CHENNAI: The proposed Upper Bhavani Pumped Storage Project (PSP) in Nilgiris district has reached a critical regulatory stage after the project authorities shortlisted one alignment from three alternative sites, citing lower forest diversion, reduced ecological risk and better technical feasibility.
The 1,000 MW project, to be developed by NTPC TN Energy Company Limited (NTECL), a joint venture of NTPC Ltd and Tangedco, has now submitted its proposal seeking forest clearance for diversion of 56.35 ha of forest land, following detailed comparative studies of three possible project configurations.
According to documents placed before the union environment ministry, NTECL evaluated the alternatives based on parameters such as tunnel length, forest land involvement, proximity to protected areas, muck generation, water availability, resettlement impacts and overall project cost. All three options relied on existing reservoirs, Upper Bhavani as the upper pond and the Avalanche-Emerald system as the lower pond, eliminating the need for new submergence.
Alternative 1, which involved a shorter aerial distance from Mukurthi National Park, was rejected primarily due to limited year-round water availability, higher muck generation and increased seepage risks from natural streams. Alternative 3, while technically feasible, would have required diversion of a larger forest area and passed through sensitive shola forest patches, besides affecting Toda tribal settlements.
Alternative 2, eventually selected, was assessed as offering the “best balance” between engineering feasibility, cost and environmental impact. It involves 56.35 ha of forest land, the lowest among the three options studied, and a 7.68-km water conductor system, which project proponents say reduces head loss and construction complexity. The tunnel alignment largely passes through stable hillside rock, lowering geological and seepage risks.
Officials say the selection of Alternative 2 also reduced the estimated muck generation to 38 lakh cubic metres, lower than other two, and avoided direct impacts on shola forests.
Following this selection, NTECL submitted the forest diversion proposal to TN’s Project Screening Committee, which examined the component-wise land requirement and sought clarifications related to mapping, geo-referencing and compensatory afforestation. The nearest project component under the selected alignment is located 987.79 m from Mukurthi Park, placing the project within the zone requiring wildlife clearance scrutiny.
The project has since applied for recommendations from the Standing Committee of the National Board for Wildlife and received Terms of Reference from the union environment ministry for conducting an EIA. While proponents argue that the alternative-site analysis shows a conscious effort to reduce ecological harm, conservationists are cautious as even the “least-impact” option still involves forest diversion in the fragile Nilgiris landscape.