NHPC Halts Upper Subansiri Dam Work, Uncertainty Looms Over Lower Subansiri Project

The Central government has finally acknowledged the potential dangers posed by large dams constructed on the Subansiri River. In a significant development, the National Hydroelectric Power Corporation (NHPC) has announced the suspension of construction work on the Upper Subansiri Hydroelectric Project. The move has reignited public debate over when construction of the controversial Lower Subansiri (Gerukamukh) dam will also be halted.

NHPC issued an official notification on December 12, 2025, stating that work on the Upper Subansiri mega dam has been suspended due to prevailing law and order issues triggered by sustained protests from various student organisations. The notification further cited security concerns for NHPC officials and employees, adding that construction will remain suspended until further instructions.

The decision has drawn renewed attention to the Lower Subansiri Hydroelectric Project, which has long faced intense opposition. The project, located in a seismically active zone and built on fragile hill soil, has been flagged as one of the most risky hydropower ventures in the region. Experts and activists have repeatedly pointed out serious technical irregularities during its construction.

Sources indicate that following the suspension of work at Upper Subansiri, the Lower Subansiri dam could also be stopped at any moment. Although there were earlier claims that power generation from the project would be formally inaugurated by the Prime Minister, an Intelligence Bureau report reportedly highlighted multiple deficiencies in the dam. Consequently, the Prime Minister’s Office did not grant approval for the Prime Minister to inaugurate the project.

Despite this, several attempts were made to project March 2026 as the inauguration timeline. However, recurring technical failures, including the collapse of guard walls during moderate rainfall, flooding of the powerhouse, damage to turbine rotors, and other structural issues, have raised serious questions about the project’s safety and viability. Natural challenges have further complicated construction at every stage.

Under the provisions of the Assam Accord, the Subansiri dams were originally envisaged to serve the dual purpose of power generation and flood control. Critics argue that the shift towards large-scale dam construction has instead increased environmental and disaster risks, particularly for Upper Assam.

With an estimated expenditure of ₹2,600 crore, the projects have been accused of causing large-scale ecological damage, threatening biodiversity, and risking the lives and livelihoods of people in the region. Environmentalists and local organisations are now demanding a complete halt to the construction of all dams on the Subansiri River, calling the projects a misuse of public funds and a looming threat to Assam’s ecological and human security.

Also Read: PMO Withholds Approval as Lower Subansiri Dam Faces Technical Issues