How India’s Siang Dam Worth Rs 1 Lakh Crore Can Counter China's Rs 14 Lakh Crore Brahmaputra Project? Why is Arunachal Opposing?

India's proposed Siang Upper Multipurpose Project (SUMP) in Arunachal Pradesh has acquired strategic relavence amid China's construction of a massive hydropower project on the Yarlung Tsangpo River in Tibet. The Indian project, with a potential capability of 11,200 megawatts (MW), is being regarded as a possible safeguard for water security, flood management and electricity generation. However, concerns over displacement, environmental damage and the loss of ancestral land have ignited protests among local communities. 

Why China's Mega Dam Raises Concerns

China started construction of its Yarlung Tsangpo hydropower project in July 2025. The project is slated to comprise five cascade hydropower stations, with an investment of 1.2 trillion yuan, or approximately $167.8 billion. Its envisioned capability is around 60,000 MW, making it one of the world's largest hydropower projects.

The Yarlung Tsangpo flows from Tibet into Arunachal Pradesh, where it is called as the Siang, before joining other rivers to form the Brahmaputra in Assam. Since China's project is situated upstream, Indian authorities are intrigued about the possible impact of reservoir operations on downstream water flows.

Although a dam cannot simply stop the Brahmaputra's flow, its operation could impact the timing and volume of water releases. This has ignited concerns about seasonal water availability, instant discharges and flood management.

How India's Siang Project Could Help

The proposed SUMP with estimated cost of around Rs 1.13 lakh crore is developed as a storage-based multipurpose project consisting of hydropower generation with water storage and flow regulation.

According to figures cited by Arunachal Pradesh Deputy Chief Minister Chowna Mein, the project could offer approximately 9.2 billion cubic metres of live storage. The proposed reservoir could possibly regulate river flows and handle extreme water releases, depending on its design and operating settlements. 

The project could also bolster India's electricity supply and promote infrastructure development in the Northeast. However, its construction has not been cleared, and its feasibility remains under review.

Why Local Communities in Arunachal Pradesh Oppose the Project

The proposed dam is seeing resistance from indigenous Adi communities and other natives of the Siang Valley. Protesters fear the disruption of ancestral land, displacement, ecological damage, livelihoods and cultural property.

Protests turned into violence in October 2026, thus triggering additional security deployment in the region. The controversy has underscored the hurdle of balancing national security needs with the rights and grievances of local communities.

What Lies Ahead?

India's Siang project showcases an essential debate over water security, energy needs and strategic preparedness. While the government sees possible benefits in handling upstream water risks, the project's actual effectiveness will rely on technical reviews, environmental safeguards and consultation with local residents.