A well-placed drop: shaping flood resilience in Thu Duc

From a partially built wetlands with 1.1 million residents to a megacity of three million by 2050, the city of Thu Duc is rapidly transforming. Located in an area that, due to land subsidence and sea level rise, will be below sea level by the end of the century. Flooding from intense rainfall and high river levels is already a regular occurrence. Welcome to Thu Duc City: the future financial heart of Ho Chi Minh City.

Haskoning’s Netherlands-based Karel Heijnert, Team Leader for Phase 2 and Vietnam based Alexandria Norris-Moore, who led Phase 1 and now serves as Urban Resilience Expert in Phase 2, share their insights into the project.

The challenges of Thu Duc City

What makes this project stand out is its scale and timing. With a projected population growth of around 2 million people within a few decades, the city is on the brink of irreversible change. “It’s about one third developed and the rest is still empty space and wetlands,” says Alexandria Norris-Moore, “but they will be building – because they already have just down the road.”

That reality gives the project a rare window of influence. “We may be small in scale,” adds Karel, “but if you’re at the table at the right moment, you can help steer a mega-development before it locks in future problems.” This makes the Partners for Water-funded initiative more than a consultancy effort – it’s a strategic lever at a critical turning point. By combining Dutch expertise in urban water management with Vietnam’s high-level planning system, the team hopes to embed nature-based flood risk management into the DNA of a city still under construction. As Karel puts it: “This study won’t solve everything. It’s a drop. But it’s a well-placed drop in a resilient city that’s about to flood with people.”

To meet this challenge, Thu Duc City partnered with the World Bank and the Government of The Netherlands on an Integrated Flood Risk Management (IFRM) project. Funded by the Partners for Water programme and delivered by Haskoning, with its partners OMGEVING and Delta Context, the project aims to embed flood resilience into the urban planning and development of Thu Duc City.

From analysis to narrative: Phase 1

Phase 1 started with a core question: how did Thu Duc become what it is today and how did past urban decisions contribute to today’s flood risks? The project team combined a historical-spatial analysis with advanced water modelling and future growth scenarios.

“It was the first time this level of analysis had been done at this scale; connecting all of the waterways across Thu Duc City, from small canals to bigger rivers to temporary ponds,” Alexandria explains. “We created a blue-green network, linking green spaces for water storage and for spatial connection between blue and green.”

Blue-green vision reveals the bigger picture

This approach didn’t just yield technical solutions like drainage systems, polders or dikes; it told a bigger story. The narrative helped shape the city’s land use and master plan, creating a spatial logic that justified investment choices across the entire city. “RVO (Netherlands Enterprise Agency), as the implementing body of the Partners for Water programme, gave us the space to explore that full journey,” she says, “from high-level strategy to detailed interventions. And that’s what made the investment proposals for Phase 1 stronger – because they were grounded in a citywide logic, not just a local quick fix for worst-hit areas.”

Supported by the World Bank, the blue-green vision was translated into a detailed investment proposal for a pilot area in the north of the city. The proposal was approved by Thu Duc City with minimal changes and submitted directly to the national government. “It’s extremely rare,” Alexandria notes. “For a local government to approve a consultancy-led proposal with so few changes and immediately submit it for national funding; especially when a large part of it includes Nature-based Solutions (NBS).”

That last part is key. NBS are still not a preferred option in Vietnam. “They prefer hard grey infrastructure because they can see the results quickly,” Alexandria says. “So actually, trying to get them on board with some of the NBS was quite a journey. But as soon as we did, they were much keener to put forward those investment items to the national government for funding.”

A ‘clean sheet’ for resilient urban development

While Phase 1 delivered a blue-green vision and a ready-to-fund investment plan, Phase 2 focuses on the next step: supporting Thu Duc in turning that vision into action. “We worked with the city’s task force and chairman to say, well, if you’re going to really do flood management correctly, these are some recommendations you need to adopt around institutional governance and coordination. And that’s what became Phase 2,” says Alexandria. At the heart of this second phase is the focus on integrating flood risk management into the urban fabric before it is fully built.

Embedding flood resilience in urban planning

“On one hand, you have flooding problems in the already urbanised areas; on the other, there’s a clean slate – open space where we have a chance to do it right,” says Karel, team leader of Phase 2. “You need space to properly manage water over time in a city like this. That space could be on the street or in a park. But if you don’t plan for it now, you’ll be forced to solve it later with massive pumps and canals; and that’s expensive and inefficient.” And that matters in Vietnam, a country Karel describes as “a world champion in planning.” “When you have it in the zoning plans – what should be green, what should be buildings – there’s a much higher chance that it will actually happen,” he says.

Designing structural measures in combination with spatial planning

This is where Phase 2 proves most strategic. The team is developing spatial planning guidelines for water-sensitive planning in Thu Duc’s new districts – areas set that will become financial centres, high-tech hubs and modern housing areas. They are also supporting the design of integrated measures, to ensure that areas designated for water in planning are translated into functional spaces in reality. “And that’s actually what our project focuses on: Nature-based Solutions. But this it’s putting people on the wrong foot. This can be misleading but it’s really about combining structural measures with space for water. That could be green space, but not always,” Karel emphasises. “It’s about making the space multifunctional: for daily use by communities and occasionally for flood management. You can’t rely on pumps alone in a monsoon city that’s sinking below sea level.” That’s what Phase 2 is all about: embedding flood resilience into the DNA of a megacity-in-the-making.

What’s next?

While spatial planning and governance remain central to Phase 2, the next frontier lies in building the city’s digital infrastructure. One of the projects tasks is focused on designing two systems that will anchor Thu Duc’s flood risk response in data and real-time insight. The first is the Flood Risk Management Information System (TD-FRMIS), which will help authorities anticipate, monitor and respond to floods through hydrodynamic modelling, GIS mapping and early-warning capabilities. In parallel, the team is designing a Geospatial Data Sharing Platform (TD-GDSP), enabling departments to integrate and overlay spatial data on everything from land use and drainage to elevation and population density. These digital platforms will help Thu Duc City move from reactive infrastructure planning to anticipatory, risk-informed urban development.

Looking ahead, continued collaboration with Ho Chi Minh City as the administrative authority of Thu Duc will be essential. A newly installed city administration is expected in the third quarter, providing a critical opportunity to align on priorities, integrate digital systems and further embed flood resilience into strategic decision-making. Ensuring institutional continuity and support from both local and metropolitan levels will be key to scaling the project’s impact.

International collaboration at its best

Thu Duc’s development highlights the importance of embedding flood risk management early on in urban development. With clear spatial guidelines, institutional support and smart digital systems, the city is taking concrete steps toward long-term resilience. This approach of linking strategic planning, practical tools and local ownership offers valuable lessons for other fast-growing cities in delta regions. As the project moves forward, continued collaboration between Dutch and Vietnamese partners will be essential to ensure the results have lasting impact, both in Thu Duc City and beyond.