On December 25, 2024, China officially approved the construction of a mega hydropower project to generate 70,000 MW of electricity on the Yarlung Tsangpo River, known as the Brahmaputra in India and Jamuna in Bangladesh, at Medog County in the Tibetan autonomous region. The project site is located at the river’s great U-turn, only a few miles from the Indian border in Arunachal Pradesh, where India itself plans to construct a medium-sized dam. This transboundary river, with its ancient geological history, has sustained agricultural and pastoral civilizations along its 2,900-kilometer journey from Tibet’s Lake Mansarovar to the Bay of Bengal. Throughout its course across the three countries, the river already supports numerous water management structures, including dams for irrigation, hydropower generation, drinking water supply and flood control.

China’s rapid economic and population growth has led to unprecedented levels of energy consumption and CO2 emission. As a global manufacturing hub, the country relies heavily on fossil fuels to power its national and multinational industries. Now the world’s largest energy consumer and carbon emitter, China is actively pursuing green energy alternatives to balance energy needs with environmental concerns. This shift toward hydropower aligns with China’s commitment at the Intergovernmental Panel on Climate Change (IPCC) Summit to achieve net-zero carbon emissions by 2060.

The planned hydropower project, estimated to cost $137 billion, will employ a Run -the-Of-River (ROR) operating model, to generate 300 billion kilowatt hours of green energy annually. With its massive water utilization and power generation capacity of 70,000 MW, the Brahmaputra dam project is set to become the earth’s largest hydropower project, generating three times more energy than the Three Gorges Dam on Yangtze River. The project will harness the immense hydropower potential of the Great Bend, where the river’s sharp turn through steep cliffs enables the construction of 6-10 tunnels, each approximately 20 kilometers long, through the adjoining mountain range’s cascading rock formations.

The world’s largest water infrastructure project has drawn global attention for several reasons: its enormous size, its location atop earthquake-prone regions and concerns about how such a mega project might affect the earth’s rotation given their sheer mass. While China claims to have thoroughly studied the site’s suitability for hosting the world’s largest hydropower production center, the interaction between planetary forces and such massive human-made structures requires further research.

The altered hydrological flow of the river is expected to significantly impact people along the river in India and Bangladesh, forcing them to adapt to new socioeconomic realities. The river’s natural course includes a dramatic descent through the Great Bend, where it drops 2,000 meters in elevation before reaching Arunachal Pradesh in India, with a gradient of 40 meters per kilometer. Once the hydropower project is operational, the river’s natural flow will be replaced by a controlled regime dictated by the project’s operational schedule and volume requirements. This transformation threatens the livelihoods of millions of people living along the Brahmaputra and Yamuna flood plains. Traditional practices dependent on monsoon floods for rice cultivation and fishing will be disrupted, as will the natural deposit of nutrient-rich silt. The controlled flow will endanger diverse aquatic and terrestrial species in wetlands and mangrove forests. Additionally, drinking water sources from natural sources may dry up, while changes in surface and subsurface water flows will affect underground storage as well as glacial lakes and permafrost zones.

Communities downstream will face dual threats: potential flooding when China releases water for power generation, and water storages during storage period. The geological risks are equally concerning. The project site’s location at the intersection of the Tibetan, Indian and Eurasian plates could amplify seismic activity, risking catastrophic dam breaches that would flood Indian and Bangladesh territories. The devastating 1950 Assam-Tibet earthquake, with epicenter in Medog County, serves as a reminder of the region’s seismic vulnerability. According to United States Geological Survey (USGS) reports, the 8.6 magnitude earthquake claimed at least 780 lives, with effects felt as far as Kolkata in India’s West Bengal state, destroying 2,000 buildings, including temples and mosques throughout the Brahmaputra river basin in Northeast India.

In 2015, China’s National Development and Reform Commission incorporated this mega hydropower project on the Brahmaputra into its future power strategy, aiming to supply electricity to the country’s power-deficient western and southern regions. With strong political backing from the Communist Party of China, the project has become both a symbol of national pride and a demonstration of China’s sovereign rights over its water resources. The government has successfully fostered widespread public support by framing the project as essential to national water security.

China’s geographical advantage as the upstream nation for major rivers originating in the Hindu Kush Himalayan region, including the Brahmaputra and Indus, gives it considerable control over water flow into downstream nations like India. These transboundary rivers lack established prior water rights, as they are not registered under the Convention on the Law of the Non-Navigational Uses of International Watercourses that came into force in 2014. This legal vacuum strengthens China’s position to utilize these waters at its discretion. As reported by the Indian daily, The Hindu, on January 6 2025, while China and India have the expert-level mechanism (ELM) for sharing hydrological data, the absence of a comprehensive bilateral treaty, combined with ongoing border disputes, has intensified security concerns in the Brahmaputra basin. 

The announcement of this mega power project on the higher reaches of the Brahmaputra has heightened concerns in downstream nations India and Bangladesh. Beyond geopolitical implications, the project has raised significant environmental, social and economic contexts. Some analysts speculate that during periods of international tension, the upstream reservoir could be weaponized - either through intentional flooding of India’s lowland border regions or contamination of drinking water sources, tactics historically known as ‘water bombs’.

NASA’s impact assessment of Three Gorges Dam of China, currently the biggest hydropower project generating 22,500 MW, provides a sobering precedent. The Three Gorges Dam - standing 185 meters high and two kilometers long, with a water storage capacity of 40 billion cubic meters - has directly impacted the earth's daily rotation, extending days by 0.06 microseconds and causing the planet’s center to bulge as it accommodates the redistributed water mass.

The Brahmaputra dam, situated on the seismically active Tibetan plateau, presents even greater engineering challenges. Beyond permanently altering the pristine Hindu Kush Himalayan landscape, it could impact earth’s planetary rotation more significantly than the Three Gorges Dam. These potential impacts, ranging from regional and global to celestial scales, warrant attractions from organizations dedicated to preservation of this planet. While efforts to mitigate global warming are welcome, the physical redistribution of earth’s mass for green energy production could have serious planetary consequences beyond climate change.

(Adhikary is a former Director General of the Department of Water Resources and Irrigation.)

(This opinion article was originally published in March 2025 issue of New Business Age Magazine.)