Green Nod Granted for Teesta Project Restoration After 2023 Flash Floods
The Teesta Hydroelectric Project Stage-III in Sikkim, a critical source of hydroelectric power, has been given conditional green clearance to begin restoration work after devastating flash floods triggered by a glacial lake outburst in October 2023. The approval, granted by the environment ministry’s expert panel on January 10, marks a significant step toward the revival of the 1,200 MW project, which has been out of operation since the disaster.
The 2023 flash floods caused widespread damage to the project’s infrastructure, including the destruction of the dam and flooding of the underground powerhouse, which halted operations. The impact of the disaster left much of the underground electro-mechanical equipment damaged, requiring extensive restoration work. Despite the setbacks, the project developers, Sikkim Urja Ltd (SUL), have received a green light to proceed with the necessary repairs and upgrades. One of the key updates in the restoration process is the redesign of the dam. The original plan called for a ‘concrete faced rockfill dam,’ but due to concerns about the structure’s stability, particularly after the devastating flash floods, the project developers have now opted for a ‘concrete gravity dam.’ This design change is aimed at increasing the dam’s resilience and reducing the risk of failure due to over-topping, which was a major concern raised during the approval process. The project developers have made it clear that, in addition to the redesign, they will implement several other safety measures to ensure the project’s ability to withstand future natural disasters. These include enhancing the dam’s spillway capacity and installing an early warning system.
SUL has also conducted a comprehensive study of the region’s vulnerability to glacial lake outbursts, which was one of the key observations made by the environment panel in their review of the project’s modifications. In granting approval for the restoration, the expert panel imposed several conditions, most notably the requirement for all necessary permissions from the Central Electricity Authority (CEA), the Central Water Commission (CWC), and other relevant agencies regarding the project’s design and safety parameters. These measures are essential to ensure that the revised design meets the highest standards of safety and environmental compliance before construction work can recommence. The project’s location in Mangan district of Sikkim, which is prone to extreme hydrological events, makes it critical to ensure that the infrastructure is designed to withstand the region’s unpredictable weather patterns. The panel’s review emphasised the need for a thorough evaluation of the dam’s structural integrity, especially given the potential threats from glacial lakes that have been identified in the area.
Although much of the underground infrastructure and electro-mechanical equipment can be restored within the next 10 to 12 months, the clearance amendment aims to expedite the restoration process and avoid further delays. With the green clearance in place, SUL is hopeful that the project will be up and running again soon, continuing its role in providing much-needed electricity to the region. The Teesta Project was originally commissioned in February 2017 and had been operating successfully until the flash floods disrupted its operations in 2023. The restoration of the project is crucial not only for power generation but also for the local economy and the livelihoods of people dependent on the region’s hydroelectric capabilities.
The Teesta Hydroelectric Project’s restoration is a significant step toward ensuring that critical infrastructure in flood-prone regions is designed with resilience and sustainability in mind. The development serves as a reminder of the challenges faced by infrastructure projects in areas vulnerable to extreme weather events and the importance of implementing design changes that address these risks. The progress of this project will be closely watched, as it sets a precedent for other infrastructure projects in similar regions. As the restoration work begins, officials and stakeholders are optimistic that the improvements will not only increase the safety of the project but also contribute to the sustainable development of the region’s energy infrastructure.
