Upper Tamakoshi resumes power generation after 88 days

The 456 MW Upper Tamakoshi Hydropower Station, Nepal’s largest hydropower facility, partially resumed power generation after 88 days on Tuesday at 7:40 pm following repairs to damage caused by landslides on Sept 27 and 28. 

Currently, the station generates 120 MW of electricity, fully utilizing the available water flow in the Tamakoshi River. Operations had been suspended since 7 PM on Sept 27 due to heavy rainfall that significantly increased the river's flow. The subsequent landslides on Sept 28 caused extensive damage to the control room building, the sand-sluice pond (desander), and the underground canal (culvert) that channels water from the dam to the desander. Additionally, large rocks blocked the approximately 300-meter access road between the Gongar power plant and the Lamabagar dam site, requiring explosives for clearance. Rainfall also damaged Tower 46 of the Gongar-Khimti 220 kV transmission line, which transmits electricity from the station.

The damaged desander has been partially repaired, enabling the hydropower station to operate using river flow for the time being. Full capacity generation, allowing four hours of operation during peak demand periods (morning and evening), will be possible once ongoing desander repairs are completed. The maintenance is scheduled to be finalized by December, ensuring peak-hour operations.

On Dec 3, Kulman Ghising, Executive Director of the Nepal Electricity Authority (NEA) and Chairman of Upper Tamakoshi Hydropower, visited the site alongside the company’s board of directors and CEO to oversee the progress. The team set Dec 25 as the deadline to complete repairs and fully restart electricity production. Ghising later announced that repairs had been completed ahead of schedule, enabling electricity generation to resume partially. 

“The descender was filled with rocks and debris. Additionally, two company employees and two soldiers lost their lives in a landslide, creating fear among the remaining workforce. With no access road, no power supply, and challenging circumstances, our team worked tirelessly to restore operations. Through collective efforts, we managed to resume partial electricity generation,” said Ghising.

Ghising also noted that restarting the country’s largest power plant eases electricity supply challenges and reduces dependence on imports from India during peak hours. 

Mohan Prasad Gautam, CEO of Upper Tamakoshi Hydropower, highlighted that the repair efforts followed a detailed action plan informed by expert recommendations and regular monitoring. This collaborative approach allowed electricity generation to resume earlier than expected.

The repair costs will be covered by the company’s insurance. An initial claim of Rs 1.78bn has been filed with National Insurance Company, which is jointly assessing the damage with the hydropower company. The insurance will also compensate for two months of lost revenue from electricity sales, as outlined in the agreement.