The Sikkim government has decided to send a 32-member team of experts to undertake expeditions to glacial lakes and assess the dangers posed by the high-altitude waterbodies in the Himalayas.

The study comes at a time when 16 glacial lakes have been categorised as high-risk in Sikkim.

Sikkim and parts of north Bengal had been devastated by a glacial lake outburst flood (GLOF) from the South Lonark Lake in north Sikkim on the intervening night of October 3 and 4, 2023.

The Sikkim study, the first of its kind in the country, will start on Wednesday and will be completed by September 14.

Sources said the expeditions would be jointly spearheaded by the Sikkim State Disaster Management Authority (SSDMA) and the department of science and
technology.

The departments of mines and geology; land revenue and disaster management; water resources, forest and environment, and information and public relations will be engaged in the study.

“The team will also include experts from the Sikkim University, the Geological Survey of India and the Central Water Commission,” said a source.

The Indian Army and the Indo-Tibetan Border Police (ITBP) will assist the experts.

Sandeep Tambe, the secretary of the science and technology department, said: “Sikkim has 16 high-risk lakes, 13 of which are in Mangan district and three in Gyalshing district.”

The experts will study five of the high-risk glacial lakes in Mangan district. “These are the Khangchung Choo, Gurudongmar Lake A, Gurudongmar Lake B, Gurudongmar Lake C and the Shako Chu,” said the source.

The team will seek to reduce the hazards from the glacial lakes through four steps — preliminary identification of high-risk lakes, multi-disciplinary studies, actual
structural intervention and mitigation plans.

The structural intervention could involve siphoning, tunnelling and reshaping the lake bed to reduce the
water level.

Sources have said every lake has its characteristics. “There are lakes which do not have proper outlets,” said another source.

The GLOF on the South Lonark Lake, which is considered the first such instance in Sikkim, brought the focus to such a disaster at a time when global temperatures are on
the rise.

Following the Sikkim disaster, the Central Water Commission (CWC) has decided to review the design of all existing and under-construction dams vulnerable to GLOFs.

According to the Central Electricity Authority under the Union ministry of power, 47 dams — of which 38 are commissioned and nine are under construction — are likely to be affected by GLOFs in India.

A high-level committee chaired by the Union home minister has approved a GLOF risk mitigation project for ₹150 crore for Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh to support the efforts of respective state governments to take up various mitigation measures.

More than 100 people were killed by the Sikkim GLOF.

Sikkim chief minister PS Tamang (Golay) had submitted to the Centre a report that said ₹3673.25 crore was needed for recovery and reconstruction in the state.