Recently an expert committee constituted by the Ministry of Environment, Forests and Climate Change recommended a proposal to rebuild the Teesta-3 dam on the Teesta river in Sikkim

Climate Change and Glacier Melting 

• Global Warming: Global warming is accelerating glacier melting. 
• Impact of Black Carbon: Black Carbon (soot) particles speed up melting. 
• Increase in Glacial Lakes: Glacial lakes have increased by 33.7% from 2011 to 2024. 
• Expansion: South Lhonak lake expanded from the 1960s to 167 hectares in 2023.

Key Issues in Teesta-3 Dam Reconstruction

• Pre-Disaster Viability: The dam was considered commercially viable before the disaster. 
• Risk Factors: Concerns include earthquake and landslide risks. 
• Regulatory Issues: Non-compliance with regulations and alleged corruption. 
• Environmental Concerns: Environmentalists question the safety of large hydro projects in the Himalayas.

Proposed Design of Teesta-3 2.0

• Construction Material: Constructed using only concrete (no rocks). 
• Enhanced Spillway Capacity: The spillway (water release system) will be three times larger. 
• Safety Measures: An early-warning system will be installed. 
• Climate Resilience: Based on ‘worst-case scenario’ rainfall predictions by IMD.

Safety of New Design

• Unpredictability: Climate change is unpredictable, and floods may differ from past events. 
• Limitations of Rainfall-Based Modeling:  Experts argue that rainfall-based modeling is unreliable. Sediment transport, erosion, and riverbed changes are not fully accounted for. 
• Risk of Stronger Floods: If a more intense flood occurs, damage could be even worse.

Expert Opinions and Concerns

• Flaws: IIT Bhubaneswar, IISc Bangalore, and ITBP studies highlight flaws in GLOF modeling. 
• Challenges in Climate Predictions: Climate models struggle to predict extreme rainfall accurately.
• Limitations of Engineering Solutions: US experts argue, “Engineering cannot solve climate change; retreat is inevitable.”
• Need for Risk-Focused Decision-Making: Priority should be risk mitigation, not just economic viability.

Possible Solutions

• Shifting Focus: Shift focus to small-scale hydro projects with less risk.
• Strengthen Early Warning Systems: Improve early warning and monitoring systems.
• River Basin Management: Implement effective river basin management. 
• Disaster-resilient infrastructure: Build disaster-resilient infrastructure. 
• Risk Assessment: Develop a clear risk assessment framework with safety thresholds

Conclusion

The Teesta-3 case is a critical lesson in environmental governance.  Infrastructure projects should prioritize safety over profit.  Climate change makes disaster risks unpredictable and severe.  A balanced approach is needed – economic growth with sustainability.

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