Sikkim faced a devastating flash flood followed by a sudden glacial burst on Wednesday which has claimed several lives according to the reports. The flash floods caused immense damage to the residents’ homes, bridges, and even roads. The sheer force of the flash flood washed away many homes.
The Teesta River itself took the form of a calamity that destroyed everything in its path including parts of the state’s biggest hydropower project, Sikkim Urja.
Due to the flash flood, various new challenges arose such as mudslides, destroyed roads, and immense damage to communication systems that made rescue operations a true challenge.
The Cause of the Sikkim Flash Flood
The disaster occurred due to a cloudburst over Lhonak Lake in northwest Sikkim early on Wednesday at around 12 a.m. The cloudburst was so heavy that it caused the water levels to rise at an extremely fast pace, beyond the capacity of the lake. The area received more than five times the usual amount of rain it receives.
The cloudburst combined with the Lhonak Glaciers melting resulted in the Glacier Lake outburst flood which suddenly released a massive amount of water.
As the water level kept rising, a warning was sounded by the authorities, but around 1 a.m., the Teesta Stage 3 dam which is also known as the Urja project, got washed away by the flash flood which made it extremely difficult to evacuate people who were near the river.
The Urja dam which is located 5,000 feet above sea level at Chungthang, and a bridge which was 200-meter- long, connecting the powerhouse were washed away with the entire powerhouse being submerged due to the floods.
Experts have revealed that according to their assessments, the water level in Teesta was below the danger mark before the Urja dam burst. But, after the dam was destroyed, several housing facilities such as houses, and buildings were destroyed with roads being washed away. At least 11 bridges have collapsed.
Areas such as Dikchu, Singtam, Bardang, Mangan, Rangpo, and Chungthang were hit hard by the flash floods.
The cloudburst itself was the main trigger with around 10 cm of rainfall within 10 square kilometres in an hour. Scientists also pointed out the possibility of an avalanche as the banks of the lake most likely burst after huge chunks of ice fell into the water which created an even more powerful wave.
Warnings Which Were Ignored
The tragedy that occurred was just a disaster waiting to happen as multiple experts already knew about the possibilities of this happening and yet they ignored it.
In 2013, the National Remote Sensing Centre in Hyderabad altered the authorities about some of the glacial lakes that are located in the upper reaches of Sikkim were increasing in size at an alarming rate which also including the South Lhonak Lake. The state government dispatched a team that reported the inflow towards the lake was indeed more than the outflow so some outlets were created to increase the discharge of water.
In 2016, another team went up and again reported that the discharge of water was indeed low from the lake. That’s when Sonam Wangchuk was brought to Sikkim where he decided to use several 150-metre-long pipes that would suck water out of the lake and keep it under control. He called it the Siphoning system.
Alas, seven years later, satellite imagery has shown that the two lakes in Sikkim’s upper region had expanded significantly. So, in September of 2023, a team comprising officials of the National Disaster Management Authority, or the NDMA, the Sikkim State Disaster Management Authority or SSDMA, and the Swiss Development Corporation went there to set up a monitoring system.
While the authorities have claimed that the monitoring system for Shako Cho Lake is working absolutely fine, the system for South Lhonak Lake failed on 21 September which was just a few days after they were set up around 15-18 September. It was said that the experts from Switzerland were expected to arrive any day to fix the problem and set up the Early Warning System which never happened.
The alarm was only sounded when a camp of the Indo-Tibetan Border Police or ITBP, located close to the South Lhonak lake at Janak, called officials at Chungthang around 11 pm on 3 October. IBTP reported that the water in Lachen River has risen drastically and to which the SSDMA raised an alarm immediately. While many thought that the alarm was merely a drill, it sure wasn’t.