- With the partial repair of both sand-settling ponds damaged by the landslide completed, the project has resumed generating 456 megawatts of electricity.

- On October 28 last year, a landslide buried both desanders of the hydropower plant, along with the power operation control room and the underground tunnel.

The domestically funded Upper Tamakoshi Hydropower Project has begun generating electricity at full capacity around the clock. Following the partial repair of both sand-settling ponds (desanders) damaged by a landslide, the plant has resumed 24-hour electricity generation at its full capacity of 456 megawatts.

On October 28 last year, a landslide buried both desanders of the hydropower plant, along with the power operation control room and the underground tunnel (culvert). This caused significant damage to those structures, resulting in a three-month shutdown of electricity production.

Last January, after repairing the left-side desander among the two sand-settling ponds, the plant began generating electricity based on river flow by opening all the dam gates. Following the partial repair of the right-side desander, the plant started storing water at the dam site and resumed full-capacity operation, according to project manager Purnagopal Ranjit. He stated that since Thursday afternoon, the Upper Tamakoshi Hydropower Project has started generating 456 megawatts of electricity around the clock.

“We have brought the Tamakoshi Hydropower Plant into full operation,” said Ranjit. “The reconstruction has not yet been completed to restore it to its original state. However, to minimize losses during the three months of the monsoon, we have operated the plant by partially bringing both desanders into use.” He added that it will take another 45 days to fully complete the reconstruction of both desanders.

“Waiting another one and a half months for full reconstruction would have further increased the financial burden on the Tamakoshi company, so for now, we prepared the structures partially and resumed full-capacity generation,” he said. “The underground tunnel damaged by sediment has been repaired. By storing water in the dam, 456 megawatts of electricity will be generated around the clock until October.”

As it is the monsoon season, electricity generation will be carried out while also considering the risk of flooding, said Ranjit. The design discharge (water flow capacity) of the Tamakoshi Hydropower Plant is 66 cusecs. During the continuous rainfall last October, the flow of the Tamakoshi River at the dam site had reached 461 cusecs. According to the Power Purchase Agreement (PPA) signed with the Authority, the power plant must be shut down if the water flow exceeds 250 cusecs.

The construction of the power control room of the hydropower plant is currently underway. The landslide had completely destroyed the control room building, claiming the lives of two staff members and two army personnel. Upper Tamakoshi had filed an insurance claim worth NPR 1.8 billion for damages caused by the landslide to civil structures, electromechanical systems, and other equipment.

Tamakoshi has the capacity to produce electricity worth 40 million rupees per day. It has been facilitating load management by generating electricity according to demand for the Nepal Electricity Authority throughout the country during the winter season. In winter, the authority operates Tamakoshi as a backup for load management. The Upper Tamakoshi project, which is of the semi-reservoir (PROR) type, operates at full capacity during the monsoon and for four hours daily during winter.

During the winter season, Upper Tamakoshi Hydropower Company Limited is constructing a new project to divert water from the Rolwaling River to extend the hydropower plant’s full capacity operation to six hours. This project will generate an additional 22 megawatts of electricity. After power generation, the water from this project will be discharged into the Tamakoshi Hydropower Plant’s dam site.

Source: Kantipur