Second diversion tunnel of Tanahun Hydro Project makes breakthrough

By Amar Raj Naharki,Tanahun, Mar. 13: Breakthrough was made in the diversion tunnel-2 of the 140 MW Tanahun Hydropower Project, which is under construction at Jhaputar in Rishing Rural Municipality-1 Tanahun, on Sunday.

Such breakthrough was made in 539-metre tunnel-1 one and a half months ago.  Shyamji Bhandari, managing engineer of Tanahun Hydro Power Limited, informed that both diversion tunnels were made to divert the river water to construct the dam of the project.

He informed that the  tunnel-2 is 626.92-metre long.  

“The river can be made dry for the dam construction even during the rainy season by sending water from the two tunnels. However, the tunnels built on the riverbed will be closed after constructing the dam,” he said.

According to the project, both the tunnels are 11.4 meters in diameter. 

Rajabhai Shilpkar, chief of the project, said that 35.34 per cent of the project work has been completed so far. Work is being done in three phases and 31.82 per cent of financial progress has been made so far. 

During this period, 13.75 billion have been spent so far, he added.

Under the first package of the project, structures including a 140-meter high dam are being constructed by Song Da Corporation, Vietnam-Kalika Construction Private Limited and Nepal JV.

For the construction of the main dam, the diversion tunnels, tunnels, excavation of the upper part of the dam and slope and upgrading of the access road are being done.

The second phase construction including the project’s tunnel, powerhouse construction and import, supply and installation and operation of hydromechanics and electromechanical equipment is being done by the Sino Hydro, China.

Under the third package of the project, the construction work of a 220 KV double circuit transmission line from Damauli to Bharatpur in Chitwan is being done by KEC, India. The overall construction of the project is targeted to complete by June/July 2026.

The total cost of the project is 500.5 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.