Reuters reported on Wednesday that China’s environmental ministry has okayed the construction of a new hydroelectric dam on the Dadu River in the Sichuan province, which when completed will be the country’s largest.
China’s energy mix was 9.4 percent renewable as of 2011, and the Sichuan project is part of the country’s effort to boost itself to 15 percent by 2020. Hydroelectric power is anticipated to make up most of that increase.
The environmental ministry acknowledged that the project is massive enough to damage the local ecology, negatively effecting certain rare fish species and plant life. The dam’s developers have promised to try and offset those effects with “counter-measures,” and the project still requires the approval of China’s ruling cabinet.
To be built over 10 years by a subsidiary of state power firm Guodian Group, it is expected to cost 24.68 billion yuan ($4.02 billion) in investment.Right now the title for China’s tallest dam goes to the Xiaowan project, at 292 meters, while the tallest dam in the world is currently Tajikistan’s Nurek dam, at 300 meters. The Sichuan dam will top 314 meters when all is said and done.
The ministry, in a statement issued late on Tuesday, said an environmental impact assessment had acknowledged that the project would have a negative impact on rare fish and flora and affect protected local nature reserves.
Developers, it said, had pledged to take “counter-measures” to mitigate the effects.
China has been at the forefront of hydroelectric development for a while now, with an enormous number of dams either constructed, in the works, or in the planning stages. Even individual projects can be of tremendous scale, providing in at least one instance an electrical capacity equal to nearly half of Britain’s entire national grid, and preventing 200 metric tons of carbon emissions each year. As of 2010, worldwide hydroelectric capacity was 850 to 900 gigawatts, meaning about one-fifth of the world’s electricity — and half the electricity for almost two thirds of the world’s countries — comes courtesy of hydropower. Though that use varies widely: the United States and Europe have developed 70 and 75 percent of their hydroelectric potential, while Africa has only taken advantage of 7 percent.
At the same time, the large bodies of water and massive landscape alterations that are part and parcel of large dam projects mean hydroelectricity can come with unusually significant downsides. The construction of the Three Gorges Dam in China’s Hubei province, for example, caused significant ecological damage, increased the risk of landslides, flooded a number of archeological and cultural sites, and displaced 1.3 million people. And the constricted water flow can hurt downstream populations that rely on the rivers for their fresh water supplies.
Meanwhile, climate change itself is also making hydropower less reliable, as altering weather patterns dry up some river flows, boost others, and generally make the future availability of water flows more difficult to predict.
One answer to those challenges could be small scale hydropower. Studies suggest there’s as much as 30 gigawatts of unused potential for such projects in the United States. These set-ups generally provide 10 kilowatts to 30 megawatts a piece, and don’t require damming rivers. (Or they can be built into already existing dams, the vast majority of which are not hydroelectric.) Unfortunately, regulatory red tape is in many ways the major hurdle to taking advantage of small scale hydro.