In Dalat, Vietnam, a Dutch–Vietnamese consortium led by Fresh Studio has completed a 30-month pilot to improve water management in greenhouse horticulture. Supported by Partners for Water, the project introduced drain water collection and UV disinfection to reduce nutrient losses. The results show savings of up to 40 percent for fertiliser and 35 percent lower water use for participating pepper growers. René van Rensen from Fresh Studio explains how the system works and what it takes to scale it.

In the highlands of Dalat, greenhouses stretch across the hillsides. Inside, vegetables are grown in substrate rather than soil – a method that offers higher yields and better control over water and nutrient supply. Yet beneath that efficiency, a hidden loss takes place. “When you grow in substrate, crops need 20 to 30 percent more water,” says Van Rensen. “Without a collection system, that excess water drains away and is lost.” In the Netherlands, this water is typically recirculated in closed systems.

For greenhouse growers in Vietnam, improving water management is not only about sustainability, but also about reducing input costs and securing long-term production. As fertiliser prices rise and water resources come under increasing pressure, practical solutions such as drain water reuse are becoming increasingly relevant.

To address this, the consortium – Fresh Studio, Ridder, Royal Brinkman and HollandDoor – introduced a closed-loop drain water system. By capturing, disinfecting and reusing drain water, the team aimed to improve water management while reducing both costs and environmental impact.

Turning drain water into a resource

In substrate systems, part of the irrigation water flows out of the pots as drain water. In the Netherlands, this water must be collected and reused by law. In Vietnam, this is not yet common practice. “The water just goes into the ground,” Van Rensen explains. “All the nutrients go with it. Eventually, they can end up in groundwater or surface water. This means that water is wasted and pollution occurs at the same time.” Simultaneously, water itself is rarely paid for. “If farmers need more water, they simply drill deeper,” he says. “Ten years ago, farmers would pump at 30 metres. Now they go down to 100 metres.”

The real incentive for reusing drain water lies elsewhere: “Fertilisers are one of the biggest cost components in horticulture,” Van Rensen notes. “In substrate-based greenhouse vegetable production, they can account for up to 40 percent of input costs.” Plants do not use all the nutrients in the fertiliser solution. By collecting and reusing nutrient-rich drain water, farmers can significantly reduce those costs. “That means they can recover their investment within two to three years.”

Proven results accelerate adoption

At first, growers were cautious. The full installation costs between 75,000 and 100,000 US dollars. “That is a serious investment,” Van Rensen acknowledges. “Farmers are understandably hesitant. Yet once the results became visible, interest grew more quickly.”

Encouraged by the results, both participating farmers expanded the area covered by the drain water collection system at their own expense. “During the project, this increased to full coverage on one farm (1 hectare) and to around 50 percent (1.5 hectares) on the other,” says Van Rensen. The grower with three hectares is continuing to expand the system, aiming for full coverage by 2027. “In Vietnam, farmers can be sceptical,” Van Rensen says. “But if they see something works, they often move fast.”

Beyond the greenhouse

The project also feeds into a broader discussion about water management in Dalat. Rapid greenhouse development has contributed to local flooding during heavy rainfall. “Greenhouses are sometimes seen as part of the problem,” Van Rensen says. “But they can also be part of the solution.” If each greenhouse were required to capture and store rainwater – an approach already widely applied in Dutch greenhouse horticulture – it could both reduce flood peaks and decrease groundwater extraction, he argues. The consortium is sharing these ideas with the Netherlands Embassy in order to explore possible policy dialogue. “Changes in regulation take time,” he says. “But projects like this show what is possible.”

Building trust for scaling up

For Van Rensen, one lesson stands out. “For solutions to be adopted by farmers, it is very important to demonstrate clear results,” he says. “A pilot site that farmers can visit is therefore very helpful.” Equally important, he emphasises, is local presence. “A strong local partner and a hands-on team are essential. Without people on the ground who understand the local context and can solve problems quickly, implementation will be difficult.”

Building on these experiences, the consortium now aims to see two to five additional growers adopt the system in the coming years. By combining Dutch water technology with local entrepreneurship, the project shows how improved water management can deliver both environmental and economic gains. As Van Rensen concludes: “If the results are clear and the system proves reliable, farmers will decide for themselves.”

Vietnam is one of the delta countries where Partners for Water works together with local partners to address water challenges. Are you working in Vietnam or interested in exploring opportunities there? Visit our Vietnam delta country page to learn more.

Partners for Water recently supported the development of a Serious Game in Vietnam’s Mekong Delta, a region under severe water pressure. Led by Deltares, The Water Agency, and Can Tho University, the project used interactive gaming to help farmers, students, and policymakers understand the real-life consequences of groundwater use. The game has since evolved into an educational and policy tool across Vietnam.

In the fertile plains of Vietnam’s Mekong Delta, where rice paddies stretch to the horizon and millions depend on agriculture for their livelihoods, an environmental crisis is unfolding beneath the surface. Groundwater depletion, saltwater intrusion, and land subsidence threaten the very foundation of the region’s agricultural economy.

To address the problems, in 2018 the Vietnamese government implemented new national legislation prohibiting all groundwater extraction, even for domestic use, to maximize aquifer protection in vulnerable areas.

“But you can’t prohibit something essential to farmers like groundwater and not come up with an alternative” explains Niels Mulder, a hydrogeologist specialising in groundwater and subsurface systems at Deltares.

Rather than relying on conventional approaches to environmental education and awareness, this sparked a groundbreaking collaboration between the Dutch research institute Deltares, The Water Agency, and Can Tho University. Together they developed an innovative solution: a serious game that transforms complex environmental science into engaging, hands-on learning experiences.

From research to reality

The project originated in an unconventional request from the RVO (Netherlands Enterprise Agency) via local Vietnamese partners who recognized that traditional policy communication wasn’t working. A game could provide an easy, accessible way to invite farmers to a session or meeting, and give them insight into the problem.

“We brought board games with us to a cafe and played them for a few hours. We were particularly inspired by ‘Terraforming Mars’, a game about making Mars habitable”. The team deliberately avoided digital solutions, despite their potential for precise calculations. “We wanted people to sit at a table together, in order to get a dialogue,” explains Trang Dinh. He facilitated the sessions at Can Tho University and is the country coordinator at Deltares for the Mekong region.

The physical board game format enables interpersonal dynamics that digital alternatives cannot replicate. For instance, player 1 can say to player 2, “you are now going to extract a lot of groundwater which has consequences for me”. They then find out that the only way to ‘win’ the game is by collaborating, explains Marta Faneca from Deltares. She played an important role in conceptualizing how gaming could bridge the gap between scientific knowledge and practical understanding.

It was also clear from the beginning that instead of providing a groundwater model, the game should give insights into the economic differences between, for instance, growing bananas or nuts. Initially the earnings will be higher, but then the game will show the enormous amounts of water needed. Where will this water come from? It needs to be stored. Can you store it yourself, or should neighbouring farmers be involved?

Everyone was excited. Trang explains: “even after the game was finished, people carried on talking. This outcome exceeded the team’s initial expectations and demonstrated the game’s effectiveness in generating motivation for sustainable practices.”

Policy implementation

The educational approach is designed to empower choice rather than prescribe specific solutions. So the game presents broad categories of interventions – water efficiency improvements, surface storage solutions, and managed aquifer recharge systems – while allowing players to explore their applicability to different situations.

The game’s development involved extensive testing with three distinct audiences, each bringing different perspectives and learning needs.

University students, particularly those without water resources backgrounds, approached the game with curiosity but a limited understanding of groundwater consequences. The game provided these students with their first tangible experience of how individual decisions create collective environmental problems. They gave the developers an open-minded insight into the use of the game.

Another audience, government officers, brought extensive technical knowledge but played with extreme caution. Trang: “They already have a lot of knowledge about the groundwater problem, and they play the game very carefully from the beginning. They almost never make mistakes”.

This observation of these three distinct audiences led to crucial insights about policy implementation and how different groups engage with environmental challenges.

Expanding impact

The game’s evolution from initial testing at Can Tho University in November 2023 to featuring at Hanoi’s UN Youth Festival in August 2025 demonstrates both its educational effectiveness and its scalability. Over three hour-long sessions, young participants from diverse backgrounds played the game, creating an inclusive environment that transcended language barriers.

Participants rated the experience an impressive 4.8 out of 5, with many commenting that it was “harder than expected” because it required balancing profit with sustainability. This difficulty was not a design flaw but a feature: it accurately reflected the real-world challenges faced by farmers and policymakers in managing competing economic and environmental priorities.

The development team discovered that successful implementation required constant adaptation to local contexts. The solution was to empower facilitators to modify game parameters in real time. Eight professional games are now circulating among universities, provincial departments, and communities, supplemented by locally produced versions using printed materials and Lego pieces. Another advantage is that no expensive technology is needed and the games can easily be adapted to local languages and contexts.

Learning by playing

“The project is finished. But that does not mean the game is over,” explains Niels Mulder. He feels it would be helpful to integrate this type of ‘learning by playing’ into higher education because it makes complex environmental systems tangible. Vietnam’s Ministry of Natural Resources and Environment sees the potential for integrating the game into policy consultation processes for new water resource regulations.

The Water Agency and Deltares are scaling up these efforts, developing training for new facilitators, adapting the game for different regions, and creating digital versions in order to reach broader audiences. However, they recognize that the physical board game format offers irreplaceable benefits: face-to-face interaction, collaborative problem-solving, and the tangible nature of gameplay that digital simulations cannot replicate.

Trang’s firsthand observations reveal how games can transform traditionally difficult conversations into engaging collaborative experiences. The game successfully introduced both familiar and novel water management technologies. “Drip irrigation is popular with farmers,” Trang noticed, “and managed groundwater recharge is new to them. Explanations about how alternative techniques can help save water were very welcome.”

Turning Insight into Impact

Investing in Managed Aquifer Recharge (MAR), taking water from channels or rivers, and purifying it to appropriate standards is becoming more attractive in the long term. But this approach requires infrastructure investment and technical expertise. The process is more labour-intensive than simply drilling deeper wells and needs proper planning as it’s not an overnight solution. The goal is for everyone to benefit: both individual farmers and the broader community.

Government incentives can encourage farmers to adopt sustainable practices and offer solutions to reduce groundwater dependency. Players often ask for more information after playing, indicating genuine interest, and the game successfully raises awareness about how individual actions affect the broader delta ecosystem.

Most importantly, The Rethinking Groundwater Use Serious Game demonstrates that learning about environmental challenges need not be abstract or disengaging. It can be immediate, collaborative, and even fun, creating memorable experiences while still conveying crucial scientific concepts and fostering the systemic thinking needed for sustainable futures. As Marta Faneca concludes: “maximizing profit alone leads to a loss for everyone, not only regarding water, but also the environment and quality of life”.

What do you do when a city floods during the monsoon, yet faces water shortages in the dry season? Or when you aim to build resilient infrastructure but are confronted with challenges such as informal settlements? For many cities, climate change is exposing these urban vulnerabilities, particularly in delta and coastal areas. Yet it also presents an opportunity to make cities not only more resilient, but also more liveable. We explored what makes a climate-resilient city, and the experiences of five delta cities on the front line of climate change: Semarang, Thủ Đức, Cartagena, Chennai and Beira.

Climate change poses a direct threat to the wellbeing of billions of urban residents. In all cities, climate-related risks are on the rise. At the same time, urbanisation continues to intensify. By 2050, nearly 70% of the world’s population will live in cities. This growth is putting increased pressure on infrastructure, water, space and public health. Mitigation alone is no longer enough. We must adapt to a climate where extremes are the new normal: too much, too little, or polluted water, as well as heatwaves and droughts.

Without action, damage to urban infrastructure could reach $415 billion per year. The urban poor are hit hardest, often living in high-risk areas without adequate protection. Yet urgency also brings opportunity. By approaching cities as interconnected systems, and working with water and nature, we can build climate-resilient cities that are not only robust, but also greener, healthier and more inclusive.

What is a climate-resilient city?

A climate-resilient city can absorb shocks, adapt to changing conditions, and recover quickly from extreme weather events such as sea level rise, heatwaves, flooding or drought. Resilience goes beyond physical structures – it also applies to institutions, governance systems, and communities. Increasingly, cities are moving from a mindset of control to one of working with change. With smart design, risks can be turned into opportunities: rainwater is captured and reused, urban heat becomes a driver for green and shaded spaces, and nature is integrated as vital infrastructure. Cities that plan ahead and reduce future risks can remain liveable, even under pressure.

Nature-based Solutions and climate-resilient cities

Nature-based solutions (NBS) are approaches to societal challenges that harness natural processes, such as vegetation, soil and water. For cities, they offer an important alternative to traditional ‘grey’ infrastructure such as drainage systems and concrete flood barriers. Because they evolve with changing conditions and deliver multiple benefits simultaneously, NBS are particularly well suited to strengthening urban resilience. Examples include green roofs that reduce heat stress and retain rainwater, or city parks and mangroves that buffer water and slow down flooding. When they are well integrated into urban planning and policy, NBS can create synergy between climate mitigation and adaptation, while also enhancing liveability and biodiversity.

Despite their proven value, NBS are still applied on a relatively limited scale compared to grey infrastructure. Upscaling is essential to ensure cities can withstand increasing pressure from heat, drought and extreme rainfall. Partners for Water works from a systems perspective to maximise the benefits of these solutions, developing sustainable approaches with a strong focus on operation and maintenance.

Five climate-resilient cities around the globe

Semarang

Semarang is a fast-growing coastal city on Java’s north shore that faces some of Indonesia’s most pressing climate challenges. The city’s population has grown from around 1 million to about 1.7 million over the past twenty years. Severe land subsidence – in some areas up to 20 centimetres per year – combined with tidal flooding, flash floods and water scarcity affects residents’ daily lives. Rapid urbanisation and reliance on groundwater extraction further worsen the risks. But the tide is turning: the city aims to become climate-resilient by 2045 through long-term, integrated planning.

To tackle its water challenges, Semarang applies a mix of measures. These include rainwater harvesting in homes and shared spaces to mangrove rehabilitation along the coast, vetiver planting to prevent landslides, and early warning systems for floods and vector-borne diseases. Building on these efforts, the Water as Leverage programme, supported by Partners for Water, pilots integrated, multi-stakeholder solutions that combine NBS with conventional infrastructure and smart data technologies. By bringing together Dutch and Indonesian expertise with strong local involvement, these projects support Semarang towards becoming a climate-resilient city. Read more about Semarang.

Cartagena

Colombia’s historic port city Cartagena is under pressure. The city is growing rapidly but faces rising sea levels, flooding and extreme heat. Most of its one million residents live in low-lying areas, making them especially vulnerable to flooding. By 2050, projections suggest that sea levels around Cartagena – amplified by ongoing land subsidence – could rise by more than 30 centimetres. These predictions put even greater pressure on coastal neighbourhoods. Through the Water as Leverage programme, with support from Partners for Water, residents, local experts and city officials are working together on plans that address both climate risks and socio-economic inequality.

The projects are small in scale but strategically placed, and include water plazas, elevated walkways, mangrove restoration, and improved access to drinking water. This approach integrates all the relevant aspects: design, nature, the social and environmental aspects, as well as the economic and financial ones. By placing local ownership at the heart of the process, the city is building a strong foundation for lasting, inclusive change. Read more about Cartagena.

Thủ Đức City

Thủ Đức City in Vietnam is a city in the making. Today it has just over one million inhabitants, but by 2050 it is expected to grow to around three million residents. Situated between the Saigon and Đồng Nai rivers, the new city is highly exposed to flooding. Extreme rainfall, high river levels, land subsidence and the interaction of these factors make water management a central challenge for its development.

With support from Partners for Water, a blue-green vision has been developed. It combines natural buffers, flood retention zones and smart urban design to better manage excess water. This vision has been translated into spatial plans and policy recommendations focused on working with water, alongside digital systems that support real-time water management. Without adaptation, annual flood-related losses are estimated at nearly USD 67 million and could more than double by the end of the century. By embedding Nature-based Solutions and digital water management systems into its spatial planning, Thủ Đức aims to grow into a resilient metropolis that can withstand both climate pressures and urban pressures. Read more about Thủ Đức City.

Chennai

Chennai is a fast-growing megacity in southern India. It faces a paradox of water extremes: severe flooding during the monsoon followed by extreme drought. Simultaneously, the city is steadily losing its capacity to retain water due to paved-over infrastructure, unregulated urbanisation and polluted waterways. Chennai’s traditional water bodies, known as ‘tanks’, once held around 188 million m³ of water. Urbanisation since the early 1900s has reduced this capacity by about 7%. The remaining 93% is located mostly outside the city and is increasingly threatened by encroachment, pollution and poor maintenance. To reverse this trend, the Water Resources Department aims to triple the city’s storage capacity by 2050.

The City of 1,000 Tanks project, supported by Partners for Water, supports this goal by drawing on the city’s ancient water infrastructure. The project restores these systems and links them to new NBS such as infiltration fields, retention ponds and other green infrastructure. By capturing, filtering and slowly recharging water locally, the project tackles both water scarcity and excess. The approach is modular, scalable and rooted in local collaboration with schools, businesses and communities. Chennai shows that climate adaptation is not only about innovation, but also about reviving and revaluing traditional knowledge. Read more about City of 1000 Tanks.

Beira

Mozambique’s port city of Beira is on the front line of climate change. In 2019, it was devastated by Cyclone Idai, which damaged around 70% of the city’s housing stock. Two years later, Cyclone Eloise in 2021 left another 20,000 homes – roughly 17% – damaged or destroyed. Together, the two storms caused over USD 2.4 billion in losses. But rather than focusing solely on recovery, Beira is pursuing structural transformation. Through the Masterplan 2035, developed with support from Partners for Water, the city is investing in climate-resilient urban development: from improved drainage and wastewater treatment to coastal protection and stronger local governance.

Through public and private partnerships, Beira is building climate-resilient homes with minimal construction costs or rent-to-buy schemes. This makes safe housing accessible to residents for whom home ownership would otherwise be entirely out of reach. Simultaneously, the city is updating its municipal cadastre to improve property registration and enable the collection of property taxes. This is a long-term strategy, focused on system change in order to become a truly climate-resilient city. Read more about Beira’s system change approach.

Seven building blocks for a climate-resilient city

1.        Systems thinking and integrated approaches

Climate adaptation only works when water, infrastructure, public health and governance are seen as part of an interconnected system. It must be addressed across all spatial scales, from the pavement to the metropolitan region.

2.        Making space for water

When cities actively allocate space for water through buffers, temporary retention zones and natural systems, rainfall becomes a manageable design element. It can even become a resource for future droughts.

3.        Flexibility and adaptive capacity

A resilient city is flexible and evolves as the climate and associated risks change. This requires future scenarios, room for experimental development, phased planning, and the ability to adjust course when needed.

4.        Monitoring and data analysis

Digital tools and modelling software can help detect risks early and support an effective response. Data collection and management form the foundation for improved policy and governance.

5.        Participation and local ownership

Solutions only have lasting impact when they are supported by the local community. Local engagement ensures context-specific solutions and fosters long-term ownership.

6.        Collaboration and governance

Coordination between governments, public and private organisations, knowledge institutions and residents are crucial for implementation and lasting impact.

7.        Working with nature

By cooperating with the natural processes of vegetation, rivers or mangroves rather than trying to control them, cities can develop sustainable and flexible solutions that support both climate adaptation and urban liveability.

Partners for Water for climate-resilient cities

When we view cities as interconnected systems and choose to work with nature rather than against it, we can build urban environments that are more resilient, greener, and more liveable than ever before.

Partners for Water supports cities around the world in building climate resilience through an integrated, systems-based approach. We promote the use of NBS and advise cities on innovative and sustainable water management. In doing so, we not only address water security, but also biodiversity, food security and healthy living environments.

Our support spans strategic guidance, from policy advice and planning to capacity-building within local governments. We also fund and facilitate pilot and feasibility studies that test scalable, sustainable and innovative water solutions.

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.

How to make aquaculture more sustainable and efficient?  In Vietnam’s Mekong Delta efforts towards establishing a nature-based filtration system to make aquaculture more sustainable and efficient are progressing. Two Dutch companies and one Vietnamese company have joined forces to use mangroves to address issues around groundwater extraction, water contamination and coastal protection in relation to shrimp farming.

This article elaborates on a feasibility study financed by Partners for Water and the consortium partners: Larive, Van Oord and RYNAN Smart Aquaculture.

The need for change in shrimp farming practices

Rogier Becker, an emerging market advisor at Larive International, is part of an initiative alongside Nienke Oostenbrink from Ocean Health, a programme by the Dutch marine contractor Van Oord, and Minh Anh Tran Ng from RYNAN Smart Aquaculture, a Vietnamese company focused on innovation in shrimp farming. Together, these three organisations have developed a model to transform the traditional shrimp farming practices in the Mekong Delta, which have been passed down through generations.

From left to right: Rogier Becker, Nienke Oostenbrink and Minh Anh Tran Ng.

Coastal protection and mangrove destruction

Becker begins by explaining the need for change. “The coastal regions of Vietnam, particularly the Mekong Delta, are characterised by vast rice fields further inland and extensive aquaculture, primarily shrimp farming, nearer  the coast where the water is brackish. A natural belt of mangroves along the shoreline has played a vital role in preventing coastal erosion by trapping sediment and safeguarding the land.”

Water travels through various mangrove plots when flowing from aquaculture facilities to the river. These mangroves absorb nutrients from shrimp farming, using them for their own growth, creating a natural purification system. Over the years, many shrimp farmers have cleared parts of the mangrove belt to expand their operations. This deforestation has led to increased coastal erosion, shrinking the once-protective mangrove belt to a fraction of its former size.

Water pollution

“Another significant problem is water pollution”, Becker continues. “Upstream farmers use pesticides and other chemicals on their crops, which contaminates the Mekong River as runoff flows downstream. As the water continues its journey, it picks up additional pollutants from each subsequent farm, exacerbating the contamination. This is cumulative, creating a domino effect,” he explains, “leaving the farmers furthest downstream with severely degraded water quality, posing a serious challenge to the quality of the shrimp and the overall ecosystem.”

The TOMGOXY model

Becker, together with the other consortium partners, have been at the forefront of innovative technology.  Now known as the TOMGOXY model, this digital system for operating shrimp farms in a sustainable manner has resulted in more efficient use of resources and less negative impacts on the environment. This approach is supported by replanting mangroves and integrating them into farming systems.

Becker explains, “We’re exploring a combined approach of aquaculture and mangrove restoration, involving local farmers. While mangrove replanting is welcome, many restoration projects fail due to poor location selection and monoculture planting. Our process involves transplanting seedlings from nurseries to carefully chosen sites where suitable conditions for mangroves are generated, with the goal of creating a diverse ecosystem.” By carefully selecting and nurturing mangrove seedlings in nurseries before planting them pitfalls are avoided, ensuring a better chance of survival

Testing and preliminary results

Becker adds, “We’re in a testing phase, exploring opportunities and preparing to report on the results at the beginning of next year. Tests to assess mangrove growth and water purification will start soon. While the business model exists due to shrimp profitability, we’re still determining the optimal ratio of mangrove blocks to shrimp ponds for economic efficiency. Previous tests have confirmed mangroves’ purifying capabilities, but we’re now focusing on creating a circular system for water reuse. The difference between these methods lies mainly in the density of shrimp in the ponds and the amount of oxygen they need.”

Mangrove integration in other regions

In some Vietnamese regions, like Cà Mau, intensive shrimp farming is naturally integrated into mangrove forests. Shrimp are grown in nets within the mangroves, benefiting from the natural environment. However, the model under development now involves a more controlled method where shrimp are raised in tanks. The wastewater from these tanks, which contains nutrients like nitrate, is not immediately released into rivers. Instead, it is first filtered through plots of mangroves, which use the nutrients for their growth, helping to purify the water before it is released back into the environment.

Van Oord’s role: designing and testing

Nienke Oostenbrink, from Van Oord’s Ocean Health initiative, oversees the restoration initiative in Vietnam. “We collaborate closely with RYNAN, to strengthen their ‘TOMGOXY solution’, by adding the mangrove component to it. During testing at the demonstration site in Vietnam, we aim to gather valuable insights into the filtering capacity of mangroves in different set ups.”

While RYNAN implements the broader concept, Van Oord’s expertise lies in designing and testing how mangroves can naturally filter wastewater. According to Oostenbrink, the TOMGOXY concept allows for hyper intensive farming, producing high outputs per square meter. This reduces the need for land and makes space available for restoration of mangrove areas.

Studying mangrove filtration capacity

“We study the capacity of mangroves to absorb nutrients by pumping wastewater from the shrimp ponds into three different mangrove plots. The three plots have unique experimental conditions, allowing us to identify the most favourable conditions for nutrient uptake and mangrove growth. In order to obtain this information, the nutrients in the water and soil and health of the mangroves are closely measured. After the experimental phase, we have acquired the necessary knowledge of the filtration capacity of mangroves in combination with shrimp farming using TOMGOXY.”

The project is complex and will require about nine months of testing before definitive conclusions can be drawn. Even then, the scalability of this solution depends heavily on local conditions. Oostenbrink acknowledges that mangroves require specific environmental conditions to thrive, such as tide-induced flooding of and salinity levels. The design of the mangrove area and site conditions need to be tailored to the selected location.

Scalability and future goals

Ultimately, the success of this project depends on demonstrating that the mangrove filtration system is both effective and economically viable. “If so,” Oostenbrink states, “we will upscale from the current demonstration project to a larger pilot project, where a site needs to be selected and prepared for large scale filtration of aquaculture effluent by mangroves.” This will entail ongoing collaboration with local partners, insights from continued experimental testing and the development of a sustainable financial model. Partners for Water helped finance the initial feasibility study and Oostenbrink highlights how crucial this support was in getting the project off the ground.

RYNAN’s optimism

Minh Anh (RYNAN) embarked on this ambitious project in early 2024. She explains that the collaboration with Van Oord represents a significant development in the net-zero shrimp farming paradigm, lays out a strong foundation for maximising the effect of mangroves in reducing  the amount of gas emissions released from shrimp farming activity and also “seeks to overcome the limitations of relying solely on NGO and government funding for such initiatives.”

While RYNAN has been working on shrimp farms issues, the mangrove integration aspect is relatively new for them. Based on Van Oord’s specifications, RYNAN is preparing to collect data using advanced digital tools, including drones and a network of IoT devices that automate operations and assist in real-time measurement. The testing will involve monthly data collection to assess the effectiveness of the mangrove-shrimp farming system in terms of:

• Treating waste water from shrimp farming activities;
• Reduce the gas emissions amount from shrimp farming;
• Potential scale up to apply to wider range of shrimp farming/mangrove rehabilitation.

Challenges and concerns

In order to ensure the accuracy of the measurements, Van Oord also helped in surveying and conducting comparison experiments with natural mangrove sites. The project promises to not only resolve the environmental issues of the area, but also the social and economic problems faced by local farmers and agricultural funding.

While the team is optimistic about the project’s potential, they have identified some concerns. Minh Anh notes, “The project duration might be extended if turbulent weather conditions occur”. She also questioned the next step of scaling up the project amongst the local shrimp farming community, which farmers are not technically prepared for.

Conclusion

In summary, the model represents a significant departure from traditional shrimp farming methods, paving the way for a more responsible and productive shrimp farming industry.

Partners for Water in Vietnam

Are you currently working on water projects in Vietnam or exploring how to do so? Or just curious about participating in the Partners for Water initiatives?
Visit the Vietnam Delta Page to discover ways in which you can get involved.

This May, Tamar Meibergen joined Partners for Water as a Programme Advisor

She will work on various projects, such as the Vietnam programme, the subsidy scheme, the monitoring and evaluation framework and an event about Nature-based Solutions. In her spare time, she is also all about water sailing competitively on an all-female team. Nice to meet you, Tamar!

International Ambition

‘While I was studying, water was always the focal point. First with my bachelors in Social Geography and Planning in Utrecht and then later with my masters in Environmental Geography in Amsterdam.’ As a part of her studies, Tamar did an internship at the NGO Wetlands International in Mali. ‘I worked on many interesting projects there, like a flood warning system for illiterate farmers and figuring out how to make gold extraction sustainable.’ After her studies, Tamar worked for 2,5 years as a Water and Climate Consultant at TwynstraGudde. ‘Although I learned a lot, I also realised that I want to invest more time in implementing projects internationally, while working together with all kinds of different people. So, when the opportunity arose to work with Partners for Water I decided to go for it.’

Innovation and Experimenting

Tamar believes her consultancy experience will prove to come in handy at Partners for Water. ‘Although I have only just started, I can already tell that there is a lot innovation and experimenting here. If you see an opportunity there is room to go for it. Applying a proactive approach is something I learned both at TwynstraGudde and while doing a ‘Inclusieve Groene Groei’ (Inclusive Green Growth) internship at the Ministry of Foreign Affairs. These work experiences also taught me how to develop strong networks. It will be interesting to be on ‘the other side’ as now I’ll be working with consultants instead of being one myself. I think knowing both perspectives will help me too.’

Vietnam Experience

‘I’ll be working on several topics over the next few months. For example, I will spend time on our Vietnam programme while the designated Programme Advisor is away. Luckily, I already have some prior knowledge of Vietnam. I was there for my master thesis, which was about the export of Dutch water expertise and how trade missions contribute to them. I will also work on our subsidy scheme as well as our monitoring and evaluation framework, which will helps us see the results of our work more tangibly. Lastly, we will organise a Nature-based Solutions event when the World Bank and Asion Development Bank delegates visit in June.

Meaningful Cooperation

Tamar appreciates the changes made in the way the Dutch water sector works with international partners. ‘We used to present a solution without really consulting with our counterparts. Nowadays, there is meaningful cooperation in the whole process making use of local knowledge.’ Water is not only important to Tamar in her professional life, but also in her private life. That is why she devotes a lot of time to competitive sailing. ‘I’ve been on the water since I was young. The team I’m involved in is all-female,  which is pretty unique in the competitions we enter. When I’m sailing, I not only see trash in the water, but also the daily problems that are connected to water management. This make it all the more motivating to make the most of my time at Partners for Water.’