A newly formed artificial lake in Bhutan breached on Friday after a landslide, washing away temporary bridges and prompting authorities in Bengal’s Alipurduar and Assam’s Dhubri to monitor downstream conditions following a glacial lake outburst flood in the same river system last week.
The lake was created when a massive landslide struck the right bank of Sinthaphu Lake in Bhutan’s Gasa district on Wednesday night. Sinthaphu Lake drains into the Mo Chhu, which flows downstream into Bengal’s Alipurduar and Assam’s Dhubri as the Sankosh river.
The breach occurred on Friday morning, with water flowing downstream from a location around 1km upstream of Taktsemakhang in Laya block, according to information cited by The Telegraph. The Gasa district administration confirmed the breach on Friday afternoon.
“Following the breach…, temporary bridges recently built at Tongchudra and Taktsemakhang have been washed away completely. In view of the current situation, the public is strongly advised not to travel towards Laya until further notice,” the district administration said in a Facebook post.
The latest incident follows a glacial lake outburst flood, or GLOF, from Sinthaphu Lake last week. After that flood, an alert was issued and around 8,000 people were moved to safer locations. However, residents returned to homes along the Sankosh after the river receded swiftly.
The formation and subsequent breach of the artificial lake has created a fresh risk in a river corridor that crosses national boundaries before reaching communities in eastern India. The immediate effects reported from Bhutan include the loss of the temporary bridges at Tongchudra and Taktsemakhang and restrictions on travel towards Laya.
A joint team from Bhutan’s National Centre for Hydrology and Meteorology and the Department of Geology and Mines inspected the site after the breach. Kuensel, Bhutan’s national newspaper, reported that the inspection team found that landslides were still active.
The authorities advised communities and other stakeholders downstream to remain vigilant while asking them not to panic. The warning comes as local administrations in India continue monitoring the Sankosh system after the earlier GLOF and the return of residents to riverbank settlements.
District administrations in Alipurduar and Dhubri, along with India’s Central Water Commission, are monitoring the situation. No further downstream impact or evacuation order in the Indian districts was specified in the supplied report.
The Gasa administration’s travel restriction towards Laya remains the immediate official measure cited after the breach. Monitoring by the Bhutanese agencies, the two downstream district administrations and the Central Water Commission is expected to continue as authorities assess conditions along the river system.
