Floods and Landslides in Northeast India

In late May and early June 2025, widespread torrential rainfall triggered severe floods, landslides, and infrastructure collapse across the Northeastern states of India. Over 3.64 lakh people were affected in Assam alone, while more than 900 houses were damaged in Manipur and Mizoram. Tourism, connectivity, and public safety were severely impacted. This event underscores the region’s high vulnerability to compound climate and environmental hazards.

Natural Disasters in the Northeastern Region – Causes, Consequences and Governance Challenges

1. Geophysical and Environmental Drivers of the Disaster

• Climate-Induced Extreme Weather Events
  • The Indian Meteorological Department (IMD) has noted a sharp rise in intensity and frequency of pre-monsoon downpours in the Northeast.
  • The IPCC Sixth Assessment Report (AR6) and India’s National Climate Vulnerability Assessment identify the Northeast as a high-risk zone for extreme climate variability, including flash floods and cloudbursts.
• Fragile Geology of the Eastern Himalayas
  • The region is part of the young fold mountains, making it structurally weak and prone to frequent landslides, soil creep, and rockfalls.
  • Saturated slopes, especially in Sikkim, Arunachal Pradesh, and Mizoram, collapse under heavy rainfall.
• Riverine and Flash Flooding Dynamics
  • The Brahmaputra and Barak river systems, along with Teesta and Subansiri tributaries, overflow during intense rainfall, breaching embankments in Assam and Manipur.
  • Riverine floods were worsened by siltation, unregulated construction, and obsolete floodplain zoning.

2. Structural and Institutional Shortcomings

• Unplanned Urbanisation and Infrastructure Stress
  • Construction on steep, landslide-prone slopes (e.g., Aizawl, Gangtok) continues unabated, violating building norms.
  • Lack of stormwater drainage, encroachments, and informal housing in Imphal East and Senapati districts worsened flood impacts.
• Inadequate Disaster Preparedness and Inter-State Coordination
  • Delayed early warning and evacuation in Sikkim and Manipur exposed deficiencies in the functioning of District Disaster Management Authorities (DDMAs).
  • Rescue efforts, such as IAF's Mi-17 airlift in Arunachal, highlight central capacity but coordination remains fragmented across state borders.
• Environmental Degradation due to Land Use Practices
  • Shifting cultivation (jhum) and deforestation in Mizoram, Arunachal, and Nagaland reduce slope stability and increase runoff velocity.
  • Infrastructure projects, including roads and dams, have flouted Environmental Impact Assessment (EIA)

3. Social and Economic Fallout

• Impact on Livelihoods, Safety, and Connectivity
  • Over 8 lakh people in Assam and 1,500 tourists in Sikkim were stranded due to road and rail disruptions.
  • Agricultural loss, especially in flooded plains of Manipur and hilly farms in Meghalaya, risks food insecurity and income collapse.

Way Forward: A Multi-Sectoral and Region-Specific Strategy

• Strengthen Early Warning Systems (EWS) and Forecasting: Invest in real-time flood forecasting and mobile-based early warnings, especially for hill districts.
• Revise Urban and Hill Area Planning Norms: Introduce hill-specific building codes, zoning laws, and mandatory landslide vulnerability mapping before construction approvals.
• Promote Ecosystem-Based Adaptation: Restore degraded forest slopes and incentivise alternatives to jhum through agroforestry and MGNREGA convergence.
• Strengthen Inter-State Disaster Coordination: A North-East Regional Disaster Risk Reduction Authority can ensure collective floodplain management and shared EWS protocols.
• Mainstream Resilience in Development Planning: Ensure Environmental Impact Assessments (EIA) are scientifically rigorous and not bypassed through exemptions.