One of the major challenges faced by humanity is water scarcity. According to United Nations estimates, more than half the global population will live in water-stressed or water-scarce countries by 2025 with majority of them being in India and China. As the countries struggle with their resources, they are facing water constraints. Of the rivers that cross the Sino-Indian border, Brahmaputra is the most important. The rivers in Ganges basin can also be controlled by China directly through Tibet or indirectly using neighboring countries who are allies of China.

The Brahmaputra flows from China, India, and Bangladesh on its journey from the Himalayas to the Bay of Bengal. China has embarked upon a series of dam-building and water-diversion projects that have the potential to significantly alter the river’s course with the potential of harming those downstream. The river has a massive hydropower potential, particularly at the river’s Great Canyon, with water dropping thousands of feet through a mountainous stretch. China is the world’s most aggressive dam builder, and Chinese water projects have already been accused of causing environmental damage and forced displacement of people in neighbouring downstream countries. If they decide to construct a large dam, India will have no choice but oppose them, possibly requiring military intervention.

India is home to about 17% of the world’s population but less than 4% of water resources, and the country is dependent on foreign originating rivers for about a third of its surface water. With the population still rising and unpredictable weather patterns, India is in a state of water crisis. Approximately half of nationwide precipitation falls over just 15 days, and 90 percent of river flows are concentrated in the wettest four months of the year.

The Tibetan part of the river “boasts a water energy reserve of about 100 million kilowatts, or one-sixth of the country’s total, ranking second behind the Yangtze River, China’s longest.”

The overall effects of large-scale dam construction include decreased volume of water available for downstream use; disruption of natural flooding cycles; the holding back of nutrient-rich sediment; and changes to riparian, marine, and fishery ecology and economy.
In future years, climate change may well worsen these effects, particularly in glacier-fed rivers like the Brahmaputra and Ganga. Higher temperatures are likely to increase the rate at which glaciers melt, leading to increased river flows in the short run but decreases long-term. If China moves ahead with its dam building, the result will be control by Beijing over an ever-larger percentage of a constantly shrinking river. It is this possibility that suggests why Beijing and New Delhi may be on a collision course over the Brahmaputra.

Because there is no major world market for trading water itself, to understand how water moves around the globe today it is necessary to look at trade in other goods, introducing the concept of virtual water. All finished products require water to greater or lesser degrees for their production. Therefore, importing intermediate or finished products is an indirect way of importing the embedded water required to grow or make them. In China and India, where agriculture currently accounts for 70 percent and more than 50 percent, respectively, of water consumption, the most significant tradable commodities from a water perspective are foodstuffs.

The concept of water scarcity leading to food insecurity is one of the thorniest issues in most cross-border water disputes, and the conflict over the Brahmaputra is no exception. China’s ability to control the river’s flow through damming and diversion could potentially give Beijing the ability to choke off the food supply to its largest neighbour.

For India, even the intimation of such a threat in the context of the Brahmaputra could be an existential hazard.

References:

https://digital-commons.usnwc.edu/cgi/viewcontent.cgi?article=1007&context=ciwag-case-studies