- China controls the Brahmaputra's source and is building a large dam near border
- But China contributes only 30-35% of Brahmaputra's flow, mainly from glaciers
- India generates 65-70% of Brahmaputra's water through heavy monsoon rains
A prominent Chinese commentator recently sparked a debate by warning India about its river waters. Speaking at a seminar in Islamabad, Victor Gao, vice president of the Beijing-based Center for China and Globalisation, suggested that if India tries to "weaponise" the Indus Water Treaty against Pakistan, China has the power to do the same with rivers originating in Tibet.
Addressing the gathering, Gao reminded India that the Indus river system starts in the Tibetan plateau. This geographical reality, he pointed out, places China right at the source of several major rivers that flow down into South Asia. Quoting the ancient Chinese philosopher Confucius, he said, "Don't do unto others what you don't want others to do unto you," basically advising India against using water as a geopolitical tool.
Can China 'Turn Off' Our Water?
Naturally, statements like this make headlines and cause concern. The most crucial river connecting China and India is the Brahmaputra.
China is currently building the world's largest hydroelectric dam in the lower parts of the Yarlung Tsangpo River in Tibet, just about 50 km away from the Indian border. For context, the Yarlung Tsangpo originates in Tibet and enters India through Arunachal Pradesh, where it is known as the Siang River. As it flows down into Assam, it becomes the mighty Brahmaputra, a lifeline for millions of Indians.
So, if China controls the source and is building mega-dams, should India hit the panic button? The short answer is no.
If we look closely at the hydrology of the river, geography heavily favours India.
Who Really Feeds Brahmaputra?
While it's true that a large portion of the river's total length (about 50.5%) lies in China, length doesn't equal water volume. China actually contributes only about 30% to 35% of the Brahmaputra's total water flow, primarily through melting glaciers and limited rainfall in the Tibetan region.
The real magic happens once the river enters India (which holds 28.5% of the river's length). A massive 65% to 70% of the Brahmaputra's water is generated right here in India.
This is where the stark contrast between the two regions comes into play. China's dry Tibetan plateau simply cannot compete with India's massive monsoon downpour when it comes to water volume. For instance, states like Arunachal Pradesh receive over 2,500 to 3,000 mm of rainfall annually, acting as a massive, natural sky-reservoir that constantly replenishes the river.
This heavy rainfall, combined with torrential monsoon showers across Assam, Nagaland, and Meghalaya, pours colossal volumes of water into the basin. Additionally, as the river flows through the Northeast, it is joined by powerful local tributaries like the Subansiri, Lohit, Kameng, Manas, Dhansiri, Jia-Bharali, and Kopili, along with significant runoff from the Khasi, Garo, and Jaintia Hills via rivers like the Krishnai, Digaru, and Kulsi.
Image source: Central Water Commission
The Data That Proves The Point
To understand just how much water gets added within Indian territory, look at the flow rate. At the Indo-China border in Tuting (Arunachal Pradesh), the water flow is roughly 2,000 to 3,000 cubic metres per second.
By the time the river reaches the plains of Assam say, near Guwahati, the flow swells to a staggering 15,000 to 20,000 cubic metres per second during the monsoons. This massive jump proves that the Brahmaputra's true strength comes from Indian rains and local tributaries, not Tibetan glaciers.
Indian Rivers That Power The Flow
Our local tributaries do the heavy lifting for the Brahmaputra basin. For instance, the Subansiri alone contributes nearly 8% of the river's total yield. Other crucial contributors lying within Indian territory include:
- Kameng (also known as Jiabharali)
- Dhansiri and Kopili
- Manas
- Jaldhaka and Torsa
- Teesta (The largest river of North Bengal, rising from the Himalayas in North Sikkim)
Ultimately, while China does have an upper-riparian advantage geographically, turning off the tap to India is practically impossible. Nature, driven by the powerful Indian monsoon and a vast network of local tributaries, ensures that the Brahmaputra will continue to flow strong.
