China has approved the construction of the world's largest dam on the Brahmaputra River (known as the Yarlung Zangbo River in Tibet) near the Indian border. This new dam is set to produce 300 billion kilowatt-hours of electricity annually, according to an estimate provided by the Power Construction Corp of China in 2020. This would surpass the 88.2 billion kWh designed capacity of the Three Gorges Dam, currently the world’s largest, in central China. It could be a milestone in the hydropower and renewable energy sectors. However, the construction of this dam raises serious concerns—particularly for downstream countries, especially India, which relies heavily on the Brahmaputra River. This article will explore the dam's compliance with international law, potential environmental impacts, and broader implications for regional stability and water security in South Asia.
Chinese foreign ministry spokesperson Guo Jiakun said, “The project will not have a negative impact on the ecological environment, geological conditions, and the rights and interests related to water resources of downstream countries.” However, considering the region where the dam is being constructed, which is prone to earthquakes and landslides, the situation becomes more complex. The area has experienced such incidents in the past, and recently, on January 7, 2025, a 6.8 magnitude earthquake struck near Shigatse, Tibet, causing multiple deaths. Chinese authorities inspected 14 dams and identified issues, including cracks, in five of them. The detection of cracks and other structural problems in multiple dams underscores the vulnerability of hydropower infrastructure in seismically active areas. This could pose a significant danger to the environment, the river’s ecosystem, and aquatic life. Cracked or damaged reservoirs can alter the water flow. Sudden releases of water or reduced flow can harm aquatic ecosystems downstream by disrupting breeding cycles, food sources, and habitats for fish and other aquatic organisms. Additionally, damaged reservoirs may degrade water quality by releasing sediment, construction debris, and pollutants into the river, causing problems for people living in the region and damaging agriculture. Excessive sedimentation in downstream agricultural areas can reduce soil fertility, impacting local farming communities reliant on the Brahmaputra for irrigation.
But how does all of this affect India and other South Asian countries? The Brahmaputra plays a significant role in northeastern India, flowing through the states of Arunachal Pradesh and Assam. It also plays a pivotal role in agriculture, with its annual deposition of alluvial soil in its floodplains. The Brahmaputra is a source of irrigation, and if disrupted, it could impact millions of lives. Not only does it play a significant role in India, but also it plays a critical role in other countries, such as Bangladesh and Bhutan. Known as the Jamuna in Bangladesh, the Brahmaputra is a vital resource for agriculture, water supply, and livelihoods. Even though China claims it will have no negative impact, dams interrupt the natural flow of rivers, reducing sediment transport downstream. The Brahmaputra River plays a critical role in depositing fertile sediments in floodplains and deltas in northeastern India and Bangladesh. Disrupted sediment flow could lead to reduced agricultural productivity and increased erosion in these areas, which will cause multiple social problems for people in northeastern India and Bangladesh.2
Furthermore, this new Chinese dam could also be a strategic political move for controlling the flow of the Brahmaputra river against India, as it might provide leverage in times of political tension to the Chinese Government. There are possibilities that they would potentially manipulate water resources as a pressure tactic, impacting India’s water security and agricultural productivity. This situation is compounded by China’s other advancements to reinforce its territorial claims over Arunachal Pradesh (which it refers to as "South Tibet"), such as border infrastructure development and the standardization of place names. In December 2021, China's Ministry of Civil Affairs released names for 15 places in the region, a move seen as reinforcing its territorial claims. India has consistently rejected these assertions, maintaining that Arunachal Pradesh has always been an integral part of India and it always will be.
Under the light of these incidents, China having control over the Brahmaputra River could become a significant threat for India in the future. The lack of any formal water-sharing agreements with India, similar to the Indus River dispute with Pakistan, further complicates the matter. China’s non-party status to the UN Convention on the Law of the Non-Navigational Uses of International Watercourses (1997) doubles the challenge. Under international law, the only legal obligations China faces are the “Principle of Equitable and Reasonable Utilization” and the “Obligation Not to Cause Significant Harm,” as outlined in Customary International Law. These principles require shared water resources to be utilized equitably and reasonably among the riparian states. By constructing a dam without consulting downstream countries (e.g., India and Bangladesh), China risks monopolizing the resource, potentially affecting equitable access and failing to ensure that its actions do not cause significant harm to others. If the dam reduces water flow, it would affect ecosystems, disrupt livelihoods downstream, as it would breach the principle of not causing harm to others. Moreover, the lack of an adequate accountability system has now brought India and other South Asian countries to face an alarming danger.
To ensure the right use of the Brahmaputra Dam, China and all the affected countries should take a diplomatic stand and must ensure that their decisions would not hurt any nation’s sovereignty, while ensuring the dam construction is used to its full potential in good faith.
