Reports on India’s 1500MW Nathpa Jhakiri project on the Satluj river say the project is over 30 months behind schedule and 10% over budget. Originally scheduled for completion by 2001, the project is now expected to come on stream by 2003.
The US$2.5B scheme is located in the state of Himachal Pradesh and has been affected by geotechnical problems since it began in 1992.
Himachal Pradesh is located in the foothills of the Himalayas and is associated with difficult and varying geological conditions, which have required several changes in design and extensive unanticipated work by the contractors. Furthermore, work on the 60.5m high concrete dam is only possible during the non-monsoon period when the river is low.
The project is partly financed by World Bank loans and is being implemented under three contracts by the Nathpa Jhakiri Corporation, a joint venture of India’s federal government and the government of Himachal Pradesh.
The contract for the dam and the desilting works is the responsibility of a joint venture between Foundation Canada and a local firm called Continental, who have completed the coffer dam and a 730m long tunnel to carry 350m3/sec of river diversion flow. The diversion tunnel was extended to its present length from 410m after a large rock fall on the right bank.
The 10.15m diameter power tunnel and the 300m high surge shaft are being constructed by Impregilio of Italy and Hindustan Construction Company of India.
The poor ground conditions in a 3km length resulted in rock falls and bywater, delaying the advance of the tunnel to about 0.8m/day.
Jaiprakah Industries of India is constructing the underground powerhouse with Hyundai of Korea. About one-third of the excavation of the four underground chambers has been completed.