Er.energyNP@Gmail.com

Construction of the 140 MW Tanahun Hydropower Project, a national-priority reservoir project being developed under the full ownership of Nepal Electricity Authority (NEA), has gathered momentum, with overall physical progress reaching 77.5 percent.

The project, being constructed on the Seti River with concessional financing from the Government of Nepal, NEA and international development partners including the Asian Development Bank (ADB), Japan International Cooperation Agency (JICA) and the European Investment Bank (EIB), has divided its major construction works into three packages.

The project is regarded as strategically important for strengthening Nepal’s energy security and expanding the country’s experience in developing reservoir-based hydropower projects.

Main dam construction reaches 62 percent

Under the first package, construction of the 140-metre-high main dam and associated structures is being carried out by Sinohydro-Kalika JV.

The Seti River diversion and construction of the cofferdam at the dam site have already been completed. Concrete placement for the main dam began in March/Chaitra 2025, and approximately 448,516 cubic metres of concrete has been placed so far.

The overall physical progress of Package I has reached 62 percent.

The dam is one of the most critical components of the project, as the reservoir created by the structure will enable regulated water flow and support electricity generation throughout the year.

Underground powerhouse and electromechanical works advance

Construction under Package II is being carried out by Sinohydro Corporation. Major civil works related to the underground powerhouse, main tunnel, cable tunnel and surge tank have already been completed.

The overall progress of the second package has reached 78.5 percent.

With major excavation and civil works substantially completed, the project has entered a crucial phase involving the installation of electromechanical equipment. Turbines, generators, main inlet valves, transformers and other equipment are being installed.

The main access tunnel, audit tunnels, main tunnel and the 46.88-metre-high intake shaft with a diameter of 14.3 metres have been excavated completely.

Concrete works for the powerhouse, cable tunnel and tailrace structures have also been completed, while installation of turbine, generator and transformer equipment is continuing.

Tanahun Hydropower Limited Project Manager Shyamji Bhandari said construction was progressing according to schedule.

“We are working according to the timeline, and more than 77 percent of the project has already been completed,” Bhandari said. He added that work on the hydromechanical components, transmission line and dam was progressing rapidly.

According to him, completion of the project will strengthen Nepal’s energy security while also increasing confidence in the development of additional reservoir-based hydropower projects in the country.

220 kV transmission line reaches 81 percent

Construction of the 35-kilometre, 220 kV transmission line from Damauli to Bharatpur, being developed under Package III, has also reached its final stage.

The package is being implemented by India-based KEC International, with overall progress reaching 81 percent.

Of the total 94 transmission towers, foundation works for 82 towers have been completed, while 72 towers have already been erected.

Tree cutting and safe storage within community forests along the transmission line right-of-way in Tanahun and Chitwan are being carried out in accordance with prescribed health, safety and environmental standards.

Orientation programmes on tree cutting and safe storage have also been conducted in the affected community forests before the work was undertaken.

Community and environmental programmes continue

Alongside the physical construction, the project has continued social and environmental safeguard programmes in affected areas.

Under community development programmes implemented through local consumer committees, dozens of projects have already been completed, including access roads, bridges and school buildings. The project management says several additional schemes are currently under implementation.

In the affected areas, consultations are also continuing with local residents on land acquisition in the buffer zone, verification of claims over ailani (unregistered) land and compensation determination.

The compensation determination process has been accelerated, including collection of claims relating to ailani land in the dam inundation and buffer-zone areas and field verification by surveying technicians.

As part of the Gender Equality and Social Inclusion programme, women from the Magar community in Paltyang of Rishing Rural Municipality-8 have been supported through off-season vegetable farming and financial literacy training. Agricultural equipment and hand tractors have also been distributed under the programme.

Orientation on safeguard policies has additionally been provided to officials of the compensation determination committee to make land acquisition and compensation distribution more transparent.

ADB delegation reviews project progress

An ADB delegation led by an alternate member of the ADB Board of Directors visited the project site in July 2026 to review the overall progress and implementation of environmental and social safeguard policies.

Following the field visit, the delegation reportedly assessed the project’s progress as satisfactory.

Lower Seti project being advanced

The Tanahun project is also expected to create an opportunity for further hydropower development downstream.

A 126 MW Lower Seti Hydropower Project is being advanced in the downstream area by utilizing the regulated flow from the Tanahun project.

The detailed project report (DPR) for Lower Seti has been prepared, while its Environmental Impact Assessment (EIA) report has been submitted to the Ministry of Forests and Environment for approval. Work on an exploratory tunnel is also underway.

The development of the Lower Seti project is expected to enable further utilization of the regulated water flow generated by the Tanahun reservoir.

Project cost exceeds $500 million

The total estimated cost of the Tanahun Hydropower Project stands at approximately US$505 million, including the transmission line, rural electrification and interest during the construction period.

Of the total financing, ADB is providing US$150 million, JICA US$184 million, EIB US$85 million, while the Government of Nepal and Nepal Electricity Authority are contributing US$87 million.

Loan agreements between the Government of Nepal and the respective development partners, as well as subsidiary loan agreements between the Government and NEA and between NEA and Tanahun Hydropower Limited, have already been concluded.

With the dam, underground powerhouse, electromechanical installations and transmission infrastructure moving ahead simultaneously, the project is now entering a decisive stage of construction.

The authorities are aiming to complete the project within the stipulated timeframe, with the 140 MW reservoir-based plant expected to make a significant contribution to Nepal’s domestic electricity supply, energy security and long-term hydropower development.