What is the course of the river Brahmaputra?
The Brahmaputra (called Yarlung Tsangpo in China) is one of the longest rivers in the world. Starting in the Himalayas in Tibet, it enters India in Arunachal Pradesh, then passes through Assam, Bangladesh, and empties into the Bay of Bengal. The Brahmaputra, a perennial river, is the lifeline for communities living along its banks. They use it for irrigation, fisheries and inland water transport. In its lower course, the river is both an advantage and a disadvantage. On the one hand, it deposits huge quantities of fertile alluvial soil suitable for agriculture, but on the other, due to geographical and climatic conditions, it causes periodical, disastrous floods in Assam and Bangladesh.
Why is China building it?
The dam is to be built on the river in Medog county, where it drops by 2,000 metres, making it an ideal place to harness hydropower. This region is located in the Tibet Autonomous Region, governed by China.
According to the Chinese officials, the hydroelectric project in the Medog county is part of the country’s renewable energy generation initiatives and that it will help China achieve carbon neutrality by 2060 and also pave way for development in the Tibet Autonomous Region.
In 2010, China began construction of small dams along the mainstream of the Yarlung Tsangpo, two of them have already been completed and at least three are under construction, according to reports. The proposed one is the largest of them all.
How big is this project?
The new dam could help generate up to 60 gigawatts of power, three times that of central China’s Three Gorges Dam, which has the largest installed hydropower capacity in the world now. The new dam could provide 300 billion kWh of clean, renewable and zerocarbon electricity annually. The power generated would help Beijing meet its clean energy goals and strengthen water security, according to Yan Zhiyong, chairman of the Power Construction Corporation of China.
What will be its impact on India?
Such a huge dam could hold back massive amount of silt carried by the river. (Silty soil is more fertile than other types of soil and it is good for growing crops.) This could aﬀect farming in the areas downstream.
The construction of dams upstream will have a signiﬁcant eﬀect on areas downstream. China has claimed that it is building a run-of-theriver hydropower project, which do not involve storage or diversion of the waters of the Brahmaputra. (Run-of-the-river hydroelectric systems are hydroelectric systems that harvest the energy from ﬂowing water to generate electricity). However, experts say it could still reduce water ﬂow downstream, especially during the dry season. India is also worried about the release of water during the monsoons, when north-eastern states such as Assam experience ﬂoods. If China released water from the dam, it could be disastrous for an already inundated Assam.
Water as a weapon?
Being an upstream area, China has a clear advantage in building dams and other infrastructure to store or divert the ﬂow of the river system. There is the potential to signiﬁcantly change the ﬂow rate during times of standoﬀ between the countries. India has agreements with China that require the latter to share hydrological data of the river during monsoon season between May and October. The data is mainly of the water level of the river to alert downstream areas in the event of ﬂoods. However, during the 2017 Doklam border standoﬀ between India and China, China stopped communication of water ﬂow levels from its dams. Though data sharing resumed in 2018, India has reasons to believe that China may withhold data.
The Himalayan region is vulnerable to earthquakes and other seismic activities. The sheer size of the infrastructure projects undertaken there poses a signiﬁcant threat to the populations living downstream.
Several species of ﬂora and fauna are endemic to this part of the world and some of them are critically endangered. The ecosystem in the Himalayan region is already on the decline. The glaciers have been retreating due to climate change. Deforestation, soil erosion and landslides are some of the other issues here. The combined dam plans of China and India (See next question) could have disastrous consequences in this ecologically sensitive zone.
What is India’s response?
India has urged China to ensure that the interests of downstream states are not harmed by any activity in upstream areas. Meanwhile, India is considering building a 10 gigawatts (GW) hydropower project in the Dibang valley in Arunachal Pradesh, to mitigate the adverse impact of the Chinese dam.