Bhotekoshi Flood: A 10-Hour Timeline from Tibet Surge to Devghat

A devastating flood surge originating in Tibet rapidly moved downstream through Nepal's Bhotekoshi and Trishuli rivers over a 10-hour period, according to a technical assessment by the Flood Forecasting Division. Authorities received initial information at 9:05 am on Wednesday that a major flood had entered the Bhotekoshi from the Tibetan side, initiating a cascade of events that would impact multiple districts.

The report details a critical sequence of events. A magnitude 4.4 earthquake was recorded at 8:37 am, shortly before the water-level monitoring station in Syabrubesi, Rasuwa, ceased transmitting data at 8:50 am. Its last reading showed the river at a relatively low 1.62 meters, far below the warning level of 6 meters. Just minutes later, at 9:05 am, the flood's entry from Tibet was confirmed.

Authorities responded by issuing early warnings. Between 9:15 am and 9:16 am, over 600,000 SMS alerts were sent to residents in high-risk areas of Rasuwa, Nuwakot, Dhading, and Chitwan. The Betrawati water-level monitoring station also stopped transmitting data at 9:20 am, having last recorded a level of 3.55 meters. By 10:28 am, the flood was projected to reach the Dhading-Galchhi area, prompting further warnings along the Prithvi Highway and the Muglin-Narayanghat road.

The flood's destructive path continued, with the Phurke river bridge and other structures swept away by 11:43 am. By 1 pm, confirmation arrived that the flood had passed Muglin, and warnings were issued to communities along the river as far as Devghat. The river level at Devghat reached 4.76 meters by 1:30 pm, with initial estimates predicting a peak of around 8 meters. The Kalikhola monitoring station later recorded a peak level of 12.3 meters before the water level at Devghat peaked at 6.57 meters at 4 pm, eventually receding by 6:30 pm.