Flash flood in Sikkim - Cloud and Lake Burst many missing

Introduction

Midnight Lake Outburst in North Sikkim Leads to High-Velocity Flooding, Prompting Cross-Border Flood Forecast

In the early hours of October 4th, 2023, a sudden and significant lake outburst occurred in the vicinity of Lhonak Lake in North Sikkim. The resulting surge of water, reaching speeds of approximately 15 meters per second, surged downstream, surpassing the CWC Melli FF site’s measurement point, which stood at 227 meters. This water level exceeded the danger level by nearly 3 meters by 6:00 AM.

The cloudburst was so heavy that it led to a sudden rise in water levels, quickly taking the lake beyond its holding capacity. The area received at least five times the usual amount of rain.

The cloudburst, coupled with the melting of the Lhonak Glacier, resulted in the Glacier Lake outburst flood (GLOF), a sudden release of a massive amount of water.

Teesta river rises to 300ft after Lhonak lake burst at North Sikkim

The Sikkim flash flood, in which 14 people have been killed and 102 others are missing, has been so intense because it was the result of a cloudburst causing a glacial lake to overflow. A glacial lake outburst flood, or GLOF, usually results in more damage and destruction than a flood caused by excess rainfall alone.

All of this water flowed downhill, leaving destruction in its wake, and reached Sikkim’s biggest hydropower project – the Teesta-III project in Chungthang – about 5,000 feet above sea level. The water, with all the debris it picked up along the way, rammed into the dam, causing parts of it to give way.

“Five bodies have been recovered from Golitar and Singtam region,” PTI quoted Gangtok sub-divisional magistrate (SDM) Mahendra Chettri as saying.
Another official said besides the 22 army personnel, 47 civilians were also missing, while 166 people have so far been rescued, including an armyman.

Tourist Advisory

We personally suggest tourist visiting Sikkim to please post pond your travel journey to last week of November as the lake is still ticking and can be burst if any natural calamities happen. As its continue raining in North Sikkim and other adjacent areas. TravelGangtok Tourism request you to check once again and either cancel or post-pond the date of visit.

Below is the advisory issued by Sikkim Tourism Govt of Sikkim.

Flood Forecasts

Concurrently, flood forecasts were issued for both India and Bangladesh at 6:00 AM, projecting conditions at 2:00 PM. Notably, the river Teesta’s water level, monitored at the CWC Domohani FF Station, was reported to be below the warning level at 6:00 AM, standing at 84.83 meters. However, experts anticipate that it will breach its warning level within the next 6 hours.

This unfolding situation has raised concerns among authorities and residents, emphasising the need for vigilance and preparedness in the affected regions.