At least 14 persons were killed and another 120 people, including 23 army personnel, went missing after a flash flood triggered by a glacial lake outburst following heavy rains in north Sikkim in the early hours of Wednesday.
The toll is expected to rise sharply with officials saying that at least 40 bodies have been recovered by different agencies after the disaster struck.
“The Glacial Lake Outburst Flood (GLOF) in portions of Lhonak lake in Mangan district, which caused the rise of water levels with very high velocities downstream along the Teesta River Basin in the early hours of October 4, 2023, has caused severe damage in Mangan, Gangtok, Pakyong, and Namchi Districts,” said a statement issued by the Sikkim government.
The flash flood also washed away the Teesta – III dam at Chunthang. At least six bridges were washed away and the National Highway 10 (NH10) was damaged in multiple areas.
“North Sikkim has been totally cut off from the rest of the state while Sikkim has been cut off from the rest of India as the flood had badly hit NH10,” said Prabhakar Rai, director of Sikkim’s disaster management department, said.
North Sikkim received around 39 mm rain between Tuesday morning and Wednesday morning.
“The rains had probably triggered an avalanche which led to a GLOF. As huge volumes of water and debris comprising boulders came gushing down they hit the hydro dam in Chunthang. The dam was washed away and the entire load gushing down with tremendous force,” said Ashim Sattar, a scientist with IISc Bengaluru, who had studied the lake and the glacier extensively.
Scientists said that over the years the Lhonak glacier retreated and the lake has grown in size making it vulnerable to GLOF.
“We are all aware of the recent natural calamity that has struck our state. Emergency services have been mobilised to the affected areas, and I personally visited Singtam to assess the damages and engage with the local community,” Prem Singh Tamang (Golay) chief minister of Sikkim wrote on his X handle.
According to the Central Water Commission (CWC), the flood took place around midnight. Officials said that the water level started rising very fast , at nearly 15 metre per second. At around 6 am the water level in the Teesta river near Melli was flowing 3 metre above the danger level.
“The flood water reached Chungthang around 1 am and triggered heavy damage in the Teesta-III hydro dam. By around 2:30 pm the low-lying areas in the districts downstream were flooded,” said an official.
Until Wednesday evening, the different agencies had rescued at least 600 people mostly those who lived on the highway near the river.
“Four major bridges, a GREF (General Reserve Engineering Force) crusher plant and hundreds of other houses have been damaged. NH-10 is blocked at multiple places. Some labourers at the GREF plant are also missing,” the official added.
Meanwhile, four National Disaster Reserve Force (NDRF) teams are working in Sikkim and the other bordering areas near Sikkim-West Bengal border along the banks of the Teesta river.
With Teesta river flowing through four districts of West Bengal before entering Bangladesh, a flood alert was also sounded in the districts of north Bengal and neighbouring Bangladesh.
“Release of huge volumes of water triggered a flood-like situation in the north Bengal districts. On the instructions of chief minister Mamata Banerjee, a team comprising state ministers and bureaucrats rushed to north Bengal to oversee rescue operations,” said a West Bengal government official.
Around 5800 people have been rescued from the four districts of north Bengal and shifted to safer places. One column of the army was requisitioned to rescue a family stranded in Rangpo area.
Meanwhile, a low pressure over Jharkhand and an associated cyclonic circulation triggered heavy rain in West Bengal. The India Meteorological Department has forecasted enhanced rainfall activity in the eastern state till Thursday.
“Heavy rains couple with discharge of water from DVC barrages have resulted in flood-like situation on Bankura, Howrah, Hooghly, West Midnapore, and South 24 Parganas. The state government has set up 190 shelter camps and evacuated more than 500 people,” said an official.
