The renewed protests against large hydropower projects in Arunachal Pradesh, particularly the proposed 11,000-MW Siang Upper Multipurpose Project (SUMP), are being driven by a combination of environmental concerns, indigenous land rights, questions over consultation and the sheer scale of the state’s planned hydropower expansion.
The immediate trigger has been the resumption or continuation of pre-feasibility surveys and drilling associated with the Siang project. In September 2026, local communities protested survey activities, while a state human-rights organisation called for the surveys and drilling to be halted pending wider consultation.
The agitation, however, cannot be understood simply as opposition to a single dam. It comes at a time when Arunachal Pradesh is being positioned as one of India’s major future hydropower regions. The state government has declared 2025–2035 the “Decade of Hydropower” and is targeting nearly 19,165 MW from 33 upcoming projects, against an estimated state potential of more than 50,000 MW.
The contrast between an ambitious expansion of hydropower and renewed resistance among affected communities has become a central source of tension.
A Dispute Over The Scale Of Development
One of the underlying issues is the scale and concentration of proposed hydropower development.
Arunachal Pradesh is estimated to have more than 50,000 MW of hydropower potential. The Central Electricity Authority’s broader Brahmaputra-basin planning has identified 208 large hydropower projects across 12 sub-basins, with 64.9 GW of conventional hydropower and another 11.1 GW of pumped-storage potential. Arunachal Pradesh accounts for about 52.2 GW in that assessment.
For policymakers, those figures represent a significant economic and energy opportunity. For communities living along the rivers, they also raise concerns about the cumulative effects of dams, roads, tunnels, transmission lines and associated construction across multiple valleys.
As a result, the debate is increasingly moving beyond the question of whether one particular dam should be built to a broader question: how much hydropower development can an individual Himalayan river basin absorb?
A project may meet environmental requirements when assessed individually, while the combined effects of several projects could be substantially greater. These may include changes in river flows and sediment movement, forest loss, impacts on wildlife corridors and changes to settlement and livelihood patterns.
Why the Siang Project Has Become The Focal Point
The SUMP has become particularly contentious because of its proposed scale. The project has been described in recent reporting as an 11,000-MW proposal, although some local reports and public campaigns have used different capacity figures as project details have evolved. Its final configuration and capacity remain matters for the formal appraisal process.
The project has nevertheless acquired significance beyond its proposed generating capacity.
A March 2026 research brief from Shiv Nadar University documented how members of the Adi community have mobilised traditional institutions and customary forms of collective decision-making in response to the project. In August 2025, hundreds of Adi villagers from four districts reportedly participated in a Bogung Bokang Kebang at Geku, a traditional deliberative institution, to discuss the proposed dam.
The involvement of customary institutions is significant because it shows that opposition is not being organised solely through conventional environmental organisations. Traditional community institutions have also become part of the process through which affected communities debate the project and express their concerns.
Land is at the centre of that dispute.
Organisations supporting the protests have warned about the possible loss of agricultural and ancestral land. One advocacy group has estimated that at least 27 villages could be affected by the proposed Siang dam, although the precise number of affected settlements will depend on the final project design and authoritative impact assessments.
In Arunachal Pradesh, land can have several overlapping meanings. It can provide agricultural and forest-based livelihoods, form part of ancestral territory, support village institutions and provide access to hunting, fishing and gathering areas. It may also contain sites of cultural and spiritual significance.
As a result, compensation for physical property may not address every concern associated with displacement or the loss of access to customary land and resources. This is one reason some communities have remained opposed to the project even as development packages and compensation have been discussed.
Consent, Environmental Risk And An Old Debate
Trust has become another major issue in the dispute.
The debate increasingly centres on whether affected communities have been adequately consulted before surveys and other preliminary activities take place. The state government has itself acknowledged the sensitivity of the issue. In July 2026, Chief Minister Pema Khandu said the government would not rush the Siang project's pre-feasibility study and would seek to address the concerns of families likely to be affected before moving forward.
For the government, surveys and drilling are preliminary technical activities needed to establish the project's feasibility. For some affected communities, however, the continuation of such activities can be interpreted as evidence that the project is moving ahead before there is sufficient agreement over its broader implications.
That difference in perception can turn a technical exercise into a political confrontation.
Environmental concerns form another major part of the opposition.
Arunachal Pradesh lies within the seismically active Eastern Himalaya and has steep terrain, high-rainfall catchments, extensive forests and complex geological formations. These conditions do not by themselves rule out hydropower development, but they increase the importance of project-specific geological, seismic and climate assessments, particularly for projects involving large dams, extensive tunnelling and major road construction.
Opponents have also pointed to disasters associated with Himalayan infrastructure elsewhere. International Rivers, for example, has cited the 2023 Teesta III disaster in Sikkim in its discussion of opposition to the Siang project. Such incidents do not establish that the Siang project would face a similar failure, but they have contributed to wider concerns about infrastructure risks in the Himalayan region.
The environmental debate therefore extends beyond conventional concerns about forests, biodiversity, fisheries, sediment and river flows. It also involves low-probability but potentially high-consequence risks associated with earthquakes, landslides, extreme floods and cascading infrastructure failures.
Climate change adds another layer of uncertainty. Changes in precipitation patterns, extreme rainfall and high-altitude hazards are complicating assumptions traditionally used in infrastructure planning. Historical hydrological records remain important, but for projects expected to operate for several decades, questions about future climate conditions and extreme events are also increasingly relevant.
The renewed protests also draw on the history of hydropower controversies in Arunachal Pradesh.
The Lower Subansiri project, for instance, became the focus of prolonged disputes over construction, safety, downstream impacts and environmental concerns. Such experiences have contributed to what can be described as an institutional memory among communities and activists. New promises of development are often assessed against earlier experiences involving land acquisition, construction disruption, environmental assessments and rehabilitation.
This history helps explain why even preliminary surveys can generate opposition before construction begins.
At the heart of the dispute is also a question of distribution: who receives the benefits of hydropower and who bears its risks?
Electricity generated in a remote Himalayan valley can enter a regional or national grid, while many of the immediate impacts—submerged land, altered river systems, construction activity and exposure to infrastructure-related hazards—remain concentrated in the project area.
This creates a distributional challenge. When the costs of a project are concentrated locally while its benefits are distributed more widely, local opposition can remain strong even when a project is expected to generate substantial national or regional economic benefits.
A Movement Broader Than One Dam
Another significant development has been the growing ability of local organisations to connect environmental concerns with indigenous rights and customary governance.
The Siang movement now involves farmers' groups, customary institutions, civil-society organisations and rights groups. Research by Shiv Nadar University has documented the role of traditional governance systems in organising community responses to the proposed project.
As a result, the debate has expanded beyond the question of whether a dam should be built. It now includes questions about ancestral land, customary authority, meaningful consultation, environmental risk, benefit-sharing and the role of indigenous institutions in decisions affecting rivers and communities.
India's strategic concerns about Chinese upstream dam development also form part of the wider context. Those concerns may strengthen the government's interest in developing hydropower in the region, while simultaneously raising apprehensions among some local communities that strategic considerations could accelerate decisions on projects affecting their land and rivers.
The current confrontation is therefore the result of several pressures converging at the same time: an expansion of hydropower planning, concerns over land and livelihoods, distrust surrounding preliminary project activities, environmental and geological risks, the growing role of indigenous institutions, and the strategic importance of the eastern Himalayan region.
The immediate challenge is not necessarily to resolve the larger question of whether Arunachal Pradesh should develop hydropower. It is to establish a decision-making process that communities regard as credible.
A more comprehensive approach could include cumulative assessments of multiple projects within individual river basins, greater public access to geological and environmental studies, detailed disclosure of downstream inundation and dam-break scenarios, and stronger participation by affected villages and customary institutions.
Independent reviews of seismic, landslide and flood risks could also play a role, particularly for large projects in geologically sensitive areas. If projects proceed, questions about benefit-sharing, employment, local infrastructure, health, education and long-term revenue-sharing are likely to remain important to affected communities.
Alternative sources of electricity, including smaller hydropower projects where appropriate, solar generation, improvements to the transmission grid and energy-storage technologies, could also form part of a broader assessment of future energy needs rather than treating large dams as the only option.
The significance of the Siang protests ultimately extends beyond the question of hydropower generation.
They reflect a wider debate over the relationship between the state and indigenous communities in Arunachal Pradesh and over the extent to which communities should participate in decisions that affect their ancestral lands and river systems.
For the government, Arunachal Pradesh's rivers represent a major energy resource at a time when India is seeking additional renewable generation and greater strategic resilience along its northeastern frontier. For communities in the project areas, the same rivers are also sources of land, livelihoods, culture and local identity.
The central question is therefore not simply whether dams should be built or opposed. It is whether a model of hydropower development can address geological and environmental risks while also dealing with indigenous land and cultural concerns, benefit-sharing and meaningful public participation.
The September 2026 protests indicate that this question remains unresolved.
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Neha Desai is an independent writer based in Arunachal Pradesh and a graduate of Jawaharlal Nehru University
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