From an environmental economics perspective the externalities of river diversion are all too clear. Those downstream of a river are at the mercy of those upstream.
When the upstream country is China and the downstream country is India it is not hard to see tensions in the region rising.
There are a number of telling quotes:
Chinese Prime Minister Wen Jiabao has said that water scarcity threatened the very "survival of the Chinese nation".
Increasing consumption of water, rapid industrialization and pollution have rendered the waters of many of China's rivers unusable.
So what is the story. Read on:
India quakes over China's water plan [Asia Timess]
BANGALORE - Even as India and China are yet to resolve their decades-old territorial dispute, another conflict is looming. China's diversion of the waters of a river originating in Tibet to its water-scarce areas could leave India's northeast parched. This is expected to trigger new tensions in the already difficult relations between the two Asian giants.
Prime Minister Manmohan Singh is reported during his recent Beijing visit to have raised the issue of international rivers flowing out of Tibet. Chinese Prime Minister Wen Jiabao has said that water scarcity threatened the very "survival of the Chinese nation".
The river in question is the Brahmaputra, which begins in southwestern Tibet where it is known as the Yalong Tsangpo River. It flows eastwards through southern Tibet for a distance of about 1,600 kilometers and at its easternmost point makes a spectacular U-turn, known as the Shuomatan Point, or the “Great Bend”. This is just before the river enters India, where it is joined by two other major rivers; from this point of confluence it is known as the Brahmaputra. It then snakes into Bangladesh, where it is joined by the Ganges River to create the world's largest delta before emptying into the Bay of Bengal.
It is at the Great Bend that China plans to divert water, in addition to its hydroelectric power project that is expected to generate 40,000 megawatts of power. The diversion of the waters is part of a larger hydro-engineering project, the South-North water diversion scheme, which involves three man-made rivers carrying water from the icy Tibetan plateau to the arid north.
This water diversion scheme will draw from the waters of the Yalong, Dadu and Jinsha rivers, which rise in the Tibetan plateau, and channel them to the Yellow River. The aim of the project is to provide water for human use, including farming and industry in China's water-scarce areas in the north and northwest. This water diversion project involves three diversion routes - the eastern, central and western routes. The diversion of the Yalong Tsangpo at the Great Bend is the western route of the project - the most technologically challenging and controversial of the three routes.
For Beijing, the argument in favor of the water diversion project is simple. More than a quarter of China is classified as desert. Its north and northwest areas are water scarce. Increasing consumption of water, rapid industrialization and pollution have rendered the waters of many of China's rivers unusable. Besides, sections of the Yellow River run dry. In contrast, rivers that rise in the Tibetan plateau's glaciers have much water. Once completed, the water diversion scheme is expected to transfer over 40 billion cubic meters of water annually to China's water scarce areas, relieving China's thirst to a significant extent.
It is true the Tibetan plateau is a source of much water. It is Asia's principal watershed and the source of 10 of its major rivers, including the Yalong Tsangpo/Brahmaputra, the Sutlej and the Indus. China, India, Bangladesh, Nepal, Pakistan, Thailand, Myanmar, Laos, Cambodia and Vietnam, indeed 47% of the world's population, are dependent on water rising in the Tibetan plateau.
But while rivers with sources in the icy Tibetan plateau are rich in water, critics of the water diversion project say they are not inexhaustible, as Chinese officials claim. The Tibetan plateau is ice-covered but it is an arid desert with very little rainfall. The source of much of its water bodies and rivers is glaciers, which are melting due to global warming. If, alongside the impact of rising temperatures on glaciers, China diverts water from its natural course, Tibet will be a water-scarce region in a few decades. Critics also point to the environmental and ecological destruction it is likely to cause.
The water diversion project at the Great Bend spells disaster not only for the Tibetan plateau but also for the lower riparian countries - India and Bangladesh. These countries view the project with some concern as it represents a direct threat to the lives and livelihoods of millions of people living downstream.
With the Yalong Tsangpo's waters being diverted, the amount of water in the Brahmaputra will fall significantly, affecting India's northeast and Bangladesh. It will severely impact agriculture and fishing there as the salinity of water will increase, as will silting in the downstream area.
A shortage of water in the Ganges has already affected the lives and livelihoods of millions in Bangladesh, pushing them to migrate to India, especially to its northeast. This migration of Bangladeshis has changed the demographic composition of vast tracts in the northeast (especially in Assam) and triggered serious ethnic conflicts there. A shortage of water in the Brahmaputra will accentuate these problems to dangerous levels.
There is concern too that with the water diversion project taking off, China will acquire great power and leverage over India, worsening tensions between these two countries.
It seems that India can only watch helplessly as China steams ahead with its water diversion ambitions.