ITANAGAR, Dec 29: The Centre has said the exact reasons for the change in the turbidity of the water of the Siang river is not yet known, and that it may be possibly be due to landslide, earthquake, or any other activity in the upstream region across the international border with China.
Replying to a Lok Sabha question on Friday, Minister of State for Water Resources, Arjun Ram Meghwal, said that during the recent visit of the foreign minister of China to India, matters concerning trans-border rivers, including the recent reports about the unusual change in the water quality of the Siang river, were raised with the Chinese side.
As a lower riparian state with considerable established user rights to the waters of the river, the Government of India has conveyed its views and concerns to the Chinese authorities, including at the highest levels of the Chinese government, and has urged them to ensure that the interests of downstream states are not harmed by any activity in the upstream areas, the minister’s response read.
“The change in the colour of the Siang’s water was noticed on 10 November at the Tuting Hydrological Observation site by the Central Water Commission (CWC) in Arunachal Pradesh. The cause of such change in the colour of the river’s water appears to be due to excess silt. Analysis of the water samples of the Siang by the Tuting and Pasighat CWC shows that all observed water quality parameters are within permissible limits as per BIS 10500:2012 drinking water standard, except turbidity,” the minister said.
In addition, the results of water quality tests conducted by the state’s PHE&WS department on samples from Pasighat shows turbidity and iron in excess of permissible limits. Besides this, physico-chemical analysis of the water samples collected from the Siang across Pasighat and Jonai, conducted by the NERIWALM, shows higher concentration of aluminium and iron beyond acceptable and permissible limit for drinking, the minister said.
“Change in the water level was also observed by the CWC at Tuting, and it was found that there was a decrease in the flow of water at Tuting from 18 to 19 November (about 1.96 metres in level and approximately 50 per cent drop in the water flow). Thereafter, the flow got restored to the previous level,” the minister added.
The Lok Sabha question was jointly placed by Ramen Deka, Kaushalendra Kumar, Dr Thokchom Meinya, Ninong Ering, and Chintaman Navasha Wanaga.