Experts express concern over 'Great Bend Dam' in China

The seminar on "Ensuring Water Security, Ecological Integrity, and Disaster Resilience in the Sub-Himalayan Region: The Case of the Brahmaputra" hosted by North East's premier think tank Asian Confluence shed light on the possible devastating impact of the proposed 60,000 MW power plant dam at the Great Band in China.

The seminar sought to foster a collaborative dialogue between governmental agencies, civil society organizations, environmental practitioners, and academicians on the immense challenges posed by the proposed dam in Tibet, amidst the looming threat of climate change.

This initiative aligns with Asian Confluence's mission to facilitate meaningful dialogue and actionable solutions on rivers and water security in the region.

The Brahmaputra river is part of a major river system in Central and South Asia and it flows through Tibet, India, and Bangladesh, and empties into the Bay of Bengal.

The river is fed by snow and glacial melt and is known for its large and variable flow. Brahmaputra is one of the largest rivers in the world and ranks fifth with respect to its average discharge.

The river originates from the Kailash ranges of Himalayas at an elevation of 5300 M. After flowing through Tibet (China), it enters India through Arunachal Pradesh and flows through Assam and Bangladesh before it joins Bay of Bengal. The river slope is very steep when it enters India.

From Tibet, the river enters India's Arunachal Pradesh, where it is known as the Siang. In Assam, it is joined by tributaries such as the Dibang and Lohit and is then called the Brahmaputra. The river continues into Bangladesh and finally flows into the Bay of Bengal. Due to this sudden flattening of river slope, the river becomes braided in nature in the Assam valley making the region susceptible to flooding.

During its course in Assam valley from Kobo to Dhubri the river is joined by about 20 important tributaries on its North bank and 13 on its South bank. Joining of these tributaries bringing high sediment load activates braiding.

The catchment area of Brahmaputra in Tibet is 2, 93,000 Sq. Km; in India and Bhutan is 2,40,000 Sq. Km and in Bangladesh is 47,000 Sq. Km. The Brahmaputra basin extends over an area of 5,80,000 Sq. Km up to its confluence within Bangladesh.

The sub-basin lies in the States of Arunachal Pradesh, Assam, Nagaland, Meghalaya, West Bengal and Sikkim. Thus Brahmaputra has an indelible effect on the lives, livelihoods of millions in the lower riparian states spanning China, the North eastern states of India, Bhutan and Bangladesh.

On December 25, China approved the construction of the world's largest dam on the Brahmaputra River in Tibet near the Indian border referred to as the Great Bend Dam. This site is where the Yarlung Tsangpo makes a U-turn in China's Medog County before entering Arunachal . On completion, the 60,000 MW project will have the capacity to produce three times the electricity of the world's largest hydro project, the Three Gorges Dam in central China. This project, estimated to cost USD 137 billion, has raised alarms in both India and Bangladesh.

According to China, the dam will help transition away from conventional energy sources and contribute to achieving net carbon neutrality by 2060.

The dam could disrupt water flow from Tibet, posing risks of flash floods or reduced water availability downstream.

A 2020 report by the Lowy Institute, an Australia-based think tank, noted that controlling these rivers effectively gives China a stranglehold on India's economy. The dam also threatens the fragile Himalayan ecosystem, home to critically endangered species.

Climate change, deforestation, and soil erosion compound the potential ecological risks. The region's dramatic topography presents significant engineering challenges. The site of the project lies along an earthquake-prone tectonic plate boundary, raising concerns about the safety of such a massive structure. Chinese researchers have previously warned that extensive excavation and construction in the steep and narrow gorges will increase the frequency of landslides and earthquakes.

Reports suggest the colossal development will require at least 420 km of tunnels to be drilled through the Namcha Barwa Mountain, diverting the flow of the Yarlung Tsangpo River. The risks to displaced communities, loos of habitat to many life forms, loss of intangible culture and lifestyle of riverine communities.