Extreme rainfall event in the Darjeeling district: 04/05Oct2025 (Part IIIA - 'Overall damage and fatal landslides')

 BEFORE & AFTER LANDSLIDE IMAGES FROM NATIONAL REMOTE SENSING CENTER (NRSC)

The Darjeeling district, particularly the Kurseong and Mirik subdivisions, experiences extremely high annual rainfall, averaging over $3000\text{ mm}$. This concentrated precipitation, which falls largely between May and October, makes the region highly susceptible to recurrent landslides, resulting in a long history of such events:
September 1899 (72 fatalities reported in the region).
October 1968 (A massive landslide event combined with a great flood, resulting in over 667 fatalities in Darjeeling, Kalimpong, Teesta Bazar, Lebong, and other areas). Covered in our blog, see here.
June-July 2015: Landslides occurred in Mirik, Tingling, Nimki Dara, and Sukhia Pokhari. Covered in our blog, see here.
October 2025 Disaster: Relentless overnight rainfall on October 4 and 5, 2025, triggered one of the worst recent landslide disasters. Rainfall data of the event is given below:

Fatalities
As per media reports 32 people lost their lives in the deluge with 21 people dying in Darjeeling and 9 & 2 losing their lives in Jalpaiguri and Cooch Behar respectively.

Damage
The disaster damaged 81 roads, 11 bridges, innumerable culverts. It breached 1128m of embankments and washed away 12,680m of river protection works were washed away. Electrical infrastructure was also badly damaged with 272 transformers and 1340 poles being restored till 16Oct2025. Several schools, health centers and drinking water systems were also damaged. Massive damage was reported to the tea industry as well.The tables below will be updated:

Fatal Landslides 

1. Toklang Dara Gaon (Coords: 26.869383N, 88.192072E), Mirik subdivision, Darjeeling district. ('Gaon' is 'Village' in Nepali/Hindi)

Four members of a family were killed by the landslide at this home on 05Oct2025

a. Fatalities: Four — all members of a family who had returned to their home in Taklong  from Salbari, Siliguri, after eight years to celebrate the Dasain festival together.
b. Time of Occurrence: Around 3 a.m. on 05Oct2025.
c. Details: This large landslide occurred during intense thundershowers which moved in from Nepal on 04Oct2025 afternoon. According to local residents, a huge boulder perched on the hilltop — which had earlier been reported to both the local administration and the media — was dislodged by the heavy rainfall, triggering the disaster. Locals also pointed out that inadequate drainage on a newly constructed road above the site had added weight to the slope crown, contributing to the failure.
d. Damage: In addition to the four fatalities, several livestock were lost, and four houses — including a large building — were damaged.
During their survey, the SaveTheHills (STH) team observed numerous landslides along nearby roads, underscoring how road construction and drainage issues remain major triggers for slope failures in the Himalayan terrain.

    Toklang Dara Village (gaon) in Mirik. The hills in the distant are in Nepal

Drone image of the large landslide at Toklang  Dara (Mirik) which
killed 4 people on 05Oct2025.

Large boulders which were dislodged by the intense rain caused immense damage to the village besides the fatalities.

2. Jasbeer Gaon (Coords: 26.895N, 88.2064E) Mirik subdivision, Darjeeling district. ('Gaon' is 'Village' in Nepali/Hindi)

a. Fatalities: Two (husband and wife killed in the landslide - the daughter, aged 15, survived)
b. Time of Occurrence: Around 3 a.m. on 05Oct2025.
c. Details and damage: This massive landslide at Jasbir Gaon extends nearly 1,200 metres down to the Rangbhang River (see map above). According to local residents, a fissure that appeared on the road at the crown of the slope allowed water to seep in, eventually triggering the collapse.
The impact was devastating: once-flourishing orange orchards were wiped out, homes and livestock were lost, and two lives were tragically claimed. The disaster has left deep scars on the landscape and on the community’s livelihood. Many displaced families are now taking shelter in a relief camp at Soureni Bazar, Mirik.

Drone image of Jasbir village landslide near the crown of the landslide.

Drone image of the landslide where it meets Rangbhang river at the base of the mountain. The slide is more than 1.2km in length from the crown (top) to the toe (bottom).

Jasbir Gaon fatal landslide. Two people lost their lives in this area in the early hours of 
05Oct25. In just a few minutes, the massive landslide swept through the slope, turning once-bountiful orange orchards into a barren, rocky wasteland.

Rangbhang river below Jasbir Gaon. The overnight rainfall on 04/05Oct2025 transformed this tiny stream into a raging torrent which gouged out large parts of the valley in its path.

3. Bishnulal Gaon, 11th Mile, Mirik subdivision (Coord 26.89512N 88.17635E)

a. Fatalities: Two of a family (son 9yrs, niece 11yrs of Rabin Chhetri)
b. Time of occurrence: Early hours of 05Oct2025.
c.  Details: Tragedy struck a home at Mirik when a landslide claimed the lives of a nine-year-old son and eleven-year-old niece of Rabin Chettri. The family’s house was completely destroyed, and their neighbor’s home was left half-buried under the debris. Continuous rainfall since the previous evening had saturated the already unstable slope. Just a year earlier, a kutcha road had been hastily constructed along the crown of the hill, using heavy machinery and without any retaining walls or proper drainage which according to Rabin may have caused the landslide. The presence of four borewells at the toe of the slope, coupled with waterlogging, may have further destabilized the ground. When the slope finally gave way around 3:30 a.m., the debris not only engulfed the houses but also buried the borewells, cutting off water access for the entire neighborhood.

Drone image of the slope failure and where two children died at 11th Mile, Mirik on 05Oct2025.

Frontal view of a smashed home where the fatalities occurred.

Partly buried borewell at the base of the landslide. Locals suspect that the water from these wells may have exacerbated the slope failure. Right now, drinking water is a problem for the community in the area because the borewells are non-functional.

Drone image of the landslide gives a clue as to what may have caused the landslide. On the extreme left, there appears to be a jhora or stream which could have led to the slope failure. Notice the reddish color of the soil and the absence of any boulders and rocks.

4. Lakeside landslide, Mirik municipality (Coords:26.89130, 88.18340)
a. Fatalities: Three of a family
b. Time of occurrence: At around 3.00am on 05Oct2025.
c. Details: The family members that the STH team talked with were incredulous that a landslide had taken place in their area at all. They clearly said that the area had no instability or drainage problem and that the only reason that the small slip had taken place was that soil from a nearby construction had been dumped above their home and that during heavy rainfall, this soil had  slid down in the early hours of the 05Oct2025, and extinguished the lives of 3 members of the family. In fact, the whole event had occurred so quietly that they only discovered the landslide and the death of their members at around 6am on 05Oct2025.

Where three lives were snuffed out at around 3am on 05Oct2025 Lakeside, Mirik.

Notice the red soil of the area which many locals say is the reason why Mirik is so landslide prone. The landslide at 3 am of 05Oct2025 went completely unnoticed by other members of the family who only discovered it later at around 6am. By that time, two elders of the family and a relative who was visiting them from Nepal had been dead for several hours, buried by the red soil in a small landslip. 

The red, granular soil tends to lose its cohesion and frictional strength when it becomes wet or moist.

STH team interviewing family members at Lakeside, Mirik during their survey.

Report on fatal and other landslides will be continued.

Report by STH Survey team
Praveen Chhetri (all drone images and photographs): junkeristudio@gmail.com
Steve Rai(interviews and videos with Praveen)
Shreya Gurung (Interviews): shreyagurung07@gmail.com
Yukta Acharya (Interviews and records): yuktaa1999@gmail.com

with sincere thanks and appreciation to Roshan, Rajen bhai and Priya of Darjeeling Himalaya Initiative (DHI)
and also to Aachal (Anugyalaya DDSSS) for helping with resource persons and information.

Praful Rao
savethehills@gmail.com
9475033744

Extreme rainfall event in the Eastern Himalayas: 04/05Oct20205 (Part II - 'The damage and fatalities in Nepal and Bhutan')

The October 2025 rains (see previous blog) were among the most intense to strike Eastern Nepal, the Darjeeling Himalayas, and Bhutan in recent years. The storm system, which crept in from northern Uttar Pradesh and Bihar, tracked east-northeast, impacting Eastern Nepal — including Kathmandu — first. The devastation it caused has been extensively covered by the media. Below, we’ve compiled a selection of key excerpts:

Nepal

Rainfall data (mm): Kathmandu 145, Rautahat 330, Ilam 330mm (reported 37 fatalities)

Fatalities, damage and cost:
a. 66 fatalities have been reported, 69 people are missing. 37 people died in Ilam district.
b. Huge damage on development infrastructure like roads, bridges and drinking water projects across Koshi province amounting to Nepalese Rs2.06 billion. Road projects worth about Rs190 million have been lost in Ilam alone.Bridges worth an additional Rs385 million have been destroyed. 226 homes were reported submerged in Kathmandu and a total of 4,059 households affected (ReliefWeb / GDACS summary of national reports).
c. Across Panchthar, Taplejung, Sankhuwasabha, Solukhumbu and Okhaldhunga, dozens of rural roads have been blocked or buried under landslides. Of the 73 roads, 44 still remain completely obstructed, while 12 of 23 motorable bridges have been totally destroyed. A total of 20 suspension bridges remain impassable due to flood damage.

Bhutan

Bhutan lies directly to the east of Kalimpong district (West Bengal) and Sikkim. As the powerful October 2025 storm swept across the Darjeeling–Sikkim Himalayas, it reached Bhutan on 5 October, bringing with it widespread devastation. The rainfall recorded during the event is shown in the map above.
Like Nepal, Bhutan is crisscrossed by several major rivers — Jaldhaka, Diana, Torsa, Sunkosh, Raidak, Jayanti, and Kaljani — which flow from its mountains into the fertile plains of North Bengal and Assam. These rivers are lifelines for irrigation and agriculture in the region. However, intense rainfall in Bhutan’s highlands often translates into dangerous flooding in the plains downstream.

Fatalities and damage reported

As per The Bhutanese, '3 people are likely dead as two persons are reported missing in Haa Dzongkhag due to flash floods in Sertena, Gakiling Gewog and one was washed away in Kazhi in Wangduephodrang. 1 body from Haa was recovered on 6 October 2025 from Cooch Bihar'.
Further '17 bailey bridges, six suspension bridges, three culvert bridges, three wooden bridges and three private bailey bridges were washed away'. Details of the damage are available here.
According to Kuensel, Bhutan’s national newspaper, “across Bhutan, numerous roadblocks, landslides, and washed-out bridges have cut off several communities. The southern and western highways have reported significant disruptions, and several homes have been damaged or flooded.”

One of the most critical impacts was on the country’s extensive hydropower infrastructure. Authorities in North Bengal were placed on high alert after a technical failure at the Tala Hydropower Dam caused it to overflow, sparking fears of downstream flooding in the Dooars region.
In response to the severe weather, five major hydel projects — Tala, Suchhu, Dagachhu, Punatsangchhu, and Chhuka — were temporarily shut down. This unprecedented situation not only disrupted power generation but also highlighted the growing vulnerability of Himalayan infrastructure to extreme weather events.

Further details on the damage to Bhutan’s dams can be found here.

Praful Rao,
SaveTheHills
savethehills@gmail.com
9475033744