Ten labourers working inside a tunnel of the 99 MW Chuchajen hydro electric power project being developed by Gati Infrastructure were killed when water overflowing from the Rongli river flooded the tunnel yesterday night here at Chuchajen in East Sikkim.
A coffer concrete gravity dam being constructed was also partly swept away by the surge on the Rangpo/Rongli river a tributary of the river Teesta being developed by Gati Infrastructure Limited at Lamaten in the vicinity of Chujachen village under Rongli sub division in east
According to official reports heavy rains flooded the catchment area with the force of the water flooding into the 120 metre long Adit III tunnel of the power project due to a flash flood triggered by heavy rainfall in the catchment area Tsomgo Lake, the source of Rangpo river, B. K Khabrani, the general manager of the Gati power project said.
Officials inform ten labourers were washed away in the flash flood which occurred at around 9:30 pm yesterday night, the water levels rose alarmingly high over the temporary coffer dam built near the Adit 3 tunnel. The water swelled above the 19 m coffer dam and could not be rapidly discharged by the adjoining diversion tunnel.
Finding no outlet, the water then recoiled back and surged into the Adit 3 tunnel where 18 labourers were engaged in night shit to drill the tunnel. Out of them, 8 were inside the tunnel while ten were outside the tunnel, police officials overseeing the restoration works at the damaged spot informed sources.
The labourers outside the tunnel saw the danger and fled barring two who went inside to alert the 8 others working inside the 1.1 km tunnel. However, none returned back and there is zero possibility that none of the 10 labourers may have survived, admitted the police and the project officials. Whiule the names of the labourers are yet to be revealed it has been learnt that most of them belonged to
Presently the works are on to pump out the water from the Adit 3 tunnel to recover and fish out the bodies. The flash flood also swept away the coffer tunnel along with other
machines and vehicles in the site. 8 persons have died in separate incidents in the project site last year.
This has taken back our project schedule by another 3 months, Khabrani said. he said the damages caused by the flash flood is being assessed and could run into several crores.
“However, at the moment our main focus is to find those inside the tunnel”, he added.
Sub divisional police officer of Rongli, R. K Sundas said that a case has been registered against the project developers. Investigations will be carried out to find out whether any negligence is there on the part of the project developers, he said.
The Chujachen project a run of the river hydroelectric power project is about 60 Kms from Gangtok and has two interconnected reservoirs with an installed capacity of 99MW.
The Rangpo river is a major tributary of the Teesta river. The project has two intakes each with a storage reservoir and headrace tunnel each joining together to a common headrace tunnel, an underground surge shaft, a surface penstock and open air powerhouse with two units and an outdoor switchyard.
The construction of the coffer dam and the tunnels were entrusted to Coastal Energy a construction company by GATI it has been learnt Chief minister Pawan Chamling had laid the foundation Stone for the Chujachen HEPP in February 2007, and speedy implementation of the project was being undertaken by GATI Infrastructure a unit of the
cargo express company and was expected to be completed by the end of this year.
Gati Infrastructure had entered into an agreement with the Sikkim Power Development Corporation (SPDC) Limited, a Government of Sikkim undertaking and Goverment of Sikkim for development and implementation of three hydro projects out of which one of the one is the Chujachen project on a Build, Operate, Own and Transfer (BOOT) arrangement at a cost of Rs. 625 crores.
Source: The Telegraph
(The tunnel where the unfortunate incident took place)