Landslides triggered by incessant rains damaged transmission pylons along the Dana-Kushma section of the 220kV Kaligandaki corridor on Sunday, forcing 12 hydropower plants with a combined capacity of 358.2 MW to shut down. Including plants taken offline as a precaution, over 790MW was knocked out off the national grid, according to the Nepal Electricity Authority (NEA).

The disruption halted power from key projects, including Nilgiri-1 (38MW), Nilgiri-2 (71MW), Mistri Khola (42MW), and the newly grid-connected Rahughat Hydroelectric Project (40MW).

“The transmission pylons themselves have sustained structural damage,” said NEA Spokesperson Rajan Dhakal. “Power supply from the region cannot resume until technicians assess and reconstruct the damaged towers. All projects along the Kaligandaki corridor are currently offline.”

Dhakal added that flooding forced precautionary shutdowns of an additional 600MW of generation along the Madi and Marsyangdi corridors to protect power plants. To manage the resulting 1,000MW shortfall, the utility cut around 300MW electricity supply to factories in major industrial hubs including Birgunj, Amlekhgunj, Parwanipur, Sunwal, and Butwal.

Project developers said their powerhouses remain intact despite the grid failure. “Our projects suffered no structural damage, but production is entirely halted because the transmission line is down,” said Isha Shrestha, a project promoter.

However, the 40MW Rahughat project sustained physical damage when floodwaters breached its tailrace gate. “The surge damaged the tailrace gate, and erosion is now threatening the switchyard,” said Ganesh KC, managing director of Raghuganga Hydropower Limited, the promoter of Rahughat, adding that the plant had only commenced test production on Wednesday.

This latest disruption exacerbates existing grid vulnerabilities. Heavy flooding in late August had already disconnected 432.1MW along the Trishuli corridor following severe damage to the Trishuli-Chilime transmission line, leaving several major facilities indefinitely out of service.