The Upper Siang Hydropower Project (USHP) is one of India’s most ambitious and strategically significant infrastructure initiatives. Proposed on the Siang River (the Brahmaputra in Assam and Yarlung Tsangpo in Tibet) in Arunachal Pradesh, this multipurpose project is designed not only to generate massive amounts of clean energy but also to address regional water security, flood management, and geopolitical challenges posed by China’s upstream hydropower activities.

Project Overview

Location:

Upper Siang District, Arunachal Pradesh, India, on the Siang River—a major tributary of the Brahmaputra.

Implementing Agencies:

National Hydroelectric Power Corporation (NHPC) and North Eastern Electric Power Corporation (NEEPCO).

Capacity and Scale:

• Installed Capacity: 11,000 MW (among the largest in India and the world).
• Reservoir Storage: 9–10 billion cubic meters (BCM).
• Reservoir Area: Approximately 14,900 hectares with a 300-meter-high dam.
• Annual Generation: Estimated 47,000–48,000 million units (MU) of electricity.
• Estimated Cost: ₹1.13 lakh crore (approx. $13 billion).
• Project Timeline: Construction planned in phases over 15–20 years.

Project Components:

• Main storage dam across the Siang River.
• Multiple hydropower dams (phased development).
• Transmission infrastructure to integrate with the national grid.
• Multipurpose design: power generation, flood control, water storage, navigation, and regional development.

Strategic Context:

• Conceived as a countermeasure to China’s massive hydropower and water diversion projects upstream on the Yarlung Tsangpo.
• Aims to secure India’s water and energy interests in the Brahmaputra basin.

Merits of the Upper Siang Hydropower Project

1. Massive Renewable Energy Generation

• With an installed capacity of 11,000 MW, USHP will be the largest hydropower project in India, significantly boosting the country’s renewable energy portfolio.
• Expected annual generation of 47,000–48,000 MU will help phase out coal-based power, reducing greenhouse gas emissions and supporting India’s climate commitments.

2. Energy Security and Grid Stability

• Hydropower provides reliable, dispatchable electricity, supporting grid stability and enabling the integration of intermittent renewables like solar and wind.
• Arunachal Pradesh will receive 12% of generated power (about 1,320 MW) free of cost, yielding annual revenue of ₹3,384 crore, and 1% of project revenue will be distributed among local project-affected families.

3. Flood Control and Water Security

• The massive reservoir will modulate river flow, reducing downstream flood risks in Arunachal Pradesh, Assam, and even Bangladesh, especially during sudden water releases from China.
• Ensures year-round river flow, particularly during lean seasons, supporting agriculture and daily water needs for millions downstream.

4. Strategic and Geopolitical Importance

• Acts as a strategic counter to China’s upstream projects, which threaten to reduce water flow or cause artificial floods in India.
• Under international law, once India initiates its project, it strengthens its claim to the river’s natural flow and limits upstream interventions by China.
• Enhances India’s bargaining power in transboundary river management and water diplomacy.

5. Economic and Regional Development

• The project will spur infrastructure development, create jobs, and stimulate economic growth in a remote and underdeveloped region.
• Ancillary benefits include fisheries, water transport, and tourism opportunities in the reservoir area.
• Improved connectivity and access due to new roads and infrastructure.

6. Climate Change Mitigation

• Hydropower is a clean energy source, and the USHP is expected to prevent the release of about 32 million tonnes of CO₂ annually by replacing coal-based power generation.
• Supports India’s net-zero emissions goals and Paris Agreement commitments.

7. Multipurpose Benefits

• Besides power generation, the reservoir can be used for irrigation, navigation, and even water sports.
• Provides a buffer system to protect downstream communities from both floods and droughts.

Demerits of the Upper Siang Hydropower Project

1. Displacement and Social Impact

• Large-scale submergence of villages and agricultural land will displace thousands, mostly from the indigenous Adi tribe, threatening their livelihoods, cultural heritage, and traditional practices.
• Loss of ancestral lands and social disruption are major concerns for local communities, fuelling protests and resistance.

2. Environmental and Ecological Risks

• Submergence of vast tracts of forest and biodiversity-rich areas, leading to loss of flora and fauna, and potential extinction of endemic species.
• Disruption of aquatic ecology and sediment flow, impacting river health and downstream agriculture.
• Large-scale deforestation and habitat fragmentation.

3. Seismic and Geological Hazards

• The region is seismically active, raising concerns about dam safety and risk of catastrophic failure in the event of a major earthquake.
• The area’s geology, with loose sedimentary rocks, may not be ideal for such a massive structure.

4. Cultural and Spiritual Impact

• The Siang River is considered sacred by the Adi tribe (“Ane” or Mother Siang), and the dam threatens their spiritual and cultural connection to the river.
• Loss of traditional farming and fishing practices, impacting cultural identity.

5. Governance and Community Opposition

• Strong local opposition, including protests and sit-ins, has stalled project progress and complicated survey and feasibility work.
• Allegations of inadequate consultation, lack of transparency, and insufficient compensation and rehabilitation.

6. Downstream and Transboundary Concerns

• Changes in river flow could negatively impact downstream regions in Assam and Bangladesh, affecting agriculture, fisheries, and water availability.
• If China diverts or manipulates upstream flow, the effectiveness of the Indian project could be compromised, and sudden releases could cause artificial floods.

7. Financial and Logistical Hurdles

• High cost (₹1.13 lakh crore) and complex logistics in a remote, hilly, and ecologically sensitive area.
• Rehabilitation and resettlement of affected populations remain a major challenge.

Project in the Context of India-China Water Relations

China’s construction of large-scale dams and water diversion projects on the Yarlung Tsangpo, including the 60,000 MW “Great Bend” project, poses significant risks for India’s water security. China is not a signatory to international water-sharing conventions and has the technical capacity to divert or manipulate river flows. The Upper Siang Hydropower Project is thus seen as a strategic imperative for India to:

• Maintain the natural flow of the Siang/Brahmaputra river throughout the year.
• Mitigate flood risks from sudden upstream water releases.
• Assert India’s rights and interests in the transboundary river system.

Environmental and Social Opposition

The project faces sustained opposition from local communities, particularly the Adi tribe, and environmental activists. Key concerns include:

• Displacement and loss of livelihoods for thousands.
• Irreversible ecological damage to the Eastern Himalayas, a global biodiversity hotspot.
• Threats to cultural heritage and spiritual traditions.
• Inadequate compensation and lack of meaningful community participation in decision-making.

Despite these concerns, the government maintains that the project is essential for national security, energy transition, and regional development, and has promised to implement robust environmental safeguards and fair rehabilitation policies.

Summary Table: Merits vs Demerits

Aspect	Merits	Demerits
Energy	11,000 MW renewable power, grid stability, reduced CO₂	High cost, logistical complexity
Economy	Revenue for Arunachal, jobs, regional development	Displacement of local communities, loss of livelihoods
Environment	Reduced coal use, flood control, water security	Submergence of forests, biodiversity loss, seismic risk
Society & Culture	State revenue, local benefits (free power, compensation)	Loss of ancestral land, cultural and spiritual disruption
Strategic	Counters China’s upstream dam, secures river flow	Effectiveness depends on upstream (China’s) actions
Governance	National priority, policy support	Strong local opposition, lack of community consent

Conclusion

The Upper Siang Hydropower Project stands at the intersection of India’s energy ambitions, environmental stewardship, and national security imperatives. Its successful implementation could transform the energy landscape of the Northeast, provide a bulwark against upstream Chinese interventions, and drive regional development. However, the project’s scale and location in a fragile ecological and sociocultural landscape mean that its costs—in terms of displacement, biodiversity loss, and social disruption—are significant and contentious.

A balanced approach, emphasizing robust environmental safeguards, transparent governance, fair compensation, and meaningful community participation, will be essential. The future of the Upper Siang Hydropower Project will likely be decided not only by technical and economic feasibility but also by the ability to reconcile national interests with the rights and aspirations of local communities and the imperatives of ecological sustainability.