KATHMANDU (TIP): Scientists are exploring whether the strong earthquake that struck Nepal and the surrounding region on October 3 is responsible for the south Lhonak lake outburst, which triggered a flash flood in the Teesta river basin in Sikkim.
The lake outburst also resulted in the breach of the Chungthang dam, which is the largest hydropower project in the state.
This dam is part of the 1,200-megawatt (MW) Teesta Stage III Hydro Electric Project, in which the state government is the majority stakeholder.
Satellite images released by the Hyderabad-based National Remote Sensing Centre showed that the area of south Lhonak lake reduced by over 100 hectares compared to its size on September 17. This suggests that the lake outburst caused a flash flood in the Teesta River basin in north Sikkim. Officials said at least eight people died and 69 more, including 22 army personnel, were missing. Scientists are exploring whether the earthquake that hit Nepal might be a cause of the flash floods in Sikkim. The lake was already vulnerable and covered an area of 168 hectares.
Its area has now reduced to 60 hectares, indicating that about 100 hectares of water volume has breached the level, explained a senior official at the Central Water Commission (CWC) to PTI. The official stated that while it’s difficult to determine right now, a cloud burst does not cause such results. Some experts who have visited the site believe that the earthquake may have triggered the floods there.
The flood alerts were also shared with Bangladesh.
The NRSC satellite imagery revealed that the lake covered approximately 162.7 hectares.
Its area increased to 167.4 hectares on September 28 but drastically reduced to 60.3 hectares.
In this satellite data, it is evident that the lake area has significantly reduced compared to the September 17, 2023, RISAT 1A MRS satellite data, read an NRSC report.
The glacial lake outburst flood (GLOF) in portions of Lhonak Lake, Mangan district, which caused a rapid rise in water levels with very high velocities downstream along the Teesta River Basin in the early hours of October 4, has resulted in severe damage in Mangan, Gangtok, Pakyong, and Namchi districts, the State Disaster Management Authority said.
The Chungthang NHPC dam and the bridge were washed away. (pti)