The Tehri Hydro Development Corporation (THDC) has received a crucial preliminary clearance from the Union Environment Ministry’s Expert Appraisal Committee (EAC) for its proposed 1,200 MW Pumped Hydro Power Project situated near the ecologically significant Malshej Ghat, spanning parts of the Thane and Pune districts of Maharashtra.
During its meeting on November 12, 2025, the Sectoral EAC on river valley and hydroelectric projects approved the Terms of Reference (ToR), which authorises THDC to commence the detailed Environmental Impact Assessment (EIA) studies required for the project.
The preliminary approval is conditional and comes with specific directions, notably requiring THDC to submit comprehensive water utilisation mapping. The project, estimated to cost Rs 6,815 crore, is designed to operate on a closed-loop system, thereby avoiding continuous withdrawal of water from the Kalu River. The project is strategically important to the Centre’s agenda, which is aggressively promoting pumped hydro technology to support national net-zero goals and the target of achieving 500 GW of non-fossil power capacity.
However, the project’s location presents substantial environmental sensitivities. The planned facility lies in the Kalu River valley, known for the picturesque Kalu waterfall and popular monsoon trekking spots. Critically, the directly affected villages, Diwanpada, Sawarne, and Thitabi Tarf Vaishakhare are demarcated as eco-sensitive zones under the Centre’s 2024 draft notification concerning the protection of the Western Ghats. Furthermore, the project site is positioned approximately 3 km from the Kalsubai Harishchandragad Wildlife Sanctuary.
The EAC noted that the proposed plan, which requires approximately 310 hectares of land (including 74 hectares of forest land), could potentially disrupt small feeder streams that flow into the Kalu River. Consequently, the committee mandated that THDC must ensure that no such rivulets or streams are disturbed or negatively impacted during the establishment of the project.
Given that several pumped hydro proposals rely on the Kalu River, the EAC also directed THDC to secure necessary hydrological clearances from both the Central Water Commission and the Maharashtra government before the proposal advances to the next stage of environmental appraisal.
The technical plans include constructing a high rock-filled dam (28–31 metres) for the upper reservoir, with the lower reservoir initially planned to be filled using Kalu River water. Since the entire site falls within the fragile Western Ghats, the EAC will deploy a specialized sub-committee for an on-ground inspection before moving the proposal forward towards the crucial final environmental clearance.
