Tue , 28/06/2022, 17:09:00 (GMT+7)
Dak Ba HP was undertaken by Bach Thien Loc Joint Stock Company (a unit with 100% of the capital of Vinaconex Corporation) as the investor, on the Dak Ba stream (having the local name of Dak Bua), which is a level 1 line of the Dakdrinh River’s upstream that belongs to Son Bua and Son Mua communes, Son Tay district, Quang Ngai province.
The project's exploitation diagram contains a run-of-river combined with a spillway dam on Dak Ba stream, an energy route in penstocks on the left dam side (the energy route includes water intake – penstocks - outflow), an open-air power plant located in the Son Tay district's urban area, and spillway channels returning water to Lay stream that flows into the Dak Drinh river.
Typical hydropower project construction times, excluding survey and planning time, might range from three to five years. Vinaconex, on the other hand, only needs 18 months to conquer the Dak Ba "energy river".
Since the project is located in high mountains where the terrain is sharply separated by the flow, there is no optimal space to set up the sub-tunnel to speed up the process. The entire energy route has a 330-meter height difference without vertical wells that results in a 5.32% tunnel slope and more water accumulation during the rainy season. As a result, the tunneling construction faced many obstacles. To address this issue, VINACONEX organized 6 construction sections throughout the 7897-meter-long main tunnel, with each section working in three consecutive shifts 24 hours a day, regardless of weather. On June 9, 2022, the last drill G5 was completed after 444 days of construction, officially breaking through the entire tunnel of Dak Ba HP.
The open-air power plant is located right in the urban center of the Son Tay district. In order to minimize noise for local schools and administration offices, VINACONEX had made use of hydraulic hammers along with self-propelled drilling as well as out-of hours construction. VINACONEX general contractor finished 12,000 m3 of rock and soil using hydraulic hammers just in 5 months, which is a feat not accomplished by any project.
Taking into account the harsh weather and landslide-prone soil layer of the South Central Coast, at the beginning stage of executing dams, Vinaconex had a variety of inventive construction plans to deal with such obstacles. Particularly, Vinaconex completed more than 200,000 cubic meters of soil and rock, reinforced the foundation, and completed the left dam side, diversion channel in 2021 so that in 2022, the constructor could continue completing the right dam side and other items.
VINACONEX also prioritizes the project's quality along with the schedule. Many geological treatment methods, such as reinforcement, waterproofing, etc., were used before moving on to build the dam structure.
As the Dak Ba HP operates in accordance with the water column and reservoir, the project's total site planning only covers 50.53 hectares, of which there’s no natural forest or protection forest, only 3.3 hectares of production forest. As a result, the project has no great impact on the local ecology and environment.
Vinaconex not only accelerated execution during the wet season but also prioritized environmental conservation and restoration. The taluy grass system is being planted quickly to green the regions around the plant and dam. It’s expected that by the time of operation, there will be a green - clean ecosystem thanks to the early planting of trees.
Regardless of the difficulties of the pandemic and harsh weather, the Dak Ba hydropower project has attained 70% of its power production, and be ready for power generation on the national grid in December 2022. When completed, Dak Ba HP is going to have a capacity of 30 MW, an average annual power of 100.43 million kWh, and an approximate revenue of VND 130 billion per year. It would contribute more than VND 20 billion to the local budget, helping the socio-economic growth and economic restructuring of Son Tay District, which is a mountainous region with many difficulties in Quang Ngai Province.
Some remarkable photos of the Dak Ba Hydropower Plant.