Why Teesta III Dam Reconstruction in Sikkim Sparks Environmental and Safety Concerns
Advertising
The Central government seems to have prioritised corporate interests over public safety in recommending environmental clearance to rebuild the Teesta III Hydroelectric Power Project in Sikkim. This 1,200 megawatt dam was washed away in a devastating glacial flood in October 2023, killing at least 55 people and displacing 10,000 others. The nod to rebuild it comes months after the Indian subsidiary of a Mauritius-incorporated renewable energy holding company acquired majority stake in the project from the Sikkim government.
Advertising
Despite the loss of lives and livelihoods caused by the October 2023 flooding, an expert review body under the Union Ministry of Environment, Forest and Climate Change (MoEFCC) decided to forgo public consultation before recommending the revival of the dam. In a meeting held on January 10, 2025, the MoEFCC’s Expert Appraisal Committee (EAC) for river valley and hydroelectric projects chose to rely on the proceedings of public consultations held nearly 20 years ago to give its green signal for a new dam.
The minutes of the EAC meeting state: “The EAC felt no requirement of fresh public hearing as there is no involvement of additional land and other R&R [Rehabilitation and Resettlement] issues; moreover, PP [project proponent] has already conducted public hearing before grant of earlier Environmental Clearance on 4.08.2006.”
Advertising
The expert panel recommended the clearance even as a case challenging the decision of the Sikkim government to divest its stake in the project is pending in the Sikkim High Court. In February 2024, less than six months after the disaster, the Sikkim government sold its 60.08 per cent stake in Sikkim Urja Ltd, the holding company of the Teesta III project, to its minority partner, Greenko Energies Private Ltd. Incorporated in Hyderabad, Greenko Energies Private Ltd is a wholly owned subsidiary of Greenko Mauritius. In May 2024, the Competition Commission of India, a statutory body under the Ministry of Corporate Affairs that regulates and ensures fair business practices in the Indian economy, approved Greenko’s acquisition of additional shares in Sikkim Urja Ltd.
A case is also pending in the National Green Tribunal (NGT), the country’s premier environment court, on the environmental implications of the lake breach that destroyed the Teesta III dam. The NGT took up the case suo motu on the basis of media reports of the incident. The project proponent has estimated that it would cost Rs.4,189.51 crore to revive the project.
Reservations over rebuilding
A PIL petition challenging the disinvestment was filed in Sikkim High Court by Mani Kumar Subba, a local political leader, who was earlier a member of the Sikkim Democratic Front. In December 2024, the High Court turned down a demand by the petitioner to implead the MoEFCC, amongst other organisations and agencies, in the case. Subba had asked the court to issue directions to the MoEFCC to submit a copy of the impact assessment report, if any, of the devastation caused to the dam in the glacial flood of October 2023.
Advertising
However, the High Court turned down his demand on the grounds that the MoEFCC had no role to play in the disinvestment process. In an order issued on December 12, 2024, a Division Bench comprising Chief Justice Biswanath Somadder and Judge Meenakshi Madan Rai said: “… this Court is of the view that none of the parties/authorities whom the applicant/writ petitioner is seeking to implead as respondents had any role to play while a decision was taken by the State Cabinet in its meeting held on 3rd February, 2024, for disinvestment of the entire stake, i.e. 60.08 [%] equity shares…”
A source close to the petitioner told this correspondent that Subba is yet to challenge the High Court’s December 12 order. Apart from the MoEFCC, Subba also wanted to implead the Comptroller and Auditor General of India, the National Institute of Disaster Management, the Land Revenue and Disaster Management Department, the Forest and Environment Department (government of Sikkim), the Central Water Commission (CWC), and the Central Electricity Authority (CEA).
Advertising
Flash floods in the Teesta in Lachen valley, north Sikkim on October 4, 2023.
| Photo Credit:
PTI
Advertising
The Teesta III project was commissioned in February 2017 at a cost of Rs.13,965 crore. It was operational until the night of October 3-4, 2023, when water from a flash flood in a glacial lake in the upper reaches of the mountains washed away the dam and flooded the underground powerhouse.
According to the application filed with the MoEFCC for reconstructing the dam, the project proponent has decided to change its design from “a concrete gravity dam” to a “concrete faced rockfill dam”, which, it claims, “is a much more resilient structure minimising the chance of dam failure due to overtopping”. The minutes of the January 10 meeting record that the project proponent claimed that there was “a just case” to restore the project and bring it back into operation. They state: “The underground powerhouse and electro-mechanical equipment can be restored to their original condition in about 10-12 months. The water conductor system is mostly unaffected in the flash flood, hence, other than the dam most of the components can be restored in a year’s time. As most of the components would be ready in a year, there is a case for restoring the dam and bringing back the Project in operation at the earliest for which EC amendment is requested.”
Advertising
The MoEFCC’s review panel had earlier expressed serious reservations about rebuilding the dam. In a meeting held on November 30, 2024, the MoEFCC expressed concerns regarding the dam’s design and stability and “its ability to withstand potential natural disasters in the future”. It emphasised the need for a thorough review of the modifications proposed to the dam to ensure the “structural resilience and safety of the dam” in light of the region’s susceptibility to extreme hydrological events. It recommended consultations with the CEA, India’s apex agency for policy formulation and planning in the power sector, on the proposed modifications. Further, a site visit of Teesta III was conducted by an expert panel constituted by the EAC between December 26-28, 2024. On the basis of the expert panel’s site inspection report, the project proponent was directed by the EAC to incorporate certain measures during the construction and operation stages of the project to enhance dam safety parameters.
The minutes also state that a comprehensive study has been carried out to identify potential threats to the dam from glacial lakes in the upper reaches. As part of this study, as many as 119 glacial lakes were identified in the catchment area of the dam, out of which 50 lakes with an area of 10 hectares or more were shortlisted for further evaluation. The study focussed on 13 potentially dangerous lakes on the basis of parameters such as their water spread areas (40 hectares or more), volumes, and distance from the project site.
‘Hasty’ clearance
Advertising
The project proponent has reportedly taken into consideration the worst-case scenario of a simultaneous breach of two of these lakes, in which the highest volume outflow was projected at 12,946 cubic metres a second, and added this capacity to the probable maximum flood level to decide the dam’s spillway (structure to allow safe passage of excess water from the reservoir) capacity. Further, the project proponent has also said that it will coordinate with the Central and State disaster management authorities to procure information pertaining to the monitoring of the lakes.
The environmental activist Himanshu Thakkar termed the recommendation for environmental clearance as “hasty” on the grounds that the proposed rebuilding project is yet to be ratified by the CWC, the country’s apex body for controlling and regulating water resources, and the CEA. Speaking to Frontline, Thakkar, who is the coordinator of the South Asia Network on Dams, Rivers and People, an informal network of organisations and individuals working on issues related to the water sector, said: “The spillway capacity of the reservoir can be determined only after finalising the probable maximum flood level. This level has not yet been decided upon. The greater the capacity of the spillway, the more impact it will have on the ecology and environment of the areas downstream of the dam.”
“The threat of disaster persists at the dam site. There are also cascading & multiplying effects on habitations downstream.”Jairam RameshFormer Union Minister for Environment
Thakkar added that the destruction caused in the October 2023 floods was owing to shortcomings in environmental impact assessment reports in the past that did not foresee a glacial flood of this nature. He said: “Moreover, the rebuilding project should be considered as a fresh project considering the change in height and type of the proposed dam, its construction method, the massive change in spillway capacity, and the changes in upstream and downstream conditions, including glaciers, glacier lakes, and their threats. The project requires a new environment impact assessment study and a new environment management plan, including a fresh public consultation process, given the massive impact of the October 2023 flood on the lives of local people.”
Advertising
According to the rebuilding proposal, the catchment area of the dam (2,786.7 square kilometres) and the probable maximum flood limit (7,000 cubic metres a second) remain unchanged, while the maximum height of the dam has been increased from 60 metres from the riverbed level to “118.64 metres from the deepest foundation level” and the total length of the dam at the top has been reduced from 298 metres to 279.65 metres.
Thakkar pointed out that no cognisance whatsoever had been taken of a report that was prepared in the wake of the October 2023 disaster by the National Committee on Dam Safety, a panel constituted under the National Dam Safety Act, 2021, to prevent disasters related to dam failure and maintain standards of dam safety.
Political slugfest
Meanwhile, a political slugfest has broken out over the project’s clearance, with several parties alleging that the recommendation was granted by the MoEFCC in haste without considering the ground realities of the people who stand to be affected and bypassing considerations to determine the future safety of the dam.
On February 2, D.R. Thapa, president of the Sikkim unit of the BJP, wrote to Prime Minister Narendra Modi demanding that environmental clearance for the dam be kept in abeyance until a decision based on “latest scientific data, risk assessments and inclusive public participation” could be taken. As Thapa pointed out in the letter: “A fresh public hearing was not conducted, and instead an outdated consultation from 2006 has been used to justify the clearance—this is completely out of sync with present realities.”
A temporary bamboo bridge being constructed at Chungthang, connecting it to Pegong, on October 8, 2023, days after a flash flood in Mangan district, Sikkim.
| Photo Credit:
PTI
Thapa noted that a revised maximum flood study is pending, and the new dam’s structural safety and design have not been fully approved by the Geological Survey of India, the CWC, and the Central Soil and Materials Research Station. He alleged that the risk assessment of upstream glacial lakes is inadequate, with no clarity on whether the most vulnerable lakes have been accurately identified.
At the time of filing this story, there was no response to an email sent to the MoEFCC requesting clarity on these allegations.
Opposition parties have also criticised the EAC recommendation. Three days after Thapa’s letter, Jairam Ramesh, former Minister for Environment in the UPA government and the Congress’ general secretary, tweeted that it was a “thoughtless clearance” and that “the threat of disaster persists at the dam site. There are also cascading & multiplying effects on habitations downstream.”
Also Read | Dammed in the Himalayas
The Congress issued a detailed statement on the perils of mindless construction of dams along the course of the Teesta following another landslide incident on August 20, 2024, that caused major damage to the Teesta V project. This project, downstream of the Teesta III project, belongs to the public sector NHPC Ltd. In a statement dated August 24, 2024, the Congress stated: “These natural disasters, like the October 2023 catastrophe and the recent landslides, have become commonplace due to ecological destruction and unplanned constructions.… Aside from this environmental catastrophe in the making, these projects have also been undertaken without local communities in mind. The people of Sikkim and Kalimpong [this district in West Bengal was also affected by the October 2023 floods] have not gained from the hydro projects in terms of employment, share in power, or revenue generation.”
Barely a few days after the recommendation of the environmental clearance, a research article was published in the journal Science highlighting the need for a paradigm shift in glacial lake outburst flood risk-management strategies in Himalayan and other mountain environments against the backdrop of the Teesta III disaster of October 2023. It said: “The physical scale and human and economic impact of this event prompts urgent reflection on the role of climate change and human activities in exacerbating such disasters.”
Ayaskant Das is an independent journalist and writer based in the National Capital Region.
The Central government seems to have prioritised corporate interests over public safety in recommending environmental clearance to rebuild the Teesta III Hydroelectric Power Project in Sikkim. This 1,200 megawatt dam was washed away in a devastating glacial flood in October 2023, killing at least 55 people and displacing 10,000 others. The nod to rebuild it comes months after the Indian subsidiary of a Mauritius-incorporated renewable energy holding company acquired majority stake in the project from the Sikkim government.
Despite the loss of lives and livelihoods caused by the October 2023 flooding, an expert review body under the Union Ministry of Environment, Forest and Climate Change (MoEFCC) decided to forgo public consultation before recommending the revival of the dam. In a meeting held on January 10, 2025, the MoEFCC’s Expert Appraisal Committee (EAC) for river valley and hydroelectric projects chose to rely on the proceedings of public consultations held nearly 20 years ago to give its green signal for a new dam.
The minutes of the EAC meeting state: “The EAC felt no requirement of fresh public hearing as there is no involvement of additional land and other R&R [Rehabilitation and Resettlement] issues; moreover, PP [project proponent] has already conducted public hearing before grant of earlier Environmental Clearance on 4.08.2006.”
The expert panel recommended the clearance even as a case challenging the decision of the Sikkim government to divest its stake in the project is pending in the Sikkim High Court. In February 2024, less than six months after the disaster, the Sikkim government sold its 60.08 per cent stake in Sikkim Urja Ltd, the holding company of the Teesta III project, to its minority partner, Greenko Energies Private Ltd. Incorporated in Hyderabad, Greenko Energies Private Ltd is a wholly owned subsidiary of Greenko Mauritius. In May 2024, the Competition Commission of India, a statutory body under the Ministry of Corporate Affairs that regulates and ensures fair business practices in the Indian economy, approved Greenko’s acquisition of additional shares in Sikkim Urja Ltd.
A case is also pending in the National Green Tribunal (NGT), the country’s premier environment court, on the environmental implications of the lake breach that destroyed the Teesta III dam. The NGT took up the case suo motu on the basis of media reports of the incident. The project proponent has estimated that it would cost Rs.4,189.51 crore to revive the project.
Reservations over rebuilding
A PIL petition challenging the disinvestment was filed in Sikkim High Court by Mani Kumar Subba, a local political leader, who was earlier a member of the Sikkim Democratic Front. In December 2024, the High Court turned down a demand by the petitioner to implead the MoEFCC, amongst other organisations and agencies, in the case. Subba had asked the court to issue directions to the MoEFCC to submit a copy of the impact assessment report, if any, of the devastation caused to the dam in the glacial flood of October 2023.
However, the High Court turned down his demand on the grounds that the MoEFCC had no role to play in the disinvestment process. In an order issued on December 12, 2024, a Division Bench comprising Chief Justice Biswanath Somadder and Judge Meenakshi Madan Rai said: “… this Court is of the view that none of the parties/authorities whom the applicant/writ petitioner is seeking to implead as respondents had any role to play while a decision was taken by the State Cabinet in its meeting held on 3rd February, 2024, for disinvestment of the entire stake, i.e. 60.08 [%] equity shares…”
A source close to the petitioner told this correspondent that Subba is yet to challenge the High Court’s December 12 order. Apart from the MoEFCC, Subba also wanted to implead the Comptroller and Auditor General of India, the National Institute of Disaster Management, the Land Revenue and Disaster Management Department, the Forest and Environment Department (government of Sikkim), the Central Water Commission (CWC), and the Central Electricity Authority (CEA).
Flash floods in the Teesta in Lachen valley, north Sikkim on October 4, 2023.
| Photo Credit:
PTI
The Teesta III project was commissioned in February 2017 at a cost of Rs.13,965 crore. It was operational until the night of October 3-4, 2023, when water from a flash flood in a glacial lake in the upper reaches of the mountains washed away the dam and flooded the underground powerhouse.
According to the application filed with the MoEFCC for reconstructing the dam, the project proponent has decided to change its design from “a concrete gravity dam” to a “concrete faced rockfill dam”, which, it claims, “is a much more resilient structure minimising the chance of dam failure due to overtopping”. The minutes of the January 10 meeting record that the project proponent claimed that there was “a just case” to restore the project and bring it back into operation. They state: “The underground powerhouse and electro-mechanical equipment can be restored to their original condition in about 10-12 months. The water conductor system is mostly unaffected in the flash flood, hence, other than the dam most of the components can be restored in a year’s time. As most of the components would be ready in a year, there is a case for restoring the dam and bringing back the Project in operation at the earliest for which EC amendment is requested.”
The MoEFCC’s review panel had earlier expressed serious reservations about rebuilding the dam. In a meeting held on November 30, 2024, the MoEFCC expressed concerns regarding the dam’s design and stability and “its ability to withstand potential natural disasters in the future”. It emphasised the need for a thorough review of the modifications proposed to the dam to ensure the “structural resilience and safety of the dam” in light of the region’s susceptibility to extreme hydrological events. It recommended consultations with the CEA, India’s apex agency for policy formulation and planning in the power sector, on the proposed modifications. Further, a site visit of Teesta III was conducted by an expert panel constituted by the EAC between December 26-28, 2024. On the basis of the expert panel’s site inspection report, the project proponent was directed by the EAC to incorporate certain measures during the construction and operation stages of the project to enhance dam safety parameters.
The minutes also state that a comprehensive study has been carried out to identify potential threats to the dam from glacial lakes in the upper reaches. As part of this study, as many as 119 glacial lakes were identified in the catchment area of the dam, out of which 50 lakes with an area of 10 hectares or more were shortlisted for further evaluation. The study focussed on 13 potentially dangerous lakes on the basis of parameters such as their water spread areas (40 hectares or more), volumes, and distance from the project site.
‘Hasty’ clearance
The project proponent has reportedly taken into consideration the worst-case scenario of a simultaneous breach of two of these lakes, in which the highest volume outflow was projected at 12,946 cubic metres a second, and added this capacity to the probable maximum flood level to decide the dam’s spillway (structure to allow safe passage of excess water from the reservoir) capacity. Further, the project proponent has also said that it will coordinate with the Central and State disaster management authorities to procure information pertaining to the monitoring of the lakes.
The environmental activist Himanshu Thakkar termed the recommendation for environmental clearance as “hasty” on the grounds that the proposed rebuilding project is yet to be ratified by the CWC, the country’s apex body for controlling and regulating water resources, and the CEA. Speaking to Frontline, Thakkar, who is the coordinator of the South Asia Network on Dams, Rivers and People, an informal network of organisations and individuals working on issues related to the water sector, said: “The spillway capacity of the reservoir can be determined only after finalising the probable maximum flood level. This level has not yet been decided upon. The greater the capacity of the spillway, the more impact it will have on the ecology and environment of the areas downstream of the dam.”
“The threat of disaster persists at the dam site. There are also cascading & multiplying effects on habitations downstream.”Jairam RameshFormer Union Minister for Environment
Thakkar added that the destruction caused in the October 2023 floods was owing to shortcomings in environmental impact assessment reports in the past that did not foresee a glacial flood of this nature. He said: “Moreover, the rebuilding project should be considered as a fresh project considering the change in height and type of the proposed dam, its construction method, the massive change in spillway capacity, and the changes in upstream and downstream conditions, including glaciers, glacier lakes, and their threats. The project requires a new environment impact assessment study and a new environment management plan, including a fresh public consultation process, given the massive impact of the October 2023 flood on the lives of local people.”
According to the rebuilding proposal, the catchment area of the dam (2,786.7 square kilometres) and the probable maximum flood limit (7,000 cubic metres a second) remain unchanged, while the maximum height of the dam has been increased from 60 metres from the riverbed level to “118.64 metres from the deepest foundation level” and the total length of the dam at the top has been reduced from 298 metres to 279.65 metres.
Thakkar pointed out that no cognisance whatsoever had been taken of a report that was prepared in the wake of the October 2023 disaster by the National Committee on Dam Safety, a panel constituted under the National Dam Safety Act, 2021, to prevent disasters related to dam failure and maintain standards of dam safety.
Political slugfest
Meanwhile, a political slugfest has broken out over the project’s clearance, with several parties alleging that the recommendation was granted by the MoEFCC in haste without considering the ground realities of the people who stand to be affected and bypassing considerations to determine the future safety of the dam.
On February 2, D.R. Thapa, president of the Sikkim unit of the BJP, wrote to Prime Minister Narendra Modi demanding that environmental clearance for the dam be kept in abeyance until a decision based on “latest scientific data, risk assessments and inclusive public participation” could be taken. As Thapa pointed out in the letter: “A fresh public hearing was not conducted, and instead an outdated consultation from 2006 has been used to justify the clearance—this is completely out of sync with present realities.”
A temporary bamboo bridge being constructed at Chungthang, connecting it to Pegong, on October 8, 2023, days after a flash flood in Mangan district, Sikkim.
| Photo Credit:
PTI
Thapa noted that a revised maximum flood study is pending, and the new dam’s structural safety and design have not been fully approved by the Geological Survey of India, the CWC, and the Central Soil and Materials Research Station. He alleged that the risk assessment of upstream glacial lakes is inadequate, with no clarity on whether the most vulnerable lakes have been accurately identified.
At the time of filing this story, there was no response to an email sent to the MoEFCC requesting clarity on these allegations.
Opposition parties have also criticised the EAC recommendation. Three days after Thapa’s letter, Jairam Ramesh, former Minister for Environment in the UPA government and the Congress’ general secretary, tweeted that it was a “thoughtless clearance” and that “the threat of disaster persists at the dam site. There are also cascading & multiplying effects on habitations downstream.”
Also Read | Dammed in the Himalayas
The Congress issued a detailed statement on the perils of mindless construction of dams along the course of the Teesta following another landslide incident on August 20, 2024, that caused major damage to the Teesta V project. This project, downstream of the Teesta III project, belongs to the public sector NHPC Ltd. In a statement dated August 24, 2024, the Congress stated: “These natural disasters, like the October 2023 catastrophe and the recent landslides, have become commonplace due to ecological destruction and unplanned constructions.… Aside from this environmental catastrophe in the making, these projects have also been undertaken without local communities in mind. The people of Sikkim and Kalimpong [this district in West Bengal was also affected by the October 2023 floods] have not gained from the hydro projects in terms of employment, share in power, or revenue generation.”
Barely a few days after the recommendation of the environmental clearance, a research article was published in the journal Science highlighting the need for a paradigm shift in glacial lake outburst flood risk-management strategies in Himalayan and other mountain environments against the backdrop of the Teesta III disaster of October 2023. It said: “The physical scale and human and economic impact of this event prompts urgent reflection on the role of climate change and human activities in exacerbating such disasters.”
Ayaskant Das is an independent journalist and writer based in the National Capital Region.
