The river originates in the Tibetan Himalayas, flowing from China into India, through Arunachal Pradesh and Assam before flowing into Bangladesh. Officials in India claim construction within the Chinese segment of the river has caused pollution so severe it is present at a detectable level as far downstream as Assam.
Laboratory testing of the river’s water within Assam has declared the water to be turbid and unfit for human consumption. Samples from 15 locations were sent to the Indian Institute of Chemical Technology in Hyderabad and the Indian Institute of Technology Guwahati for testing following reports that the water had been progressively blackening.
The sudden reduction in the water’s quality sparked concerns for the health of those who use the river as a source of drinking water. Alongside health concerns, complaints were heard from those who use the river as a source of income. For example, fishermen along the river were complaining of noticeable reductions in fish.
A leading hydrologist at the Indian Institute of Technology, Roorkee, Nayan Sharma has attributed the change in water to Chinese construction of multiple dams. “China is constructing several dams on the Yarlung Tsangpo”, he says, noting “the Zangmo dam is located just 3-4 kilometers (2-3 miles) from the Indian border.”
Locals in towns close to the border believe that the Chinese are building tunnels in order to divert the water from the river to more arid regions of China. Lungkang Ering, president of the All Bogong Students’ Union says “the Chinese may seek to deny, but we suspect there is massive tunnel building activities to divert the Yarlung Tsangbo to Xinjiang province, particularly the Taklamakan desert region.”
While construction in China may be contributing to the issue, some rebut these claims of external contamination by pointing out potential contributing factors on the Indian side of the border.
Whilst acknowledging Chinese construction of dams and a potential water tunnel could play a role, Outlook India points out that construction activities inside of India may also be contributing. Also pointed out is that substantial levels of deforestation are occurring in proximity to the Indian section of the river. This could also be a potential cause of the contamination, particularly following heavy rains as deforestation is known to cause soil slippage.
The accusations of external contamination of the river may further strain ties between India and China. Chief Minister of Assam, Sarbananda Sonowal, has called for the central government to take up the matter up with the Chinese government.