On October 19, 2021, the Company will join the atmosphere to celebrate the 91st anniversary of the founding of the Vietnam Women’s Union (October 20, 1930 – October 20, 2021), with the consent of the Company’s Leaders. On the occasion of Vietnamese Women’s Day (20/10), the company’s grassroots delegation met and congratulated female employees of Construction Joint Stock Company 47 (HOSE: C47).

Throughout the Company’s 46-year history, generations of women of CC47 have always promoted the good tradition of Vietnamese women “Good at work – take good care of housework.” CC47’s women are always smart, hardworking, creative, and brave, and they have made significant contributions by successfully completing the goals and tasks assigned to them by the Company’s leaders, thus contributing to CC47’s success. The CC47 brand is becoming increasingly powerful.

Speaking at the meeting and presenting flowers on behalf of the Company’s leaders, Chairman of the Board of Directors Pham Nam Phong expressed his best wishes to the women while also recognizing the company’s role and importance in general, and CC47 women in particular. Chairman Pham Nam Phong hoped that CC47 women would continue to promote the precious tradition of Vietnamese women in the new era, making positive contributions in production to help the company grow.

Despite the most difficult challenges, such as the Covid-19 epidemic, the main project of Tan My Reservoir has been completed and will be operational by the end of 2021.

Multi-purpose project

Ninh Thuan is the country’s driest region, though water still flows into the sea. Ninh Thuan currently has 21 reservoir with a capacity of 194 million m3, a subsurface flow of 1.94 billion m3, and an annual amount of water transferred from Da Nhim hydropower plant to Ninh Thuan province of 0.57 billion m3. The total amount of water available from all sources is approximately 2.51 billion m3/year. Cai River is the main river of Ninh Thuan province, with most of its flow concentrated during the flood season and many peaks exceeding 5,000m3/s.

Because the flow is very low during the dry season, fluctuating between 2 and 5 m3/s in early March, the Ministry of Agriculture and Rural Development and experts have decided to build Tan My reservoir in Phuoc Hoa commune, Bac Ai district. The reservoir with a capacity of 219 million m3 is responsible for regulating the flow, which is critical in ensuring water supply and socioeconomic development in Ninh Thuan province.

Tan My irrigation system has a total investment of 5,951 billion VND. As a multi-purpose and inter-provincial project, Tan My project is the heart of Ninh Thuan irrigation and is particularly interested and closely directed by the Ministry of Agriculture and Rural Development and the People’s Committee of Ninh Thuan province.

The main components of the Tan My Irrigation System Project are the Tan My rolling weir, the 29.6 km long pressure channel pipeline system, and the Song Cai Reservoir focal cluster of works. According to the Management Board of Irrigation Construction and Investment 7 (Board 7), the investor stated that the Tan My Irrigation System design survey began in August 2010 and had been ongoing since 2008. However, due to the project’s delay, it would not be restarted until 2015.

Tan My weir and channel system from location K0-K21.8  was completed and handed over for operation from February 2020. The focal cluster of Song Cai Reservoir, including 5 connected concrete dams with 2,770m in length, 66.7m in height. The focal cluster has a capacity of 219 million m3 and was constructed in early 2018. The Project’s main tasks include: irrigation and water supply for 7,480 ha; water supply  for 12,800 ha of Nha Trinh – Lam Cam irrigation system; and water supply of 2.5 m3/s for irrigation areas of Cho Mo, Ba Rau, Song Trau, Ong Kinh, and others, as well as 2.56 m3/s of water for domestic, service, industrial, livestock, and aquaculture.

At the same time, it creates source for Bac Ai pumped-storage hydropower with a capacity of 1,200 MW and 2 hydropower plants with a capacity of 24 MW. In addition, the Tan My irrigation system also creates a source of water for the South Cam Ranh area (Khanh Hoa province); Mitigation of downstream floods and lake bed aquaculture.

Overcome difficulties to complete the construction on schedule

Due to the water shortage for production, daily lives of local residents in droughts, Ninh Thuan witnessed a heavy suffer from damages (the drought in 2015 to May 2016, the loss was about 700 billion VND; the drought in the dry season 2020 caused an economic loss of about 740 billion dong).

At the end of May 2020, leaders of Agriculture and Rural Development Department were assigned to work in Ninh Thuan Province in an attempt to help the locality overcome the drought. The leaders affirmed that the Tan My focal cluster of works would be ready for water storage by 2020 in order for overcoming drought, stabilizing the local livelihood and developing the socio-economic situation.

Under the closely direction and observation from the Leaders of Agriculture and Rural Development Department as well as the People’s Committee of Ninh Thuan province in recent years, the construction process was implemented in 3 continuous shifts, particularly in the 45-day emulation campaign to overcome the main flood in 2020.

To this point of time, the main project has completed 98 percent of the work volume, with many items was fully completed. As a result, 1.13 million m3 of various types of concrete were poured, 1.45 million m3 of soil and rock were dug and filled, 1,265 tons were processed and manufactured, and 1,513 tons of equipment were installed.

The work was inspected by the State Inspection Council on March 11, 2021, and it was agreed to allow blocking the flow and storing water; the expert group highly praised the project’s quality and management. According to the progress, after blocking the stream, it will be completed and put into use by the fourth quarter of 2021, contributing to the stabilization of people’s lives and the socio-economic development of Ninh Thuan province.

According to the leader of Board 7, the main project of Tan My Lake was built using roller compacted concrete technology. The Covid-19 epidemic broke out in many parts of the country recently, and the situation was very complicated; contractors faced many difficulties in mobilizing technical staff and workers to transport materials and equipment to the construction site, causing the project to be delayed.

“However, under the close observation of leaders from the Ministry of Agriculture and Rural Development, the People’s Committee of Ninh Thuan province, Tan My Lake has accumulated nearly 60 million m3, and will store water to a height of 181.3m with a capacity of nearly 112 million m3 after the main flood season and handed over to the locality for use by the end of 2021, contributing to the fight against drought in the following year’s dry season, as well as the socio-economic development.”

In terms of quality management, the works are built in accordance with the design process, technical instructions, and current construction standards and regulations. Material, construction product, component, and installation equipment testing and inspection results met design requirements. We conducted extensive product testing of roller compacted and reinforced concrete samples in the room with a total of 2,193 samples.

In addition, 11 experts from the construction industry, including leading scientists, industry managers, and the State Inspection Council, are participating in the construction process. The project has been inspected seven times, including one inspection and review of technical design, six site inspections, construction inspections, quality control, quality management, and acceptance work inspections.

In February 2021, the Council for State Inspection of Construction Works inspected and agreed to store water beginning March 15, 2021, two months ahead of schedule and in time to catch minor floods, contributing to participation against drought during the dry season in 2021; disbursement results in the first nine months of the year reached 66.6 percent of the assigned capital plan.

On October 7, the Construction Management Department and experts collaborated with Ninh Thuan province’s functional sectors to inspect flood and storm prevention, progress, and quality management of the works. As a result, the expert team evaluated the main construction work items meet the requirements specified in the design documents and the dam was stable.

After checking, Mr. Nguyen Tai Son, an expert from the Construction Management Department’s descriptor group, stated that the Song Cai dam was built with very good technique. The samples taken directly from the dam system met the technical requirements. The dam body’s infiltration system and drainage holes are functioning properly. The infiltration discharge rate is 24 liters/s, according to the design. The work’s current water storage height is 171 m, which corresponds to the allowable infiltration discharge rate of 14.18 liters/s, but the actual total infiltration discharge rate is 3 liters/s. As a result, the load acting on the dam is less than intended, increasing the dam’s safety margin.

Dr. Nguyen Duc Thang, a Descriptor Group expert, added that the dams in the Song Cai dam system are made of roller compacted concrete. The volume of concrete found in drilled samples from five dams exceeded the specified limit. The mass, compressive strength, tensile strength, and layer tensile strength criteria are all met. Furthermore, the coefficient of variation in dam concrete quality is between good and very good.

“The main project of Tan My is under construction, but the Tan My weir system has been effective for several years now, this system has directly and additionally supplied water to the Cho Mo, Thanh Son, Phuoc Trung irrigation reservoirs, etc. to participate in drought prevention in the dry season for the northern localities of the province with an area of over 2,000 hectares,” said Mr. Luu Anh Tuan, Deputy Director of Ninh Thuan Irrigation Works Single-member Limited Company.

The cluster of Song Cai reservoir works in Tan My irrigation system has completed 98 percent of the volume with a capacity of 219 million m3. The finished project will irrigate 7,480 ha downstream and provide water to many areas of Ninh Thuan province.

Ninh Thuan is the country’s driest province. The province has 21 reservoirs with a total capacity of more than 194 m3, but they frequently run dry during the drought season. As a result, the Song Cai Reservoir Project, which is part of the Tan My Irrigation System Project and has more capacity than the capacity of 21 existing reservoirs. Upon completion, it will play a critical role in the province.

The vital irrigation system of Ninh Thuan’s “sub-desert” region

The Ministry of Agriculture and Rural Development has invested a total of 5,951 billion VND in the Tan My Irrigation System Project.

The Song Cai lake cluster consists of five dams totaling 2,770m in length and 66m in height, with a capacity of 219 million m3. Tan My irrigation system irrigates 7,480ha downstream; water supply Nha Trinh – Lam Cam, lakes Cho Mo, Thanh Son, Ba Rau, Song Trau, and Ong Kinh irrigation system; generating source for Bac Ai pumped-storage hydropower plant and two hydropower plants. At the same time, it provides a water source for the South Cam Ranh area (Khanh Hoa) and aids in the reduction of downstream floods and aquaculture in the lake bed.

According to a representative of the Irrigation Construction and Investment Management Board 7, the project will resume in 2018 and be completed by the end of 2021. The dams have been constructed up to the dam crest level, and the major items have been completed. The volume of completed work has reached 98 percent.

Currently, the operation center is under construction. Teams are cleaning and completing items in order to report to the State Inspection Council of construction works for acceptance and acceptance of water storage as soon as possible. Because this is a critical project, the State Inspection Council has paid seven visits during the construction period.

The State Inspection Council approved the water storage project in March 2021. The reservoir currently holds 60 million m3 of water. The final inspection will be performed by the State Inspection Council in December 2021, allowing the reservoir to accumulate water to its normal water level. Following that, the project will be handed over to the province of Ninh Thuan for management and operation.

Complete the project as soon as possible in order for it to be accepted.

On the afternoon of October 7, representatives from Ninh Thuan province’s departments went to inspect the project site. Workers are cleaning and completing the corridor of the dam body, dam foundation, and dam face. The corridor bottom is dry, and the corridor wall is being cleaned.

On this occasion, the Irrigation Investment and Construction Management Board 7 met with the Ninh Thuan Department of Construction, the Department of Agriculture and Rural Development, Ninh Thuan irrigation works single-member limited company, and the Descriptor Group of the Department of Construction Management of Agriculture and Rural Development to discuss the construction situation and quality of the Song Cai Reservoir Project Cluster.

Mr. Nguyen Tai Son, an expert with the Descriptor Group of the Construction Management Department of the Ministry of Agriculture and Rural Development, stated that the Song Cai dam was built with very good technique after an inspection. The samples taken directly from the dam system met the technical requirements.

The monitoring system for measuring infiltration inside the dam body and the temperature of the concrete placed on the dam body and at the dam’s foot all well function above 90%.

Mr. Nguyen Duc Thang, a Descriptor Group expert, agreed with Mr. Son and added that the Song Cai dam system is made of roller compacted concrete (RCC). The volume of concrete exceeded the regulation by nearly 50 kg/m3 when the drill samples were tested at 5 dams. As a result, the dam will increase safety.

This expert determined that the mass, volume, compressive strength, tensile strength, and layer tensile strength criteria were all satisfactory. Furthermore, the quality fluctuation of dam concrete is good to excellent.

Mr. Ho Ngoc Tien – Deputy Director of Ninh Thuan Department of Construction – requested the Project Management Board to prepare and review all the documents for acceptance; check and re-treat cracks according to technical specifications; develop procedures for dam operation and safety assessment for handover in accordance with the local situation.