Large dams in the eastern Himalaya are often justified on strategic grounds. Critically examine this rationale with reference to the Siang Upper Multipurpose Project.

The Siang Upper Multipurpose Project (SUMP) is NHPC's proposed dam on the Siang, the name of the Brahmaputra in Arunachal Pradesh. It would be 280–300 m high and generate 11,000–11,200 MW [1]. It is presented as India's answer to China's upstream Medog project. The strategic concern is real, but the rationale is only partly convincing.

Strategic case for SUMP

• Buffer against upstream shocks: about 9.2 BCM of live storage could absorb a sudden release from Medog or a failure there [1].
• Downstream rights: having its own storage strengthens India's claims as the downstream user of the river [1].
• Other benefits: the government says it would control floods in Assam, produce power and create jobs for youth [1].

Weaknesses in the rationale

• Conflicting reservoir goals: to catch a surge from upstream, the reservoir must be kept partly empty. To earn from power, it must be kept full. No Detailed Project Report (DPR) exists to say which comes first. The proposal was returned in July 2024 for lack of DPR progress, and the project is still at "preliminary investigation" [2].
• Earthquake risk: the 1950 Assam–Tibet earthquake struck this area. One large quake could hit Medog and SUMP together, so a second reservoir could add to the danger downstream.
• Damage across the basin: the CWC counts 44 hydro projects proposed in the Siang basin, which has 114 fish species [3]. Judging SUMP alone hides the combined harm.
• Consent deficit: the Adi say 27 villages would be submerged. Activists have been detained, and protest groups rejected the State's offer of talks in November 2026 [1]. The Centre treats the protests as an "outreach" problem [2]. This weakens the free, prior and informed consent the Forest Rights Act, 2006 requires through gram sabhas.
• Excluded stakeholders: Assam bears both the promised flood benefit and the risk if the dam fails, yet it has no formal role in consent.

Way forward

• Appraise SUMP using the CWC's basin-wide study [3].
• Seek gram sabha consent without security forces at survey sites.
• Get an independent earthquake-design review at the DPR stage, under the Dam Safety Act, 2021.
• Consider a smaller design whose first purpose is flood control.
• Push China for real-time sharing of river-flow data.

China's dam makes an Indian reservoir worth considering, but scale alone does not deliver security. A transparent design, independent safety review and real tribal consent would make SUMP a sustainable hedge (SDG 6, SDG 13) that keeps the Constitution's promise of dignity for Scheduled Tribes.