The Nathpa Jhakri Dam is a concrete gravity dam on the Satluj River in Himachal Pradesh, India. The primary purpose of the dam is hydroelectric power production and it supplies a 1,500 MW underground power station with water. Before reaching the power station, water is diverted through a 27.4 km (17 mi) headrace tunnel. Construction on the project began in 1993 and it was complete in 2004. The last two of the 250 MW Francis turbinegenerators went online in March 2004. It is owned by SJVN Ltd.