Centre asks Himalayan States to step up monitoring of glacial lakes and avalanche zones
Can a warning reach a mountain village before a glacial lake empties into the valley below?
Published 4 September 2026. Written by Pratidin from the reports linked at the end; every fact checked by a separate review before publishing. How we work
On 3 September 2026, Union Home Secretary Govind Mohan chaired a meeting in New Delhi to review how prepared the Himalayan States and Union Territories are for glacial lake outburst floods (GLOFs) and snow avalanches. Chief Secretaries and State Disaster Management Authorities of Uttarakhand, Himachal Pradesh, Sikkim, Arunachal Pradesh and Jammu and Kashmir attended, along with the Ministry of Home Affairs, the National Disaster Management Authority (NDMA), the Central Water Commission (CWC), the India Meteorological Department (IMD) and the Defence Geoinformatics Research Establishment (DGRE). The review followed recent GLOF events in Nepal. A GLOF is the sudden release of water held back by a glacier or a moraine, the loose ridge of ice, sand, pebbles and debris left by a glacier.
The Home Secretary asked the States to move from response alone to "risk-informed planning, preventive mitigation and community-level preparedness". They were told to review their preparedness plans regularly, identify gaps in early warning and evacuation arrangements and take corrective action ahead of extreme events, and keep up coordination among State agencies, district administrations and scientific institutions. He also asked them to speed up the GLOF mitigation projects the Centre sanctioned for them in 2024. The States presented their work on monitoring vulnerable lakes, strengthening early warning systems, planning for flood flow paths, community preparedness and positioning resources in high-risk areas.
The 2024 sanction refers to the National GLOF Risk Mitigation Project, approved in August 2024 with an outlay of ₹150 crore for Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand. It targets 189 high-risk glacial lakes out of about 7,500 in the Indian Himalaya, with a separate programme planned for Jammu and Kashmir and Ladakh. The CWC monitors 902 glacial lakes and water bodies. The NDMA issued guidelines on managing GLOFs in October 2020. The risk is real: in October 2023, an outburst of South Lhonak lake in Sikkim sent a flood down the Teesta that breached the Chungthang dam. Retreating glaciers are creating new lakes, so the number of lakes to watch is rising.
Prelims facts
- On 3 September 2026, Union Home Secretary Govind Mohan reviewed GLOF and avalanche preparedness of Uttarakhand, Himachal Pradesh, Sikkim, Arunachal Pradesh and Jammu and Kashmir.
- States were asked to shift to risk-informed planning, preventive mitigation and community-level preparedness, and to speed up GLOF mitigation projects sanctioned in 2024.
- The National GLOF Risk Mitigation Project (₹150 crore, approved August 2024) covers Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand and targets 189 high-risk lakes.
- The Central Water Commission monitors 902 glacial lakes and water bodies; NDMA issued GLOF guidelines in October 2020.
- The October 2023 South Lhonak GLOF in Sikkim breached the Chungthang dam on the Teesta.
Quick recall
- What is a GLOF?
- A glacial lake outburst flood: the sudden release of water held back by a glacier or a moraine.
- What is a moraine?
- A natural ridge of ice, sand, pebbles and rock debris left behind by a glacier.
- Who chaired the 3 September 2026 review of GLOF and avalanche preparedness?
- Union Home Secretary Govind Mohan.
- When did NDMA issue guidelines on managing GLOFs?
- October 2020.
- Outlay and States of the National GLOF Risk Mitigation Project?
- ₹150 crore; Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand.
- How many high-risk glacial lakes does the national project target?
- 189, out of about 7,500 glacial lakes in the Indian Himalaya.
- How many glacial lakes and water bodies does the CWC monitor?
- 902.
- Which dam did the October 2023 South Lhonak GLOF breach?
- The Chungthang dam on the Teesta in Sikkim.
Prelims practice question
With reference to the National Glacial Lake Outburst Flood Risk Mitigation Project, consider the following statements:
1. It was approved with an outlay of ₹150 crore.
2. It covers Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand.
3. It is implemented by the Central Water Commission.
Which of the statements given above are correct?
- 1 and 2 only
- 2 and 3 only
- 1 and 3 only
- 1, 2 and 3
Show answer
Answer: (a) 1 and 2 only. Statements 1 and 2 are correct: the project was approved in August 2024 with ₹150 crore for these four States. Statement 3 is incorrect: the project is implemented through the National Disaster Management Authority; the CWC is one of the participating technical agencies.
Use this in UPSC Mains: previous-year questions
Recurring theme: Himalayan disaster risk: glacial hazards, climate change and the institutional shift from relief to prevention.
- How to use this
Use GLOF preparedness to show how hazard risk must be built into infrastructure planning in the Himalaya, with the Chungthang breach as the warning.
- In October 2023 the South Lhonak lake outburst in Sikkim sent a flood down the Teesta that breached the Chungthang dam.
- On 3 September 2026 the Union Home Secretary asked Himalayan States to shift from response to 'risk-informed planning, preventive mitigation and community-level preparedness'.
- Hazard is often not built into approvals for dams and roads; require risk assessment of all infrastructure downstream of glacial lakes.
- How to use this
Use glacial lake growth to show a concrete way climate change threatens India's Himalayan States.
- Retreating glaciers are creating new lakes; the National GLOF Risk Mitigation Project targets 189 high-risk lakes out of about 7,500 in the Indian Himalaya.
- The October 2023 South Lhonak GLOF in Sikkim breached the Chungthang dam on the Teesta, showing the downstream exposure of settlements and hydropower.
- The ₹150 crore project (August 2024) covers Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand; the CWC monitors 902 glacial lakes and water bodies.
- How to use this
Cite the Chungthang breach to show that external hazards like glacial lake outbursts are a cause of dam failure in the Himalaya.
- In October 2023 the South Lhonak glacial lake in Sikkim burst, and the flood down the Teesta breached the Chungthang dam.
- GLOFs are sudden releases of water held by a glacier or moraine; heavy rain, ice or rock avalanches, landslides and earthquakes can breach such natural dams.
- Remedies: NDMA's October 2020 GLOF guidelines cover lake mapping, early warning, lake lowering and community training; risk assessment is also needed for all infrastructure downstream of glacial lakes.
Mains practice question
Glacial lake outburst floods are an emerging hazard in the Indian Himalaya. Explain why the risk is rising and evaluate India's institutional preparedness to deal with it. (250 words)
Model answer
A glacial lake outburst flood (GLOF) is the sudden release of water held back by a glacier or a moraine. On 3 September 2026, the Union Home Secretary reviewed the preparedness of five Himalayan States and UTs after recent GLOF events in Nepal.
Why the risk is rising
- Glacier retreat: melting glaciers form new lakes and enlarge old ones behind weak moraine dams.
- Triggers: heavy rain, ice or rock avalanches, landslides and earthquakes can breach these dams.
- Exposure: roads, settlements and hydropower projects in narrow valleys lie in flood paths. In October 2023, the South Lhonak outburst in Sikkim breached the Chungthang dam on the Teesta.
Institutional preparedness
- Law: the Disaster Management Act, 2005 set up the NDMA (chaired by the PM), State and district authorities, and the National Disaster Mitigation Fund.
- Guidelines: NDMA's GLOF guidelines of October 2020 cover lake mapping, early warning, lake lowering and community training.
- Projects: the ₹150 crore National GLOF Risk Mitigation Project (August 2024) targets 189 high-risk lakes in Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand.
- Monitoring: the CWC monitors 902 glacial lakes and water bodies.
Gaps
- Few lakes have on-site sensors; most monitoring is by satellite.
- Projects sanctioned in 2024 need to move faster, as the Home Secretary noted.
- Last-mile alerts and evacuation drills in remote valleys remain weak.
- Hazard is often not built into approvals for dams and roads.
Way forward
- Early warning systems with sirens and mobile alerts at high-risk lakes.
- Controlled lowering of dangerous lakes.
- Community teams trained as first responders.
- Risk assessment for all infrastructure downstream of glacial lakes.
Preparedness must shift from rescue after the flood to prevention before it, as the 3 September review urged.
The basics
Why this matters
As Himalayan glaciers retreat, meltwater collects in lakes held back by loose natural walls. When a wall fails, a lake can empty in minutes, sending a wall of water, mud and boulders down valleys full of roads, towns and dams. These Glacial lake outburst floods are one of the fastest-growing mountain hazards, and they cross borders: the Home Secretary's review of 3 September 2026 followed floods in Nepal.
How a GLOF happens
- 1Glacier retreatsAs the climate warms, the glacier's snout melts back and leaves a ridge of debris called a moraine.
- 2Lake formsMeltwater pools behind the moraine or behind ice, forming a glacial lake.
- 3Trigger strikesHeavy rain, an ice or rock avalanche, a landslide or an earthquake adds water or a surge wave.
- 4Dam failsThe loose moraine or ice wall breaches, releasing the lake suddenly.
- 5Flood travelsThe water, carrying debris, rushes downstream, damaging bridges, settlements and dams.
How big is the problem
The National GLOF Risk Mitigation Project, approved in August 2024 with ₹150 crore, covers Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand. Its tools include hazard assessment, automatic weather and water-level stations, early warning systems and lowering of dangerous lakes.
Who does what
- 1Ministry of Home AffairsNodal ministry for disaster management; chaired the review
- 2NDMASets national policy and guidelines; issued GLOF guidelines in October 2020
- 3Central Water CommissionMonitors 902 glacial lakes and water bodies
- 4India Meteorological DepartmentWeather forecasts and warnings for rain and snow triggers
- 5DGREDefence research body that studies snow, avalanches and terrain
- 6State Disaster Management AuthoritiesPlan and act on the ground with district administrations
This structure comes from the Disaster Management Act, 2005. The review asked States to move from response to prevention, a lesson reinforced by the South Lhonak GLOF of 2023.
Go deeper
In one line: On 3 September 2026, the Union Home Secretary told five Himalayan States and UTs to strengthen monitoring, early warning and prevention for glacial lake outburst floods and avalanches.
Why it matters for UPSC
GLOFs link physical geography (glaciers, moraines), climate change and disaster management. Mains asks about Himalayan vulnerability and the clash between infrastructure and disaster risk; Prelims asks about agencies, laws and events.
The core idea
Glacial lake outburst floods happen when a lake held by a moraine or ice fails. The Centre's answer is the National GLOF Risk Mitigation Project, run through the NDMA under the Disaster Management Act, 2005. The review said States must spend sanctioned funds faster and prepare communities before a flood, not after. The South Lhonak GLOF of 2023 showed how a single lake can take out a dam and devastate a river valley.
Numbers and dates to remember
- Review meeting: 3 September 2026, chaired by Home Secretary Govind Mohan
- States and UTs: Uttarakhand, Himachal Pradesh, Sikkim, Arunachal Pradesh, Jammu and Kashmir
- NDMA GLOF guidelines: October 2020
- National GLOF Risk Mitigation Project: ₹150 crore, approved August 2024, four States
- 189 high-risk lakes out of about 7,500 glacial lakes
- CWC monitors 902 glacial lakes and water bodies
- South Lhonak GLOF: October 2023
Where to go next
- Glacial lake outburst floods: what they are and what triggers them
- National GLOF Risk Mitigation Project: the Centre's main programme
- Disaster Management Act, 2005: the legal and institutional frame
- South Lhonak GLOF of 2023: the event that showed the stakes
Go deeper: prevention versus response
The argument for prevention. Disaster management in India began as relief after the event. The Disaster Management Act, 2005 shifted the aim to prevention, mitigation and preparedness. For Glacial lake outburst floods, prevention means mapping and watching dangerous lakes, lowering lake levels where needed, and putting sirens and phone alerts in the flood path. NDMA's October 2020 guidelines recommended identifying changes in lakes using Synthetic-Aperture Radar imagery, structural measures such as controlled breaching, pumping out water or tunnelling through moraines, and training local teams, since most early rescue is done by local people.
The implementation gap. The Home Secretary's direction to expedite projects sanctioned in 2024 suggests the National GLOF Risk Mitigation Project has been slow on the ground. Many high lakes are hard to reach and can be visited only in short summer windows.
The infrastructure question. The South Lhonak GLOF of 2023 destroyed the Chungthang dam on the Teesta. It raised the question of whether hydropower and roads in glacial valleys account for upstream lakes. UPSC asked in 2026 how rapid infrastructure and disaster-risk reduction can be reconciled in ecologically sensitive areas.
The regional angle. Glacial hazards cross borders: the review followed floods in Nepal, and many lakes feeding Indian rivers lie outside India. Data sharing with neighbours is part of any complete answer.
Glacial lake outburst floods
What a GLOF is and what sets one off
In one line: A glacial lake outburst flood is the sudden release of water dammed by a glacier or a moraine.
How the lakes form
As a glacier retreats, it leaves behind a moraine: a natural ridge of ice, sand, pebbles and rock debris. Meltwater collects behind it. Unlike an engineered dam, a moraine is loose and can fail suddenly, releasing huge volumes of water in minutes to days. Moraine-dammed lakes are the most dangerous type.
What triggers a burst
Heavy rain, ice avalanches, landslides into the lake and earthquakes can all set off a breach. Warming increases the number and size of lakes, so the hazard grows over time.
Why it is in the news
The Centre asked Himalayan States on 3 September 2026 to watch vulnerable lakes continuously and improve early warnings.
Where to go next
National GLOF Risk Mitigation Project
The Centre's main programme to tame dangerous lakes
In one line: The National GLOF Risk Mitigation Project is a ₹150 crore programme approved in August 2024 to reduce outburst risk in four Himalayan States.
What it covers
It covers Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand and targets 189 high-risk glacial lakes out of about 7,500 in the Indian Himalaya. The NDMA implements it with technical agencies including the Central Water Commission and the Geological Survey of India. Components include detailed hazard assessment, automatic weather and water-level stations, early warning systems, lake-lowering measures and community involvement in monitoring and alerts. A separate programme was planned for Jammu and Kashmir and Ladakh.
Why it is in the news
On 3 September 2026, the Home Secretary asked States to expedite the GLOF mitigation projects sanctioned for them in 2024.
Where to go next
Disaster Management Act, 2005
The law that sets up India's disaster management bodies
In one line: The Disaster Management Act, 2005 created a three-level system of disaster authorities and shifted India's focus from relief to prevention and preparedness.
Key bodies
- NDMA: national apex body chaired by the Prime Minister; lays down policies, plans and guidelines.
- National Executive Committee: chaired by the Union Home Secretary; coordinates implementation.
- State Disaster Management Authority: chaired by the Chief Minister.
- District Disaster Management Authority: chaired by the District Collector or Magistrate.
- Funds: the National Disaster Response Fund (Section 46) and the National Disaster Mitigation Fund (Section 47).
Why it is in the news
The Ministry of Home Affairs is the nodal ministry for disasters. Its Secretary chaired the 3 September 2026 GLOF review.
Where to go next
Disaster Management Act, 2005: every story that connects to it (2)
South Lhonak GLOF of 2023
The event that showed how one lake can wreck a valley
In one line: In October 2023, South Lhonak lake in north Sikkim burst, and the flood down the Teesta breached the Chungthang dam.
What happened
South Lhonak is a moraine-dammed lake at about 17,000 feet in north-west Sikkim. Continuous rain and possibly an avalanche set off the outburst. The flood hit the Teesta and affected the districts of Mangan, Gangtok, Pakyong and Namchi, and the Chungthang dam gave way, adding to the damage. Earlier, in 2016, an effort led by Sonam Wangchuk used pipes to drain part of the lake, showing that lakes can be lowered in advance.
Why it is in the news
The 3 September 2026 review urged a shift to prevention, the central lesson of South Lhonak.
Where to go next
Take the 4 September 2026 quiz: 30 Prelims-style questions with answers