China on 13-10-2015 operationalised the $1.5 billion Zam Hydropower Station, the largest in Tibet, built on the Brahmaputra river, which has raised concerns in India over the likelihood of disrupting water supplies.
All six of the station's units were incorporated into the power grid on Tuesday, the China Gezhouba Group, a major hydropower contractor based in Wuhan, capital of Hubei Province in central China told state-run Xinhua news agency. Located in the Gyaca County, Shannan Prefecture, the Zam Hydropower Station also known as Zangmu Hydropower Station, harnesses the rich water resources of Brahmaputra known in Tibet as Yarlung Zangbo River, a major river which flows through Tibet into India and later into Bangladesh.
The Zangmu Dam is a 116 m (381 ft) tall and 389 m (1,276 ft) long concrete gravity-type. On its right bank is the spillway, plunge pool and bottom outlet (for silt). On the dam's left bank, the retaining dam section is 80 m (262 ft) tall and the power plant sits at its toe. The entire dam is 76 m (249 ft) wide at its base and 19 m (62 ft) wide at its crest. Sitting at the head of a 157,668 km2 (60,876 sq mi) catchment area, the dam's reservoir has a daily active capacity (pondage) of 86,600,000 m3 (70,208 acre·ft) and normal reservoir elevation of 3,310 m (10,860 ft). The dam's power station will contain six 85 MW Francis turbine-generators for a total installed capacity of 510 MW.
The dam considered to be the world's highest-altitude hydropower station and the largest of its kind will produce produces 2.5 billion kilowatt-hours of electricity a year. "It will alleviate the electricity shortage in central Tibet and empower the development of the electricity-strapped region. It is also an important energy base in central Tibet," the company said.
Officials said when the electricity is ample in the summer season, part of the electricity will be transmitted to the neighbouring Qinghai province, Xinhua report said. Investment of the hydropower station, about 140 kilometers from Tibetan capital Lhasa, totalled 9.6 billion yuan (about USD 1.5 billion). The first unit began operations last November.
Reports in the past said besides Zangmu, China is reportedly building few more dams.
China seeks to ally Indian fears saying that they are the run-of-the-river projects which were not designed to hold water. The dams also raised concerns in India over China's ability to release water in times of conflict which could pose serious risk of flooding. An Indian Inter-Ministerial Expert Group (IMEG) on the Brahmaputra in 2013 said the dams were being built on the upper reaches and called for further monitoring considering their impact on the flow of waters to the lower reaches. The IMEG noted that the three dams, Jiexu, Zangmu and Jiacha are within 25 kms of each other and are 550 kms from the Indian border.
India has been taking up the issue with China for the past few years the two countries reached. Under the understanding reached in 2013, Chinese side agreed to provide more flood data of Brahmaputra from May to October instead of June to October in the previous agreements river water agreements in 2008 and 2010.
India is concerned that if the waters are diverted, then projects on the Brahmaputra, particularly the Upper Siang and Lower Suhansri projects in Arunachal Pradesh, may get affected.