Sikkim flash floods death toll mounts to 14; 102 people, including 22 Army personnel, still missing

The confirmed death toll from the flash floods in Sikkim rose to 14 on Thursday with 102 people, including 22 Army personnel, still missing after the glacier-fed Lhonak lake in north Sikkim triggered a flash flood in the Teesta river basin on October 4.

The floods have severely damaged the Chungthang dam that is the mainstay of a key hydropower project, the Teesta -3, situated along the Teesta river that courses through Sikkim, West Bengal and Bangladesh.

Sikkim flash floods updates | October 5, 2023

On Thursday, Pankaj Agrawal, Secretary, Ministry of Power, convened an “emergency meeting” to ascertain damage to projects operated by the National Hydropower Corporation (NHPC).

All bridges downstream to the Teesta-V hydropower station were submerged or washed out, disrupting communication.

“The floodwater overtopped the dam of the Teesta V power station [510 MW]. All connecting roads to the project sites as well as parts of the residential colony have been severely damaged,” the Power Ministry said in a statement, “Presently the power station is shut and not generating any electricity.” The Teesta 3 power project is not operated by the NHPC.

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One NHPC employee at the Teesta V power station lost his life. All of the organisation’s other personnel at the site were safe. Works on the under-construction Teesta VI (500 MW) of the NHPC were disrupted with water entering into the powerhouse and transformer cavern.

Dams and hydropower projects in downstream West Bengal were not significantly affected but were kept shut from heavy siltation that resulted from the floodwaters.

”The NHPC is making all possible efforts to maintain supply of essential commodities such as food, medicine and electricity,” said the Power Ministry.

26 relief camps

The State government has set up 26 relief camps in the four affected districts, the Sikkim State Disaster Management Authority (SSDMA) said on Thursday, with at least 1,025 people taking shelter in the eight relief camps in Gangtok district.

The flood destroyed 11 bridges in the State, with eight bridges getting washed away in Mangan district alone. Two bridges were destroyed in Namchi and one in Gangtok. Water pipelines, sewage lines and 277 houses, both kuchcha and concrete, have been destroyed in the four affected districts.

Chungthang town bore the maximum brunt of the flood with 80% of it getting severely affected. The NH-10, considered the lifeline of the State, sustained extensive damage at several places.

The South Lhonak lake in northern Sikkim is situated about 5,200 metres above sea level. Scientists have previously warned that the lake had been expanding over years, possibly from the melting of the ice at its head. Nearly half the lake was drained out, according to a press statement by the National Disaster Management Authority (NDMA). This was likely caused by an “avalanche from the ice-capped feature.” There is still uncertainty on the exact trigger for the glacial lake outburst, as the phenomenon is called with suggestions that excessive rain or an earthquake might have been a trigger. With heavy rain in the region, the India Meteorological Department has forecast rain till late Friday.