The scale of China's hydroelectric ambitions has regional and global political implications. India and others downstream have issues. China is using hydro power for clean electricity and for their own water security. The North is dryer and has more demand for water. They also use the dams to deepen rivers to allow 10,000 ton barges to go over more of the country. This is more efficient transportation of cargo from the coast and enables better and more even development of the interior. By enable the increase of per capita GDP in the inland areas it reduces the tension and reduces the economic gap between the rich cities and the interior cities. China can use the engineering to help solve power, water, farming, transportation, urban development, GDP growth and reduce income inequality. On the other end are the other countries India, Vietnam and others that also need water. Mishandling this situation and not finding a way to give equitable amounts of water to those downstream is a higher risk for conflict than the Taiwan situation. There is also the resource situation in the South China Sea.
Yet, China has stepped up its reengineering of river flows in two ways: by portentously shifting its focus from internal rivers to international rivers; and by graduating from building large dams to building megadams.
For example, its newest dams on the Mekong River are the 4,200-megawatt Xiaowan — taller than Paris’s Eiffel Tower and producing more electricity than the installed hydropower-generating capacity of all of the lower Mekong countries together — and the 5,850-megawatt Nuozhadu, which when complete will be even bigger in storage volume but not in height.
In mid-2010, China’s state-run hydropower industry published a map of major new dams approved for construction, including one on the Brahmaputra River at Metog (or “Motuo” in Chinese) that is to be twice larger than the 18,300-megawatt Three Gorges Dam, which Beijing likes to trumpet as the greatest architectural feat since the Great Wall was built despite the dam’s increasingly damaging effects on the Yangtze River system. The Metog site is close to the disputed border with India.
Daduqia, almost on the border with India, has been officially identified as the site for another mega-dam to impound the Brahmaputra’s waters. Both Metog and Daduqia are to harness the force of a nearly 3,000-meter drop in the river’s height as it takes a sharp southerly turn from the Himalayan range into India. This area is in the Brahmaputra’s “Great Bend,” so called because the river there makes a hairpinstyle turn around Mount Namcha Barwa, forming the world’s longest and steepest canyon in the process. The Brahmaputra Canyon—twice as deep as the Grand Canyon in the U.S.—holds Asia’s greatest untapped water reserves.
New Scientist - Already, China has completed a series of dams on tributaries of the Brahmaputra. The first on the river's main stem, the $1-billion Zangmu dam, will be completed in 2014. Next up could be the Tsangpo canyon dams: Motuo, which would deliver 38 gigawatts, and Daduqia, at 42 gigawatts. [Three Gorges is 18 gigawatts]
It is not just water flowing into India and Bangladesh that China has in its sights. Its other neighbours are also growing restive. The latest flashpoint is the Myitsone dam being built by China on the Irrawaddy in northern Burma. Burmese generals approved the scheme three years ago, even though 90 per cent of the electricity from the 6-gigawatt plant will go to China.
By building giant dams near the borders on the major rivers flowing to Southeast Asia, South Asia, and Central Asia, China is acquiring the capability to control cross-border flows and fashion water into a potential political weapon. Water is as essential as the air we breathe, and China is acquiring the capability to control the lion’s share of Asia’s cross-border river flows. This will give it tremendous leverage over its neighbors. In fact, with the rapid accumulation of Chinese economic and military power and the growing regional power asymmetry, Beijing has been emboldened to embark on water-diversion plans.
China’s frenzied dam building, far from slowing, has only picked up more momentum in the name of increasing its renewable-energy capacity. Even with 25,800 of the world’s approximately 50,000 large dams, China remains on a dam-building spree, with a plan to boost its hydropower-generating capacity from 170 gigawatts to 250 gigawatts by 2020. Renewable energy now serves as a useful plank to pursue what China has been doing for long — over-damming its rivers. The silting of the reservoir of the world’s biggest dam, Three Gorges, has only prompted the construction of more dams upstream, including in ecologically sensitive areas, to help flush the silt.
The plain fact is no country in history has been a greater dam builder than China. The dam-building spree started under Mao Zedong but it has accelerated in the post-Mao period. Although China already boasts more dams than the rest of the world put together, it has recently unveiled a mammoth 4-trillion-yuan ($635-billion) fresh investment in water infrastructure over the next decade, more than a third of which will be utilized for building dams, reservoirs, and other water-supply structures. Its vice minister of water resources announced October 12, 2011, that the new investment would be aimed at harnessing the waters of the country’s rivers, rebuilding or reinforcing more than 46,000 reservoirs, and extending the irrigation networks. The vice minister also admitted China's uncontrolled economic growth has left up to 40 percent of its rivers badly polluted and that the country faced “huge pressures” on supplies of water.
“Industrialization and urbanization, including ensuring grain and food security, are exerting higher demands on water supplies ... while our water use remains crude and wasteful,” Jiao Yong said at a press briefing.