The 140-megawatt Tanahu hydropower project in the Tanahun district has achieved 63 percent physical progress, raising hopes of power production by its stipulated completion deadline of May 2026.

Divided into three packages, the overall financial progress of the project is 58 percent.

Nepal has only two storage projects—Kulekhani I (60 MW) and Kulekhani II (32 MW).

The project, which will be Nepal’s third storage type, is 150 km west of Kathmandu on the Seti river near Damauli in the Tanahun district.

Shyamji Bhandari, project chief, said grouting is being done in the lower level area of ​​the main dam under package 1. Grouting is one of the most popular methods for controlling water leaking in fill dam constructions.

According to him, a 140-metre tall dam will be constructed on the Seti river, which flows through the border of Rishing Rural Municipality-1 and Byas Municipality-5 in Tanahun district.

“We are preparing to start constructing the main dam soon,” Bhandari said.

The first package—a 140-metre-tall dam and other structures—is being constructed by a joint venture of Song Da Corporation, Vietnam, and Kalika Construction Pvt Ltd. Bhandari said that the physical progress of the first package has reached 36 percent.

Similarly, under package 2, work has been underway on the concrete lining, a layer of cement placed on the subbase of the 1,493-metre-long tunnel starting from the reservoir's intake and ending at the penstock pipe.

Bhandari said the installation of the penstock pipe is in the final stage.

"The water from the main tunnel will be released through a 213-metre-long penstock pipe to a powerhouse, which will be underground," he said.

The hydro-mechanical works have been contracted to Sinohydro Corporation of China.

The project said the construction of the powerhouse is also in the final stage, adding that the construction of the switchyard and installation of equipment in the powerhouse are underway. The physical progress of package two is about 62 percent.

KEC International Limited India is undertaking package 3, which consists of building a 220 kV double-circuit transmission line from Damauli to Bharatpur in Chitwan.

According to the project, out of the 94 towers in the 34.7 km transmission line, the foundation of 78 towers has been laid, and 69 towers have been erected. The progress of this package is 74 percent.

The project said the overall construction is set to be completed by May 2026.

The project will be one of Nepal’s biggest storage-type projects, with an estimated annual energy generation capacity of 587.7 GWh for the first 10 years and 489.9 GWh from the 11th year. During the dry season, the project can generate energy for six hours daily.

The project is being co-funded by the Asian Development Bank (ADB), the Japan International Cooperation Agency (JICA) and the European Investment Bank.

A $150 million loan agreement was signed with the ADB on February 21, 2013. A similar loan agreement for $183 million was signed with JICA on March 13, 2013, and an agreement with the European Investment Bank on May 7, 2013, for a $70 million loan, which was later increased to $85 million.

The government and the Nepal Electricity Authority will use their money to build the infrastructure during pre-construction. The project is estimated to cost $505 million, and the Nepal government will contribute $86 million.

On Monday, a team consisting ADB country director for Nepal Arnaud Cauchois and Nepal Electricity Authority executive director Kulman Ghising, including the chairman of the board of directors of Tanahu Hydropower Limited, conducted on-site monitoring of the project and instructed it to complete the construction on time.

Under the project's social development programme, the rural electrification and distribution system to electrify Tanahun district has been completed through the project management directorate of the Nepal Authority.

Under this, two 33/11 kV substations for local electricity supply have been built and operated in Ghiring Rural Municipality-4 and Bandipur Rural Municipality-6.

A 33 kV line has been constructed to supply electricity to the substations.

The project said that distribution transformers of different capacities have been installed, and 11 kV lines have been constructed in various places to make the electricity supply of Tanahun district sufficient, reliable and of good quality.

Under the community development programme, 63 projects, including education, health, drinking water, roads, river embankment construction, etc., have been completed in the project-affected areas. Ten projects are currently running. Various skill-based trainings are being conducted to generate livelihood and income for project-affected people.

Tanahu Hydropower Limited, a subsidiary of Nepal Electricity Authority, has also advanced the development of the 126MW Lower Seti Hydropower project downstream of the Seti river.

The Consultant, JV of WAPCOS Limited, India and Nippon Koei Co. Ltd, Japan, submitted the final Detailed Design Report in June 2024.