Siang Upper Multipurpose Project (SUMP): Balancing Hydropower and Himalayan Ecology

📌 GS Paper Mapping for UPSC
  • GS Paper 2: Governance, Tribal/Local Communities and Environmental Governance Themes: Water Security, Flood Management, Northeast Development, Community Participation
  • GS Paper 3: Environment, Ecology & Infrastructure

Why in News?

The Arunachal Pradesh Cabinet has approved an empowered high-level committee to guide and coordinate the pre-feasibility survey and related activities for the proposed Siang Upper Multipurpose Project (SUMP).

What is the Siang Upper Multipurpose Project?

The Siang Upper Multipurpose Project is a proposed large storage-based project on the Siang River in Arunachal Pradesh. It is significant not merely as a hydropower project but because of its implications for India’s energy security, flood moderation, water storage, the development of Arunachal Pradesh, environmental sustainability and the strategic importance of the Brahmaputra basin.

Why is the Siang River important?

The Siang is the principal river that enters India from Tibet and subsequently forms the Brahmaputra system in Assam.

This gives the project significance beyond electricity generation.

The Brahmaputra basin is characterised by:

  • high monsoonal flows,
  • substantial sediment loads,
  • fragile Himalayan terrain,
  • seismic vulnerability,
  • extensive floodplains downstream, and
  • significant hydropower potential.

Significance of Siang Upper Multipurpose Project:

  1. Hydropower potential: Arunachal Pradesh has one of India’s largest concentrations of identified hydropower potential.
  2. Energy security and grid balancing: Unlike solar and wind generation, reservoir-based hydropower can provide electricity with greater operational flexibility.
  3. Flood moderation: Reservoir storage can potentially regulate a portion of high flows and thereby reduce downstream flood peaks.
  4. Regional development: Project can facilitate regional socioeconomic development and water and energy security.

Challenges of Siang Upper Multipurpose Project:

  1. Displacement and submergence: Large storage projects require substantial land and can affect settlements and agricultural land.
  2. Fragile Himalayan ecology: The Eastern Himalayas are environmentally sensitive.
  3. Seismic vulnerability: Arunachal Pradesh lies in a highly tectonically active part of the Himalayan region.
  4. Local community concerns

The China factor

The Siang is strategically important because its upper reaches lie across the international border in Tibet, where the river is known as the Yarlung Tsangpo.

China has announced plans for a very large hydropower project (Medog Hydropower Station) on the Yarlung Tsangpo.

This gives the Upper Siang project an additional strategic dimension concerning:

  • downstream water security,
  • hydrological data,
  • China’s upstream infrastructure,
  • India’s presence and infrastructure development in the Northeast,
  • disaster preparedness.

Mains Practice Question:

Q. Large Himalayan hydropower projects present both an opportunity for India’s energy and water security and a challenge to fragile mountain ecosystems. Discuss with reference to the Siang Upper Multipurpose Project.

UPSC Prelims Practice Question

Q. With reference to the Siang Upper Multipurpose Project (SUMP), consider the following statements:

  1. It is proposed in Arunachal Pradesh on the Siang River.
  2. The project is envisaged as a multipurpose project with hydropower generation and flood-moderation objectives.
  3. The project is located within the Brahmaputra river system.

Which of the statements given above are correct?

A. Only 1 statement is correct
B. Only 2 statements are correct
C. All are correct
D. 1 and 3 are corret

Answer: C. All are correct