Tanahun Hydro's dam construction in full swing

By Our Correspondent,Tanahun, Aug. 11: The construction of the 140-megawatt Tanahun Hydropower Project under construction in Jhaputar of Rishing Rural Municipality-1, Tanahun, is moving in full swing. 

Project chief Shyamji Bhandari said that work on the main dam is in full swing and 73,000 cubic metres of concrete have been constructed in a short period of time.

Bhandari said that out of the approximately 900,000 cubic metres of concrete required to be constructed for the main dam, 73,000 cubic meters have been constructed so far.

He said that the work for the concrete of the main dam began on March 20, 2025 and the work has been accelerated. Under the project's 'Package-1', the dam construction has been taken forward by diverting the Seti River in Vyas Municipality-5 and Rishing Rural Municipality-1, according to the project. 

According to Bhandari, concrete blocks have been lifted to an average height of 10 metres above the foundation of the dam for the construction of the 140-metre-high dam. 

As the temperature control of the large concrete of the high dam is considered very sensitive, the work is being done keeping that in mind. The foundation digging work began on November 6, 2023 and was completed in July 2024.

The work began by diverting the Seti River, which flows through the border of Rishing Rural Municipality-1 and Vyas Municipality-5, from the upper coastal area above the construction site of the 140-metre-high concrete main dam and constructing a 626.92-metre-long tunnel. 

The water channeled through the diversion tunnel was released back into the Seti River through the lower coastal area from the main dam construction site. The construction of the 140-metre-high dam under Package-1 began on August 30, 2021, and the progress so far is 43.5 per cent. 

According to Bhandari, the structural work inside the power house under 'Package-2' has been completed and equipment are being installed. He said that about 67 per cent progress has been made in the underground power house under 'Package-2' and 74 per cent in the construction of the transmission line under 'Package-3'. Project Chief Bhandari said that the work has been affected due to delays in the use of land in the forest area for the construction of the transmission line and the removal of trees and plants there. 

For that, the project is conducting necessary consultations, coordination and facilitation with the concerned bodies, he said. The overall construction of the project is targeted to be completed by mid-July 2026. The total cost of the project is 505 million US dollars. 

Of that, Asian Development Bank will bear US$ 150 million, Japan International Cooperation Agency (JICA) US$ 184 million, European Investment Bank US$ 85 million and the Government of Nepal/Nepal Electricity Authority US$ 86.

It is estimated that the project will generate an average annual electricity of 587.7 million units for the first 10 years after the start of electricity production and 489.9 million units thereafter.