It’s been a year since China shared information on the flow of the Pareechu, a tributary of the Sutlej originating from the Tibetan Autonomous Region, raising concerns in the Central Water Commission which has sought the external affairs ministry’s help to assess the river’s hydrology.
“We wrote to the ministry 10 days ago. China stopped sharing information about the tributary’s flow last year. They said that the water monitoring site across the border is damaged,” AK Gupta, the commission’s regional director, said.
The commission has two monitoring stations: One in Chumar near Leh and the other in Sumdoh in Lahaul and Spiti district, at the confluence of the Sutlej and its main tributary, the Spiti river. The flow is also monitored at Khab where the Sutlej has been dammed to generate 1,500 MW of power for the Nathpa-Jhakri hydel project.
The Himachal Pradesh government constantly monitors the flow in the Pareechu through its department of science and technology. The lakes formed in the catchment areas of rivers originating from Tibet are monitored using satellite imaging.
Monitoring the river’s flow is crucial to minimise damage in case of flooding. The Pareechu wreaked havoc on June 26, 2005, when a glacial lake was formed after its course was breached. The lake, the size of 20 football grounds, burst, flooding the Sutlej. The water washed away the strategic Hindustan Tibet road or National Highway 22 at a number of places. Ten bridges and 11 ropeways were swept away. Fifteen bridges were damaged on the 10-km stretch of the highway between Wangtoo and Samdoh alone.
Though no loss of life was reported, 5,000 people were evacuated under the army’s Operation Varuna. The total loss due to flooding was pegged at Rs 800 crore.
The Pareechu originates in India and meanders through Tibet before merging into the Sutlej at Sumdoh. The glacial lake was formed in 2004 after a landslide blocked the flow and it burst on June 26, 2005.