Roadmap for building a "sponge city
On the morning of July 15, within the framework of the fifth session (regular mid-2026 session), the 17th Hanoi City People's Council, term 2026-2031, held a question-and-answer session on the group of issues that voters are particularly concerned about, which is flood prevention and control.
Answering questions from delegate Tran Khanh Hung (Delegation No. 8) about the direction of building a "sponge city" to solve the flooding problem, Director of the Department of Construction Nguyen Phi Thuong said that this solution shifts from rapid drainage to water retaining, water seepage, water regulation and water reuse.
This issue is in the process of consideration and has not been specifically implemented. However, the Department of Construction has taken steps and procedures to implement the development of regulations and standards on seepage materials, so that as soon as the project is approved, there is a basis for immediate implementation.
The Director of the Department of Construction affirmed that not the entire city will immediately implement the roadmap for building a "scum city", but will implement it according to the roadmap. Areas such as parks, flower gardens, and sidewalks will be implemented first to ensure thrift and efficiency; in addition, the "scum city" will be applied to new urban areas.
Regarding the situation of sidewalks being dug up and filled continuously, which was questioned by delegate Tran Khanh Hung, Director of the Department Nguyen Phi Thuong said that all sidewalks are decentralized to the ward and commune levels for management.
However, the Department of Construction is undertaking the task of undergrounding all "sky trash", including power lines and telecommunications systems. This is being implemented in 3 central wards, and at the same time, expanded to wards in the inner city area.
It is unavoidable to dig up and fill sidewalks. We try to connect all stages to minimize continuous digging up and filling down and pay attention to restoring the ground after construction" - Mr. Nguyen Phi Thuong said.
Answering questions from delegate Tran Anh Tuan (Delegation No. 22) related to the connection of drainage infrastructure of urban areas, the Director of the Department of Construction said that the unit has reviewed all 52 urban areas in the city, 26 urban areas and residential areas have been fully completed and the entire technical drainage infrastructure has been handed over to the city. For the remaining 26 urban areas, the Department of Construction will try to complete the connection in 2026.
Regarding the request for the investor to complete the entire regulating lake system, pumping station, drainage culvert and connection point in accordance with the approved plan and design, Mr. Nguyen Phi Thuong proposed not to accept or put the project into use when the drainage system is not complete.
Director of Department explains the situation of "floating water" after the rain on July 9th
Also at the question-and-answer session, delegate Nguyen Thi Thanh Thuy cited the rain on July 9 that caused one person to fall into a manhole and die in Ngoc Ha ward. The delegate requested the Director of the Department of Construction to clarify specific solutions as well as strong enough sanctions to thoroughly overcome the shortcomings in the coming time.
Regarding the rain on July 9, the Director of the Hanoi Department of Construction assessed that this was not a heavy rain, the highest rainfall measured was about 80mm in some areas.
Mr. Thuong used the phrase "splashing water" to describe the situation in Quang Trung street area and some other streets after this rain.
Explaining this phrase, Mr. Thuong said "flooding means 30cm deep and flooding for more than 20 minutes", while "waterlogging is only at a depth of more than 20cm".
Mr. Thuong said that newly completed flood control projects are still in the process of acceptance and handover to management and operation units.
At the time of the rain, the faucet at Bay Mau Lake had not been opened in time, so water could not be drained. After opening, 30 minutes later, the entire area drained, showing that the drainage system had taken effect.
Regarding the "waterlogging" situation in some other areas after the rain on July 9, Mr. Thuong said that these are all locations in the list of 120 flooded points identified by the city.
According to the Director of the Department of Construction, the 10 emergency flood control projects that have just been completed have only promoted initial impacts in improving drainage capacity.
