Marvel or menace? Thirteen cities were razed to build Three Gorges (Image: Zhang Xiaofeng (Hubei)/Corbis)
The superlatives fly when it comes to the Three Gorges, but is it delivering the promised benefits? 麻豆传媒 travelled down the Yangtze to find out
OUR Chinese guide waves a flag above his head and we follow him past manicured gardens and a delicate lady playing a four-stringed 鈥減ipa鈥�, until we reach a lookout point. Here, with the Three Gorges dam looming in the background, the gushing commentary continues.
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鈥淭he dam is the largest in the world, built with 27 million cubic metres of concrete. It has the largest generating capacity in the world and the largest鈥︹��
I am distracted by the fact that we can鈥檛 actually see much of the dam, thanks to China鈥檚 notorious pollution. The 2-kilometre-long dam wall disappears into a cloud of smog. Somewhat fitting, given that our guide was telling only half the story anyway. This is the biggest dam in the world, but it also has the biggest problems 鈥� from unexpectedly fast silt build-up to dam-triggered earthquakes and erosion far downstream.
A few years ago, the Chinese government openly acknowledged that there were 鈥渦rgent problems鈥� that need to be addressed. Since then, things have gone quiet. So I embarked on a 1500-kilometre journey down the Yangtze river to find out what is happening.
See our interactive map of Hadfield鈥檚 journey: 鈥�A trip along the Yangtze鈥�
My journey started at the other end of this extremely long and thin reservoir, 600 kilometres away in the inland city of Chongqing (pronounced 鈥淐hong-ching鈥�). Thanks to the dam, which got the go-ahead in 1992, tankers and cargo freighters can now travel all the way to this city. The increased ship traffic has made Chongqing one of the fastest-growing cities in China.
Even this far inland, just above the reservoir, the river is impressive: several hundred metres wide and fast-flowing, thick with brown sediment. This turns out to be the first sign that something has gone wrong.
鈥淏efore the dam was built, they modelled everything,鈥� says Fan Xiao, an engineering geologist with the Sichuan Bureau of Geological Exploration and Exploitation of Mineral Resources. The model predicted that the water would slow down as it entered the top of the reservoir, near Chongqing, and drop most of its silt there, he says. But the flow through the reservoir is faster than predicted, so more silt is being carried further downstream towards the dam wall, and building up throughout the reservoir.
鈥淪ilt is building up much faster than predicted. One channel is already blocked鈥�
鈥淎ccording to a 2012 report, the dam is now retaining as much as 90 per cent,鈥� Fan says. In some parts of the reservoir, silt is building up to a depth of 60 metres 鈥� nearly two-thirds the maximum depth of the reservoir itself. The dam continues to accumulate silt at the rate of around 200 million cubic metres a year.
As a result, says Fan, one of two navigation channels that pass either side of an island in the reservoir has been completely blocked, forcing ship traffic in both directions to follow a single channel. Worse still, silt is building up at the dam wall. A lot of it has to be cleared by dredgers to make sure it doesn鈥檛 interfere with the turbines that generate around 2 per cent of China鈥檚 electricity and the massive locks that allow ships to travel through.
The only way to slow the process is to build more dams upstream to trap the silt. Many were already being planned. If they are all built, instead of a river. But this, as I found out later, won鈥檛 help areas downstream of Three Gorges that are suffering from lack of sediment.
From Chongqing I have to catch a hot and sweaty bus through the mountainous folds of Sichuan province to the city of Fengjie, about two-thirds of the way down the reservoir, from where I can get a ferry to the dam wall. At least, this is the latest version of Fengjie. The original, as traders in a market delighted in telling me with drowning gestures, is now deep underwater.
The reincarnated city of Fengjie is as much of a marvel as the dam itself. It had to be rebuilt in its entirety at the top of a mountain to escape the rising waters of the reservoir. Every apartment complex, office block, school, hospital, road and shopping centre has been built from scratch, perched on slopes held back by massive concrete retaining walls. What looked on the map like a 500-metre walk from my hotel to the ferry terminal turned out to be a labyrinthine schlep through skywalks, stairs and winding roads.
Fengjie is just one of 13 cities, 140 towns and 1350 villages drowned by the rising waters of the Three Gorges dam. Around 1.3 million people had to be moved. This new city at least seems to be thriving. In the evening the squares are filled with troupes of formation-dancing grannies, and the tables of crowded eateries spill into the street. At a restaurant where dozens of residents came to gawk at the only foreigner in town, one women told me she and her husband had moved to Fengjie from Chengdu in 2008. 鈥淲e love it here.鈥�
鈥�13 cities, 140 towns and 1350 villages were drowned. About 1.3 million people had to move鈥�
Further downstream lies the city of Badong. It was struck by a 5.1 magnitude quake in December last year, causing minor damage. It has long been known that the filling of a dam can trigger earthquakes, so the swarm of small quakes that have occurred around the Three Gorges over the last 10 years was expected. The seasonal raising and lowering of the reservoir may continue to trigger seismic activity.
Badong, however, is unlucky enough to lie on top of two fault lines. Fan thinks the pressure of the reservoir is forcing water into these fault lines, where it acts as a lubricant. 鈥淭he water started triggering quakes at small fault lines about two kilometres down,鈥� says Fan. 鈥淣ow it鈥檚 reached 10 kilometres down, and this is where the more serious fault lines occur. I am predicting much bigger quakes in the near future.鈥� Some other geologists, however, say the Badong quake was not linked with the dam, and do not expect any future quakes to be much larger.
鈥淭he water started triggering quakes鈥� I am predicting much bigger quakes鈥�
The filling of the reservoir has also destabilised some of the steep slopes lining the dam. Landslides are common, blocking roads and threatening villages. In September, on one of the tributaries that feed the reservoir.
As the ferry from Fengjie skims over the calm surface of the reservoir, through the spectacular gorges after which the dam is named, gashes of bare earth can be seen marking the sites of recent landslides. Our boat glides over a part of the river once so treacherous that a Chinese poet described it as 鈥渁 thousand seas poured into a cup鈥�. Now the waters are easily navigable.
Well, except for the fact that the boat has to push its way through a thick sheet of discarded plastic bottles, bags, algae and industrial crud that coat the surface of the reservoir; another side effect of the Three Gorges dam. Pollution that used to be flushed downriver and out to sea is now trapped and backing up in the Yangtze鈥檚 numerous tributaries. It covers a massive area despite 3000 tonnes being collected every day. Indifferent to the problem, a young man on the bank has cast a fishing line in the water. I make a mental note not to eat fish for the rest of the trip.
Eventually we reach the dam wall itself. Alongside the dam, there is a set of five staircase locks that lift freighters from the river below, a height of over 90 metres. Our guide tells us it takes 4 hours to negotiate them all. There is a parallel set of locks for ships going in the opposite direction.
(Image: Lin Mu/Imaginechina/Corbis)
There is no talk here of the environmental problems, only the benefits. And they are huge. Even critics concede that the Three Gorges dam is providing around 2 per cent of China鈥檚 electricity 鈥� energy that would otherwise be produced mainly by dirty coal-fired power stations. To ensure an adequate winter supply of water for the dam鈥檚 32 turbines (鈥淓ach weighs the same as the Eiffel tower,鈥� says the fascinating-fact guide), the reservoir is filled to capacity every September.
Floodplain dries up
What the guide does not say is that this reduces the flow downstream, bringing forward the start of the Yangtze鈥檚 natural low-water period. The result is that the Yangtze鈥檚 once bountiful floodplain is now drying up. 鈥淐hina鈥檚 two largest freshwater lakes 鈥� Poyang and Dongting 鈥� now find themselves higher than the river,鈥� says Patricia Adams of Probe International, a Canadian environmental foundation that has written a number of critical reports about the Three Gorges dam. 鈥淭he effect of that is that their water is flowing into the river and essentially draining these very important flood plains.鈥�
The lower water levels, combined with slower flow, pollution and restricted movement, have caused the Yangtze鈥檚 fish population to crash. No one knows that better than the fisherman I met at Wuhan, waiting patiently for a catch in a dilapidated cabin on the riverbank. His net had been lowered into the water with a huge bamboo hoist, one of many on the bank. He was the only one trying his luck that hot afternoon. I asked what the fishing was like. 鈥淭he fish are too small,鈥� he grumbled. 鈥淲ay smaller than before.鈥�
He emerged from his little cabin and pulled on a rope, hoisting the net out of the water. Empty. He lowered it again, retired to his chair and waited. Twice more he hauled out an empty net before, on the third try, we saw a couple of little silver fish flopping around. 鈥淭hey鈥檙e small! Way too small.鈥�
From Wuhan I travelled to my final destination, Shanghai. China鈥檚 largest city is built on the river delta, on the billions of tonnes of sediment deposited by the Yangtze over the millennia. The main city is built around a small tributary of the Yangtze, so to see the river itself I had to take a suburban train and then walk. When I reach the Yangtze it is obscured by a high barrier designed to protect the headland against erosion.
Like all deltas, the mouth of the Yangtze is a tug of war between deposition and erosion. Between 1050 and 1990, according to , deposition won. During these 900 years the Nanhui foreland, which marks the south bank of the estuary, grew nearly 13 kilometres. But more recently, erosion began to dominate.
The dam has made things even worse by nearly halving the amount of silt entering the delta, leading to in the erosion rate. This could become a major problem for a city that鈥檚 just 1 metre above sea level on average and facing a sea level rise of perhaps 2 metres over the next century.
In the nearer term, the dam is allowing more seawater than ever to intrude into the Yangtze estuary by prolonging periods of low river flow. 鈥淔rom January to February there was always salinisation, even before the Three Gorges dam,鈥� says Fan Xiao. 鈥淏ut since the dam was built, the salinisation has begun much earlier, in September, and it鈥檚 stronger than before. It鈥檚 affecting the drinking water.鈥�
In 2011 and 2013, the Shanghai Water Authority reported 鈥渟alt tides鈥� affecting drinking water. And in February this year was the worst yet. All of these were drought years, but the Three Gorges dam is a contributing factor.
The problems don鈥檛 even stop at the river mouth. According to one study, the reduced flow is greatly decreasing the productivity of fisheries in the South China Sea.
Elsewhere in the world, many dam projects are acknowledged to have generated fewer benefits and greater drawbacks than anticipated. In China, the previous government openly admitted that there were serious issues. 鈥淲hile the Three Gorges project has brought great and comprehensive benefits,鈥� said a statement by China鈥檚 ruling State Council three years ago, 鈥渢here are problems that must be urgently resolved in the resettlement and wealth-making of immigrants, environmental protection and geological disaster prevention.鈥� It suspended or scrapped other controversial dam projects.
Since 2011, there has been a change of leadership in China. Scientists who were once critical of the Three Gorges dam are now reluctant to talk publicly. One of them told me he had been warned not to speak out.
鈥淭here are more controls on the media because of the new government 鈥� it鈥檚 a lot stricter,鈥� said Fan, one of the few still willing to talk on the record. 鈥淵ou have to be careful about what you say and about what you write.鈥� He was speaking freely to 麻豆传媒, he said, because the government was more concerned about what was written in Chinese publications than overseas ones.
More dams to come
The change of government in 2012 has also led to a reinvigoration of hydropower. Many dam projects scrapped by the previous regime have now been reinstated. The official line is that there may be problems, but they can be addressed, and the benefits outweigh them.
鈥淭he Three Gorges project is doing more good than harm,鈥� Zhengshou Ren, deputy secretary general of the China Society for Hydropower Engineering, earlier this year. By June 2014, he says, the Three Gorges power station had saved the equivalent of 568 million tonnes of carbon dioxide.
This does not take into account the emissions associated with building the dam and moving cities, or the methane released from dam reservoirs. Still, over their life cycle dams produce far less CO2 and other pollutants per gigawatt of electricity than coal-fired power stations. Without the Three Gorges dam, I might not have been able to see even half way across the wall.
As I left the river behind me I couldn鈥檛 help feeling a tinge of guilt. We all benefit from the Three Gorges dam, after all, even though we live nowhere near it, because CO2 emissions would be rising even faster without it. It is the people living along the Yangtze, who have and will continue to pay a heavy price.
This article appeared in print under the headline 鈥淩iver of the dammed鈥�
