HISTORY:
The Karcham Wangtoo Hydroelectric Plant is a 1,200 megawatts (1,600,000 hp) run-of-the-river hydroelectric power station on the Sutlej River in Kinnaur district of Himachal Pradesh, India. The dam and power station are located between the villages of Karcham and Wangtoo where the plant also gains its name. Jaypee Karcham Hydro Corporation Limited of Jaypee Group signed a memorandum of understanding to develop the dam in 1993 and after years of delays, construction on the power station began on 18 November 2005. In 2015 Jaypee Group sold out Karcham Wangtoo Project to JSW Group.The first generator was commissioned in May 2011, the second in June and the final two in September. The 98 m (322 ft) tall dam at Karcham (31°30′00.26″N 78°10′39.54″E) diverts a substantial portion of the Sutlej into a 10.48 m (34.4 ft) diameter and 17.2 km (10.7 mi) long headrace tunnel to the underground power station downstream at Wangtoo. At the station, the water powers four 250 MW Francis turbine-generators before it is sent back into the Sutlej via a 1.2 km (0.75 mi) long tailrace tunnel. The difference in elevation between the dam and the power station affords a gross hydraulic head of 298 m (978 ft). Water not diverted by the dam is sent over the spillway and down the normal course of the river. The main spillway is along the crest of the dam and is controlled by six radial gates. Just upstream of the dam is the 300 MW Baspa II Hydroelectric Plant and downstream of the Karcham Wangtoo is the 1,500 MW Nathpa Jhakri Dam.