Hanoi invests nearly 5,600 billion VND to build 10 emergency flood prevention works

In the rainy and flood season of 2025, Hanoi recorded a series of localized flooding points, at times many traffic routes were paralyzed, seriously affecting people's lives.

Statistics show that during the heavy rain from August 25 to 27, 2025, the measured rainfall reached about 350mm. In the Phung Hung - Bat Dan - Duong Thanh - Nha Hoa areas, the flooded water level is commonly from 0.6 - 0.8m, the flooding time lasts about 4 hours.

Flood control solutions show that, with a similar rain scenario (peak rain of about 43mm), the above-mentioned area will no longer experience flooding when underground regulating tanks are put into operation. With calculated capacity, underground tanks are capable of storing all rainwater on the road surface at flooded points, thereby reducing pressure on the existing urban drainage system.

After the rain ends, when the water level in the main culverts drops and drainage conditions are ensured, or before the forecast time of the next rain, water in the regulating tank will be pumped forcibly into the common drainage system for about 4 hours. The water discharge process is strictly controlled to avoid overloading the downstream culvert system.

In order to solve the prolonged flooding situation every time it rains heavily, the Hanoi Department of Construction has advised the Hanoi People's Committee to issue a decision to invest in the construction of 10 emergency flood prevention works, with a total estimated investment of nearly 5,600 billion VND.

Before this proposal, the Hanoi People's Committee requested relevant units to prioritize allocating resources, shorten investment procedures, and ensure that the main items of 10 projects are basically completed before the 2026 rainy and storm season.

Through review, Hanoi City determined that the cause of flooding stems from the lack of synchronization of the drainage system and key drainage works, many projects are behind schedule; drainage sources and key pumping stations are invested very slowly; the construction of regulating lakes in the area is also not synchronized.

Therefore, investing in 10 emergency flood control projects is identified as an urgent task of the Capital before the 2026 rainy and storm season, hoping to gradually overcome the localized flooding situation that has lasted for many years.

Talking to a reporter from Lao Dong Newspaper, Mr. Nguyen Duc Hung - Director of Hanoi City Technical Infrastructure Management Center (Hanoi Department of Construction) said that the unit has completed a feasibility report on the plan to build two underground tanks to regulate rainwater to prevent flooding.

According to Mr. Hung, the underground regulating tank in the Duong Thanh - Bat Dan - Nha Hoa area is built to store rainwater, treat flooded points, and contribute to reducing the load on the existing drainage system.

Meanwhile, the underground tank in Long Bien area is expected to be built on an empty land plot at Cau Duong slope, Phu Dong commune. This is an area with high traffic density, and also has the Hanoi - Lang Son railway running through it.

Thien Duc street currently has sidewalks, water intake ditches and manhole systems along both sides, connected to underground ditches and draining into the Thien Duc River. However, this area is still frequently flooded in the rainy season because the railway underpass section has a low altitude, which is the water convergence point of Cau Duong slope and Ha Huy Tap slope.

When heavy rain occurs, the amount of water poured in exceeds the drainage capacity of the current system, causing prolonged flooding, directly affecting the Cau Duong slope traffic junction and people's lives.

The proposed plan is to build an underground tank with a capacity of about 1,800m3, collecting all surface water on Thien Duc street. The tank is built of reinforced concrete, drains water from box culverts and installs water level regulating vents. At the same time, two submersible pumps with a total upgraded capacity of 1,000m3/hour will be installed, meeting emergency drainage requirements. The total estimated investment is about 6.7 billion VND.

This item is part of the project to build and install additional pumping stations for lakes, regulating tanks and drainage pipelines in the To Lich - Ta Nhue basin, which was submitted to the Hanoi City People's Council in December 2025.

According to reports, the second underground tank is expected to be built in the vacant land in front of Hang Da market - an important traffic hub area, the intersection of many streets such as Duong Thanh, Hang Da, Ngo Tram, Nguyen Van To and Hang Dieu. At the central location, there is currently a traffic lane circulation roundabout.

This area also concentrates many important technical infrastructure systems such as electricity, telecommunications, water supply and other underground works. The current drainage system belongs to two main basins of Hanoi, the Kim Nguu and To Lich river basins.

The underground tank in the Hang Da market area is designed with a capacity of about 2,500m3, reinforced concrete structure, installed with a regulating pumping station with a capacity of 0.09m3/second per pump, along with auxiliary items such as connection culverts and regulating vents. The total estimated investment is about 18.2 billion VND.