Sikkim's fragile mountains are cracking under development pressure

Ecologically vulnerable areas are sensitive because of extreme climates, steep topography, low carrying capacity, and unique biodiversity.  In North Sikkim and its fragile ecology, most of these factors play a significant role. 

The region strikes a visitor with its abundant natural beauty and rich resources—coupled also with evidence of their stark imbalance. 

Over the past 10 years (up to January 2025), 440 earthquakes of magnitude 4.0 or higher occurred within 300 km of Sikkim, with a yearly average of about 44. Studies indicate a significant number of landslides, identifying 265 mapped landslides between 1989 and 2022, showing increased vulnerability. 

This tiny Himalayan state, which through a referendum in 1975 voted to become the 22nd state of India, has many little gems tucked away, each sparkling in its own unique way. But how enduring that sparkle is—and how ecologically safe these places are—is a point of serious concern. 

With every monsoonal deluge, the northern part of Sikkim gets quagmired. The North Sikkim region, by its very geological nature, is in a vulnerable position, close at the foothills of the mighty Himalayan ranges that are still young and prone to tectonic plate movements. 

The variable climate, differences in altitude, fickle weather and heavy rainfall, combined with the steep terrain, make the region prone to landslides and erosion. To add to all these are man-made indiscriminate acts of deforestation as a course for developmental projects such as building of dams, etc. 

The construction of hydroelectric projects in this disaster-prone area has increased human settlement, adding to the greater threat in numbers to the local population and infrastructure, vulnerable to the flood risk. 

The dam of the 1200 MW Teesta III project in Chungthang on the feisty river Teesta was washed away on the intervening night of October 3 and 4, 2023, on account of a glacial lake outburst flood (GLOF) from the South Lhonak lake, triggered by torrential rains. The lake had been a ‘ticking bomb’ for a potential GLOF for over a decade. 

The cascading effect continued downstream, affecting four other dams: Teesta V, Teesta VI, Teesta Low Dam III, and Teesta Low Dam VI. 

This catastrophe has had a lasting impact, altering the topography of these areas of north Sikkim, making them even more vulnerable to any such future mishap. There is enough evidence of the damage caused along the route to Mangan. Massive boulders and raw, gaping mountainsides sliced off like big chunks of cake, vanished roads and torn bridges.

The sight is deeply disturbing and frightening. 

This disastrous incident has attracted the attention and analyses of activists, scholars and scientists and the outrage of local communities. Two important facts have come to the fore: first, the suitability of the region for such ambitious power projects and second, whether policies are tailored to suit the steep mountainous terrain.

According to the Environmental Policy Goddard Chair Group, the remedial measures should include: 

Providing public access to data, information, and future disaster predictions

Accounting for deep uncertainties 

Including local interests in planning processes and disaster response  

Formally funding contingency measures 

Sharing lessons learned both locally and from other locations 

It is essential for power, water and infrastructure planners—and government agencies—to understand that the capacity of the small state of Sikkim to generate power is very limited. Consuming only around 400 MW of energy, it was generating 2,300 MW.

On our way to Dzongu from Lachung, at Chungthang, we witnessed the devastation and the abandoned hydroelectric power project. The magnitude of the damage gives a sobering glimpse into the might of natural forces when thwarted. 

The Teesta, which originates from the Teesta Khangtse glacier, and Rangit, its tributary, nourish the state. A forceful river, if angered, can sweep away mountainsides, roads, bridges and homes. 

The Lepcha tribe’s stand  

An equally strong and emotional reason is that of the Lepcha tribe, to whom the Dzongu district belongs, according to the 1956 notification. They are nature worshippers, and their connection with their land, flora and fauna and water bodies is deep and reverential. 

Gyatso Tongden Lepcha, secretary of the Affected Citizens of Teesta, says, "We have observed several landslides, flash floods and earthquakes after the construction of dams on the Teesta River in Dikchu and Chungthang; we believe dams are not the solution to sustainable development." 

To keep the developmental projects going while handling the negative anthropogenic impact of them is a difficult issue to solve.  A complete and deeply studied overhaul of the outlook on development may help to an extent. 

These words of Chief Seattle come to my mind: ‘We do not inherit the earth from our ancestors, we borrow it from our children.’

(The author is a freelance travel writer, artist and children's author based in Bengaluru)

Disclaimer: The views expressed above are the author's own. They do not necessarily reflect the views of DH.