The Tsarap River has its source in the glaciers near Pankpo La Pass at the border of Ladakh and Himachal Pradesh. After rising from its source, the Tsarap River flows southwest up to Sarchu, a camping site at the Leh-Manali Highway, here the Tsarap River joins a confluent of three rivers of Lingti, Yunan and Sarchu River. At village Purne, the Tsarap River is joined by Kargyag River which originates near Shingo La pass. Then the Tsarap River flows down in the main Zanskar valley, through the towns of Mone, Tichip, Jamyang Lang, Dorzong and Chia. The river then passes a confluence with its tributary, the Stod River, at Padum, the capital of Zanskar. Together, these two rivers form the Zanskar River, a tributary of the Indus River. The Tsarap River contributes to the minimal agricultural production of the Zanskar valley, mainly to the lower areas of Chia, by providing irrigation to the fields of barley, wheat, buckwheat and peas. Accessible in the summer, the Pensi La mountain pass which connects Zanskar with rest of the country, receives heavy snowfall along with the other pass Zojila, which results in the valley being cut off during winter from rest of the state, with the river freezing during this season. The river source at Pankpo La near Sarchu lies southeast from the nearest airport of Leh. The Tsarap River is famous for adventure sports. Rafting events are organised in the Tsarap, Stod and the Zanskar rivers.
Landslide Dam
A lake has been formed on the Tsarap River due to a landslide dam at, upstream of Padum the commercial hub of Zanskar. The landslide, which occurred on 31 December 2014 between Shun and Phuktal villages, was first noticed when the Alchi Hydroelectric Power Projectdown the river reported recession in water level. The dam created by the debris is high, wide and long and the artificial lake is at 80% of the height of the debris. As of 1 February 2015, the artificial lake formed behind the dam is nearly long and covered about 110 hectares of land. The material of barrier is believed to be of fine-grained with boulders having a narrow crest. A report submitted by local authorities prohibited the use of explosives to clear debris as it would trigger more landslides and aggravate the situation. They have called up on the National Disaster Management for assessment of the situation. According to the deputy collector of Zanskar, "The lake has been created around 90 km from the Padam area of Zanskar and beyond 43 km no one can go by foot. After consulting all local engineers, including Army engineers, we were not able to do anything". On 20 February 2015 the National Disaster Management after a ground survey submitted a report on which the Committee headed by the Union Cabinet Secretary deployed a team at the site to carry out controlled blasting and manual work to allow channelized flow of water. The severe temperatures in the region which are below -20 °C have frozen the lake and chances of a breach will rise with a rise in temperature in the following days. Authorities have closed down the old trade route, the Chadar Trek and have airlifted the people stranded therein to the safer places. People living in downstream areas of Tsarap have also been informed to move to higher and safer places. Control rooms have been set up at Padum and Phuktal to keep a close watch on the situation.
