Proposing additional solutions to prevent flooding in Vinh city

Pearl• October 9, 2018 06:31

(Baonghean) - Faced with the current situation of Vinh city continuously experiencing flooding during the rainy season, many opinions from scientists and planners have pointed out fundamental solutions to this problem.

Worrying reality from infrastructure
Currently, the flooding situation and wastewater treatment in Vinh are still a major concern for the city's residents and all levels and sectors, especially when the weather and natural disasters are complicated. Flooding occurs quite quickly and lasts for a long time when there is heavy rain.

Vinh market has been flooded many times during heavy rains. Photo: Archive

Typically, the rain on August 17, 2018, with 130mm of rainfall, flooded most of the wards such as Vinh Tan, Le Mao, Quang Trung, Le Loi, Ha Huy Tap... The reason is that the level 1 canals leading water to the suburbs such as canals No. 1, No. 2, No. 3, Hong Bang canal, Dong Vinh... were heavily silted due to not being dredged periodically and being caused by the urbanization process...

A large basin from the North of the city to the North Canal is too far away, the current underground drainage of surface water from there to the North Canal is not guaranteed. It is known that in 1995, when planning to build 3/2 Avenue from the end of Truong Thi Street to the airport, there was a parallel level 1 open ditch, starting from Bac Nghi Phu connecting to the North Canal, but due to the failure to implement, the vacant land intended for the ditch was converted into construction land. Therefore, the large area to the North of the wards and communes: Nghi Phu, Ha Huy Tap, Quan Bau is still flooded due to the lack of level II ditches and culverts to collect water to the North Canal.
In recent years, the city has been stepping up investment in upgrading infrastructure and drainage. These include projects to upgrade and renovate the North Canal, build a regulating lake, upgrade and renovate the moat around Vinh Citadel, upgrade and renovate Cua Nam Lake, upgrade and renovate some main drainage ditches, including: ditch No. 3, Dong Vinh ditch...

These programs and projects have contributed to improving the flooding situation in some areas. In the project areas, which were previously heavily polluted, garbage and domestic wastewater were dumped directly into ditches and lakes. Now, they have been dredged, and additional settling pits have been built, reducing environmental pollution. However, the city still needs more resources and solutions to ensure the management of the city's drainage situation.

Vinh Tan ward (Vinh city) was submerged in water after heavy rain at the end of 2017. Photo: Archive

Currently, the WB Project is expanding the wastewater collection network, which is expected to increase wastewater collection from 30% to 75% when completed. Therefore, the Wastewater Treatment Plant (WTP) will need to be upgraded and expanded to be able to receive the wastewater. Recent projects have improved wastewater drainage but have not met the requirements because many areas are often flooded locally and the WTP is also nearing its peak capacity.
Propose new solutions
According to the Management Board of the Integrated Drainage and Wastewater Management Project of Can Tho, Vinh, Hai Duong cities (Vietnam), to prevent flooding in Vinh city, the following solutions need to be implemented: First: Embankment and dredging of Vinh river wastewater pipeline. Second: Upgrade Vinh central drainage system, invest in level II drainage system for Quan Bau ward and Nghi Phu commune; Third: Build Rao Dung drainage pumping station, expand Hung Hoa wastewater treatment plant. Fourth: Dredge and upgrade main drainage canals in Vinh city: canal 1, canal 2, canal 3, Hong Bang canal, Dong Vinh canal; Fifth: Invest in main drainage pumping station system south of the regulating lake and Rao Dung river.
According to Mr. Nguyen Canh Tai - Head of Science and Technology Department - Nghe An Institute of Planning, Architecture and Construction, to prevent flooding in Vinh city, it is necessary to build a new main canal in the North of Vinh city (Bac Vinh). This canal starts at the Hung Dong pumping station, flows eastward into the Northern regulating lake (Nghi Phu commune, Nghi Duc) connecting with the regulating lake (Hung Hoa commune, Hung Loc and Hung Dung ward) flowing into Lam river at Rao Dung culvert.

Cua Nam Lake (Vinh city) has increased its drainage and wastewater treatment capacity after being renovated. Photo: Tran Chau

Engineer Bui Ngoc Thanh - Nghe An Urban Planning and Development Association highly agrees with the above solutions. In addition, according to Mr. Thanh, Vinh city needs to adjust the basin in the south of the North canal, including part of Hung Binh and Hung Phuc wards, and part of Hung Dung, to drain water along canal number 2 to the south to flow back to the North canal.

To do so, adjust and rebuild the sewer lines south of the North Canal by widening the aperture and sloping back to the North Canal at the following routes: sewers along Nguyen Van Cu Street, Hermann Gmainer Street, 3/2 Street and some other sewer lines. This will ensure a great improvement in the flooding situation in the northern basin of Hung Binh, Hung Phuc wards, part of Hung Dung, including the central area of the city...

Particularly for the northern basin of Nghi Phu, Ha Huy Tap and Quan Bau wards, in the condition that the main northern canal (80m canal) is not yet qualified for implementation, to avoid the situation of having to endure flooding and increasingly severe flooding, a feasible solution is to build a number of transfer pumping stations to pump rainwater to the northern canal. To do this, land must be available soon for construction.
Drainage planning is an important issue that Mr. Nguyen Xuan Son - Head of Nghe An Agricultural and Irrigation Planning Delegation is particularly interested in. Mr. Son said: "Establish a detailed drainage plan for Vinh city in accordance with the drainage plan for the Nam - Hung - Nghi region approved by the Provincial People's Committee, in which the drainage area, drainage direction, and ground leveling elevation for each specific region are clearly defined" - Mr. Nguyen Xuan Son said.

Khi hồ điều hòa xử lý nước thải thành phố Vinh hoàn thành, vấn đề ùn tắc lòng kênh và tình trạng ô nhiễm môi trường sẽ được giải quyết. Kênh Bắc sẽ trở thành một dòng sông nhỏ trong lòng thành phố Vinh. Ảnh: Hoàng Hảo

When the wastewater treatment lake in Vinh city is completed, the problem of canal congestion and environmental pollution will be solved. The North Canal will become a small river in the heart of Vinh city. Photo: Hoang Hao

This year's rainy season, Vinh City has experienced several floods and the causes have been clearly identified. The important issue is to supplement and deploy solutions regarding resources to implement the planning. Vinh City needs to mobilize resources to complete the drainage system, canals, ditches, pumping stations associated with wastewater treatment.

At the same time, plan to prioritize urgent drainage projects; focus on maintaining drainage canals. During that process, strengthen urban construction management, avoid urban development at all costs. In addition to the overall solution, there needs to be detailed wastewater drainage solutions for each project, each urban area, and each specific project.

Vinh is a class I city in Nghe An province, with an area of 105.07 km2 and a population of about 315,000 people in 2015, of which the urban population accounts for 78%. The average population growth rate of the city is about 3.0-3.6%/year. The average household size is 4.7 people. Rapid population growth and urban development are among the causes of flooding in the city.