Heavy rain during the past week has also led to river Teesta breaching its bank at the dam site in Dikchu, 50 km from here, almost washing away the NHPC office located there.
Chief Engineer G.P. Maurya said: “The remaining portion of the office is precariously perched and officials have shifted to the guest house at the top of the dam which is now being used as a temporary office.”
The office has lost most of its foundation with the crate walls washed away and the entire parking lot submerged by the river water.
Power generation at the dam was stopped at 2 a.m. May 27 due to heavy siltation jamming the machinery. The amount of silt coming down the river went up 10 times to 5,000-6,000 particles per minute from the normal levels of 500-600.
NHPC officials said it would take two-three days to clear the clogged silt and bring the machines back into operation.
The officials said that the loss incurred by the state-run NHPC would amount to nearly Rs.2 crore (Rs.20 million) per day.
All five sluice gates of the dam were opened Monday to let out the water which was attaining dangerous heights in the reservoir.
The water level at the reservoir rose to nearly 590 metres Tuesday from the normal 575 metres submerging all the three height reading pillars, Maurya said.
NHPC contractor Naresh Chettri, whose individual losses in damages and washed away machinery runs into crores of rupees, said the water flow suddenly increased from 300 cumecs on Monday to 1,800 cumecs Tuesday, sweeping away the equipment he maintained at the site.