Express View on Teesta dam: Safety first 

On October 2023, a glacial flood ravaged four districts of Sikkim, killing more than 40 people and washing away a 60-metre-high dam of the Teesta III hydel power project. Less than 15 months later, the environment ministry’s expert appraisal committee (EAC) has cleared a proposal to construct a 118-metre high dam in its place. The panel’s decision raises questions because the design of the new structure has not been cleared by the Central Water Commission, the Geological Survey and Central Soil and Materials Research Station. A public hearing has not been held to make sure the project addresses the concerns of local people. It’s particularly disquieting that the EAC has allowed the dam’s construction before its own safety-related questions were addressed. As reported by this newspaper, the EAC was not convinced of the structure’s ability to withstand the force of flood waters. The project does not seem to have adequately factored in threats from overflowing glacial lakes.

Teesta III is part of a mega hydel power push in the Eastern Himalayas that was envisaged more than two decades ago. The project has been dogged by ecological and safety-related concerns. Hydrologists and other experts have questioned the infrastructure push in a region prone to earthquakes, landslides and climate change-related disasters. A section of the local population has opposed the project because its construction involves alteration and destruction of parts of mountains, forests and a flowing river. However, authorities in charge of the projects do not appear to have always paid heed to these issues. In 2014, for instance, the National Hydropower Corporation told the National Green Tribunal that Teesta III faced no threats from glacial lake overflows. The project took more than 12 years to construct, exceeding its budget more than two-and-a-half times. It came apart in October 2023, proving the power corporation wrong. A year later, a landslide caused a loss of more than Rs 300-crore to another project on the Teesta River — thankfully no lives were lost.

Infrastructure projects in the mountains — dams, bridges, buildings, highways — must be subjected to stringent safety measures. The bar must be set particularly high for structures close to rivers or other water bodies. As the 2023 flood underlined, dams are the first to be hit when glacial lakes overflow. A growing body of scholarship shows that climate change-driven ice mass loss is exacerbating the threat of glacial lake floods. The environment ministry must, therefore, not be hasty in going ahead with its committee’s latest recommendation on Teesta III. No effort must be spared to ensure that the disaster of 2023 is not repeated.