocky cliffs loom over the waters of the Little Three Gorges in Wushan County.

Anthony Kuhn, NPR

One of the farmhouses awaiting destruction on the banks of the Three Gorges Reservoir in Miaohe village, Zigui county, Hubei province. The government is relocating residents following a spate of landslides this year. Anthony Kuhn, NPR hide caption

toggle caption

Anthony Kuhn, NPR

One of the farmhouses awaiting destruction on the banks of the Three Gorges Reservoir in Miaohe village, Zigui county, Hubei province. The government is relocating residents following a spate of landslides this year.

Anthony Kuhn, NPR

Next year, China is expected to reach a milestone when the giant reservoir behind Three Gorges Dam on the Yangtze River reaches its maximum height.

Beijing has long touted the dam — the biggest hydroelectric plant in the world — as a way to stop flooding, increase river shipping and generate clean power.

But in September, officials publicly admitted that the project could lead to environmental disasters, prompting speculation that China's leaders wanted to distance themselves from the project.

Intentions for the Dam

The dam on the Yangtze, the world's third-longest river, is 600 feet high and nearly a mile and a half across. In 2009, when the dam is completed, it will have taken 17 years to build, at an estimated cost of around $24 billion.

About a half-century ago, Chairman Mao wrote a poem envisioning how the dam would conquer the river.

"The dam will cut through the clouds and rain of the Wuxia Gorge, and a smooth lake will appear amid the deep canyons," he wrote.

That's pretty much what it looks like now. The river's once fierce current has been turned into a placid lake, extending for about 370 miles upstream from the dam.

Locals Experience Dam's Changes

Carpenter Ran Yunnong has witnessed the changes. Ran used to work for a shipping company that went bankrupt when one of its boats capsized in a whirlpool, drowning 30 people.

"The whirlpools were big back then. If your boat got caught in one, it would spin you around. Now the river's easy to navigate. Honestly, a 15-year-old kid could steer a boat up it, no problem. There are no big waves anymore," he says.

Across the river, fisherman Wang Zaiguo is tidying up his boat. He says that the rising waters have dramatically changed the river's ecology and affected his livelihood.

"The rising waters have made it hard for us to catch fish," he says. "The fish hide in the middle of the reservoir where the water is deepest and dense water plants prevent our nets from catching them."

A Warning Comes

At a Sept. 25 meeting, top officials in charge of the Three Gorges Project warned that without preventive measures, the dam could cause an ecological catastrophe.

The admission came as a major surprise to critics of the dam, who were used to having their views steamrolled by the government.

"In the past, these problems were taboo," says Wu Dengming, head of the Green Volunteer League of Chongqing. "NGOs and experts have raised them for a long time, but this is the first time the government has done so. This was a great encouragement to us environmental activists."

Deng says the administration of President Hu Jintao has begun to face up to the environmental costs of development. It has taken a cautious attitude toward mega-construction projects. And observers noticed when no central government leader showed up for the ceremony last year marking the official completion of the dam.

At a press conference in November, the government appeared to backpedal hard from its warnings. Wang Xiaofeng, a top cCbinet official in charge of the Three Gorges Project, cited an official 1991 environmental impact assessment. He said its conclusions were still valid.

"The conclusion was that environmental issues will not affect the feasibility of the project. On the whole, the impact of the Three Gorges Project on the environment will have more upside than downside," he says.

The Concerns Over Silt

One concern about the Three Gorges is the issue of silt. Here on the banks of the Yangtze, you often see large shoals of big, flat river rocks. These rocks make a heavy sort of silt, and it takes a strong current to wash it downstream.

Wu Dengming says that 600 million tons of silt enters the reservoir each year. Meanwhile, the dam has slowed the river's flow from its original maximum speed of 13 feet per second.

"Now the speed on the surface is about one foot a second. And at the middle and lower depths of the reservoir, the speed is about zero. This will cause large quantities of silt to accumulate in the Three Gorges," he says.

At the November press conference, government expert Pan Jiazheng rebutted this criticism.

"The amount of silt entering the reservoir is less than 40 percent of what we had estimated," he says. "And the amount of silt discharged downriver through the dam is greater than we had predicted. So everything is under control."

Residents Worry About Pollution

The government also insists that pollution in the reservoir is under control. They point to newly built sewage treatment plants, and sanitation workers who skim thousands of tons of floating rubbish off the reservoir each year.

But problems remain. Residents on the Jialing River, a tributary of the Yangtze River near the city of Chongqing, have been campaigning for years against a local chemical plant that they say is illegally polluting. Qu Guoxiao says he has watched many co-workers die of cancer in the 30 years he has worked at, and lived near, the plant. He adds that the pollution aggravates his own asthma.

"Every night, the factory emits dust and smoke from those chimneys," he says. "It settles on our homes and on the ground, which turns yellow when it rains. It contains acid, mercury and other chemicals and has a great impact on residents' health."

Residents point to a spot where they say the factory dumps polluted water at night, which flows into the Three Gorges Reservoir.

About 20 miles upstream from the dam, residents of Miaohe village are being resettled following a major landslide in April. In September, officials warned that the dam is causing more frequent geological disasters.

As his wife cooks sweet potatoes, one farmer recalls the April landslide. He says officials have warned them not to talk to reporters, and he asks that his name not be used.

"A big crack suddenly appeared in our wall, this wide, stretching from the ceiling almost to the floor. We reported it and local officials came over. They moved us to shelter in a tunnel, where we lived for several months," the farmer says.

Environmental activists concede that the Three Gorges Dam is already a reality, and no amount of criticism will make it go away.

Activist Wu Dengming says that all that can be done now is to keep the threat of environmental catastrophe disaster to a minimum. If there is an environmental disaster, he warns, it won't just be China's problem, it will be the world's problem.

Concerns Rise with Water of Three Gorges Dam

January 2, 200812:01 AM ET

First in a three-part series.

Carpenter Ran Yunnong (behind his home) fixes his boat by the side of the river. He says the river is easier to navigate now, since the dam has been built. Anthony Kuhn, NPR hide caption

toggle caption

Anthony Kuhn, NPR

Carpenter Ran Yunnong (behind his home) fixes his boat by the side of the river. He says the river is easier to navigate now, since the dam has been built.

Anthony Kuhn, NPR

As a massive Chinese reservoir is filled to capacity, concerns resurface about the project's impact on the environment, resettled residents and the region's cultural heritage. Read a series overview.

Rocky cliffs loom over the waters of the Little Three Gorges in Wushan County. Anthony Kuhn, NPR hide caption

toggle caption

Anthony Kuhn, NPR

Rocky cliffs loom over the waters of the Little Three Gorges in Wushan County.

Anthony Kuhn, NPR

One of the farmhouses awaiting destruction on the banks of the Three Gorges Reservoir in Miaohe village, Zigui county, Hubei province. The government is relocating residents following a spate of landslides this year. Anthony Kuhn, NPR hide caption

toggle caption

Anthony Kuhn, NPR

One of the farmhouses awaiting destruction on the banks of the Three Gorges Reservoir in Miaohe village, Zigui county, Hubei province. The government is relocating residents following a spate of landslides this year.

Anthony Kuhn, NPR

Next year, China is expected to reach a milestone when the giant reservoir behind Three Gorges Dam on the Yangtze River reaches its maximum height.

Beijing has long touted the dam — the biggest hydroelectric plant in the world — as a way to stop flooding, increase river shipping and generate clean power.

But in September, officials publicly admitted that the project could lead to environmental disasters, prompting speculation that China's leaders wanted to distance themselves from the project.

Intentions for the Dam

The dam on the Yangtze, the world's third-longest river, is 600 feet high and nearly a mile and a half across. In 2009, when the dam is completed, it will have taken 17 years to build, at an estimated cost of around $24 billion.

About a half-century ago, Chairman Mao wrote a poem envisioning how the dam would conquer the river.

"The dam will cut through the clouds and rain of the Wuxia Gorge, and a smooth lake will appear amid the deep canyons," he wrote.

That's pretty much what it looks like now. The river's once fierce current has been turned into a placid lake, extending for about 370 miles upstream from the dam.

Locals Experience Dam's Changes

Carpenter Ran Yunnong has witnessed the changes. Ran used to work for a shipping company that went bankrupt when one of its boats capsized in a whirlpool, drowning 30 people.

"The whirlpools were big back then. If your boat got caught in one, it would spin you around. Now the river's easy to navigate. Honestly, a 15-year-old kid could steer a boat up it, no problem. There are no big waves anymore," he says.

Across the river, fisherman Wang Zaiguo is tidying up his boat. He says that the rising waters have dramatically changed the river's ecology and affected his livelihood.

"The rising waters have made it hard for us to catch fish," he says. "The fish hide in the middle of the reservoir where the water is deepest and dense water plants prevent our nets from catching them."

A Warning Comes

At a Sept. 25 meeting, top officials in charge of the Three Gorges Project warned that without preventive measures, the dam could cause an ecological catastrophe.

The admission came as a major surprise to critics of the dam, who were used to having their views steamrolled by the government.

"In the past, these problems were taboo," says Wu Dengming, head of the Green Volunteer League of Chongqing. "NGOs and experts have raised them for a long time, but this is the first time the government has done so. This was a great encouragement to us environmental activists."

Deng says the administration of President Hu Jintao has begun to face up to the environmental costs of development. It has taken a cautious attitude toward mega-construction projects. And observers noticed when no central government leader showed up for the ceremony last year marking the official completion of the dam.

At a press conference in November, the government appeared to backpedal hard from its warnings. Wang Xiaofeng, a top cCbinet official in charge of the Three Gorges Project, cited an official 1991 environmental impact assessment. He said its conclusions were still valid.

"The conclusion was that environmental issues will not affect the feasibility of the project. On the whole, the impact of the Three Gorges Project on the environment will have more upside than downside," he says.

The Concerns Over Silt

One concern about the Three Gorges is the issue of silt. Here on the banks of the Yangtze, you often see large shoals of big, flat river rocks. These rocks make a heavy sort of silt, and it takes a strong current to wash it downstream.

Wu Dengming says that 600 million tons of silt enters the reservoir each year. Meanwhile, the dam has slowed the river's flow from its original maximum speed of 13 feet per second.

"Now the speed on the surface is about one foot a second. And at the middle and lower depths of the reservoir, the speed is about zero. This will cause large quantities of silt to accumulate in the Three Gorges," he says.

At the November press conference, government expert Pan Jiazheng rebutted this criticism.

"The amount of silt entering the reservoir is less than 40 percent of what we had estimated," he says. "And the amount of silt discharged downriver through the dam is greater than we had predicted. So everything is under control."

Residents Worry About Pollution

The government also insists that pollution in the reservoir is under control. They point to newly built sewage treatment plants, and sanitation workers who skim thousands of tons of floating rubbish off the reservoir each year.

But problems remain. Residents on the Jialing River, a tributary of the Yangtze River near the city of Chongqing, have been campaigning for years against a local chemical plant that they say is illegally polluting. Qu Guoxiao says he has watched many co-workers die of cancer in the 30 years he has worked at, and lived near, the plant. He adds that the pollution aggravates his own asthma.

"Every night, the factory emits dust and smoke from those chimneys," he says. "It settles on our homes and on the ground, which turns yellow when it rains. It contains acid, mercury and other chemicals and has a great impact on residents' health."

Residents point to a spot where they say the factory dumps polluted water at night, which flows into the Three Gorges Reservoir.

About 20 miles upstream from the dam, residents of Miaohe village are being resettled following a major landslide in April. In September, officials warned that the dam is causing more frequent geological disasters.

As his wife cooks sweet potatoes, one farmer recalls the April landslide. He says officials have warned them not to talk to reporters, and he asks that his name not be used.

"A big crack suddenly appeared in our wall, this wide, stretching from the ceiling almost to the floor. We reported it and local officials came over. They moved us to shelter in a tunnel, where we lived for several months," the farmer says.

Environmental activists concede that the Three Gorges Dam is already a reality, and no amount of criticism will make it go away.

Activist Wu Dengming says that all that can be done now is to keep the threat of environmental catastrophe disaster to a minimum. If there is an environmental disaster, he warns, it won't just be China's problem, it will be the world's problem.

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