The river, which flows along the boundary of Rishing Rural Municipality-1 and Byas Municipality-5, is 140 meters wide. In order to facilitate the construction of the concrete main dam, a tunnel measuring 626.92 meters in length was built and diverted from the upper coastal region.
The water that was diverted from the main dam construction site through the diversion tunnel has been released d into the Seti River in the lower coastal region.
A 40-meter high temporary concrete coffer dam will be built to redirect the river during the construction of he main dam. The dam will be constructed before the next monsoon.
Under package-1, PECC1 and Song Da – Kalika Joint Venture is building a 140-meter-high dam.
Since the issuance of the construction supervision consultant's order to commence work under the purchase agreement, Sino Hydro has been actively operating at the project site since January 6, 2075 and is currently progressing with the construction work.
Excavation of the underground power plant has been successfully completed, with equipment installation including concreting and turbines underway. The tailrace tunnel construction has been completed, and the main tunnel excavation is ongoing. The construction progress for the civil aspect of this package has exceeded 70%, while the overall progress stands at around 47%.
Under the social development initiative of the project, the Tanahun rural electrification and distribution system enhancement project was implemented through the project management office of the Nepal Electricity Authority for the purpose of electricity access in Tanahun district.
Two 33-11 kV substations were constructed and commissioned in Ghiring Rural Municipality-4 and Bandipur Rural Municipality-6 to provide electricity to the local communities.
A 33 kV line was constructed to supply electricity to the substations. To ensure reliable and high-quality power supply in the Tanahun district, distribution transformers of various capacities were installed in different locations, and 11 kV lines were constructed.
The total cost of the capital structure and financial management project for the company is $ 500.5 million. The cost includes expenses for transmission lines, rural electrification, and interest during the construction period. The Asian Development Bank (ADB) will provide 1 $ 150 million, the Japan International Cooperation Agency (JICA) will contribute $ 184 million and the European Investment Bank will provide $ 180.4 million. Additionally, the Government of Nepal/Nepal Electricity Authority will contribute $80.6 million.
This has been the highest dam in any hydropower project in Nepal so far with very complicated topography and geology. The project has been presently received great attention from the government and people of Nepal.
The Tanahu HPP with a capacity of 140 MW was built to meet power demand in Nepal, especially during the dry winter months. This hydropower plant will operate as a load control plant for the remaining time of the year. The plant's average annual power output is estimated to be 587.7 GWh (From 1st year to 10th year) and 489.9 GWh (from 11th year 11 onwards). The project is designed to reduce fossil fuel-based power generation and will help stabilize Nepal's power supply system and reduce transmission losses. The project's overall construction progress is currently at 46%, with the target completion date set for May 2026.
In package 1 of the project, PECC1 plays the following main tasks:
- Update and evaluate the hydro-meteorological and geological conditions of the headworks.
- Prepare Technical Design and Construction Drawing for headworks including 140m gravity concrete dam, spillway with 4 bays with their dimension of 12.7x12.7m, discharge capacity of 7377m3/s, 2 low-level outlets with their dimension of 3.8x3.8m, sand flushing hole of 5x5m, and the environmental discharge hole of 1.2x1.2m.
- Design stilling basin and auxiliary concrete dam at the downstream;
- Design six grouting galleries in the dam (total length of 1,350 m) and the access adits to the grouting galleries as well as to the US cofferdam (total length of 1,020 m);
Some photos at the ceremony are given below:
Guests and delegates taking part in the ceremony