New Delhi: Lessons not learnt. Till the time of filing of this report, 36 bodies have been recovered following the breach of the Chungthang Dam in Sikkim on Wednesday sparked by a glacial lake outburst flood (GLOF) in the northern part of the state. At least one body has been recovered from river Teesta downstream in Cooch Behar district bordering Bangladesh.
The Chungthang Dam was washed away because of a GLOF from the South Lhonak Lake in northwestern Sikkim. In recent days, the South Lhonak Lake has been building up. Receiving the information about this, the Sikkim government sent a team to drain out the lake. But, since the lake has been building up abnormally, it was very difficult for the team to siphon the water out. Due to the lack of electricity in the area, centrifugal pumps could not be used. The team placed normal suctioning pipes, but these were not enough.
The Indian Space Research Organisation (ISRO) on Wednesday issued a statement based on satellite images taken between September 28 and October 4 of the South Lhonak Lake. It referred to temporal changes in the lake area on September 17, September 28 and October 4.
“It is observed the lake is burst and about 105 hectares has been drained out, which might have created a flash flood downstream,” the ISRO stated. After the lake burst, water came hurtling down from the Himalayan heights of over 17,000 feet to the dam that was built at a height of around 5,500 feet. The velocity of water rushing down can well be imagined. Not surprisingly, the dam burst leading to a flash flood in river Teesta downstream claiming lives and affecting a large number of communities.
Also read: Damages due to flash flood worth thousands of crores of rupees: Sikkim CM
The Chungthang Dam is the biggest hydropower project in Sikkim. It is part of the 1,200 MW Teesta Stage III Hydro Electric Project. The Sikkim government has a little over 60 per cent in the project, which has a valuation of Rs 25,000 crore. The dam is located in the Mangan district in north Sikkim. It was commissioned in February 2017 and started making profits from last year after generating more power than the expected capacity.
It is not that the disaster this week was unexpected. Way back in 2014, Tom Clement, a reporting fellow of the Pulitzer Center, had warned about the dangers the Chungthang Dam posed for the environment and people nearby. “In North Sikkim, two glacier-fed rivers, the Lachung and the Lachen, meet at Chungthang's southern tip to form the Teesta river,” Clement had written. “At this confluence, the Teesta III is under construction, set to start generating power in 2015. At this point the full reservoir will surround Chungthang and the city will become a peninsula. The reservoir level will be five metres below the bridge crossing the Lachen River into Chungthang.”
He went on to predict that a GLOF can be expected to overflow the reservoir surrounding Chungthang. “Rocks and debris that accompany the glacial flooding amplify the destructive force of a GLOF event. In Chungthang, a sudden influx of glacial debris is likely to compromise the flush gates and the discharge capability of the dam,” Clement wrote.
Yet, call it greed or politics, rampant exploitation of the potential water resources in the Himalayas has led to Mother Nature unleashing her fury on the environment and humanity as well. Government estimates suggest that the region has the potential to generate 115,550 MW of power with its installed capacity of 46,850 MW. Till November 2022, the 10 states and two union territories in the Himalayan region had 81 large hydropower projects (above 25 MW) and 26 projects under construction. As many as 320 large projects are in the pipeline, according to the Central Electricity Authority under the Union Ministry of Power.
The Changthang Dam disaster is not the first such case. With the rising number of hydropower projects in the region, disasters linked to these have increased in recent years. In 2012, flooding in the river Assi Ganga damaged the Assi Ganga Hydro Electric Projects (HEPs) 1 and 2. The next year, the Kedarnath floods severely damaged Phata-Byung, Singoli-Bhatwari and Vishnuprayag HEPs. In 2021, a rock and ice avalanche destroyed the Rishi Ganga project and damaged the Vishnugad-Tapovan HEP, leaving over 200 people dead and estimated losses of Rs 1,500 crore.
In December last year, a slope failure occurred at the Urni landslide zone in Kinnaur district of Himachal Pradesh where construction work has been going on at the 1,091 MW Karcham Wangtoo hydroelectric plant. A slope failure is a phenomenon in which a slope collapses abruptly due to weakened self-retainability of the earth under the influence of rainfall or an earthquake. Due to the sudden collapse of a slope, many people fail to escape from it if it occurs near a residential area, thus leading to a higher rate of fatalities.
In Arunachal Pradesh, there have been a series of disasters during the course of the construction of the 2,000 MW Lower Subansiri HEP being built by the National Hydro Power Corporation (NHPC). It is the largest run-of-the-river hydropower project under construction in the country. Student Unions and Civil Societies in the neighbouring state of Assam have been running continuous campaigns against the project warning about the dangers it may pose to people living downstream of river Subansiri, a tributary of the mighty Brahmaputra.
In a paper titled 'Hydropower in the Himalayan Hazardscape: Strategic Ignorance and the Production of Unequal Risk', Amelie Huber of EuroNatur writes that in the Himalayan hydropower sector, the “strategic mobilisation of the ‘unknowns’ about environmental and technological risks is a pervasive practice employed both by state and corporate actors”.
“The Himalayas are naturally hazard-prone,” writes Huber. “As one of the world’s most geologically and seismically active mountain ranges transected by a multitude of steep, fast-flowing, silt-laden rivers, earthquakes, landslides, and floods are recurrent phenomena. Yet, anthropogenic activities including urbanisation, deforestation and infrastructure development have led to an intensification of hazard potential in recent decades.”
In 2008, the National Action Plan on Climate Change (NAPCC) was launched in India by the Prime Minister's Council on Climate Change. Of the eight national missions forming the core of the NAPCC, one is the National Mission for Sustaining the Himalayan Ecosystem (NMSHE). The NMSHE’s mandate is to evolve measures to sustain and safeguard the Himalayan glaciers, mountain ecosystems, biodiversity and wildlife conservation and protection.
But, given the current state of affairs, little heed is being paid to this mandate. A political blame game has come into play for such disasters. The Chungthang Dam disaster is a case in point. Sikkim Chief Minister Prem Singh Tamang has blamed substandard construction for the dam being washed away. In other words, the previous government in the state is to blame. The question is: When will people learn?
