Context: Supreme Court of India has expressed deep concern about the deteriorating condition of the Sutlej river, a historically perennial river in North India.

Sutlej River

• About: It is longest of the five tributaries of the Indus River that give the Punjab (meaning “Five Rivers”) region its name. 
• Origin: On the north slope of the Himalayas in Lake Rakshastal in southwestern Tibet.
• Drainage Basin: Himachal Pradesh, Punjab, Ladakh and Haryana.
• Flow Through Punjab: The river then flows through Punjab near Nangal before meeting the Beas River.
• Formation of Border: The merger of these two rivers goes on to form 105 Km of the India-Pakistan border.
• Course: The river continues to flow for another 350 Km before joining the Chenab River.
• Formation of Panjnad: The combination of the Sutlej and Chenab Rivers form the Panjnad, which finally flows into the Indus River.
• Length: 1550 km, out of which 529 km is in Pakistan.
• Major Tributaries:  Baspa, Spiti, Nogli Khad, and Soan River being its main ones.
• Water Allocation: Water from the Sutlej River has been allocated to India according to the Indus Waters Treaty of 1960.
• Hydroelectric Projects: There are several major hydroelectric projects on the Sutlej, including the 1,000 MW Bhakra Dam, the 1,000 MW Karcham Wangtoo Hydroelectric Plant, and the 1,530 MW Nathpa Jhakri Dam.

o The only trans-Himalayan river in India, the Sutlej, has turned into a rivulet because of the construction of several dams, changing the entire ecosystem and eco-chain.