Hanoi 'submerged in water', Department of Construction sends apology to people

With the extremely heavy rainfall on September 30, exceeding the capacity of the drainage system, Hanoi city was flooded extensively.

People in the capital waded through water in the heavy rain on September 30, 2025. Photo: Hoai Nam/Vietnam+

Regarding the heavy rain that hit Hanoi on September 30, causing widespread flooding and inadequate drainage, the Hanoi Department of Construction said that this was an unexpected natural disaster that greatly affected daily life. At the same time, it apologized and hoped that people would share and understand.

According to Mr. Le Van Du, Head of the Department of Water Supply and Drainage Infrastructure Management (Hanoi Department of Construction), the rainfall on September 30 was extremely heavy, exceeding the load-bearing capacity of the urban drainage system, which was designed for a rainfall intensity of 310mm/2 days. For example, the rainfall in the O Cho Dua area was up to 527.2mm (exceeding 170% of the design capacity) and Hai Ba Trung was 407.7mm (exceeding 131.5%).

“The heavy rainfall has overloaded the drainage system. Rainwater continues to flow onto the road surface, converging on low-lying areas, causing deep flooding,” Mr. Du assessed.

In addition to the extreme weather factor, the Department of Construction also frankly admitted the limitations of infrastructure when Hanoi's drainage system still has many shortcomings, is not synchronized, and is not connected to each other. In particular, many key projects and regulating lakes have not been built on schedule; some new urban areas are not synchronized, the ground is lower than the surrounding area, making it easy for local flooding to occur when it rains heavily.

In addition, some new urban areas are even lower than the surrounding areas, causing water from other places to rush in very quickly when there is heavy rain, causing serious local flooding. The situation is even more difficult when the planned discharge sources and pumping stations have not yet been fully built.

Due to the impact of storm No. 10 (Bualoi), since September 27, the Department of Construction has directed drainage units to pump down the water level in the system and inner-city lakes to increase water storage capacity. All 100% of the workforce (over 2,479 people) along with more than 500 machines and equipment have been mobilized for duty.

The Department of Construction has also coordinated with the Department of Agriculture and Environment to lower water levels on rivers, canals and irrigation lakes to aid drainage.

To overcome this, units are organizing 24/7 on-call, assembling human resources and equipment at flooded locations. Existing drainage works are operating at maximum capacity, prioritizing drainage for the To Lich river basin to Yen So pumping station through the Yen So reservoir's regulating gates.

By 2 p.m. on October 1, most of the flooding in the inner city had basically receded, but many areas on the left and right of the Nhue River were still flooded due to high water levels. The Department of Construction opened the Thanh Liet dam, diverting water from the Nhue River to the Yen So pumping station to drain into the Red River, in order to reduce flooding on Thang Long Avenue, My Dinh, Cau Giay and areas on the right of the Nhue River.

Regarding long-term solutions, the Department of Construction proposed to build localized flood treatment works such as underground water tanks in public lands, parks, and flower gardens, combined with step-change pumping stations to enhance drainage capacity.

In the process of developing the Capital's elevation and drainage plan until 2045, with a vision to 2065, the Department of Construction will recalculate scenarios for responding to climate change, especially with rainstorms with intensity greater than 310mm/2 days, to improve the city's resilience in the future./.

PV (synthesis)

Source: https://baohaiphong.vn/ha-noi-chim-trong-bien-nuoc-so-xay-dung-gui-loi-xin-loi-den-nguoi-dan-522307.html