West Bengal issues alert as Bhutan glacial flood targets Sankosh River

UPDATE - follow-up to Bhutan glacial lake outburst triggers flood, no injuries reported: West Bengal state authorities have issued urgent evacuation warnings for residents along the Sankosh River after a glacial lake burst its banks in Bhutan. State Forest and Environment Minister Manoj Kumar Oraon urged people to spread warnings quickly, noting that a dam breach in Bhutan could send floodwaters rushing downstream within one to one-and-a-half hours. The specific areas placed on high alert include the upper Sankosh forest village, the NKC Sankosh Tea Garden, Kumargram CD block, Chengmari, Valka Barabisa, Jharaguri, and Pakriguri.

Damage And Response

The disaster began when the Shintaphu glacial lake, located below Wakila Mountain in the Gasa district, suffered an outburst. The torrent destroyed structures at the Gasa Tshachu natural hot springs in northern Bhutan and tore apart two portable Bailey bridges. Portions of the road leading to Laya village were swept away, prompting an indefinite traffic closure. According to the state broadcaster BBS, residents in Bhutan had already been evacuated before the high waters arrived, and no injuries or deaths have been recorded.

Context

Glacial lake outburst floods happen when melting ice rapidly fills mountain lakes until natural barriers give way, sending massive walls of water downstream into river valleys. Authorities in both India and Bhutan maintain close watch over these vulnerable Himalayan watersheds as rising global temperatures increase the frequency of such sudden alpine floods.