Dragon's water weapon against India

Just as China has changed the status quo in the South China Sea through an island-building strategy, it is working to re-engineer cross-border flows of international rivers that originate in Tibet, which Beijing annexed in 1951.

No country will be more affected by China's dam frenzy than India because of one telling statistic: out of the 718 billion cubic metres of surface water that flows out of Chinese-held territory yearly, 347 billion cubic meters (or 48.3% of the total) runs directly into India. Several major Indian rivers originate in Tibet, including the Brahmaputra, the Kosi, the Sutlej and the Indus.

China already boasts more large dams than the rest of the world put together. More importantly, it has emerged as the key obstacle to building institutionalized collaboration on shared water resources in Asia.

In contrast to the bilateral water treaties between many of its neighbours, China rejects the concept of a water-sharing arrangement or joint, rules-based management of common resources.

India has water-sharing treaties with both the countries located downstream to it: Pakistan and Bangladesh. These treaties govern the Indus and the Ganges.

By contrast, China, despite its unrivalled international status as the source of river flows to more than a dozen countries, stands out for not having a single water-sharing arrangement with any neighbour.

India's treaties with Pakistan and Bangladesh have actually set new principles in international water law. The 1996 Ganges treaty — which coincided with the 25th anniversary of Bangladesh's Indian-assisted independence — set a new standard by guaranteeing delivery of specific water quantities in the critical dry season.

The Indus treaty stands out as the world's most generous water pact, in terms of both the sharing ratio (80.52% of the aggregate water flows in the six-river Indus system are reserved for Pakistan) and the total volume of basin waters for the downstream state (Pakistan gets 90 times greater volume of water than Mexico's share under a 1944 pact with the US).

China, in rejecting the 1997 UN convention that lays down rules on shared water resources, contended that an upstream power has the right to assert absolute territorial sovereignty over the waters on its side of the international boundary — or the right to divert as much water as it wishes for its needs, irrespective of the effects on a downriver state.

Today, by building mega-dams and reservoirs in its borderlands, China is working to divert the flows of major rivers that are the lifeline of lower riparian states.

Since the last decade, China's major dam building has moved from dam-saturated internal rivers to international rivers located in ethnic-minority homelands like Tibet.

On the Brahmaputra, China is racing to complete several additional dams located in close proximity to each other. This cascade of dams is likely to affect the quality and quantity of downstream flows into India and Bangladesh.

Only five rivers in the world carry more water than the Brahmaputra and only one — mainland China's Yellow River — carries more silt. The Brahmaputra is the world's highest-altitude river. It represents a unique fluvial ecosystem largely due to the heavy load of high-quality nutrient-rich silt it carries from forbidding Himalayan heights.

The Brahmaputra's annual flooding cycle helps to re-fertilize overworked soils in India's Assam plains and large parts of Bangladesh, where the river is the biggest source of water supply.

The silt-movement impediment by China's upstream dam projects constitutes a bigger threat to the biophysical vitality of the river and to the soil fertility of downstream plains than even the likely diminution of cross-border flows.

China's centralized, mega-projects-driven approach to water resources is the antithesis of the policy in India, where water is a state (not federal) subject under the Constitution and where anti-dam non-governmental organizations (NGOs) are powerful. India's Narmada Dam project, which remains incomplete decades after its construction began, symbolizes the power of NGOs.

The largest dam India has built since independence — the 2,000-megawatt Tehri Dam on River Bhagirathi — pales in comparison to China's giant projects, such as the 22,500-megawatt Three Gorges Dam and the new mega-dams on the Mekong like Xiaowan, which dwarfs Paris's Eiffel Tower in height, and Nuozhadu, which boasts of a 190-square-km reservoir.

China's population is just marginally larger than India's, but its internally renewable water resources (2,813 billion cubic meters per year) are almost twice as large as India's. In aggregate water availability, including external inflows (which are sizeable in India's case), China boasts virtually 50% larger water resources than India.

India's surface-water storage capacity — an important measure of any nation's ability to deal with drought or seasonal imbalances in water availability — is one of the world's lowest: Amounting to 200 cubic metres per head per year, it is more than 11 times lower than China's. The 2030 Water Resources Group, an international unit, has warned that India is likely to face a 50% deficit between water demand and supply by 2030.

In the coming years, China, by ramping up construction of dams on trans-Himalayan rivers, could fashion water into a political weapon against India.

(He is author of award-winning "Water: Asia's New Battleground")