Teesta-3 Dam Proposal and Environmental Concerns
In January 2025, an expert committee under the Ministry of Environment, Forests and Climate Change recommended rebuilding the Teesta-3 dam on the Teesta River in Sikkim. The dam had been destroyed in October 2023 by a glacial lake outburst flood (GLOF) from the South Lhonak lake, which resulted in significant casualties and damage.
Background and Impact of the GLOF
- The GLOF led to over 100 deaths and affected more than 80,000 people in four districts.
- The disaster was triggered by a slope failure that destabilized a moraine, leading to a massive water spill.
- Satellite data indicated approximately 50 billion litres of water were released, causing downstream landslides.
Environmental and Climatic Concerns
- Global warming and black carbon are accelerating Himalayan glacier melting, forming new lakes and increasing risk.
- The Central Water Commission reported a 10.8% increase in glacial lakes and a 33.7% rise in their surface area from 2011 to 2024.
- Environmentalists express concerns about the dam's location in an earthquake and landslide-prone area, and issues related to its techno-economic and green clearance.
Rebuilding Proposal and Criticism
- The proposal includes building Teesta-3 2.0 with concrete and a larger spillway, based on a "worst-case scenario" rain model.
- Critics argue that focusing solely on rainfall ignores other risk factors like geological instability and atmospheric soot.
- Experts questioned the causal link between heavy rain and the 2023 GLOF, noting insufficient local rainfall records.
Social and Economic Considerations
- Commercial viability of Teesta-3 pre-GLOF highlights India's growing power demand.
- The dam's reconstruction should prioritize minimizing risks to local communities and enhancing socio-economic resilience.
- Professor Brian Stone, Jr. argues that engineering solutions cannot fully address climate change, suggesting retreat as necessary.
Recommendations for Future Actions
- Develop a framework prioritizing risk minimization and socio-economic resilience.
- Include costs of risk management in hydroelectric power tariffs, ensuring sustainability.