| PYQ Relevance[UPSC 2016] The Himalayas are highly prone to landslides. Discuss the causes and suggest suitable measures of mitigation. Linkage: The PYQ examines the geological fragility of the Himalayas and the need for mitigation measures while undertaking developmental activities. The Teesta-VI blast highlights that infrastructure projects in the young and unstable Himalayan geology require rigorous geological investigations, continuous hazard monitoring, and strict compliance with environmental clearance conditions. |
Mentor’s Comment
An explosion triggered by trapped methane in an NHPC (formerly National Hydroelectric Power Corporation) Limited tunnel at the Teesta Stage-VI hydroelectric project in Sikkim has killed at least 15 workers. What remains unresolved is not whether the hazard existed, but whether the environmental clearance conditions meant to guard against it were ever verified in practice.
Why was gas in the Teesta-VI tunnel foreseeable rather than a surprise?
- Geological setting: The Teesta basin sits in a seismically active zone with young, heavily fractured rock capable of trapping compressed gas pockets laid down long ago.
- Known hazard type: Methane is a well-recognised hazard in underground excavation generally, not specific to this project.
- The real open question: What is unresolved is not whether gas could exist, but whether its risk was assessed and modelled during project planning, and whether detection and ventilation safeguards were functioning.
What does the region’s recent history of underground disasters show?
- Meghalaya, February 2026: An explosion at an illegal coal mine killed about 30 workers.
- Uttarakhand, 2023: A road tunnel under construction collapsed, trapping 41 workers for 17 days before rescue.
- South Lhonak lake, October 2023: A glacial lake outburst flood destroyed the Teesta-III dam and killed more than 100 people downstream.
- Pattern, not exception: Together, these episodes show underground and Himalayan infrastructure work carries recurring risk, not isolated misfortune.
What complicates accountability for Teesta-VI specifically?
- Change of developer: Teesta-VI was absorbed by the public-sector NHPC Limited after its original private developer, unable to afford escalating costs, went into insolvency.
- Carried-over clearance conditions: A change in developer partway through a project raises the question of whether environmental-clearance conditions were re-verified under the new operator.
- Internal inquiry is not an oversight: NHPC has announced its own investigation, but an internal inquiry by the project operator is not a substitute for independent verification of clearance compliance.
What must happen once the emergency response ends?
- Immediate priority: Relief and rescue for workers still trapped must remain the first priority.
- No isolated-incident framing: The government must not treat the disaster as an isolated misfortune once the emergency passes.
- Independent review required: An independent review is needed to verify whether the environmental clearance conditions attached to Teesta-VI were strictly met in practice, not merely granted on paper.
Conclusion
The Teesta-VI blast is the latest in a pattern of underground and Himalayan project disasters recurring because environmental clearance compliance is not independently verified after approval. Once relief operations conclude, the government must order an independent review of whether the clearance conditions attached to Teesta-VI, and comparable Himalayan hydropower projects, were actually met in practice.