Dam over Yarlung Zangbo
The Brahmaputra, a trans-boundary river flows within the Brahmaputra Sub-basin, which is part of the Ganga-Brahmaputra basin. Both the rivers discharge into the Bay of Bengal. The Brahmaputra and its major tributaries have a catchment area of 580000 sq. km according to a World Bank report. About 50% of the basin lies within the Chinese territory and 33.6 % lies within the Indian territory. The rest lies in Bhutan and Bangladesh. There are over eight sub-sub basins within Indian, Bhutan territories contributing a significant amount of water to the river. The surface run-off in the Brahmaputra varies from 3,244 m3/s in March (mostly due o glacial melt) to 44,752 m3 /s in July (due to the Indian Monsoon). The rain-fall within these eight sub-basins varies from 1000 to 4000 mm/year while the tributaries of Tsangpo River (Yarlung Zangbo, River Brahmaputra as it is known in Tibet), lying within the Tibetan plateau receives an annual rain-fall about 100-400 mm/y. The surface run-off in Tsangpo River is due to glacial melt that happens mostly during the April-May months. The Lunpo Gangri, Nyainqentanglha Feng, Bairiga, Gyala Peri, and Namcha Barwa are the glaciers supplying water to Yarlung Zangbo River. The Yalung Zangbo river, originating in Lunpo Gangri glacier in NW Tibetan Plateau, flows in an easterly direction for about 1625 km before taking a southerly bend at ( Shuomatan Point ) NE part of Arunachal Pradesh and is joined by the eight tributaries before discharging into the Bay of Bengal. So, the major run-off in the Brahmaputra is due to the eight tributaries located within India, Bhutan, Nepal, and not in Tibet. Further, most of the time the water in Yalung Zangpo is frozen and the flow is only during summer-glacial melt time. The best example to understand this phenomenon is the Stakna dam in Leh, Ladakh. This dam generates 2 MW only for two to three months in a year. China has already constructed Zangmu Dam (hydroelectric) with a generation capacity of 510 MWe in 2010 that is operational now.