Sikkim flash floods: Toll increases to 14 as damaged infra hampers rescue ops

The toll from the flash floods triggered in Sikkim on Wednesday after a glacial lake overflowed following torrential rains has increased to 14 even as continuing rainfall and damaged infrastructure hampered search and rescue operations when it resumed on Thursday morning. Officials said they feared the toll could mount further as 102 people remained missing in the Himalayan state, which remained cut off from the rest of the country.

An official said three National Disaster Response Force (NDRF) companies flown to Bagdogra in the neighbouring West Bengal remained stranded as choppers could not take off for Sikkim. “As soon as the weather clears, one company would be flown to the worst-hit Chungthang in the Mangan district. The remaining two companies would be stationed at Gangtok and Pakyong.”

Officials at the disaster management control room in Gangtok said roads and communication lines in Chungthang have been snapped and that were in the dark about the situation. “We have absolutely no communication with Chungthang where the flash flood washed away a dam. The town has also been affected. ...people were evacuated soon after the water level in the Teesta started rising in the early hours of Wednesday...the casualties have not been much. The town has been hit though,” said a second official.

At least 11 bridges were washed away. The lifeline National Highway 10, which connects Sikkim with the rest of the country, has been severely damaged at multiple places.

A third official said Mangan has been cut off from the rest of the state and that police, residents, and NGOs were carrying out rescue operations. Around 650 people have been put up at 22 relief camps while over 200 people have been evacuated to safer places.

Pakyong district collector Tashi Chopel said 23 army personnel were among the 58 people missing in his area while four bodies have been recovered. An army camp in Pakyong’s Bardang was among those hit.

Another Pakyong district official said some of the missing persons were feared buried under debris and some swept away. “Excavation and rescue works are in progress.”

District collector H K Chhetri said the toll was four in Mangan. He refused to comment when asked whether the Lhonark Lake had burst. “An official statement would be issued.”

Over 3000 tourists remained stranded in places such as Lachen and Lachung, which have remained cut off from other parts of the Mangan district amid continuing rainfall.

Chhetri said the immediate task was to rescue the injured and to search for the missing persons. “All the tourists are safe in their hotels.”

The roads leading to Lachen and Lachung were closed. At least four bridges between Mangan and Chungthang were washed away. West Bengal governor CV Ananda Bose, who was in neighbouring Kalimpong district, was forced to leave for Bhasua.

In West Bengal, a team of ministers and bureaucrats were rushed to the state’s flood-hit north. Bose was also scheduled to visit north Bengal on Thursday.

The flash floods down the Teesta, which flows through West Bengal before entering Bangladesh, washed away homes and highways and smashed through a dam that powers the region. Torrents of water began coursing downstream around 1.30am on Wednesday and marooned hundreds of people.

The weather office said it did not have an accurate reading of the rainfall due to the remoteness of the terrain. Experts attributed the floods to unusually intense showers and a glacial lake outburst flood (GLOF) in the South Lhonak Lake in northwestern Sikkim around 1am. They said that the climate crisis had left the Himalayan region more vulnerable to such stresses and disasters than ever. The Indian Space Research Organisation (Isro) said its satellites observed that the lake had burst. In a statement, Isro said the lake reduced in area from 167.4 hectare on September 28 to 60.3 hectare on October 4.

A GLOF is caused when the moraine (debris accumulated over the years by a glacier) that usually functions as a dam, creating a lake, is breached. It was not immediately clear as to what may have triggered the GLOF although the risk has loomed large for at least a decade, said experts.

Sikkim declared the floods a disaster while a flood alert was also sounded in north Bengal and Bangladesh. Officials said 45 people were rescued and around 4,000 people evacuated on Wednesday.

Visuals showed a swollen Teesta roaring caking every inch of its path in mud and debris and leaving little standing.

The India Meteorological Department (IMD) said north Sikkim received around 39mm rain between Tuesday morning and Wednesday morning, possibly triggering an avalanche that in turn led to the GLOF in the lake.

The weather office said it has no automatic weather stations in the affected region, making it nearly impossible to estimate how much rain pounded South Lhonak Lake.

Teesta Urja, the second biggest run-of-the-river hydro power project in India, suffered massive damage due to flooding caused by the breach in Lhonak Lake. The 1,200MW power project on Teesta river, one of the most dammed rivers in the country, is located between Chungthang and Mangan in Mangan district in north Sikkim and is the biggest of nine working hydro projects on the river in Sikkim.