Why in News?

Recently, Assam Chief Minister downplayed concerns over Chinese dams on the Brahmaputra, stating that 65–70% of the river’s flow originates within India. He added that any reduction in flow from China might even help control Assam’s annual floods.

Originating as the Yarlung Tsangpo in Tibet, the Brahmaputra enters India in Arunachal Pradesh as the Siang, flows through Assam, and becomes the Jamuna in Bangladesh.

What’s in Today’s Article?

• Proposed Chinese Interventions on the Brahmaputra
• Water Yield of the Brahmaputra: India’s Dominant Contribution
• Impact of Upstream Interventions on the Brahmaputra’s Flow
• India’s Utilisation of the Brahmaputra’s Water Potential
• Impact of Chinese Dams on the Indus and Sutlej Rivers
• India’s Strategic Approach on the Brahmaputra Issue

Proposed Chinese Interventions on the Brahmaputra

• India continues to monitor China’s infrastructure projects along the Brahmaputra, most of which are hydropower-based with minimal water storage.
• These are located far upstream and currently pose no significant impact on Arunachal Pradesh or Assam.
• The Medog Hydropower Project: A Potential Game-Changer
  • The proposed 60,000-MW Medog project near the ‘Great Bend’ in Medog County is of major concern.
  • If built, it would be the world’s largest hydropower facility—three times the capacity of China’s Three Gorges Dam.
  • While specific details are scarce, it is believed to have limited water storage, reducing its potential downstream impact.
• South-North Water Diversion (SNWD): Long-Term Speculations
  • China’s long-term SNWD plan, especially its Western Route, is rumored to include diversion of water from the Yarlung Tsangpo to arid northern regions.
  • However, there is no official confirmation or detailed study available on these diversion plans.

Water Yield of the Brahmaputra: India’s Dominant Contribution

• Despite covering only 34.2% of the Brahmaputra basin, India contributes over 80% of its total water yield.
• This disproves the perception that China’s Tibetan Plateau is the river’s primary source.
• Climatic Differences Drive Yield Disparity
  • The Tibetan Plateau receives scant rainfall (around 300 mm annually), while India’s portion of the basin receives an average of 2,371 mm, with very few areas getting less than 1,200 mm.
• Tributaries and Monsoon Boost Indian Contribution
  • The Brahmaputra gains volume through numerous tributaries in India, especially during the monsoon (June–September).
  • Snowmelt from the Indian Himalayas also adds significantly to the river’s yield.

Impact of Upstream Interventions on the Brahmaputra’s Flow

• Due to substantial rainfall, monsoon-fed tributaries, and snowmelt in Indian territory, upstream interventions by China are unlikely to significantly reduce the Brahmaputra’s total flow in India.
• Seasonal Flow Variations Pose Challenges
  • Changes in flow patterns may impact hydropower projects on the Siang, especially during the dry season or peak power demand periods.
• Strategic Mitigation through Storage Projects
  • India can manage flow variability by building storage infrastructure.
  • Projects like the Upper Siang Hydropower Project can serve dual purposes—energy generation and flow regulation.
• Risk of Sudden Flooding Events
  • Unexpected floods may result from reservoir mismanagement, dam failure, landslides, or seismic activity in Tibet, posing downstream risks.
• Ecological Implications
  • Alterations in natural flow can affect river morphology, impacting aquatic ecosystems and biodiversity along the Brahmaputra.

India’s Utilisation of the Brahmaputra’s Water Potential

• The Brahmaputra and its tributaries hold over 30% of India’s total water resources and 41% of its hydropower potential, according to the CWC-ISRO Brahmaputra Basin Atlas.
• Hydropower Development Focused in Arunachal Pradesh
  • Arunachal Pradesh remains the primary site for hydropower development.
  • However, progress has been slow due to land acquisition issues and concerns over forest submergence.
• Inter-Basin Water Transfer Proposals
  • India has proposed two major river-linking projects to transfer Brahmaputra basin water to water-scarce regions of the Ganga basin:
    • Manas-Sankosh-Teesta-Ganga Link
    • Jogighopa-Teesta-Farakka Link
• No Major Threat from Upstream Chinese Projects
  • These proposed water transfer links are unlikely to be significantly affected by China’s upstream interventions in Tibet.

Impact of Chinese Dams on the Indus and Sutlej Rivers

• China has constructed and planned hydropower projects on the Sutlej and Indus, both of which originate in Tibet.
• Limited Impact on Sutlej Due to Indian Storage Capacity
  • The Bhakra Dam (Gobind Sagar reservoir) in Himachal Pradesh provides a buffer, absorbing flow variations in the Sutlej.
  • However, generation patterns at projects like Nathpa Jhakri may still be affected.
• Minimal Consumptive Use on the Indus
  • India's use of the Indus is largely non-consumptive.
  • While there may be minor impacts on run-of-the-river plants like Nimoo Bazgo in Ladakh, overall risks remain limited.

India’s Strategic Approach on the Brahmaputra Issue

• Strengthen Scientific Assessment and Monitoring
  • India must invest in detailed, multi-disciplinary studies to evaluate the impact of upstream interventions and develop adaptive, evidence-based strategies.
• Enhance Diplomatic Engagement
  • Continuous diplomatic efforts are needed to secure hydrological and project-specific data from China for informed downstream impact assessments.
• Establish Robust Data-Sharing Mechanisms
  • India should push for formal data-sharing protocols with China to ensure early warnings, improve disaster preparedness, and reduce flood-related risks.