Anti-flood planning is outdated
This year's early rains continue to show that the flooding situation in Ho Chi Minh City has not improved significantly.
Thu Duc market area is still one of the "flood centers" of the city. Every time it rains heavily, Duong Van Cam, Kha Van Can, Dang Thi Ranh, Ho Van Tu, To Ngoc Van streets... are deeply flooded, many cars stall, traffic is chaotic, and business operations are affected.
Not only the inner city area, flooding has spread to many suburban areas such as Nguyen Van Khoi street (Thong Tay Hoi ward), Chien Luoc (Binh Tri Dong ward)... Meanwhile, in the high tide season, Tran Xuan Soan, Huynh Tan Phat, Binh Quoi streets... are frequently flooded by rising river water, affecting people's lives.
According to the Ho Chi Minh City Department of Construction, after expanding the boundaries, the whole city currently has 159 frequent flooding points, including 76 points in the old Ho Chi Minh City area, 52 points in Binh Duong and 31 points in Ba Ria - Vung Tau.
In the past 20 years, Ho Chi Minh City has implemented many large-scale flood control programs. Plan 752 (2001) and Plan 1547 (2008) once set a target to build about 6,000km of drainage culverts, 103 regulating lakes, 170km of dykes and 12 tide-preventing culverts.
However, to date, only more than 60% of the sewer system has been completed, while the regulating reservoirs have not yet been deployed.
Many key projects are also behind schedule. Typically, the tidal flood control project worth nearly 10,000 billion VND has completed about 93% of the volume but is still unable to operate due to problems in payment with investors.
According to the Department of Construction, previous flood control plans are no longer suitable when built on the scenarios of rain, tides and sea level of more than 20 years ago, not fully considering the impacts of climate change and changes in urban space after mergers.
Meanwhile, the situation of land subsidence is becoming increasingly serious. Many areas subside on average about 2cm per year, in some places 5 - 8cm/year. After 10 - 12 years, the common total subsidence level has reached 20 - 30cm, even over 50cm.
This makes the design elevation of the sewer system, dyke and pumping station no longer suitable, reducing the drainage capacity when heavy rain, high tide and subsidence occur simultaneously.
Rapid urbanization, filling ponds and lakes, narrowing canals and prolonged groundwater exploitation also increase the risk of flooding.
Another challenge is investment resources. According to calculations by the Department of Construction, from now to 2030, Ho Chi Minh City needs to implement about 157 flood control projects with a total capital of about 340,000 billion VND, while the budget only meets about 30% of the needs.
Changing thinking against flooding
Faced with that reality, Ho Chi Minh City is developing a Project on flood control and wastewater treatment for the period 2026 - 2060 and a Plan on flood control and wastewater treatment for the period 2026 - 2036.
Mr. Le Ngoc Linh - Deputy Director of Ho Chi Minh City Department of Construction - said that the new project shifts to a integrated management approach according to the basin, focusing on adapting to climate change.
The core principle is "Keep - Store - Drain". Instead of just finding ways to drain water quickly, the city will protect natural drainage corridors, increase the ability to retain water in place, expand water storage space and only drain water when conditions permit.
The project also orients the synchronous development of the "gray - blue - yang" infrastructure system. In which, gray infrastructure including culvert systems, dykes, tide-preventing culverts and pumping stations continue to be invested in and upgraded. In parallel with that is the development of green infrastructure and positive infrastructure such as regulating lakes, flooded parks, seepage surfaces, restoration of canals and ditches, ecological low-lying areas and taking advantage of water surface spaces to increase natural regulation capacity and reduce pressure on the culvert system.
From a management perspective, the city will apply GIS technology, climate change simulation models, subsidence data to operate the drainage system in real time, and at the same time build an early flood warning system.
The project also aims to innovate the urban water management model in the direction of regional linkage between Ho Chi Minh City, Binh Duong and Ba Ria - Vung Tau after the merger, instead of managing according to administrative boundaries as before.
According to the roadmap, in the period 2026 - 2030, the city will prioritize handling serious flooding points, completing unfinished projects and building a management data platform. In the period 2031 - 2060, large-scale projects will be implemented along the basins, expanding the wastewater treatment system and gradually building a megacity with better resilience to climate change.
Must accept living with the water intelligently
According to Dr. Architect Ngo Viet Nam Son - urban planning expert, after expanding the boundaries, the city needs to shift from flood control thinking according to each locality to management according to river basins. The new project with the principle "Keep - Store - Escape" is the right direction, in line with the trend of many cities around the world.
Anti-flooding is not just building large culverts or adding pumping stations, but creating space for water through restoring canals, regulating lakes and ecological low-lying areas" - Mr. Son said.
According to him, Ho Chi Minh City needs to strictly control the leveling of ponds and lakes, limit concretization and strongly develop green infrastructure. If only focusing on drainage without increasing the ability to retain and store water, the flooding situation will become increasingly serious.
Agreeing with this view, Assoc. Prof. Dr. Ho Long Phi - former Director of the Center for Water Management and Climate Change (Vietnam National University HCMC) - said that sea level rise and subsidence are reducing the effectiveness of many existing flood control projects.
The city needs to synchronously combine engineering and non-engineering solutions, apply real-time data, forecasting models and smart operations" - Mr. Phi emphasized.
To make the flood control project effective, he proposed that Ho Chi Minh City prioritize completing unfinished projects, building a unified management mechanism throughout the new Ho Chi Minh City basin and promoting the mobilization of social resources in the form of PPP to meet the very large investment needs in the coming time.
