Dharali disaster: Bhagirathi blockage partially breached, monitoring failures exposed

By A Representative 

A partial breakthrough has been achieved in the efforts to drain the artificial lake that formed on the Bhagirathi river following the devastating Dharali disaster in Uttarakhand on August 5, 2025. After 11 days of mounting concern and frantic operations, the joint team of departments involved succeeded in partially breaching the blockage near Harshil on August 16, easing fears of a sudden outburst flood. The artificial lake, reportedly 1.2 to 1.5 kilometers long, formed after a flash flood in Tel gaad stream dumped a massive load of debris, uprooted trees, and silt into the Bhagirathi, blocking most of its course opposite Harshil town. The deluge, accompanied by heavy floods in Kheer gaad and Bhela gaad streams, triggered the chain of destruction in the valley.

The disaster not only submerged orchards, a helipad, and sections of the Gangotri National Highway but also damaged an Army camp on the riverbank, where nine personnel from the 14 Rajputana Rifles went missing. For days, rising water levels in the lake threatened to inundate Harshil town and downstream areas, forcing many residents to evacuate. Local people had been demanding urgent drainage of the lake, fearing a catastrophic breach. Early assurances from the irrigation authorities that the lake posed no immediate danger were dismissed by residents, who saw floodwaters inching closer to homes and orchards.

Repeated attempts to deploy heavy machinery were thwarted by difficult terrain, collapsed roads, and unstable debris. One poclain machine deployed to widen the lake’s mouth was submerged, nearly costing the operator his life. As weather hampered operations, manual methods supported by SDRF, NDRF, and UJVNL teams became the primary recourse. Geologists eventually recommended a phased drainage plan through small diversion channels, aiming to reduce the risk of a sudden downstream flood. By August 16, a new channel on the left bank began carrying a significant volume of water, providing relief to residents even as large flows continued to erode the right bank of the river, threatening government buildings, homes, and orchards.

The South Asia Network on Dams, Rivers and People (SANDRP), which has been closely monitoring developments, raised sharp questions over institutional preparedness and monitoring failures. “The Harshil station of the Central Water Commission (CWC) remained non-functional for about three days during the most critical period,” SANDRP said, pointing out that the CWC neither shared real-time data nor informed the public about the situation until prodded on social media. The group emphasized that such lapses during Himalayan disasters have been repeated, citing the February 2021 Chamoli tragedy and the October 2023 Teesta floods. “This once again exposes fundamental inadequacies of CWC’s flood monitoring and forecasting work,” SANDRP added.

Experts also recalled that the Bhagirathi river has faced such blockages in the past, including a major one in 1978 at Dabrani that created a 30-meter-high lake, which later breached, causing destruction downstream up to Chinyalisour. A smaller blockade in 1992 had forced the closure of the Gangotri road for nearly a month. The present episode, they argue, underscores the fragility of Himalayan rivers and the need for robust early warning systems, innovative monitoring technologies, and coordinated disaster preparedness.

While water levels at Harshil declined by about 0.8 meters between the night of August 16 and the morning of August 17, officials admit that erosion threats remain acute and the work to stabilize the river course will continue. With the Tehri dam reported to be safe and below capacity, the immediate flood threat downstream has been averted, but the incident has left behind serious questions about governance, accountability, and resilience in one of India’s most vulnerable river valleys.