Major policy decisions for agricultural development in Thanh Hoa: [Part 2] Building water reservoirs for the future

Cua Dat Lake - a landmark project of Vietnam's irrigation industry, a symbol of collective will, strength, and determination to overcome the challenges of complex natural and geological conditions.

Construction begins and technical challenges

On February 2nd, 2004, the upstream valley of the Chu River suddenly transformed into a bustling construction site, busy day and night. The sounds of machinery, car horns, and hurried people filled the air under the golden sun, with the wind from the mountains blowing along both banks of the Chu River. In the distance, the singing of ethnic minority girls echoed, adding a vibrant energy to this historic project, dubbed the "century project" of Vietnam's irrigation sector.

Site preparation was carried out urgently and comprehensively. In 2004 and the first half of 2005, construction teams focused on building housing for officials and workers, offices for contractors, processing workshops, construction roads, bridges over the Chu River, and preparing material quarries for dam construction.

The workload was enormous: leveling and excavating nearly 7 million cubic meters of earth and rock, completing over 50,000 square meters of camps and workshops, providing accommodation for approximately 3,000 staff and workers, along with more than 1,000 vehicles and pieces of heavy machinery.

Cua Dat Lake - a landmark project of Thanh Hoa's irrigation and agriculture sector. Photo: Thanh Tam.

The Cua Dat Reservoir was the largest irrigation project in Vietnam at the time, built on complex geological conditions. It was the first project to apply the technology of a rockfill dam with a compacted concrete face and waterproofing, requiring consultation from Chinese experts and the utilization of local materials. This was a new technology, posing a significant challenge to Vietnamese engineers and workers, but it also presented an opportunity for the country's irrigation sector to demonstrate its modern technical capabilities.

Despite a grand start, construction progress faced numerous difficulties. After eight months, the project was behind schedule. In light of this, Mr. Phan Dinh Phung, demonstrating a high sense of responsibility, took on the role of Director of the Investment and Construction Management Board for Irrigation Project 3 - Ministry of Agriculture and Rural Development to directly oversee construction, setting aside personal interests and prioritizing the project above all else.

Mr. Phung and his team of engineers and workers supervised every detail, from transporting materials and pouring concrete to inspecting the foundation and arranging auxiliary items.

Mr. Phan Dinh Phung recounts the difficulties encountered during the construction of the Cua Dat reservoir. Photo: Thanh Tam.

"Every day, we work, learn, and solve problems that arise beyond the design. There's no room for error, because this reservoir determines the safety and livelihoods of tens of thousands of people downstream," Mr. Phung shared.

Workshops, temporary shelters, and makeshift bridges were built simultaneously, with workers divided into three shifts, four teams working continuously day and night. The sounds of machinery, laborers, and even the wind in the mountains blended into a rhythm of life that was both bustling and fast-paced.

The dam collapse incident and the valuable lessons learned.

According to the design, Cua Dat Reservoir has a canal along the dam for river water to flow through, with the capacity to withstand major floods occurring 5 times in 100 years. However, on October 5, 2007, a serious incident occurred: the main dam broke during construction, sweeping away 600,000 m³ of rock. This was a once-in-a-century flood, submerging 7 communes of the former Tho Xuan district with more than 2,300 households and 12,000 people in water, with some areas more than 8 meters deep.

Contractors immediately had to build upstream cofferdams, clear foundation pits, and address vulnerable points to ensure safety. Workers were divided into three shifts, with thousands of people working day and night. The incident served as both a valuable lesson and a challenge to train hydraulic engineers in handling natural disasters beyond the design specifications.

The construction of the Cua Dat reservoir faced many obstacles, but the technical team worked together to overcome them. Photo: Archival material.

This incident demonstrates that, despite thorough preparation, natural disasters and complex geological conditions can still occur unexpectedly. Engineers and workers must utilize their experience, creativity, and seamless coordination to overcome challenges, ensuring the project's progress and safety.

Following the incident, construction work was carried out more vigorously. Engineers continued to adjust methods, allocate manpower appropriately, and expedite the construction progress. Every stage, from excavation and embankment to concrete pouring, hydraulic engineering fabrication, and material quality control, was strictly implemented.

To construct the main dam, millions of cubic meters of earth and rock were transported and leveled. Workshops manufacturing hydraulic equipment operated continuously, creating an industrial rhythm amidst the upstream forests of the Chu River. The project became a living symbol, where the spirit of labor, will, and intellect of the people converged.

The construction of the Cua Dat reservoir faced many obstacles, but the technical team worked together to overcome them. Photo: Archival material.

The pride of the irrigation industry.

On January 26, 2009, the final sluice gate in front of the tunnel was lowered, and Cua Dat reservoir officially began impounding water for agricultural production. After five years of construction, the Cua Dat reservoir headworks project was completed: 38.7 million tons of earth and rock, 321,000 m³ of steel, 105,000 tons of hydraulic machinery, with a total cost of nearly 5,000 billion VND from government bonds.

The main dam is 118.5 meters high, 987 meters long, and 10 meters wide at the crest. It was constructed using a new technology: a rockfill dam with a compacted concrete face slab for waterproofing, a technology applied for the first time in Vietnam. Thirteen people sacrificed their lives on the construction site to bring about a monumental project, serving the industrialization and modernization of the country in general, and agricultural production and irrigation in Thanh Hoa in particular.

The credit belongs to the entire political system, including Mr. Phan Dinh Phung and the Vietnam Water Resources Construction Consulting Corporation, who pioneered the surveying, design, route selection, and provision of optimal technical solutions from the pre-feasibility study to the completion of the project. In recognition of his contributions, the Government awarded Mr. Phan Dinh Phung the Labor Order, 2nd and 3rd class.

The Cua Dat reservoir is a major policy decision for the development of Thanh Hoa's agriculture. Photo: Thanh Tam.

Cua Dat Lake is not just an irrigation project, but also a symbol of the willpower, perseverance, and intelligence of the Vietnamese people. The project demonstrates the determination to combine modern science and technology with community benefit, and to integrate socio-economic development with the preservation of local spiritual and cultural heritage.

Tens of thousands of hectares of agricultural land are protected, tens of thousands of people in downstream areas are safe during the flood season, and a stable water supply serves industrial production and daily life, all creating a long-term synergistic effect. Cua Dat Reservoir has become a source of pride for Vietnam's irrigation industry, and a symbol of the combined strength of people, nature, and technology.

The construction of the Cua Dat reservoir is a major policy decision for the development of Thanh Hoa's agriculture. Photo: Thanh Tam.

Despite the setbacks, construction difficulties, losses, and sacrifices, Cua Dat Lake still stands strong, just like the spirit of the people who poured their hearts, strength, and intellect into every stone, every block of concrete, and every historical step of the project.

Today, standing by the lake and gazing at the vast expanse of clear blue water, we feel the value of a wise decision, of the unwavering dedication of its people, and the magnitude of a "project of the century"—a place where history, technology, and community converge, creating a source of pride for Vietnam's irrigation sector.

Source: https://nongnghiepmoitruong.vn/quyet-sach-lon-phat-trien-nong-nghiep-thanh-hoabai-2-xay-kho-nuoc-cho-tuong-lai-d787767.html