A glacial lake outburst flood (GLOF) in Bhutan's high-altitude region has triggered flood warnings in several districts of Assam and North Bengal, putting authorities and residents along the Sankosh River system on high alert. The outburst was reported from Sintaphu Lake on Thursday night, October 29, 2026, raising concerns about a sudden rise in water levels in downstream areas.

The development prompted authorities to issue warnings for low-lying areas in parts of Assam and West Bengal. Residents living along the Sankosh River and its tributaries were advised to move immediately to safer locations to reduce the risk to life and property.

State Minister Nisith Pramanik, speaking to ANI, said that water from the outburst was expected to reach the plains within the next five to six hours. He warned that this could create a significant risk of flooding in vulnerable areas.

The State Disaster Management Team was activated, and the National Disaster Response Force (NDRF) was notified. Disaster management volunteers were also instructed to remain present at the affected locations. The administration said it was monitoring the situation and taking precautionary measures to prevent loss of life and property.

In West Bengal's Alipurduar district, police and district authorities began coordinating evacuation and relief arrangements. Superintendent of Police Amit Kumar Shaw said that the situation was under control at the time of his statement, but the administration remained on high alert.

According to the police official, around 4,000 to 5,000 people had been moved to shelters, with school buildings being used as temporary relief centres. He also said that more than 6,000 people had been relocated to safer areas based on the water flow and the latest information available to the administration.

Authorities arranged dry food, drinking water and basic facilities at the relief centres. A red alert was also in effect for the Sankosh river system.

The incident has once again highlighted the flood risks faced by communities living near rivers that flow from the Himalayan and Bhutanese high-altitude regions. A sudden release of water from a glacial lake can travel downstream and create dangerous conditions in low-lying areas, leaving limited time for evacuation and emergency preparation.

What happened at Sintaphu Lake in Bhutan?

The flood warning followed an outburst reported from Sintaphu Lake in Bhutan on Thursday night. The incident was described as a glacial lake outburst flood, commonly known as a GLOF.

A GLOF occurs when water stored in a glacial lake is suddenly released. Such lakes can be formed by melting glaciers and may be held back by natural barriers made of ice, rock or glacial debris. If the barrier is breached or becomes unstable, a large volume of water can move rapidly downstream.

In the present case, the reported outburst at Sintaphu Lake raised concerns about water flowing into river systems connected to areas of Assam and North Bengal.

The immediate concern was the possibility of a sudden rise in water levels along the Sankosh River and its tributaries. These rivers pass through areas where communities may be exposed to flooding when water levels rise sharply.

The supplied report does not provide the exact volume of water released from Sintaphu Lake, the lake's dimensions, the precise cause of the outburst or a detailed scientific assessment of the event. It identifies Sintaphu Lake as the source of the reported outburst and describes the resulting flood alert in downstream areas.

The authorities responded by issuing warnings, activating disaster management teams and moving residents from vulnerable locations.

Why did the outburst trigger alerts in Assam and North Bengal?

The outburst triggered warnings because water released from a high-altitude lake can move downstream through connected rivers and tributaries.

In this incident, the Sankosh River system became the main focus of the warning. Authorities alerted residents living along the river and its tributaries, particularly those in low-lying areas that could be exposed to rising water levels.

State Minister Nisith Pramanik said that the water was expected to reach the plains within five to six hours. This estimate created an urgent need to inform residents and prepare evacuation arrangements.

The risk was not limited to locations immediately next to the lake. Water moving through river channels can affect settlements and low-lying areas farther downstream.

The administration therefore focused on precautionary measures rather than waiting for water levels to rise in populated areas.

Residents were advised to move to safe distances from riverbanks and vulnerable locations. Disaster management volunteers were instructed to remain on-site, while the NDRF was notified to support emergency response operations.

In Alipurduar, the police, district administration, block-level officials and disaster response teams began coordinating relief work.

The warning also led to the use of school buildings as temporary shelters for residents who had been moved from vulnerable areas.

Sankosh River system placed under red alert

The Sankosh River system was placed under a red alert following the reported glacial lake outburst in Bhutan.

The warning was intended to alert communities and authorities about the possibility of significant flooding as water moved towards the plains.

State Minister Nisith Pramanik said that residents living along the Sankosh River and its tributaries had been advised to move to safe locations immediately.

The minister also said that the State Disaster Management Team had been activated and the NDRF had been notified. Disaster management volunteers were instructed to remain present at the affected sites.

The red alert indicated that the administration was treating the situation as a serious potential flood threat. Authorities were monitoring the water movement and preparing for possible emergencies.

The Sankosh River system was a key area of concern because the reported outburst could increase water flow downstream. Residents in low-lying areas were therefore advised not to remain close to riverbanks.

The police and district administration were also coordinating with other agencies to support evacuation and relief arrangements.

The supplied report does not provide specific river gauge readings, the exact water level at different monitoring points or a list of every district covered by the red alert. It identifies the Sankosh river system as being under red alert and mentions flood warnings for several districts in Assam and North Bengal.

Nisith Pramanik says water could reach plains within five to six hours

State Minister Nisith Pramanik warned that water from the outburst was expected to reach the plains within the next five to six hours.

Speaking to ANI, he said residents living along the Sankosh River and its tributaries had been alerted and advised to move to a safe distance immediately.

The warning was important because it indicated that authorities were expecting the water to move downstream within a short period.

Pramanik said the State Disaster Management Team had been activated and the NDRF had been notified. Disaster management volunteers were also instructed to be present at the affected locations.

He said the government was taking proactive measures and closely monitoring the situation to prevent loss of life or property.

The minister's statement reflected the urgency of the response. When a sudden increase in river flow is expected, timely warnings and evacuation can help reduce the exposure of residents to dangerous conditions.

The administration's immediate focus was therefore on informing people living near the river, moving vulnerable residents to safer locations and ensuring that emergency teams were ready to respond.

The supplied report does not provide a later confirmation of the exact time at which the water reached the plains. The five-to-six-hour estimate was the warning given by the minister at the time of his statement.

Alipurduar administration shifts thousands of residents

West Bengal's Alipurduar district was among the areas where authorities began large-scale precautionary relocation.

Alipurduar Superintendent of Police Amit Kumar Shaw said the situation was under control at the time of his statement, but the administration was working in close coordination with different agencies.

According to Shaw, around 4,000 to 5,000 people had been moved to shelters, with school buildings being used as temporary relief centres.

He said the police team, District Magistrate's office, Block Development Officer and other relevant agencies were working together to manage the situation.

The State Disaster Response Force (SDRF) team was already present, while an NDRF team was also on its way. A Civil Defence team had also been deployed.

The relocation of thousands of people was a precautionary measure aimed at reducing the risk to residents living in areas that could be affected by rising water levels.

School buildings were being used as relief centres because they could provide temporary accommodation for people moved away from vulnerable locations.

The administration also arranged basic facilities to support those staying in the shelters.

The police official's statement indicated that the district authorities were trying to balance evacuation, relief arrangements and continued monitoring of the water situation.

More than 6,000 people relocated to safer areas

In a further update, Alipurduar SP Amit Kumar Shaw said that more than 6,000 people had been relocated to safe areas based on the current flow of water and the latest information available to the authorities.

The official said the intensity of the water flow had decreased slightly, but the administration remained on high alert.

The figure of more than 6,000 people represents the broader relocation update mentioned by the police official. His earlier statement referred to around 4,000 to 5,000 people being moved to shelters using school buildings as relief centres.

These figures describe different aspects of the relocation response and should not automatically be added together.

The police official said authorities would continue monitoring the situation and assess developments over the following hours.

The administration had made arrangements for dry food and drinking water. It had also ensured that other essential facilities, including toilet arrangements, were available for people moved to safer locations.

The official said the district was fully prepared to handle any emergency that might arise.

The red alert for the Sankosh river system remained in effect, indicating that the administration was not treating the slight reduction in water intensity as a reason to withdraw precautions.

NDRF, SDRF and Civil Defence teams activated

The flood warning prompted the deployment and mobilisation of multiple disaster response agencies.

The State Disaster Management Team was activated following the reported outburst. The NDRF was notified and an NDRF team was reported to be on its way to the affected area.

The SDRF team was already present in Alipurduar, according to Superintendent of Police Amit Kumar Shaw. A Civil Defence team had also been deployed.

The response involved coordination between the police, District Magistrate's office, Block Development Officer and other relevant agencies.

The role of these teams was to support evacuation, monitor vulnerable areas, assist residents and remain prepared for emergency operations.

The presence of disaster response personnel was particularly important because the flood warning involved a possible sudden increase in water levels.

The administration also instructed disaster management volunteers to remain present at affected locations.

The coordination between agencies was intended to ensure that information could be shared quickly and that assistance could reach residents if the situation worsened.

The supplied report does not provide the exact number of personnel deployed by each agency or the precise operational arrangements of the NDRF and SDRF teams.

School buildings turned into temporary relief centres

As part of the evacuation response, authorities used school buildings as temporary relief centres in Alipurduar.

According to SP Amit Kumar Shaw, around 4,000 to 5,000 people had been moved into shelters by the time of his statement.

Schools were being used to provide temporary accommodation for residents shifted from potentially vulnerable locations.

The administration also arranged dry food and drinking water for the people staying in these centres. Toilet facilities and other basic necessities were also made available.

These arrangements were important because evacuation is not limited to moving people away from a danger zone. Authorities also need to ensure that displaced residents have access to basic facilities while they remain in temporary shelters.

The police official said the district administration was working together with other agencies to manage the situation.

The availability of food, drinking water and sanitation facilities was part of the immediate relief response.

The supplied report does not identify the names or locations of the individual schools being used as shelters. It also does not provide a detailed breakdown of the number of people accommodated at each centre.

Alipurduar SP urges residents not to panic

Alipurduar Superintendent of Police Amit Kumar Shaw appealed to residents not to panic, while assuring them that authorities were monitoring the situation and working in coordination.

He said the situation was under control at the time of his statement.

The police official said that authorities were in constant touch with Bhutan and that the police, District Magistrate, Block Development Officer and other agencies were working together.

He also confirmed the presence of SDRF personnel and said an NDRF team was on its way. A Civil Defence team had also been deployed.

Shaw said the administration had already moved thousands of people to shelters and safer locations.

He further stated that the intensity of the water flow had decreased slightly according to the latest information available, but the district remained on high alert.

The police official said that arrangements for dry food, drinking water and toilet facilities had been made.

He also said authorities would assess the situation again after two hours and were fully prepared to handle any emergency.

The appeal not to panic was accompanied by a clear warning that the red alert remained in force for the Sankosh river system.

Residents were therefore expected to follow instructions from the administration and remain away from vulnerable riverbank areas.

Authorities maintain contact with Bhutan

According to Alipurduar SP Amit Kumar Shaw, local authorities were in constant contact with officials in Bhutan.

This coordination was important because the reported outburst had taken place at Sintaphu Lake in Bhutan, while the potential flood impact was being monitored in downstream areas of India.

Information about water flow and developments upstream can help authorities assess the risk faced by communities farther downstream.

The police official said the district administration was receiving updates and taking decisions based on the current flow of water and the latest available information.

The supplied report does not provide the names of the Bhutanese agencies involved or the specific technical information exchanged between the two sides.

However, the statement confirms that communication with Bhutan was part of the response.

Cross-border coordination is particularly relevant in river systems that originate or pass through more than one country. Timely information can help downstream authorities prepare evacuation measures and organise emergency assistance.

Why glacial lake outburst floods can be dangerous

A glacial lake outburst flood, or GLOF, is a sudden release of water stored in a lake formed by glacial activity.

Glacial lakes can develop as glaciers melt and water accumulates in depressions or behind natural barriers. These barriers may consist of ice, rock or loose glacial material.

If the barrier becomes unstable or is breached, a large volume of water can escape rapidly.

The released water may travel through mountain streams and rivers, carrying sediment and debris along the way. As the flow moves downstream, it can affect settlements, roads, bridges and other infrastructure located near river channels.

The danger is often linked to the sudden nature of the event. Communities downstream may have limited time to respond if the release is not detected early or if warnings do not reach them quickly.

In the Sintaphu Lake incident, authorities were concerned about the movement of water towards the plains and the possible impact on the Sankosh River system.

The five-to-six-hour estimate given by State Minister Nisith Pramanik made early evacuation a priority.

The administration responded by alerting residents, activating disaster management teams and moving people from potentially vulnerable areas.

The supplied report does not include a scientific assessment of the lake's condition or the exact hydrological characteristics of the outburst. The broader explanation of GLOFs provides context for why such incidents can create sudden downstream flood risks.

Residents along the Sankosh River advised to move to safety

One of the most important instructions issued by authorities was the warning to residents living along the Sankosh River and its tributaries.

State Minister Nisith Pramanik said people in these areas had been alerted and advised to move to a safe distance immediately.

The warning was intended to prevent residents from remaining in locations that could be affected by rising water levels.

Riverbanks and low-lying settlements can become dangerous when water levels rise suddenly. People living close to the river may have limited time to move if flooding develops quickly.

The administration therefore focused on precautionary relocation.

In Alipurduar, thousands of people were moved to shelters and safer areas. School buildings were used as relief centres, and arrangements were made for food, drinking water and sanitation.

The police and district administration were also working with disaster response teams to monitor the situation.

Residents were advised to follow official instructions and avoid returning to vulnerable locations while the alert remained in force.

What areas were placed on high alert?

The supplied report identifies several districts in Assam and North Bengal as being under flood warning following the Sintaphu Lake outburst.

It specifically highlights the Sankosh River system and Alipurduar district in West Bengal.

Residents living along the Sankosh River and its tributaries were advised to move to safe locations. Alipurduar authorities began shifting residents to temporary shelters and safer areas.

The report does not provide a complete district-wise list of all areas placed on high alert in Assam and North Bengal. It also does not identify every village or settlement covered by evacuation instructions.

Therefore, the confirmed details from the supplied report are that flood warnings were issued for low-lying districts in Assam and North Bengal, the Sankosh river system was under red alert, and Alipurduar was carrying out large-scale relocation and relief arrangements.

Relief arrangements include food, drinking water and sanitation

The administration's response also included arrangements for people who had been moved from vulnerable locations.

According to Alipurduar SP Amit Kumar Shaw, authorities had arranged dry food and drinking water for residents staying in shelters.

The administration had also ensured that toilet facilities and other necessities were available.

These arrangements were being made alongside the relocation of thousands of people.

Temporary shelters are an important part of emergency management because residents may need to remain away from their homes while water levels and flood risks are being monitored.

The use of school buildings as relief centres provided temporary accommodation for people shifted from vulnerable areas.

The police official said the administration was working with the District Magistrate's office, the Block Development Officer and other agencies to manage the situation.

The presence of SDRF, Civil Defence and the expected arrival of the NDRF team were also part of the emergency response.

Water intensity reportedly decreases slightly, but alert continues

An important update from Alipurduar SP Amit Kumar Shaw was that the intensity of the water flow had decreased slightly according to the latest information available to the administration.

However, the official made it clear that the district remained on high alert.

The slight reduction in intensity did not lead authorities to withdraw the warning. The red alert for the Sankosh river system remained in force.

The administration was continuing to monitor the water situation and had said it would reassess developments after two hours.

This approach reflected the need for continued caution. A temporary change in water intensity does not necessarily mean that all flood risks have ended.

The authorities had already moved thousands of people to shelters or safer locations. They were also maintaining contact with Bhutan and coordinating with disaster response agencies.

The police official said the administration was prepared to handle any emergency that might arise.

The supplied report does not provide a later update confirming whether water levels continued to fall, whether the red alert was withdrawn or whether any additional areas were affected.

What residents should understand from the flood warning

The key message from the authorities is that residents living close to the Sankosh River and its tributaries should take the warning seriously and follow official instructions.

The reported outburst at Sintaphu Lake has created a potential flood threat in downstream areas. Authorities have advised residents in vulnerable locations to move to safer places.

The administration's evacuation effort in Alipurduar demonstrates the scale of the precautionary response. Thousands of people have been relocated, temporary shelters have been arranged and disaster response teams have been activated.

Residents should avoid approaching riverbanks to observe rising water levels or attempting to cross flooded roads and streams. They should also follow instructions issued by the district administration and emergency response teams.

People who have been moved to shelters should use the facilities arranged by the authorities and wait for official instructions before returning to their homes.

The supplied report does not include a formal public safety advisory with detailed instructions for every district. The specific directions for residents should therefore be taken from the relevant local administration.

Key developments in the Bhutan glacial lake outburst

The major developments reported on October 30, 2026, can be summarised as follows:

• Thursday night, October 29: A glacial lake outburst was reported at Sintaphu Lake in Bhutan.

• Flood warning issued: Low-lying areas in parts of Assam and North Bengal were placed under alert.

• Sankosh River warning: Residents along the Sankosh River and its tributaries were advised to move to safer locations.

• Minister's warning: Nisith Pramanik said water was expected to reach the plains within five to six hours.

• Disaster response activated: The State Disaster Management Team was activated, the NDRF was notified and volunteers were instructed to remain on-site.

• Alipurduar evacuation: Around 4,000 to 5,000 people were moved to shelters using school buildings as relief centres.

• Further relocation update: More than 6,000 people were reported to have been moved to safer areas.

• Emergency facilities: Dry food, drinking water and toilet facilities were arranged for displaced residents.

• Red alert: The Sankosh river system remained under red alert.

• Water flow update: Authorities reported a slight decrease in intensity but continued to maintain high alert.

These developments show that the administration's immediate priority was to protect residents in potentially affected areas and prepare for any further rise in water levels.

Bhutan GLOF puts Assam and North Bengal on alert

The reported Sintaphu Lake glacial lake outburst in Bhutan has triggered a major precautionary response in parts of Assam and North Bengal.

The warning has focused attention on the Sankosh River system, with residents along the river and its tributaries advised to move away from vulnerable locations.

State Minister Nisith Pramanik said water could reach the plains within five to six hours. The State Disaster Management Team was activated, the NDRF was notified and disaster management volunteers were instructed to remain at affected locations.

In Alipurduar, authorities moved around 4,000 to 5,000 people into shelters, while a further update from the police said more than 6,000 people had been relocated to safer areas. School buildings were being used as relief centres, with dry food, drinking water and sanitation facilities arranged for displaced residents.

Alipurduar SP Amit Kumar Shaw said the situation was under control at the time of his statement and that water intensity had decreased slightly. However, he confirmed that the administration remained on high alert and that a red alert was in force for the Sankosh river system.

The authorities were also maintaining contact with Bhutan and coordinating with the police, district administration, SDRF, Civil Defence and NDRF teams.

The most important development to watch is the movement of water through the Sankosh river system and whether the flood warning can be eased as conditions change. Until authorities issue an official update, residents in vulnerable areas should follow evacuation instructions and remain in safe locations.

The incident underlines the importance of early warnings, quick evacuation and coordination between agencies when a sudden water release from a high-altitude glacial lake threatens downstream communities.