As India moves closer to commissioning its largest hydroelectric project on the Assam&ndash;Arunachal border, wildlife experts are sounding urgent alarms over the fate of one of the Northeast&rsquo;s most critical elephant corridors. The 2,000 MW Subansiri Lower Hydroelectric Project, built by NHPC, recently achieved test synchronisation with the national grid, a milestone for the country&rsquo;s renewable energy ambitions but conservation scientists warn the celebration may overshadow a looming ecological crisis.
For nearly two years, the Wildlife Institute of India (WII) has cautioned that the project&rsquo;s powerful, sudden water releases known as hydro-peaking, could &ldquo;wash away&rdquo; elephants, especially calves, as they attempt to cross the Subansiri river. These unpredictable water surges, which can raise the river by up to two metres within minutes, threaten to sever what WII describes as &ldquo;an extremely crucial link&rdquo; connecting elephant habitats across the Himalayan foothills. Repeated disruptions, the institute warns, could trigger long-term avoidance, effectively collapsing the corridor altogether.
Despite WII&rsquo;s recommendation for a multi-season hydrological study before allowing hydro-peaking, the assessment has not been commissioned. Ecologists like Raman Sukumar and researchers tracking hydropower governance say the delay reflects a troubling pattern: the project is racing ahead even as its environmental safeguards lag behind. Downstream communities from fishers and farmers to indigenous Mising families fear daily water fluctuations will disrupt not just wildlife movement but also livelihoods tied to the river.&nbsp;
Local groups argue that protecting the corridor is non-negotiable, urging NHPC to halt hydro-peaking until the study is completed and mitigation plans are put in place. Conservationists warn that failing to act now could set a new low in India&rsquo;s environmental governance. As three additional power units prepare for commissioning this month, the project stands at a fraught crossroads, celebrated as a symbol of national power generation, yet shadowed by the risk of wiping out one of the Northeast&rsquo;s most vital wildlife pathways.

Subansiri Dam Sparks Fears for Elephant Corridor

Experts warn hydro-peaking may endanger key Assam–Arunachal elephant passage

Subansiri Dam Sparks Fears for Elephant Corridor

Experts warn hydro-peaking may endanger key Assam–Arunachal elephant passage

December 8, 2025 | 24:33 IST