Teesta-3 Dam and GLOF
In October 2023, a powerful Glacial Lake Outburst Flood (GLOF) destroyed the Teesta-3 dam on the Teesta River in Sikkim, killing over 100 people and affecting 80,000 in four districts.
The flood was caused by the failure of a moraine at the South Lhonak lake, sending around 50 billion liters of water into the valley, triggering landslides and further devastation downstream.
The dam's hydroelectric power facility was largely intact, but the flood caused widespread destruction, highlighting the vulnerability of the region to such events.
Climate Change Impact
Global warming is accelerating the melting of Himalayan glaciers, resulting in more glacial lakes and increasing the frequency and severity of floods.
Between 2011 and 2024, the number of glacial lakes in the Himalayas grew by 10.8%, and their total surface area increased by 33.7%.
Climate change has also led to the destabilization of geological formations, creating new risks that cannot be fully predicted by traditional rainfall-based models.
The increase in glacial meltwater and debris contributes to higher flood risks, complicating risk assessment and mitigation efforts.
Teesta-3 2.0 Design and Concerns
The new dam design includes stronger concrete, a larger spillway, and an early-warning system for floods, using a "worst-case scenario" model for design.
However, experts express concerns that the new design may not fully address the increased risks due to climate change and the unpredictable nature of GLOFs and other geological instabilities.
The dam’s commercial viability alone is not enough justification for rebuilding, as it could expose people and property to greater risk if stronger or different types of floods occur in the future.
Previous environmental and legal issues with the dam, including concerns over its location in a seismically and landslide-prone area, have raised doubts about its safety.
Social and Economic Resilience
The region’s residents need improved social security measures to help them recover from disasters
A risk assessment framework should be integrated into the dam’s design to ensure that the impacts on local communities are minimized
The decision to rebuild should prioritize the safety of local people, their property, and their livelihoods, and should consider long-term socio-economic impacts rather than just short-term economic gains.
The cost of mitigating risks should be factored into the dam’s energy production tariffs to ensure that the project is sustainable and responsible, without externalizing its environmental and social costs.
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