The Three Gorges Dam is the world’s biggest dam.
Everything about it is huge. And that includes the controversies. It has changed China forever.
In this video, I want to talk briefly about this massive,
titanic piece of infrastructure and look at it from multiple angles.
The Three Gorges Dam remains the biggest dam in the world. It sits at the Three
Gorges area within the Chongqing Directly controlled Municipality.
The Three Gorges have been visited and admired by Chinese tourists and poets for millennia.
It is a concrete gravity dam with a maximum height of 185 meters, the size of a 45 story building.
It is designed for a normal pool height of 175 meters.
The dam itself is made of three parts. At the center is a 23-sectioned spillway dam
that is 483 meters long. Nearly half a kilometer.
On both sides of this spillway are 26 powerhouse-dam sections. Together,
they add another 1.2 kilometers.
The Dam is only one of three parts of what is called the Three Gorges Project.
The other two parts include:
The powerhouses at the foot of the dam and,
The navigation facilities that allow ships to cross the dam.
Those are pretty impressive in their own right.
The dam holds back a titanic reservoir. It extends nearly 600 kilometers upstream - about
the distance between San Francisco and Los Angeles. It stores a total capacity of some
40 cubic kilometers of water. This is 7x larger than California’s biggest reservoir - Shasta Lake.
The Yangtze River is one of China’s two great rivers and is the longest in Asia.
It's been a cradle of Chinese civilization for millennia. It has brought prosperity
and tears to the Chinese people. Hundreds of millions of people live on its drainage basin.
Chinese people have been damming the Yangtze for centuries. The Dujiang
Dam in the Chengdu area is over 2,200 years old and remains in operation.
It dams the upper part of the Yangtze River in the Sichuan province.
The idea of damming the Yangtze at the Three Gorges area has been kicking around
since the days of Sun Yat-sen. In 1919, he published an article called "A plan to develop
industry". He mentioned the possibility of building a series of large dams along the Yangtze.
And Mao always had a strong personal interest in seeing a big dam on the Yangtze.
After swimming across the Yangtze river in Wuhan in 1956, he wrote a poem that
would indicate his belief that man could stand triumphant over wild nature. But in the 1960s
the big 3 Gorges Yangtze dam was not technically feasible and in the 1970s it was too expensive.
(FYI. Him swimming the Yangtze really was super impressive. The river waters then
were already very dirty and many of the other people swimming alongside with him got sick.)
In 1982, the Chinese government began investigating the idea of building a
mega-dam in the Three Gorges area as Mao always dreamed. It progressed along for a
few years - at first with the support and funding of major international agencies.
However, strong environmentalist resistance to the project caused delays.
Feasibility studies were lukewarm on the whole idea.
There were multiple problems with sediment and the re-settling of people.
And then the Tiananmen incident in 1989 ended virtually all remaining international involvement.
In 1992, Premier Li Peng revived the dam and the project passed with a two thirds
vote - a really close vote by Chinese standards. Jailing a number of Three
Gorges activists and squashing public debate may have contributed to the project moving forward.
I want to spend some time here briefly discussing some,
but not all, of the reasons why to go and not to go forward with the dam project.
The first and most important reason is flood control. The Yangtze is one of
China's two major rivers. At 600 km long, it is the world's third
longest river. It is the cause of many of China’s successes and tragedies.
The Yangtze is very prone to flooding. Chinese records show some 200+ floods that have occurred
between 185 BC and 1911. Roughly, one every ten years.
The Yangtze basin is particularly susceptible to floods because the water level is just barely
higher than the plain itself. This is due to the fact that the Yangtze’s waters is high in silt.
Silt deposits raise the river’s levels, making it prone to spill over its banks.
These floods have massive human and financial costs.
Three disastrous floods - which happened in 1931, 1935, and 1954 - killed some
300,000 people combined. An 1870 flood killed a rumored 240,000 all by itself.
Even relatively recently, a 1998 flood killed 3,000 people,
disrupted the lives of some 300 million and inflicted $50 billion of damages.
A system of levees was built to help control the Yangtze and for the most
part it has worked. But those flood control measures have had their own consequences too.
For example, the reinforcement of the Jingjiang levee since the 1950s meant that river silt was
taken out of the Yangtze and dumped into the nearby Dongting Lake. The Dongting Lake is a
runoff lake that had previously absorbed flood water from the Yangtze. Dumping that silt into
the lake over the years reduced its capacity to absorb flood runoff capacity by nearly 50%.
Thus the Chinese government sees the Three Gorges Dam
as the most definitive and final solution to the Yangtze flooding issue.
The dam will be able to store, control and mediate the Yangtze’s floods. Before each flood season,
the dam would release its reservoir and open up nearly 22 billion cubic
meters of flood control capacity. A disastrous once-a-decade flood can be reduced to happening
only once every 100 years (climate change notwithstanding).
This benefit alone would save the country from hundreds of millions
of dollars of economic damage. It is hard to argue against.
The second big reason is electricity. China is growing fast and that growth needs energy.
The country has been a voracious consumer of petroleum fuels. The Three Gorges dam would
provide a self-sustaining, renewable energy source that is clean and carbon-friendly.
The dam’s 34 generators create 20 times more electricity annually than the Hoover
Dam in Arizona. It generates some 92 TWh of electricity per year. This power is consumed
by nine provinces and two major cities including the 24 million people of Shanghai.
There are a few other reasons. It would make the Three Gorges area
easier for boats for navigate. It would help store fresh water to help alleviate potential droughts.
And it provides water for agricultural benefit.
Big dams are immensely disruptive to the environment.
And the dam was immensely controversial even as it was being planned and built.
The World Bank and other international agencies have been in recent years discouraging the funding
and construction of major dams. This is due to the high environmental and social costs they create.
I am not going to be able to hit all the issues relating to the Three Gorges
Dam - it would fill a whole dam book - but here are a few summarized points.
First, people might argue that this: Human lives are number one. Build the dam. Stop the Yangtze
floods. People over Chinese river dolphins. End of story. But the science is a bit more nuanced.
First, the Three Gorges Dam is not ideally placed to prevent a majority of the Yangtze’s floods.
The floods in 1954 and 1998 were caused by major storms
downstream from the Three Gorges in the Yangtze middle reaches.
It is very arguable that the Three Gorges Dam could not have helped to prevent those floods.
In contrast, the Sanmenxia Dam (built 1960, though with frequent renovations) on the
Yellow River is placed such that it can control over 92% of the river’s watershed.
That’s a good dam ... well except for one thing. Silt. That’s the second problem.
Two years after the Sanmenxia Dam was complete,
it had to be substantially renovated because the Yellow River’s immense silt deposits had reduced
the reservoir’s capacity by a significant amount. It threatened another spillover.
The Yangtze is not as silt-y as the Yellow River. The Yellow River is the world’s
silt-heavy river, after all. But the Yangtze happens to be fourth.
And the amount of silt in its waters is only going to go up.
(The dam’s power generation effects by the way are also dampened by the silt deposits.
The more silt buildup, the less energy generated.)
So, every time they close the gates during flood season a huge amount of silt gets deposited at
the bottom of the Three Gorges reservoir. So eventually you will have a dam that could
potentially spill over or even collapse without constant, careful management and maintenance.
Second, the dam will flood a huge area behind it with water. Some 600 square kilometers of land
would be lost. People need to be cleared from those areas.
Many animals will lose their homes on both sides of the dam.
The Three Gorges Dam’s reservoir will inundate 4,000 villages, 140 towns,
13 cities, and 100,000 acres of farmland. Some 1.3-1.6 million people would need to be relocated.
Just because the people are gone from the cities being flooded doesn’t mean the danger is too.
Inundating these cities would contaminate the river water and turn it toxic.
And the Yangtze River’s water was not all that clean to begin with. Remember what I said about
Mao's bodyguards getting sick when they swam with him? It’s one of the most polluted in the world.
Now imagine all that water hitting and absorbing the toxic substances
from 1,300 factories and mines, 40,000 graveyards, and 200 garbage dumps. Yuck.
The government pledged to build many wastewater plants to treat this but many of those came ten
years after the dam was built. Too late for many animals and people living there.
In addition there are greenhouse effects to consider as well.
Submerged vegetation starts to decay and generate carbon dioxide, creating local climate change
effects - counterbalancing the green effects of having a nearby source of renewable energy.
I am not even talking about some of the other concerns like the concerns of the
people being relocated out of their ancestral home or the cultural heritage sites drowned
underwater. I’ll touch briefly on this as those stories have gotten a lot of press.
Substantial effort was indeed taken by the Chinese government to move people. But of course, such
efforts were controversially insufficient. Worse yet, the farmland being inundated by the reservoir
could not be easily replaced. Many lost not just their homes but also their only source of income.
1,282 cultural heritage places would be plunged under deep water.
Many of them only were recently discovered and documented before the waters rose.
The Chinese Government were able to address 453 of them.
Some were relocated - the Zhang Fei Temple was moved 32 km at the cost of $6 million.
Some were protected. The 1,200 year old Baiheliang Stone for example. This 1.6km
long stone is carved with 30 Chinese poems and was used for navigating the Yangtze’s waters.
This UNESCO site was preserved in an amazing underwater museum.
But most were simply photographed before the waters came.
Regardless, in the end the dam was built. The Party wanted it.
It got what it wanted. Let us talk briefly on the actual construction of this technical marvel.
The Three Gorges Dam was built in three stages over roughly a decade. The work is supervised
in entirety by a single, supreme body: The Three Gorges Project Construction Committee.
This committee is headed by the State Council Premier and features the heads of the relevant
ministries in addition to the provincial governors of Hubei, Sichuan and Chongqing.
To manage and own the dam, the State Council founded a corporation and
endowed it with $670 million of assets. The wordy China Yangtze River Three Gorges
Project Development Corporation. It continues to own the dam today.
The Anglo-French group GEC-Alstom and Switzerland’s ABB won the tender for
providing the first seven generators for the Three Gorges project. They were required to share their
technology with the state-owned Harbin Power Equipment Company. Harbin Power would build the
eighth generator based on their learnings. This is an instance of foreign technology transfer.
The rest of the turbines were built by a German-Canadian consortium working
with the state-owned Dongfang Machinery and Electronics Corp.
The cement for the dam would come from the Hubei Huaxin Cement Company and the
Sichuan Jinding Corporation. No foreign companies were invited to provide this.
In total, the dam would use nearly 463,000 tons of steel
(enough to build 63 Eiffel Towers) and 27 million cubic meters of concrete.
The dam sits on a foundation of high strength, homogenous granite that is mostly intact.
886 faults were identified at the dam site. Most of them were small and of low risk.
Phase I officially started in December 14th 1994 with an opening ceremony attended by Li Peng.
Phase I would see the building of support structures and closing off the Yangtze
River’s main channel for diversionary purposes.
Phase II would last from 1998 to 2003. It saw the building of the 1.7km long, 185m high section of
the dam on its left bank. This includes the first power houses and turbine generators.
Phase II saw the building of the ship lock. They also began filling
the reservoir behind the dam for the first time - topping off at the 135 meter mark.
In Phase III, the final resettlement of people would be completed with 1.2 million moved.
With everyone safely resettled out of the way,
it allowed the water level to be raised further to the final 175 meters.
The Three Gorges Dam is a divisive thing. When you bring it up to people,
they either treat it with awe or disgust.
Large dams have been important in human development for thousands
of years. But some 45,000 large dams have been built in the past 100 years alone.
China is the biggest dam-building country in the world.
They had 22 big dams (over 15 meters tall) in 1949.
Today, they have over 22,000. The United States, a country just as big as China, has 6,390 dams.
Dams are controversial for a reason. Their long term environmental and
economic effects remain uncertain. You can always have too much of a good thing.