Basic Understanding of Flash Floods
- Flash Floods are sudden, intense floods caused by heavy rainfall, cloudbursts, or glacial lake outbursts (GLOFs), usually within 6 hours of precipitation.
- In mountainous terrains, such as Uttarakhand, they occur due to:
- Steep slopes increasing runoff velocity.
- Poor drainage due to rapid urbanisation.
- Glacial melt and river swelling due to climate anomalies.
Relevance : GS 3( Disaster Management)
Geographic and Climatic Context of Uttarkashi
- Location: Uttarkashi district lies in the upper Himalayan region of Uttarakhand, prone to flash floods, landslides, and earthquakes.
- Altitude: Dharali town affected in this case is located at 8,600 feet.
- River Systems: Kheer Ganga is a tributary in the upper Bhagirathi basin, which eventually feeds into the Ganga.
- Monsoon Activity: Heavy rainfall during July–September increases vulnerability.
- Tourist Footfall: Uttarkashi is a critical stretch of the Char Dham Yatra, increasing exposure to disaster risks.
The August 2025 Flash Flood: Event Summary
- Date & Time: Afternoon of August 5, 2025, around 1:45 PM.
- Trigger: Torrential rains caused river swelling and sudden flooding of the Kheer Ganga.
- Most affected area: Dharali town – a tourist hub with hotels and markets.
- Casualties:
- 4 confirmed dead.
- 60–70 people feared trapped, including 9 Army personnel.
- Destruction:
- Complete washing away of market areas.
- Residential buildings, hotels, and people swept away.
- Entire town turned into a sludge-filled riverbed.
Rescue and Relief Operations
- Agencies involved:
- Indian Army
- State Disaster Response Force (SDRF)
- Indo-Tibetan Border Police (ITBP)
- Rescue Data:
- 120 people rescued in initial hours.
- 20 rescued by Army within first 3 hours.
- Medical Relief:
- Separate hospital wings activated.
- Medical teams, oxygen, and medicines on alert.
- Shelter:
- Relief camps set up by district administration.
Wider Impact and Follow-Up Warnings
- Sukhi Top: Another flash flood reported here later the same day; no casualties, but sharp river swelling observed.
- Travel Advisory: Tourism and trekking activities in Uttarkashi remain suspended.
- Weather Forecast:
- IMD prediction of continued heavy rain for next few days.
- High risk of secondary floods, landslides, and road blockages.
Structural Causes and Broader Vulnerabilities
- Ecological Fragility:
- Uttarakhand lies in Zone V (highest seismic zone) and is highly susceptible to ecological disasters.
- Anthropogenic Pressures:
- Haphazard construction, especially in riverbeds.
- Unchecked tourism and infrastructural overload.
- Deforestation and encroachment on drainage lines.
- Climate Change:
- Rising frequency of extreme weather events in the Himalayas.
- Disrupted monsoon patterns and glacial retreat exacerbate risks.
Past Precedents
| Year | Event | Death Toll | Impact |
| 2013 | Kedarnath Flash Floods | ~5,700+ | Worst Himalayan disaster in recent memory |
| 2021 | Chamoli Glacier Burst | ~200 | Hydro project destruction |
| 2023 | Joshimath Land Subsidence | – | Town declared sinking zone |
Way Forward: Policy and Resilience Measures
- Disaster Preparedness:
- Strengthen early warning dissemination in remote Himalayan villages.
- Community-led resilience planning and mock drills.
- Ecological Planning:
- Ban on construction within 200m of rivers in fragile zones.
- Promote eco-tourism with capped footfalls.
- Monitoring Infrastructure:
- Install AI-based water-level sensors across rivers.
- Drone surveillance in trekking routes during monsoon season.
- Capacity Building:
- Empower local Panchayats under DM Act 2005.
- Invest in mountain-specific disaster research.
