Dai Qing and Three Gorges

Reflections of a dam builder: rethinking the environmental problems associated with building hydro dams

(May 28, 2007) In an exclusive interview, Shen Ganqing, former chief engineer at the Beijing Institute for Survey and Design and professor at the Beijing Normal University talks about his 50 years of experience developing hydro dams and the lessons he learned in the process.

Interview conducted by Yan Shi, a Beijing-based journalist, for Three Gorges Probe.

I graduated from Zhejiang University in China in 1947 and continued my studies in the United States, where I majored in civil engineering but later transferred to hydropower generation. After returning to China, I was involved

with the early plan to build the Three Gorges dam on the Yangtze River (before 1949).Throughout the 1950s, I worked on the water development plan for the Yellow Valley.

During that time, I encountered some general environmental issues but never realized that building hydro dams would cause such big environmental problems until recent years. Unavoidably, we made lots of mistakes. The best example is the Sanmenxia dam1on the Yellow River, which was the largest hydro project completed in China in the 1950s. I participated in all aspects of the project, including planning, design, construction and management. I even wrote the work summary upon completion.

Dai Qing, who was a reporter for the Guangming Daily at the time, wrote an article criticizing the practice of building “high dams and huge reservoirs.” Unfortunately, I was one of the proponents of building “high dams and huge reservoirs” who believed that construction of the Sanmenxia dam was the best way to deal with problems on the Yellow River. We opposed suggestions to lower the water level of the reservoir, insisting that a high dam was needed to block silt and allow clear water to flow from the reservoir.

In her article, Ms. Dai quoted a professor at Qinghua University, Huang Wanli, who opposed the plan to build this dam on the Yellow River. He was absolutely right, but we ignored his opinion. Ms. Dai also mentioned Wen Shanzhang, who was actually working under my supervision. Mr. Wen didn’t oppose the plan outright but proposed building a smaller dam by lowering the water levels (to 335, 330 or 320 metres).

That displeased me and I tried to suppress his proposal, forbidding him to report to the high authorities. A recent graduate from Tianjin University, Mr. Wen was very young, enthusiastic and brave. He defied me and wrote to the top leaders in Beijing in an attempt to demonstrate how his new ideas could work. His letter prompted Premier Zhou Enlai to convene a meeting of 70 experts to discuss the matter. Though present at the meeting, the voices of Mr. Huang and Mr. Wen were too weak to garner support.

Shortly after publicizing his very strong opposition to the Sanmenxia dam, Mr. Huang was labeled a “Rightist” and barred from making public appearances. Mr. Wen was extremely disappointed about this. Among the experts who participated in the meeting, I argued loudly that “high dams and huge reservoirs” would play a vital role in flood control and hydropower generation in the Yellow Valley. More water was needed in order to generate enough electricity to fuel the construction of our newly born country, we argued. The higher the dams and the bigger the reservoirs, the better.  We put power generation before everything, including the potential economic, social and environmental losses we might incur in the process.

Looking back on those days, I now realize what a mistake I made. What went wrong? It turned out that after the Sanmenxia reservoir was filled, sediment carried by the river settled at the upstream end of the reservoir at Tongguan. With sediment buildup, water levels rose higher, posing a direct threat to Xi’an, the ancient city and capital of Shaanxi province. How did we deal with the problem? We blamed the Soviet experts who were helping us construct 156 projects in China at that time, although Premier Zhou Enlai was very unhappy about this. You are experts too, he said, what are you doing and why didn’t you say anything about these problems? Finally, we found a somewhat balanced way to draw a conclusion on the issue: the Soviet experts, who had limited knowledge of the area, designed the Sanmenxia project on an assumption that the Yellow River was clear when actually it was loaded with a great deal of silt.

I am aware that I made mistakes on the matter. We failed to consider the environmental impact of building the Sanmenxia dam on the Yellow River, as with many other dams on China’s rivers. I have been trying to correct my mistakes by learning lessons from the past and equipping myself with new ideas and knowledge, as well as communicating with other scholars and experts in environmental studies.

As a result, there are three things I am doing that I would like to mention here: First, I have created a model for developing water resources that incorporates ecological economics and considers three vital issues regarding China’s water: there is either too much [causing floods], too little [prompting shortages], and it is dirty [polluted]. These are the problems quoted often by Chinese leaders and officials when talking about water issues. Second, based on several decades of experience and my recent research on the topic, and in collaboration with other four experts, I have established a new subject called environmental water conservancy. At the very beginning, experts at the Ministry of Water Resources and many others disagreed with us. Recently, however, more and more people have come to accept our ideas. Finally, as part of the Chinese government’s Grand Encyclopedia project[2], I was assigned a sub-section called the Water Conservancy Encyclopedia. I wanted to use this publication to introduce the notion of environmental water conservancy, although a number of people opposed this at the beginning. With struggle and a great deal of endeavour, my ideas were eventually accepted.

Currently, nobody dares to oppose the south-north water diversion project that is underway, which is reminiscent of the stifled debate around the Sanmenxia project in the 1950s. At that time, only Mr. Huang and Mr. Wen voiced opposition to the project. Right now, I am not in favour of the water transfer program, nor the construction of the Three Gorges project. Why? Take the water transfer project as an example.

Currently, we pay about 2 yuan RMB (US$ 0.25) to use one cubic metre of water; however, if the water from the south is diverted to Beijing we will be charged around 16 yuan (US$ 2) per cubic metre. Who will this water be sold to? Can an ordinary resident afford to pay the water bill anyway? In fact, we have found a number of alternative methods for accessing water, such as water conservation, the re-use of wastewater, the use of floods and rainwater, seawater desalination and so forth. Certainly, there are a wide range of choices.

For more than half a century, decision makers and planners in water management have done almost everything possible to deal with our water issues and yet have failed to resolve the problem. The reason lies in that we have attached too much importance to a model of engineering water conservancy[3]. Instead we should commit to develop water resources in a comprehensive manner, to use the water wisely, to protect the environment vigorously and to manage the resources scientifically. I believe we can find solutions to our problems if we move towards green water conservancy, or, eco-economic water conservancy.

[1]Sanmenxia (Three Gates Gorge) Dam was built largely for flood control on the lower Yellow in 1957, with technical assistance from the Soviet Union. Within three years of reservoir impoundment in 1960, the river had deposited more than 50 billion tones of sediment at its upper end, raising the riverbed by several metres and threatening upstream areas with serious flooding. Although it was originally planned as a storage dam, Sanmenxia finally began producing power in 1973 as a 250 MW run-of-river project, which allowed as much water as possible to flow through between the July-to-October flood season – thereby negating its original function of flood control. For its 250 MW output, Sanmenxia flooded 66,000 hectares of fertile farmland and displaced 410,000 people, which is more than any other reservoir in the world. (Source: Silenced Rivers: The Ecology and Politics of Large Dams, by Patrick McCully)

[2]China’s Grand Encyclopedia project covers many subjects, including history, geography and politics. The Water Conservancy Encyclopedia is a feature of the project that was published in 2006.

[3]A traditional approach to water management that emphasizes the engineering-related benefits of building dams and reservoirs, such as flood control, power generation and increased water supply, at the expense of the associated social and environmental issues.

Yan Shi, Three Gorges Probe, May 28, 2007

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