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

Extraordinary high intensity and very localized rainfall of 29Aug2023 at Kalimpong

Meteorological conditions
28Aug2023 was a cloudy day and except for a little early morning rain, it was dry in Kalimpong. We even had a rare 'NO WARNING' for Sub-Himalayan West Bengal (SHWB) and Sikkim.

Cloud images showed fairly settled weather in our region through the day - even until 8.15pm on 28Aug2023, when I put a last post in 'Hazard Alerts' our What's App 'Early Warning' group in the Darj-Sikkim region.

                  Above image shows no major clouding in the area circled.

The clouding suddenly increased thereafter, as seen in the IR Image of 11.45pm of 28Aug2023:

              Notice the clouding which has suddenly appeared below Kalimpong

Nowcast issued by IMD is placed below

Rainfall of 29Aug2023 morning
We had sudden and very intense rainfall starting from 1.30am with peak intensities crossing 135mm/hr. The rainfall amount was 79.2mm in a very short time.

The screenshot of Damini (Lightning Alert app) showing no lightning at 3.06am in our area is below

And at 3.45am, with the rainfall declining over Kalimpong, the clouding vanished, just as quickly as it had appeared.

What is amazing in this event, besides the extremely sharp increase and decrease of rain intensity, is that it rained only over Kalimpong.
Adjoining towns of Darjeeling, Kurseong and Todey (where there are Davis automatic weather stations) had ZERO rainfall

QUESTION IS:
ARE WE PREPARED FOR THIS TYPE OF RAINFALL WHICH IS NO LONGER EXTRAORDINARY BUT BECOMING THE NEW NORMAL?

Praful Rao
Kalimpong district
Darjeeling-Kalimpong Himalaya
savethehills@gmail.com
9475033744

 

STH activities : Use of cell phones and social media in disaster communication - our experience in the Darjeeling-Sikkim Himalaya with a Whats App Group 'HAZARD ALERTS 1&2'

 

I have always been fascinated by the digital platform and its ability to record and disburse information quickly, accurately and efficiently to a large number of people and so I started this blog in Sep 2007 when SaveTheHills (STH) was formed. The blog has till date 375,052 hits & has a record of almost 12 years of landslide as well as rainfall activity of the region.
I have since made STH accounts in virtually all other major social media platforms ie Facebook, Instagram and Twitter though I have never got around to using them.
What I have used, however and which has become the STH flagship is our Whats App (WA) group 'HAZARD ALERTS' or HA which was created approx 5 years ago with the intent of disbursing heavy rainfall warnings and alerts to common people so that they become more aware and perhaps pass on the warnings to others as well.
I am glad to say that HA has become a very successful and disciplined crowd sourced platform and a knowledge bank in our region on many environmental issues of the Himalayas and messages and warnings in HA are read by a large number of people in our area even though WA only allows a maximum of 250 members.
Today HA has 244 members of which approx 25 or so are PhDs who can throw light on issues or queries which we layman have. Then we have a large number of NGOs and media people who not only pass warnings to others but also serve as vital communication links to inform about hazards, landslides, highway status and so on. We also have a large number of government officials who also participate in crowd source knowledge disbursement and information and last of all we have the lay people for whom HA was actually formed - so that they are better informed and aware of impending hazards, heavy rainfall periods and take action. All in all HA has been a wonderful experiment which has been very successful.
Since we were about to run out of space, we have formed Hazard Alerts 2  (HA2) which has approximately 50 members till now - mostly students. All posts from HA are simultaneously posted in HA2.
In Feb2021, we (my STH colleague Dr Nima Doma Lama and I) made a 5 min 'lightning presentation' on HAZARD ALERTS  for SHEAR which is available on YOUTUBE here. Do have a listen and we would be more than happy to share our experience with you.

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya

Mungpel: A village living on the edge (03Jan2021)

 As a part of our landslide surveys, I visited Mungpel, a small village in Pabringtar GP of Kalimpong (Block -1) on 03Jan2021. The village consists of 30 odd houses who are almost entirely of members of Limbu ethnic group. The sombre fact is that of these homes, approximately 10-15 overlook and are in the proximity of huge landslide.

We had carried out a landslide survey in this area in April 2011 and a map of the area from that survey is placed below:

Landslide history
As per locals, the landslide was insignificant until 2018 after which it has grown to its present size. This whole area receives very heavy rainfall and is thrashed by intense thunderstorms during the pre-monsoons but it is a pity there are no rainfall data from this place to relate the landslide activity.
However, the locals clearly said most of the damage was done during the monsoons of 2020 especially around end of Jun2020.
Coordinates of Mungpel Landslide:
N 26.95696° E088.54993°

At the base of the this hill there is a fairly big Durung khola (river) and a wonderful flat piece of land where the villagers do their agriculture and farming. As per the villagers the landslide was not due to toe erosion by the river and was caused by the inherent geology and heavy rain.
Yet another major landslide in the lower Sherwani area, nudges the Mungpel landslide and we have yet to survey that area.

As I have mentioned 3 families have already relocated to upper regions but some 10 other families also may suffer a similar fate - these monstrous landslides are seem impossible to control without serious study and funding.

Praful Rao
Kalimpong district
Darjeeling -Sikkim Himalaya

A pictoral record of the landslides of JUN 2020 in Darjeeling-Sikkim Himalaya

Shown above are the approx timelines when due to the more than normal rainfall in Jun2020, there were numerous landslides in the Darjeeling - Sikkim Himalayas and all occurred during periods of heavy rain. For example, in 6 days (17Jun-22Jun2020) Kalimpong received approx 78% of its monthly rainfall which is when all the landslides in Kalimpong took place.
More specifically:
a. Darjeeling and Kurseong area had landslides just as the SW monsoons entered the region on 12/13Jun 2020. Many of these landslides are documented here.
b. Kalimpong district which had almost no rain during this onset period, had intense rain on 17Jun which triggered a number of slides in the district.
c. Mangan (N Sikkim) and E Sikkim were the only places which had surplus rain over the winter months and continued to have very heavy rain towards June end and that triggered a number of landslides.
In order to maintain a record of the landslide events I am posting verified photos of some of them as submitted by HA members.

Kalimpong:

North Sikkim (Passingdang)

North Sikkim (District HQ: Mangan)27.4979° N, 88.5348° E

North Sikkim (Barfok)
27.509787°N, 88.437531°E

Debris Torrent as seen from across the Teesta from Mangan. No loss of lives, some houses evacuated.

Landslide at NHPC Stage V 510 MW Dam at Dikchu, East Sikkim

Landslip on Dhotrey- Maneybhanjang road (22Jun2020?)

Rimbick- Lodhoma landslide (28Jun2020)
at Chota Hatta, Kankeybong.

Breaches on NH55 (Siliguri to Darjeeling) near Pagla Jhora (Kurseong)
30Jun2020

My sincere thanks to all those who have volunteered their time and effort in 'HAZARDS ALERTS' (Whats App group)  and elsewhere to provide the information and photographs for the above record.

Praful Rao
Kalimpong district
Darjeeling Sikkim Himalaya