Human Failure One of Many Reasons for Sikkim Disaster; Lots of Work, Planning Ahead: Local Scientist

 In an interview, Vimal Khawas says to prevent future disasters, dam proponents and the government must take the science and scientific findings about development projects in the Hamalaya seriously.

Aathira Perinchery interviewed Vimal Khawas, professor at the Special Centre for the Study of Northeast India in Jawaharlal Nehru University, New Delhi, on the Sikkim disaster and what lies ahead for the region. Khawas, who hails from a remote village in Kalimpong in the Darjeeling Hills on the border of Sikkim and northern West Bengal, is one of the founding members of Sikkim University. He has worked extensively on environmental challenges, hydropower development, and their intersections with glacial lakes and climate change in the Eastern Himalaya, specifically in the Sikkim and Darjeeling Himalaya.

The Chungthang Dam after it was breached. Photo: X/@ParveenKaswan

Aathira Perinchery, The Wire: A Glacial Lake Outburst Flood (GLOF) of the South Lhonak Lake and subsequent flash floods destroyed the Teesta-III dam on the Tista River on October 4 in minutes and caused huge devastation and damage downstream. With each day, the casualties rise: more people dead, and many more missing. You’ve worked on GLOFs, and highlighted the threats these could cause in the Sikkim Himalaya. What according to you caused the GLOF event in the first place? 

Global warming has increased the intensity and frequency of extreme climatic events like GLOF in the Himalaya. GLOFs are not a new phenomenon across the Himalaya but their occurrence has become more frequent in the past couple of decades. The number of potentially dangerous glacial lakes has been increasing across the Himalaya, including the Sikkim Himalaya, in the last few decades.

Vimal Khawas. Photo: by arrangement

A GLOF is primarily an outcome of glacial melting. An accelerated retreat of the glaciers in recent times has led to an enlargement of several glacial lakes. As the glaciers retreat they leave a large void behind. The ponds occupy the depression earlier occupied by glacial ice. These dams are structurally weak and unstable and undergo constant changes due to slope failures, slumping, etc. and run the risk of causing GLOFs. 

Possible drivers of the flood from the South Lhonak Lake on the night of October 3, 2023, have been a debated topic. It started with the cloudburst theory as early as 6:00 am on October 4. By the evening of October 4, the day of the flash floods, an alternative narrative had set in, questioning the cloudburst theory. There were apprehensions like whether cloudbursts occur in the Trans-Himalayan region and that the lake area under debate typically receives minimal rainfall according to historical records or that the occurrence of cloudbursts in such a high-altitude area is somewhat surprising. There was no clear-cut answer. Nevertheless, many people were hinting towards the recent Nepal earthquake and the possibility of it triggering the lake burst. Now, with deeper analysis, geoscientists are increasingly believing that the collapse of a lateral moraine [debris such as soil and rock left behind by the edge of a melting glacier] leading to a landslide into the lake is the likely cause of the GLOF. Anything could be possible: cloudburst, the Nepal earthquake or other geomorphic processes. It will take time for the experts to ascertain what exactly led to the sizable floating ice to occupy the lake area, forcing the lake water to find its way downwards and take the form of a GLOF.

Photo: International Rivers, CC BY NC SA 2.0

Do you think that both climate change and human activities — specifically, the construction of not just the Teesta-III but all five other dams on the river — are to blame here? There are also talks of the spillways not being opened in time, which could have at least decreased the impact to some extent?

Climate change has been at the centre of the debate for the changing Himalayan geo-environment. Scientists are repeatedly warning that the Himalaya are warming comparatively faster than their lowland counterparts. The rapidly warming Himalaya has led to an acceleration of various geomorphic processes, including melting of glaciers. The rapid melting of glaciers has further given rise to many potentially dangerous Glacial Lakes, in recent times. The changes in the geomorphic processes have been rapid and dam planners/engineers were unable to foresee their increasing intensity and frequency over 20 years ago when many of our dams in Sikkim were planned. 

According to an officer of Teesta-III, “42 years of water data is needed for mega projects to be designed and recommended by National Seismic Designing Authority for the final approval of CEA (Central Electricity Authority). In the context of Teesta III, [the] highest flood measuring 680 cumecs (discharge) was recorded in 1973 in Chungthang. Based on the data the Teesta III dam was designed to withhold 7000 cumecs”.

It is important to understand that the Sikkim-Darjeeling Himalaya being a backward and less-researched region did not have such long-term data on the table when dams were planned and designed in the early 2000s. That is the reason why anti-dam activists often question the technical, environmental and human procedures followed by the proponents of hydropower dams in the Himalayan region including in Sikkim.  

With regard to the reported spillways not being opened on time, had the dam gates of Teesta-III been opened on time, the impact of the flood would have been much milder. However, by the time information was received by relevant people in Chungthang, the flood had already hit the dam forcing them to flee for their lives, instead of opening the gates. 

More worrying is the statement by a senior civil servant of the Govt of Sikkim on his Facebook page on 07.10.23.

The above statement is worth noting. It talks about how the failure of both human coordination and an Early Warning System (EWS) has worked in tandem, giving us such a big-scale disaster that ravaged a major part of the Upper Tista Basin. The statement calls for a serious investigation of the entire fiasco. We need to bring the people and machinery responsible for the purpose to book for the crime against humanity.

We cannot even imagine what would have happened to our people downstream if Teesta-V had not withstood the Tista flood and broken down instead. The combined water of two dams and the GLOF would have destroyed two more dams downstream (TDLP-III and IV) in the Darjeeling hills (Gorkhaland Territorial Administration) of West Bengal inflicting incalculable human tragedy and giving us one of the biggest human disasters in the history of Eastern Himalaya.

Under such a situation, the Tista’s water would have taken with it most of the human settlements downstream of Dikchu. It would have pushed Sevoke forest, a small stretch that separates the Tista and Mahananda Rivers, and joined the Mahananda, washing away a major part of Siliguri City. Historically, the Tista joined the Mahananda River instead of the Brahmaputra. It was only around 1,787 that the Tista changed its course and became a tributary of the Brahmaputra. The geomorphic history of the river is complex and this human failure in its upper catchment invites a detailed examination and investigations.  

Photo: Abir1907/Wikimedia Commons, CC BY-SA 4.0

The breaching of the Teesta-III dam at Chungthang and the damages this has caused brings the focus on the numerous hydropower projects in construction and being planned in the state. Do you think poor dam construction is an issue, as Sikkim’s CM mentioned? More dams are in the works in the Northeast and the eastern Himalaya including Sikkim – such as the upcoming Dibang project in Arunachal Pradesh. How can we have sufficient checks in place so that threats such as GLOFs and others are not ignored?

Scientists, researchers, activists and journalists have been warning about the unplanned and haphazard hydro development in Sikkim-Darjeeling hills for over two decades. The central government, state government and dam development proponents have, however, dismissed the concerns as fear-mongering. They do not take researchers and research papers seriously. Science and policy hardly work in coordination in India. 

It is also interesting to note that the first Human Development Report (HDR) of Sikkim (2001) advises the state to harness the rich water resources of the Sikkim Himalaya. The report further recommends the state government take the help of the private sector towards this end (page 77-84). Strangely, the same report also talks about glacier retreat and glacial lake outburst floods. The State Development Report of Sikkim (2008), takes a similar stand as taken by the 2001 HDR (page 109-119). Both reports cite the success of the Chukha Project of Bhutan as an example for the development of hydro resources in Sikkim.

The Sikkim CM’s reference to the poor construction of the Teesta-III dam is a little far-fetched as any mega development project goes through rigorous approval processes across various statutory bodies before construction actually begins. It seems to me more of a political statement as it is not backed by data and science.

However, dams, including the Teesta-III, are definitely ill-planned without properly internalising the Himalayan specificities and foreseeing the uncertainties. The consequence of ill-planned hydro ventures is before us now. I hope we shall take lessons from this largely human-made disaster and move ahead with caution taking into account the geologic and geomorphic specificities of the region.  

There is now a common voice in the region – no more dams. The voice is further strengthened by the statement of Karma Loday Bhutia, Sikkim’s forest and environment minister, opposing a dam in Chungthang following the Tista disaster. Sikkim should now concentrate on the efficient handling of the already constructed and commissioned hydropower projects instead of venturing into new ones. There should be proper human coordination and an EWS in place to manage its functional dams. The inefficiency and lack of human coordination to handle the current flash flood in the upper Tista catchment has badly exposed Sikkim. A small mistake upstream shall have tremendous human and environmental impacts downstream as it is a common river basin that we share in the Darjeeling hills, North Bengal plains and parts of northwest Bangladesh.  

Photo: Pinakpani/Wikimedia Commons, CC BY-SA 4.0

The Sikkim Himalaya is a geologically fragile and vulnerable system. What are the important steps that need to be taken to ensure that another Teesta-III does not happen in the future?

The entire Himalaya is a fragile resource zone. It is not as strong as it appears to be. Dynamics of change in the region are inextricably intertwined with factors such as climate, geology, fauna, flora, water resources etc. The region experiences various types of geo-environmental/geomorphic processes and, thereby, is prone to a number of natural hazards. Often these hazards assume the form of disaster due to the region’s inherent nature, climatic conditions and lack of adequate disaster preparedness mechanisms consequently inflicting widespread catastrophe and human insecurities. However, more recently, many of the natural processes have been accelerated by unscientific and unsustainable anthropogenic activities including the construction of mega hydropower dams among others.

The state of Sikkim, with one of the highest densities of hydropower projects in the country, needs to evolve a comprehensive regional hydropower policy in view of its unique regional environment, ecological setup and geography. We need to have a sound hydropower policy, adequately taking into account the region’s geological and geomorphic specificities. The mainstreaming of Disaster Risk Reduction (DRR) and climate change with hydropower policy needs to be prioritised.

A contingency plan for disaster management in the event of a disaster for all existing hydro-projects in the area is crucial. The Government of Sikkim has consistently insisted that hydropower projects are harmless. 

Lastly, the mainstreaming of an Environmental Management Plan (EMP), Disaster Risk Reduction (DRR) and climate change in the development processes and projects, particularly in sensitive sectors like hydropower projects, is indispensable for the sustainable development of the region. This becomes important in view of the geo-environmental fragility and socio-cultural vulnerability of the Himalayan landscape. 

The breaching of the dam due to a GLOF event was predicted by several reports and studies; in fact, a newspaper reportedly spoke of this possibility on September 23. Is there a way that such warnings can be heeded in future? What about early warning systems, do we have any in place at all? They seem to be even more crucial now than ever before.

There is no way until dam proponents and the government take the science and scientific findings seriously; ‘take research findings seriously and follow scientific recommendations religiously’ is the only mantra. Politics and economics on dams without adequate precaution will only take us to disaster.  

We have been talking about an early warning system as one of the most important instruments of DRR. That is what the Sendai Framework (2015-30) also emphasises. However, we do not have them in many critical hazard-prone areas like Potentially Dangerous Glacial Lakes. Failure to install an early warning system on time was one of the reasons why the South Lhonak Lake outburst turned into a disaster. 

The Tista has calmed down now. She has reclaimed her lost spaces across much of the upper basin. She did not chase people and their property to destroy them. The Tista has only cleared her path for her smooth flow. She was only clearing her river bed badly encroached upon by human beings. This was what she had done in 1968 and probably will do again in future if we do not stay clear of her path. Hopefully, we shall respect the space and path of the Tista, henceforth. She [Tista is a female, Rangeet (a river in West Sikkim) is male; mythologically they are lovers] just needs respect.

Photo: ISRO

Rebuilding is a tough task, but what are the main aspects that the state and centre would need to keep in mind for this? Local communities bear the most risk and many have been up in arms about the building of such large and small dams in this fragile ecosystem. How can administrations involve locals’ concerns in the location and implementation of such infrastructure projects at a time when we’ve seen a dilution in laws that can protect local people, forests and such landscapes from such activities?

There is a need for a sound and comprehensive hydro policy both in the Union and state governments that takes care of the regional specificities. 

Rebuilding is a difficult task if not impossible. We need to have clear short-, medium- and long-term plans for sustainable reconstruction and rehabilitation. This demands a multidisciplinary approach involving affected people, practitioners, social scientists, policy planners, physical scientists, elected representatives, civil societies, medical and psychological professionals. 

Every big development project talks about participatory planning on paper. However, they do not involve people and their concerns/interests while they are actually planned and implemented. This leads to conflict in the long run and makes the project unsustainable both socio-economically and environmentally. 

We need decentralised and participatory planning of development projects in the true sense.

Courtesy & source- The Wire

https://thewire.in/environment/sikkim-disaster-vimal-khawas-interview-himalaya