Arunachal Pradesh Chief Minister Pema Khandu on Wednesday warned the state Assembly of environmental disasters, including floods, for his state and neighbouring Assam if India does not respond to China's building a mega dam on the Yarlung Tsangpo River in Tibet's Medog district.
The Tsangpo flows through Tibet before entering Arunachal Pradesh as the Siang. It becomes the Brahmaputra in Assam and the Jamuna in Bangladesh before it empties into the Bay of Bengal.
To counter what some experts have called a "ticking water bomb for residents downstream (in Arunachal and Assam)", the centre plans to build a large barrage - a low-lying structure with gates to control the flow of water - across the Siang, Mr Khandu said as he sought support for the idea.
"The Indian government has raised objections over repercussions to Siang as a result of China's project. If this (the Chinese dam) happens, what will be the condition of the Siang? The river may shrink because water is diverted... we may be able to cross it on foot. There is also threat of floods if excess water is released... there will be massive floods in Siang belt, Assam and even Bangladesh."
"In case of excess water, we need to have big structures to protect ourselves from floods... the centre too has expressed concern and plans to build a barrage so we can keep Siang alive," the Chief Minister said during a Zero Hour discussion initiated by Congress MLA Lombo Tayeng.
Mr Khandu noted that some members of the public in the Siang Valley were blocking the government's initial geographical survey work and said he plans to personally visit the area to "request villagers cooperate and allow survey and investigation work for proposed barrage".
"If there is diversion of water, there will be floods and land erosion of lakhs of hectares of cultivated land. Once survey is completed then centre can give us clear picture of the matter," he said.
Underlining the serious nature of the problem at hand, Mr Khandu called on the public and Arunachal Pradesh lawmakers to think of the state and country's long-term future.
China's dam is expected to produce triple the electricity produced by the Three Gorges - the world's largest power station - and this has environmentalists in India and abroad deeply worried.
It is mentioned in China's strategic 14th Five-Year Plan, unveiled in March 2021.
The structure will span the river before it leaves the Himalayas and flows into India, straddling the world's longest and deepest canyon at an altitude of more than 1,500 metres (4,900 feet).
The river is also home to two other projects and six others are in the works or under construction.
READ | China To Build Major Dam On Brahmaputra That Could Impact India: Report
The Three Gorges created a reservoir and displaced 1.4 million inhabitants upstream and a senior official at the Stimson Center, a think tank based in the United States has said "building a dam (like this) is likely a really bad idea for many reasons", including fears of big earthquakes and landslides.