An Arunachal Pradesh minister held talks with the East Siang Downstream Dam Affected People’s Forum, which represents communities across 72 villages, on the proposed Siang Upper Multipurpose Project (SUMP). The state says a project of this importance must advance with the trust and confidence of the people.

The project is presented as a strategic and developmental asset.

• Water security: About 9.2 billion cubic metres of live storage can store and regulate Siang water, a safeguard if flows change after upstream projects in Tibet.
• Power: About 11,200 MW of hydropower would add to energy supply from the north-east.
• Flood moderation: Storage can reduce flood peaks in Arunachal Pradesh and Assam.
• Strategic hedge: China’s Medog project on the Yarlung Tsangpo has made upstream control of the river a security concern, so India wants its own storage on the Siang.

For the people of the valley, the river is a way of life.

• Displacement: The Adi community fears loss of land, homes and villages. At least 27 villages in Siang and Upper Siang districts would be directly affected.
• Cultural bond: The Adi call the river “Ane”, mother, and say their language, forests and traditions are tied to it.
• Consent dispute: The state says villages signed MoUs for the pre-feasibility survey. The forum says consent was not properly taken and that traditional councils, the kebang, were bypassed. Protests grew in 2025, including opposition to the deployment of central armed police forces at the survey site.
• Downstream worry: The new forum of 72 villages shows that people below the dam also fear its effects.

• Trust deficit: Disputes over consent and the use of security forces have weakened faith in the survey process.
• Rehabilitation: A dam of this size needs a credible plan for resettlement and livelihoods, which is still missing.
• Ecological risk: A large reservoir in the seismically active eastern Himalaya can affect river flow, sediment and biodiversity.
• Timing gap: China’s project has been under construction since July 2025, while SUMP is still at the pre-feasibility stage.
• Transboundary gap: India has no comprehensive water-sharing treaty with China, so it depends on data and consultation.

• Project: The Siang Upper Multipurpose Project is on the Siang river, near Geku village, Upper Siang district, Arunachal Pradesh.
• River system: The Siang belongs to the Brahmaputra river system, and is the upper Brahmaputra in India.
• Names along the course: Yarlung Tsangpo (Tibet) → Siang or Dihang (Arunachal Pradesh) → Brahmaputra (Assam) → Jamuna (Bangladesh).
• Entry into India: The river enters Arunachal Pradesh near Tuting, Upper Siang district.
• Tributaries: Siyom, Yamne and Simang feed the Siang. The Siyom joins it at Pangin, the headquarters of Siang district.
• Dibang tributaries: Emra and Anelih (left), and Tangon, Angolin and Amli (right). The Adi call the Dibang Sikang.
• Communities: Adi, Memba, Khamba, Idu Mishmi, Minyong and Padam are communities of Arunachal Pradesh. The Minyong and Padam are sub-groups of the Adi.
• Adi traditions: The Adi follow the Donyi-Polo faith, and their village council is the kebang.
• China’s Medog project: It is at the Great Bend of the Yarlung Tsangpo in Medog county.