China’s new mega dam raises concerns about India’s water future

China’s ambitious plan to build a mega hydropower plant on the Yarlung Tsangpo River (known as the Brahmaputra in India) has sparked heated debate across Asia. While Beijing presents it as a step towards renewable energy and climate resilience, New Delhi sees it as a threat to water security and economic stability.

Affected provinces and states

China: Tibet Autonomous Region (where the Yarlung Tsangpo originates).

India: Arunachal Pradesh and Assam, where the Brahmaputra provides water to millions of people.

Bangladesh: Downstream regions, including Dhaka and coastal provinces, depend on the river’s flow.

Key threats identified

1. Water security: Reduced flow in Indian states could cause drought in agricultural areas.

2. Flood risks: Sudden releases of water from the dam could worsen monsoon-induced floods in Assam and Bangladesh.

3. Environmental damage: Fish migration and biodiversity in one of the world’s richest river systems could collapse.

4. Geopolitical tensions: The dam project adds strain to already fragile Sino-Indian relations.

Climate economics and costs

China says the project will generate up to 60 gigawatts of clean energy, potentially surpassing the Three Gorges Dam. Estimated cost: $25 billion to $30 billion. Proponents say it could cut carbon emissions and fuel Beijing’s green energy ambitions.

But for India, the climate economy risks are huge: disruption to irrigation, food insecurity and billions in losses to agriculture and fisheries. The economic stakes for Assam, Arunachal Pradesh and Bangladesh’s delta regions are huge.

A fragile future

While China promotes its megadam as a climate solution, experts warn it could trigger a regional water crisis. Without international agreements, rivers that cross borders remain at the heart of climate geopolitics, where sustainability and sovereignty collide.