Efforts have been initiated to resume electricity production from the 456 MW Upper Tamakoshi, the largest hydropower plant currently in operation, as soon as possible.

Last Friday and Saturday, a landslide caused by continuous rainfall inflicted significant damage to the dam structures (headworks) of the Upper Tamakoshi Hydropower Center, located in Lamabagar, Bigu Rural Municipality–1, Dolakha. Several structures, including the control room building situated below the dam on the right side, the desander pond, and the underground channel (culvert) that transports water from the dam to the desander, have been severely damaged. The control room building and its equipment have been completely destroyed. The two desander ponds have been filled with mud, gravel, and large stones. It is estimated that about 75,000 cubic meters of debris, including mud and stones, have accumulated in each of the ponds.

The damage to these structures resulted from the landslide that fell from above the control room, desander, and culvert areas. Four people, including two company employees and two soldiers on security duty, lost their lives. Mud and stones are still coming down the stream.

Electricity production was halted at 7 PM on Friday when water flow in the Tamakoshi River increased due to continuous rainfall. All gates of the dam were opened, which prevented further potential damage to the project structures. The exact damage to the culvert between the dam and the desander is yet to be determined. Due to the suspension of electricity production, the promoter company of Upper Tamakoshi Hydropower is losing approximately NPR 40 million daily in revenue.

A team, including Minister of State for Energy, Water Resources, and Irrigation, Purna Bahadur Tamang, Secretary Suresh Acharya, and Managing Director of Nepal Electricity Authority, Kulman Ghising, along with experts, visited the project site on Tuesday to assess the damage caused by the landslide. The team discussed with the experts and company management various options for repairing the structures and resuming the operation of the power plant. Surveyors from the National Insurance Institute, which insures the hydropower plant, were also part of the team.

Minister Tamang emphasized that the nation is incurring significant losses due to the shutdown of the Upper Tamakoshi, and all possible measures should be adopted to resume electricity production as soon as possible. He assured that the ministry is ready to provide necessary assistance and facilitation.

Managing Director Ghising, who is also the chairman of the board of directors of Upper Tamakoshi Hydropower Ltd., the project promoter company, said that the landslide had caused extensive damage to structures like the control room, desander, and culvert. He mentioned that the risk remains high in the area due to large rocks above the site and that a LiDAR survey will be conducted for a geological study to identify potential risks.

“We can only determine the full extent of the damage to the desander once the debris, including stones and mud, is cleared. So, we are prioritizing removing the debris first,” he said.

He added, “The shutdown of the largest power plant has already created problems with domestic electricity supply, and electricity exports during the monsoon season have been severely impacted. If we fail to resume operations, it will be challenging to manage electricity demand and supply during the winter. Therefore, we are taking all possible measures to restart the power plant as soon as possible.”

Chief Executive Officer (CEO) Mohan Prasad Gautam said that the expert group has provided various suggestions for resuming the operation of the power plant, and maintenance work has already begun based on these recommendations. He mentioned that the 11 kV power line from Gongar, used to operate the dam gates and clean the desander, is being repaired, and the installation of the power transformer and cables has already begun.

Gautam also stated that around 100 meters of the access road near Kavre Cliff, leading from Gongar to the dam site, had collapsed, making transportation difficult.