The new drainage system meets about 20%
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 in urban areas.
Delegate Le Van Duc (Delegation No. 9) questioned the Director of the Hanoi Department of Planning and Architecture about the planning and development of the drainage system in the city.
Delegate Duc said that the Capital Drainage Plan was approved 13 years ago with design parameters based on rainfall of about 310mm in 2 days.
However, in reality, in recent years, many extreme rains have appeared, with rainfall reaching 500-600mm in a day in some places, far exceeding the design capacity of the existing drainage system, leading to prolonged flooding in many areas. However, these new factors have not yet been updated in the planning.
The delegate requested the Director of the Department of Planning and Architecture to clarify the progress and responsibilities in the slow updating of the Capital's Drainage Plan; the basis for determining the location, scale, and altitude of regulating lakes; contingency plans when drainage planning changes; and solutions for developing environmentally friendly drainage infrastructure and adapting to climate change.
Answering questions, Director of Hanoi Department of Planning and Architecture Nguyen Trong Ky Anh said that the implementation of the Capital's Drainage Plan has been carried out for the past 13 years and has always been associated with the process of adjusting and completing the general planning system of the city.
The drainage plan was built on the basis of concretizing the General Construction Plan of Hanoi Capital in 2011; then approved according to Decision No. 725 in 2013.
Following that, in the period 2023-2024, along with the process of adjusting the General Plan of the Capital approved by the Prime Minister in Decision No. 1668, the contents on drainage planning are also continuing to be studied and updated.
In the previous period, the plan met the requirements set for the drainage work of the Capital and was integrated into the urban development planning system" - Mr. Ky Anh said.
However, through the actual implementation process, the city also recorded many limitations.
According to current assessments, the drainage system only meets about 20% of the required capacity, while the regulating lake system and drainage works in the area have only been invested in about 20%, and the regulating lake area alone reaches about 18% compared to the plan.
This is one of the "bottlenecks" that has been pointed out many times by delegates of the City People's Council as well as central and city leaders.
The Director of the Department of Planning and Architecture said that the unit has coordinated with the Department of Construction to review relevant contents.
Drainage and wastewater drainage planning is coming soon
For the Master Plan of the Capital with a 100-year vision, the Department of Planning and Architecture has issued a deployment plan.
According to the new planning orientation, the total area of Hanoi's regulating lake will reach more than 8,000ha, an increase of about 20-25% compared to the previous plan to improve drainage capacity, adapt to climate change and extreme rain.
In addition, the master plan with a 100-year vision also for the first time comprehensively studies the underground technical infrastructure system according to the modern urban development model.
Accordingly, along with the transportation system and urban railways, the city will plan an underground water tank system and underground drainage works to improve the efficiency of regulation and urban drainage.
This is a new content that will continue to be concretized in the planning implementation process.
Regarding the progress of adjusting the drainage planning, the Director of the Department of Planning and Architecture said that the unit has agreed with the Department of Construction on the tasks and implementation roadmap.
It is expected that in September 2026, Hanoi's drainage and wastewater drainage planning will be approved and publicly announced for delegates of the City People's Council as well as the people of the Capital to monitor and supervise.
Mr. Nguyen Trong Ky Anh also said that the city is focusing on implementing key drainage projects.
Accordingly, there are currently 13 urgent projects being accelerated, including 6 regulating lake projects, along with projects to renovate the network of canals, ditches and pumping stations.
In parallel with that, the city is implementing the renovation and rectification of rivers that play an important role in drainage such as To Lich River, Kim Nguu River, Nhue River and Day River. When these rivers are cleared and water levels are lowered, it will contribute to improving drainage capacity, and at the same time, effectively serve irrigation and drainage work in the city.
The Director of the Department of Planning and Architecture also said that departments and sectors are continuing to review to overcome shortcomings in the management of ground elevation and drainage planning. In the process of adjusting the plan, the city will update new factors, including recalculating the rainfall frequency designed for the drainage system; reviewing the scale of pumping stations, rivers, canals, and regulating lakes; and integrating climate change scenarios from 2025 onwards.
