Dharali Floods Expose Perils of Riverbank Settlements

On August 5, 2025, a catastrophic flash flood, likely triggered by a glacial lake outburst or glacier collapse, obliterated half of Dharali village in Uttarkashi, Uttarakhand, leaving at least five dead, over 100 missing, and 148 buildings damaged across 16 hectares. Experts warn that this disaster, far from an isolated incident, underscores the urgent need to scrutinize settlements on riverbanks and floodplains across the Himalayan region, where unchecked construction and environmental violations are amplifying the toll of natural hazards.

Dr. Sushil Kumar, a former senior scientist at the Wadia Institute of Himalayan Geology in Dehradun, emphasized the need for comprehensive studies of settlements on river headlands—fertile floodplains rich in nutrients from deposited soil, silt, sand, and gravel. While ideal for agriculture, these areas are highly vulnerable to flooding. “The time has come to study all areas where large settlements have sprung up on riverbanks and streams,” Kumar stated, noting that the debris-laden torrent that struck Dharali followed the Khirgad seasonal river’s original path, demolishing hotels, homestays, and restaurants built in violation of environmental norms.

The disaster, which turned a picturesque stopover en route to Gangotri Dham into rubble, was exacerbated by unregulated tourism-driven development. In recent years, dozens of multi-storey hotels and homestays have mushroomed along the Khirgad and Bhagirathi rivers, often flouting eco-sensitive zone (ESZ) regulations. Environmentalist Anoop Nautiyal highlighted systemic failures, pointing to the Uttarakhand Assembly building on the Rispana River’s banks in Dehradun as a glaring example of official complicity in environmental violations. Similar encroachments, like Bhagat Singh Colony on the Rispana and Bindal rivers, reflect collusion between land mafia and government officials, locals allege.

Also Read: Uttarkashi Flash Floods: 274 Rescued, Over 60 Still Missing

Experts attribute the disaster’s severity to human interference, including deforestation, road construction, and construction within riverbeds, which disrupt natural drainage and amplify flood impacts. Prof. K Seshagiri Rao of IIT Delhi noted that encroachments in the Bhagirathi River’s bed altered its flow dynamics, intensifying the mudflow’s destructive force. Satellite imagery from ISRO and Suhora Technologies revealed that Dharali, built on an alluvial fan, was particularly vulnerable, with glacial lakes and glaciers upstream posing ongoing risks of glacial lake outburst floods (GLOFs).

The tragedy echoes past warnings, such as a 2013 report by Uttarakhand’s Disaster Mitigation and Management Centre flagging Dharali as a high-risk flood zone, and the 2023 collapse of a training academy on the Song River in Dehradun. Despite Uttarakhand High Court orders to remove encroachments along the Rispana and Bindal rivers, enforcement remains lax.

With climate change intensifying monsoon variability and glacial melt, experts like Prof. Y P Sundriyal and glaciologist Rajeev Saran Ahluwalia call for stricter land-use regulations, real-time glacial monitoring, and sustainable development to mitigate future disasters. The Dharali catastrophe, they warn, is a wake-up call for the Himalayas’ fragile ecosystem.

Also Read: Maharashtra Tourists Safe After Uttarkashi Floods, Evacuation Underway