India’s proposed 11,200-megawatt Siang Upper Multipurpose Project (SUMP) has emerged as a major point of contention in Arunachal Pradesh, with the Centre viewing it as a strategic measure to strengthen water security against China’s massive hydropower project on the Brahmaputra’s upper reaches. However, indigenous Adi communities fear the project could threaten their ancestral lands, livelihoods, environment and cultural heritage.
The opposition intensified on Friday, October 23, when protests reportedly turned violent in East Siang district. Incidents of vandalism and arson were reported at the residences of local politicians, a police station and the office of the National Hydroelectric Power Corporation (NHPC), the agency responsible for carrying out preliminary assessments of the proposed project.
With the situation remaining tense, the Centre deployed two companies of the Central Reserve Police Force’s Rapid Action Force, comprising around 250 personnel, according to a PTI report published on October 25.
At the heart of the dispute is a fundamental question: can a project designed to protect India’s strategic interests be implemented without undermining the rights and concerns of the communities living along the river?
Why India Wants to Build the Siang Dam
The Siang River originates in Tibet, where it is known as the Yarlung Tsangpo. It flows through Arunachal Pradesh before joining other rivers to form the Brahmaputra, which continues through Assam and Bangladesh.
India’s concerns have grown following China’s construction of a massive hydropower project in Medog county in the Tibet Autonomous Region. Construction began in July 2025, with the project expected to have a generation capacity of around 60,000 MW, potentially making it the world’s largest hydropower project.
The scale of the Chinese project has raised concerns in India and Bangladesh about the possible implications for downstream water security. Changes in water releases, potential diversion and sudden discharges could affect flood management, agriculture and communities dependent on the Brahmaputra river system.
Against this backdrop, the proposed Siang project is being considered as a potential strategic buffer. The Indian government believes a large reservoir could help regulate river flows, store excess water and improve preparedness for sudden fluctuations originating upstream.
Arunachal Pradesh Chief Minister Pema Khandu has cited an estimated live storage capacity of approximately 9.2 billion cubic metres for SUMP, compared with around 5.5 billion cubic metres for China’s Medog project.
Beyond its strategic importance, the proposed dam is expected to generate renewable electricity, strengthen power availability in northeastern and eastern India, improve infrastructure and create employment opportunities.
A November 2025 paper by the Manohar Parrikar Institute for Defence Studies and Analyses also placed the project within India’s broader water-security and hydro-diplomacy strategy.
However, the extent to which the proposed reservoir could mitigate downstream risks would depend on its final design, operating rules and coordination arrangements. Storage capacity alone does not guarantee protection against sudden releases or other upstream disruptions.
Why the Adi Community Is Resisting the Project
For the Adi community, which has lived along the Siang for generations, the river is far more than a source of water or electricity. It is closely connected to their identity, traditional practices, agriculture and livelihoods.
Residents fear that a project of this scale could submerge villages and agricultural land, disrupt local ecosystems and damage places of cultural and spiritual significance.
Itanagar-based journalist Tongam Rina told India Today Digital that opposition to projects on the Siang has existed for nearly four decades, with protests intensifying in recent years.
She also pointed to growing anger among young people following the police response to demonstrations, including the use of tear gas against women protesters. The issue has consequently become not only a debate over development but also one involving community rights, public trust and the treatment of protesters.
Local opponents have questioned the government’s emphasis on national security, arguing that the immediate risks to people living in the project area deserve equal consideration.
They have also pushed back against attempts to portray opposition to the dam as opposition to national interests, maintaining that protecting local communities and safeguarding the country’s strategic interests should not be treated as mutually exclusive objectives.
What Is the Dispute Over the Pre-Feasibility Survey?
The immediate trigger for the latest round of protests is the proposed pre-feasibility report (PFR) survey for SUMP, which is expected to take place over three months, from November 2026 to January 2027.
The NHPC has been tasked with conducting preliminary surveys and technical assessments to determine whether the project is feasible. The exercise is expected to examine possible dam locations, geological conditions, seismic risks and other technical considerations.
The Arunachal Pradesh government has maintained that a final decision on construction has not been taken. Chief Minister Pema Khandu has said the project will not proceed beyond the feasibility stage if experts determine that it is unsuitable.
He has also stated that any viable proposal would require environmental and social impact assessments, a detailed project report, statutory clearances and consultations with affected communities.
However, protesters fear that allowing the survey to proceed could create momentum towards construction, making it more difficult to stop the project at a later stage.
The Siang Indigenous Farmers’ Forum (SIFF) has questioned claims of local support, arguing that individual household signatures cannot replace broader consultations with village communities and traditional institutions.
The Adi Banne Kebang, the community’s apex body leading the opposition, has demanded that the Siang Upper Multipurpose Project be scrapped and the pre-feasibility report rejected.
The All Adi Youth Association has also called for dialogue through traditional kebang, or village council, institutions, the withdrawal of cases against protesters and efforts to rebuild trust between local communities and the administration.
The dispute has exposed a widening gap between the government’s position that preliminary studies are necessary to assess feasibility and the protesters’ belief that even permitting those studies could put their lands and future at risk.
Why Young People Have Joined the Anti-Dam Movement
The involvement of younger residents has added a new dimension to the protests. For many, the issue extends beyond the potential environmental consequences of a dam to questions of political representation, indigenous rights and the future of their communities.
According to journalist Tongam Rina, anger over the police response to protesters has further intensified opposition.
Young demonstrators are also questioning whether the proposed dam can provide meaningful protection against China’s upstream hydropower project. Some protesters believe a reservoir in Arunachal Pradesh would not necessarily prevent the consequences of a sudden release of water from upstream.
These concerns reflect a broader challenge facing large infrastructure projects in indigenous regions: technical and strategic arguments may not be sufficient to secure public acceptance without meaningful participation by affected communities.
The government’s assurances that the project remains at the assessment stage have so far failed to resolve the dispute.
Khandu has offered to visit affected villages and meet community representatives. During his visit to Yingkiong in Upper Siang district on September 30, however, his convoy was stopped by anti-dam protesters, underlining the depth of local opposition.
Why China’s Medog Dam Has Raised Geological Concerns
The debate over SUMP is also shaped by concerns about the geological conditions surrounding China’s Medog project.
The eastern Himalayan region is seismically active, making the construction of major dams and reservoirs particularly challenging. Large infrastructure projects in such environments require extensive geological investigations, seismic risk assessments and carefully designed safety measures.
A July report by the South China Morning Post, citing a Mandarin-language study published in Sedimentary Geology and Tethyan Geology, highlighted concerns about the active Paizhen Fault beneath the Medog project area.
Researchers associated with Chengdu University of Technology, the Civil-Military Integration Centre of the China Geological Survey and the Middle Yarlung Zangbo River Natural Resources Observation and Research Station examined geological conditions around the site.
The findings have added to scrutiny of the project’s potential geological risks. However, the study does not establish that the dam will fail, and the presence of an active fault does not, by itself, determine the safety of a project. Detailed engineering assessments and continued monitoring are essential to evaluating such risks.
The concerns have also renewed attention to the vulnerability of Himalayan infrastructure to earthquakes, landslides and extreme weather events.
For India, these geological questions reinforce the importance of understanding how developments in the upper reaches of the Brahmaputra could affect downstream communities. They also highlight the need for transparent technical assessments of any major dam proposed within the same river system.
The Bigger Question: Strategic Security Versus Indigenous Rights
The controversy surrounding the proposed Siang dam highlights two competing understandings of security.
For the Centre, the project represents an opportunity to strengthen India’s preparedness against potential changes in the Brahmaputra’s upstream flows, improve energy generation and reinforce the country’s strategic position amid growing competition with China.
For the Adi community, security means protecting ancestral land, preserving livelihoods, maintaining cultural traditions and ensuring that decisions affecting their future are not made without their consent and participation.
Neither concern can be dismissed. China’s massive hydropower development has raised legitimate questions about regional water security, while the potential social and environmental consequences of a large dam demand rigorous scrutiny.
The way forward will depend on transparent technical assessments, credible environmental and social studies, meaningful consultation with affected villages and clear communication about the project’s risks and benefits.
As India pursues its long-term energy and water-security objectives, the challenge will be to determine whether the Siang project can meet those goals without imposing unacceptable costs on the indigenous communities who depend on the river.
Ultimately, the future of the proposed 11,200-MW dam will hinge not only on its strategic value and technical feasibility but also on whether the concerns of the people living along the Siang are adequately addressed.