China’s Three Gorges Dam is one of the most ambitious engineering projects ever undertaken. BBC Future investigates the troubled history of China and its mighty rivers.

If anyone doubts that the Three Gorges Dam on the Yangtze River in China is as much about national prestige as flood control and hydroelectric power, they should pay it a visit. A tour bus will take you 40km (25 miles) from the gritty river city of Yichang and through military checkpoints guarding the visitors’ centre. You get the state-approved experience this way: ferried by electric buggy between vantage points showcasing the phenomenal engineering of the project, with chunks of the immense construction machinery displayed like historic artifacts.

The guidebook proudly lists the world records set by the dam, many of them meaningless to all but the most avid hydraulic engineering fans: “The highest intensity of concrete placement”; “The spillway dam with the largest discharge capacity”; “The inland shiplock with the highest total water head”. The book reassures visitors that the concerns raised by the dam’s opponents – silt accumulation, displacing local residents, ecological damage, loss of ancient heritage sites, earthquake risks – are all in hand.

That a pragmatic and rather ugly – if herculean – feat of engineering is being marketed as a must-see tourist attraction is pretty peculiar, when you think about it. But then you recognise that water, particularly its control, has been at the heart of Chinese statecraft for several millennia.

That continues today. The Chinese economy is already showing signs of stalling after a period of extraordinary growth, and the lack of water could cause serious concerns over the next several decades. Massive dams could deliver a sizeable slice of the nation’s power via hydroelectricity, cutting the need for polluting, coal-fired plants. The Three Gorges Dam has 18.2 GW of installed power-generation capacity, 10 times that of the Daya Bay nuclear power station in Guangdong. More dams are planned on many of China’s rivers – including, controversially, the Nu, which runs through a Unesco World Heritage site in Yunnan before passing into Myanmar and Thailand.

Competence in water management is viewed as a very big deal in China

On the other hand, China’s waterways are in a fragile, parlous state, as pollution, damming, overuse, land reclamation and climate change combine to devastating effect. Environmental degradation is estimated to be costing China around 10% of its gross domestic product every year, as Elizabeth C Economy writes in her book The River Runs Black, and water issues have been a flashpoint for many civil protests, some of them violent. Now more than ever, managing the waterways has become a bellwether of political legitimacy.

Chinese Premier Li Peng’s statement when construction of the dam was finally approved in 1992 seems to confirm that China regards it as a show of political, economic and technological might.

“The Three Gorges Dam will show the rest of the world that the Chinese people have high aspirations and the capacity to successfully build the world’s largest water conservancy and hydroelectric power project.”  

Given the general decline in enthusiasm for big dams among the global water-management community by that time, in part because of the environmental impacts, it seems hard to believe that Li really imagined that the world would applaud the decision. But competence in water management is viewed as a very big deal in China. Critics who question the financial, social and environmental costs of the dam are only seeing a part of the story. The dam is not just an attempt – some will say flawed, but nonetheless sincere – to solve the problems of the Yangtze and of China’s need for clean energy. It is also an awe-inspiring monument to the way state-building is intertwined with the management of China’s waterways.

Concrete giant

The statistics are dizzying: 185m high, almost two kilometres wide, cast from almost 30 million cubic metres of concrete, and flooding 30,000 hectares of agricultural land to create a reservoir some 31,000 sq miles. The dam is already a Chinese icon akin to the country’s Great Wall (and is considerably more visible from space).

But at what cost? With the machinery of the state driving it forward, suggestions of technical flaws have been brushed aside with high-handed dismissiveness. Some critics say the amount of retained sediment will raise Yangtze flood risks upstream in Sichuan province. And what about the effects on local ecology, or the loss of sites of priceless national heritage? What about the dam’s vulnerability to earthquakes? What if the added weight of water actually increases seismic hazards and landslides in the vicinity? Chinese government reassurance that these have been taken into account failed to instil much confidence.

One of the most controversial issues is the permanent resettlement of those whose homes were flooded within the reservoir basin. The area designated for the Three Gorges reservoir lake – covering 1,000 square kilometres and stretching more than 600km (375 miles) upstream – was home to some 1.5 million people, living in 19 counties and municipalities, 140 towns, 326 townships and 1,351 villages. All had to be relocated. Would those affected be given enough money to start a new life elsewhere? How would peasant farmers deal with an urban environment? Would the moves add to the region’s crowding problem? And what would be the psychological impact of being forced off land on which your family might have dwelt for generations?

There was no greater compliment a ruler could receive than to be compared to the virtuous Da Yu

These are complex and pressing concerns, but they have to be understood within the historical legacy of water issues and hydraulic engineering in China.

The Great Flood looms large in Chinese mythology, where it was solved by re-engineering the landscape. A minister named Yu – now often called Da Yu, or Yu the Great – was appointed by the legendary emperors Yao and Shun to carve out new channels that discharged the floodwaters into the sea. In reward for his efforts, Yu was made Shun’s successor, and he founded the semi-legendary Xia Dynasty, said to have occupied the Yellow River valley in the third millennium BC.

This idea that mountains can be moved, populations shifted and geography reordered to seize control of the natural waterways has dominated China’s approach to hydraulic engineering ever since. You can see it in the building of the Grand Canal linking the Yangtze to the Yellow River (largely during the Sui Dynasty in the 7th Century AD), or the mammoth task of building dikes for hundreds of miles along great rivers to try to stem flooding. Emperors who allowed great floods to happen (in truth they were all but impossible to prevent before 20th Century engineering technologies) risked losing the “Mandate of Heaven” which conferred their right to rule.

The Three Gorges Dam makes perfect sense within this tradition, as does the equally ambitious South-North Water Transfer Project which aims to transport water from the humid Yangtze valley along canals a thousand kilometres long to the water-strapped northern plains. There was no greater compliment a ruler could receive than to be compared to the virtuous Da Yu. When President Jiang Zemin, like several of China’s modern leaders an engineer, inscribed the characters on the gateway of the Da Yu Mausoleum in Shaoxing, Zhejiang province in 1995, he knew what a deep well of trust and veneration he was drawing from. In due course the press anointed Jiang as “The new Da Yu”: a leader who derived his authority from privileged knowledge of water control.

A massive dam on the Yangtze has been the ambition of every leader of the modern era, starting with the first president of the Republic of China, Sun Yat-sen. In his 1956 poem composed to mark his swimming of the Yangtze, Mao Zedong announced the vision like this:

Walls of stone will stand upstream to the west

To hold back Wushan’s clouds and rain

‘Til a smooth lake rises in the narrow gorges.

The gorges themselves – the Wushan mountains loom over the middle one – are filled with legend; every peak and crag seems to have some story attached to it.

Plans for the Three Gorges Dam were drawn up in the late 1950s, but the turmoil of the Great Leap Forward and the Cultural Revolution meant that it was shelved for the rest of Mao’s reign. Not until Deng Xiaoping’s policies of reform and opening up at the end of the 1970s was the debate renewed. A smaller dam – a pilot project of sorts – was begun further downriver at Gezhouba in Yichang, and the time seemed ripe for the main objective.

Contentious relocation

Contrary to common impression, the dam was not bulldozed through by an implacable state. Leading engineers expressed reservations throughout the debate, and when Li Peng sought approval for construction to begin at the National People’s Congress of 1992, one-third of the delegates voted against the plan – an unheard of level of dissent. Protestors such as the writer Dai Qing, who was jailed in 1989 after publishing a book of essays criticising the dam scheme, were victims of the post-Tiananmen Square crackdown, rather than of disapproval of opposition to the dam itself.

Even critics have to admit that since the dam was built, there have been no catastrophic floods on the Yangtze like the one that claimed 3,500 lives in 1998. But the outcomes of the massive relocation programme are more contentious. It is surely true that some of the flooded Yangtze towns were grim, under-developed places that few residents were sad to leave, and some are content to have been rehoused in new apartments with heating and running water. Others have struggled to adapt to a new life, perhaps hundreds of miles from their ancestral homes, where the local dialect is incomprehensible to them. And there have been complaints of inadequate compensation and embezzlement of resettlement funds.

Historically, the Yellow River has left even deeper impressions on the Chinese national psyche than the Yangtze

A country like China, with plenty of fast-flowing rivers and an immense demand for energy, would be unwise not to make use of its natural renewable resources to sustain economic growth. China theoretically has more hydroelectric resources – around 380 gigawatts, equivalent to hundreds of medium-sized nuclear power stations – than anywhere in the world, but is still exploiting barely a quarter of that. China’s laudable commitment to get 15% of its power from renewable sources by 2020, and to reduce its carbon emissions by 40-45% by that date, only seem feasible if hydroelectricity is a big part of the mix.

To get some perspective on the Three Gorges Dam project, I travelled some 700km (450 miles) north to the Yellow River to see the Sanmenxia Dam bordering Henan and Shanxi provinces. It was built during the Mao era half-a-century ago. The contrast with the brash, tightly orchestrated, high-security visitor experience at the Three Gorges Dam was striking – and telling.

Historically, the Yellow River has left even deeper impressions on the Chinese national psyche than the Yangtze. Long celebrated (falsely) as the “cradle of Chinese civilization”, the Yellow River and its tributaries are largely responsible for bringing water to the North China Plain. On these vast alluvial plains half of the country’s wheat and one-third of its maize is grown, and around it an estimated one trillion people have lived and died. But the Yellow River is also “China’s Sorrow”, prone to catastrophic flooding that has in the past killed millions at a stroke.

River of revolution

It was to the Yellow River that Mao first turned his attention after coming to power in 1949. Mao’s government launched an almost frantic campaign of dam-building in what was portrayed as a battle to conquer nature itself. The newspaper Renmin Ribao spoke of battling the Yellow River in the same way that legends told of struggles with river dragons: the engineering projects would “chop off the scales, claws and teeth of the wicked dragon”.

Sanmenxia (Three Gates Gorge) was the greatest of the Yellow River dams. It was an obvious place to build: the splitting of the river into three main channels by a trio of small islands offered the opportunity to span the mighty river in manageable stages. Construction began in the spring of 1957 with the help of Soviet engineers. The claim was that the dam would retain silt to stop it settling downstream, which raised up the riverbed above the surrounding plains. The Yellow River, it was argued, would be yellow no more, fulfilling an ancient prophecy which promised: “When a sage appears, the river will run clear”.

The absurdity of this belief soon became apparent. Silt began to accumulate against the dam wall at an alarming rate, and by 1962 the capacity of the Sanmenxia reservoir had been halved. Even after extensive reconstruction between 1965 and 1973, almost 40% of the dam’s capacity to retain silt was used up in the first 18 years of operation, and the hydroelectric power it generated was far less than the original estimates. In 2004, one of the engineers involved in the design of Sanmenxia admitted on Chinese television that the dam had been “a mistake”.

China’s water management has not always been framed as a battle to defeat nature

Yet today the Sanmenxia Dam continues to do its job with the air of a stubborn old soldier remaining at a forgotten outpost. There is, for China, astonishingly little security or constraint. Once I’d paid my 30 yuan ($4.70) entrance fee, I was disconcertingly free to wander among the rusting hulks and stained concrete of the Great Leap Forward era, while ageing power installations hummed ominously in the background. A few workers lounged in the sun, but there seemed to be no one who would stop me even from strolling into the old turbine halls.

“When the Yellow River is at peace,” proclaims a slogan painted in red characters about 20 feet high on the dam walls, “the country is at peace”. It is attributed to Da Yu. A statue of the legendary water hero stands guard over the parched hillsides, but I suspect he would have done things differently.

But China’s water management has not always been framed as a battle to defeat nature. Both of these two modern constructions look like crude impositions on the rivers in comparison with the ancient waterworks at Dujiangyan (“All Rivers Weir”) on the Min River, an hour-and-a-half’s drive from Chengdu in Sichuan province. The objective here was very different: to harness the Min for irrigating the Chengdu Plain. The ingenious solution found by the engineer Li Bing – involving a division of the Min into two, with the smaller channel feeding a complex network of irrigation ditches – was so successful that Dujiangyan is still in use today.

And even though the place is now a Unesco World Heritage Site, I hadn’t expected it to be quite so stunningly beautiful, dotted with temples and parks while the mountains in the distance begin the ascent to the Tibetan plateau. Li Bing’s artificial island, with a promontory called the Fish Mouth where the river surges and splits amid white froth, is now reinforced with concrete. Otherwise, the design is pretty much unchanged from the Qin Dynasty era two millennia ago.

Shrines dedicated to the engineer-god cling to the crags above the river

The irrigation system, however, wasn’t just a beneficent engineering project in harmony with nature. It was a key aspect of the conquest of the state of Shu (roughly modern Sichuan) by the neighbouring Qin – a victory that enabled the first unification of China under the harsh, despotic First emperor Qin Shi Huangdi, whose legacy includes the earliest segments of the Great Wall.

Even so, Li Bing’s waterworks made Shu a fertile land, and ultimately gave it the economic power to assert its own independence again during the Three Kingdoms period. Shrines dedicated to the engineer-god cling to the crags above the river, and people still come to offer their respects with incense sticks – a reminder that apotheosis can be the reward of anyone in China who displays the ability to tame the waters.

But in doing so, they would do well to heed the words of the classic text called the Guanzi from the 8th Century BC:

“People who are of ruling quality but are not able to respectfully preserve the forests, rivers, and marshes, are not appropriate to become rulers.”

Follow us on Facebook, TwitterGoogle+LinkedIn and Instagram.

Correction: China's hydroelectric resources – around 380 gigawatts – is equivalent to hundreds of medium-sized nuclear power stations, not hundreds of thousands as an earlier version of this article stated.