At the second matchmaking event at the Social Impact Factory in Utrecht on 16 January, seventeen projects were showcased that have recently been awarded financial support through the Partners for Water Subsidy Scheme. The presentations took place in three different rooms, where the enthusiastic audience of about fifty people was divided. Afterwards, attendees had the opportunity to visit each room, ask questions to the presenters, and, of course, make valuable connections and exchange ideas. As Hugo de Vries (PfW) explained in his introduction speech, the presentations provided valuable insights into what other organisations are working on and the goals they aim to achieve with the support of Partners for Water.

During the presentations, Gregor van Essen from The Water Agency discussed the Green Batik Pekalongan initiative. This two-year pilot project in Indonesia aims to develop a sustainable water management model for the batik industry, which has been crucial to the country since the 17th century but is known for its high water consumption. The project will test water conservation solutions at selected workshops and, in the next phase, establish a Green Batik Centre at Universitas Pekalongan (the “Capital of Batik”) to promote sustainable production practices.

Additionally, Livio Bod from SPAAK presented a pilot project in Morocco’s Boulemane region, which introduces a Nature-based Solution (NBS) to improve water catchment and retention in agricultural soils. By combining rain and flood analysis, advanced software, and local knowledge, this project aims to validate the approach for large-scale implementation across Morocco, where agriculture is a key economic sector.

The Welang River in East Java, Indonesia, is a crucial lifeline for nearby communities, providing water for daily use and supporting local agriculture. As cities expand and populations grow, however, the river has faced increasing challenges such as flooding, erosion and pollution. The Governments of Indonesia and the Netherlands, through its Partners for Water programme are investing in the Welang River Basin Transformation Project to tackle these challenges and protect both the river and the people who depend on it. This is the third article in the miniseries on the Welang River Basin project, highlighting the role of Nature-based Solutions for integrated water management.

During the rainy season, the Welang basin, specifically in Sidogiri and Welang Lama, experiences floods at least once a year. Notably during the recent rainy seasons in 2022 and 2023, floodwaters of up to one-meter caused the Welang Lama river to overflow, inundating several districts including the villages of Sukorejo and Karangketug. This disaster caused economic and infrastructural losses to affected people in this area.

In response to the recurring flooding issues, the Indonesian government, through the East Java Province, has partnered with the Netherlands government to implement the Welang River Basin Transformation Project. This initiative will be executed by a Netherlands-Indonesian consortium, consisting of Witteveen+Bos, Nuffic Southeast Asia and AidEnvironment. Sidogiri and Welang Lama were selected as pilot sites to address the flooding challenges. One of the project’s primary objectives is to design effective flood protection measures for these areas through a collaborative co-creation and design phase.

Collaborative co-creation (co-design) supports participatory design as a fundamental aspect of Sustainable Design Principles (SDPs). The co-design process involves active participation from local communities, landowners and government stakeholders, fostering inclusivity and ensuring that the final outcomes are tailored to the specific needs and contexts of those involved. The process is divided into four stages:

• Needs and Demands: this stage focuses on identifying the challenges and needs of the communities while understanding local environmental issues. To achieve this, the consortium, in partnership with students from Universitas Negeri Malang (UM), Universitas Brawijaya (UB) and Institut Teknologi Sepuluh Nopember (ITS), conducted site visits along the Sumber Pinang and Welang Lama rivers. These visits included hydraulic modelling and flood assessments to gain a comprehensive understanding of the area’s vulnerabilities.
• Co-Creation of Solution: during this stage, technical expertise is combined with local knowledge to design effective interventions. Stakeholder workshops were organised, involving the consortium, the Department of Public Works and Water Resources, universities and local villagers. These sessions facilitated knowledge sharing and discussions, leading to the identification of potential structural and non-structural measures to address flooding.
• Complementing Solutions: Solutions were refined based on community feedback and further analysis. Conceptual designs were developed in collaboration with the Department of Public Works and Water Resources, the consortium and the universities. These frameworks were then shared and discussed with villagers to ensure that the solutions reflected their needs and input.
• Validation and Implementation: The final stage involved evaluating the proposed solutions to ensure their effectiveness and alignment with institutional policies. Final outcomes were presented to the communities, outlining the next steps with an emphasis on transparency and trust-building.

By following these structured stages, the co-design process promotes inclusivity, knowledge sharing and community-driven solutions to effectively address local environmental and flooding challenges. Each phase employs distinct participatory design approaches to ensure that all parties are involved and can contribute based on their background and expertise. The following table outlines the co-design process, detailing each stage and the corresponding participatory design methods used:

Miniseries on the Welang River Basin project

This is the fourth article in the miniseries on the Welang River Basin project, highlighting the role of youth in sustainable waste management. Below you can find the links to other articles in the series:

Article 1: The role of trusted advisors
Article 2: Practical implementation of Nature-Based Solutions
Article 3: Empowering youth for sustainable waste mangement
Article 4: A participatory design approach

Miniseries on the Welang River Basin project

This is the third article in the miniseries on the Welang River Basin project, highlighting the role of youth in sustainable waste management. Below you can find the links to other articles in the series:

Article 1: The role of trusted advisors
Article 2: Practical implementation of Nature-Based Solutions
Article 3: Empowering youth for sustainable waste mangement
Article 4: A participatory design approach

On 16 January, the second matchmaking event took place at the Social Impact Factory in Utrecht. The name of the location is undoubtedly fitting, as the event brought together a diverse and enthusiastic audience of government employees, NGOs, companies, lobbyists, and even a few journalists, all eager to explore how they could support one another and collaborate more effectively to achieve a shared goal: improving water security globally. The main objective of the afternoon was to generate new subsidy applications for innovative water projects under the Partners for Water Subsidy Scheme.

Bram van der Wielen from Partners for Water kicked off the event by providing an overview of the projects currently supported by the organisation. At present, there are 57 projects in 28 countries, most notably in Vietnam, with six specific projects there. Van der Wielen explained that there are both feasibility and pilot projects running. Feasibility projects focus on research and analysis to assess whether an idea is viable, while pilot projects are focused on testing solutions in the field to confirm their practical application before scaling up.

Knowledge transfer and global water challenges

The attendees were then divided into two rounds across five tables, each focused on a specific theme. At Table 4, where Infrastructure and sustainable waterways were discussed, one participant emphasised the importance of avoiding repeated investments in the same infrastructure. This can be achieved by making locations financially, institutionally, and knowledge-wise independent. Throughout the discussions at the various tables, the focus was strongly on knowledge transfer and self-reliance, rather than dependency.

At Table 3, Water-Biodiversity-Food, one participant expressed the ambitious desire to clean “all the water in the Netherlands and beyond,” while another highlighted the urgent need for assistance in Spain, where significant social issues and rising saltwater levels have a large impact. “This is a huge problem in the Mediterranean,” was emphasised during the discussion.

Water availability, climate adaptation, and local solutions

Table 1, which was dedicated to Water Quality and Availability, was particularly crowded during the second round. Everyone took turns introducing themselves, after which Gábor Szántó from Partners for Water asked follow-up questions to explore the potential for collaboration. For example, journalist Vincent Kuypers spoke about the situation in the Nile Delta, where 2 million people have been relocated in the past two years. The local authorities had asked him: “Can you go to Holland and see how we can collaborate?” “Despite my long experience in the field, I have never seen anything like this before,” said Kuypers. The aim was for the people of Egypt —not just the wealthy—to be able to protect themselves and secure their future.

At the Climate Adaptation table, number 2, a participant from Ghana focused on giving ownership to vulnerable groups and emphasised the need to explore which crops and foodstuffs would be most economically viable in the local environment. “Does anyone have a solution for me?” he asked his tablemates directly. Cards, phone numbers, and social media accounts were exchanged in abundance.

Reflections on another dynamic matchmaking event

Given the numerous conversations between different parties in various languages—during which not only a great deal of information was exchanged but also much laughter shared—the event can be considered a success. We hope that many valuable connections were made, leading to fruitful collaborations and exciting projects in the future. We aimed to provide more information on the Partners for Water subsidy scheme, making the application process easier for everyone. Did we succeed? Or do you have any feedback? Please let us know your thoughts by sending us an email: partnersforwater@congresbureau.nl

In Kenya’s Rift Valley, millions rely on groundwater containing dangerous levels of fluoride, causing serious health issues in local communities. Julius Kubai, Director of Harbauer Limited, explains how he and his consortium partners are piloting an innovative household water treatment solution that simultaneously tackles both bacterial and fluoride contamination. Funded by Partners for Water, their unique solution aims to transform lives and make safe drinking water accessible to Kenyans.

After spending two decades working in Kenya’s water sector, Julius Kubai has witnessed first-hand the challenges communities face with contaminated groundwater. From his office in Nakuru, he shares how his journey from drilling water boreholes led to developing innovative solutions for fluoride removal. “I used to work with the local Catholic Diocese drilling water boreholes for local communities. While doing so, we consistently encountered dangerously high levels of fluoride. This pushed us to do research on appropriate technology to remove fluoride and provide safe drinking water,” explains Kubai.

In 2018, Harbauer Limited took over the fluoride removal project from the Catholic Diocese. Now, it focusses on providing filters and decentralised filter stations using HAP (hydroxylapatite) filter material for households, communities and public water suppliers. Harbauer Limited, with support from a Partners for Water subsidy together with consortium partners Resilience BV, Nazava Water Filters Ltd. and Delft University of Technology, is developing a fluoride-removing add-on to enhance the existing and widely used Nazava Water Filter, which removes bacteria from water.

Severe health issues

“In many areas, especially the Rift Valley, groundwater fluoride levels are two to six times higher than the World Health Organisation’s guideline that prescribes a maximum of 1.5 milligrams of fluoride per litre of drinking water,” says Kubai. “The impact on communities is severe. Beyond brown teeth, which affects people’s self-esteem and even job opportunities, excessive fluoride can cause skeletal fluorosis – a chronic metabolic bone disease affecting bones and joints. Growing children are particularly vulnerable to these effects.”

Rift Valley where the fluoride problem occurs.

Innovative water filter solution

Harbauer Limited has demonstrated success in cleaning groundwater using HAPaqua, a special adsorbent that significantly reduces fluoride concentration. “We’re now piloting our fluoride removal technology with Nazava Water Filter’s existing ceramic filter system,” Kubai explains. “What makes our solution truly innovative is that we’re addressing two critical water quality issues at once – bacterial and fluoride contamination – at the household level.”

Testing and development

“Currently, we’re running parallel experiments with two different water sources. One in our office compound and one in a nearby community,” says Kubai. “The water source from the community has around 10 milligrams of fluoride per litre, while the one in our office compound has about 5 milligrams. This comparative testing helps us understand how the filter performs under different conditions.” While doing so, the project brings together the expertise from its multiple partners: Resilience BV leads the consortium, with Nazava Water Filters Ltd. contributing their established ceramic water filter technology. The partners are collaborating with TU Delft and Harbauer in designing and testing the new add-on component whilst ensuring community involvement.

Community-centered approach

“Our goal isn’t just to create a filter – it’s to develop a solution that communities will actually use,” stresses Kubai. “By June, we aim to have an affordable household filter that has been tested by the community. Their feedback on design and usability is crucial. We want to ensure the final product meets their needs and is acceptable to them before scaling up.” Looking ahead, Kubai is optimistic about the project’s potential impact. “Once we have a solution that’s both affordable and meets community needs, we plan to expand throughout Kenya’s fluoride-affected areas, making safe drinking water accessible to all Kenyans who need it.”

Nineteen years ago, Haanen sold his software company in the Netherlands and moved to Africa with his wife to work for various NGOs and government organisations. After working in Ghana, Tanzania and Kenya, they settled in Zambia, where they established the Jacana Foundation, which supports small-scale local entrepreneurs. “During our travels, we saw NGOs buying products directly from manufacturers and delivering them by lorry to villages. Often, this forced local shops to dump the same products, creating unfair competition. So, we thought, let’s see how we could do this differently,” Haanen explains. With Jacana, they developed a supply chain that collaborates with NGOs and local shop owners, with the initial focus on an affordable portable solar pump to address water scarcity among Zambian farmers .

The project turned out to be a success. Now, with consortium partner MetaMeta and funding from Partners for Water, they plan to develop and roll out the concept over the next two years across Zambia and beyond.

Innovative solar pomp

In sunny Zambia, Haanen shows Tabitha Bakker, writer of this article, on a digital tour of Jacana’s office grounds, which serve as both a workshop for the innovative pump and a training centre for local entrepreneurs. A water drum and solar panel stand in the middle of the lawn in front of the office. “Look,” says Haanen, lifting a small blue pump from the drum, “the farmer places this pump in a stream or well. The portable solar panel powers the pump, drawing water through the hose from the source.” He explains that not only is the pump innovative, but so is its distribution model.

Changing the supply chain

“We’ve developed a supply chain that connects local distributors, shops and NGOs. The NGOs provide farmers with vouchers to purchase a pump at a local shop for a small fee. This personal contribution is shared between the shop owner and the warehouse. Rather than NGOs delivering pumps by lorry, they now travel by scooter with vouchers in their backpacks, benefiting local entrepreneurs too.”

Affordable irrigation technology

“The innovative aspect of this irrigation technology is that it’s extremely affordable,” explains Haanen. “Typically, pumps are designed for larger water consumption. By adapting the pump to smallholder farmers’ consumption needs, it’s become much more affordable. A farmer can recover the cost with just one good maize harvest – they don’t even need a coupon or credit for that.”

Tracking the impact

The project’s impact reaches beyond the voucher recipients. “Farmers from the recipients’ networks are also buying pumps. They’ve seen the success of the voucher programme, know where to find the shops and because the pump is affordable, they can purchase it without sponsorship.” Through a specially designed app, NGOs can track pump sales from shops and warehouses, monitoring their impact beyond the initial voucher programme.

Scaling up through partnerships

“Currently, we’re working with nine local shops, a local warehouse, MetaMeta and a Chinese manufacturer for large-scale production,” says Haanen. “MetaMeta manages various SMART Centres (Simple Market-based Affordable Repairable Technologies) across Africa. These centres train the local private sector in affordable and repairable technologies for water, irrigation and sanitation. Through this network, we aim to extend our pump and supply chain model to other African countries.”

From testing to expanding

The consortium is six months into this two-year Partners for Water project. “In this first phase, we’re testing seventy Zambian-made pumps to optimise the supply chain and software. In parallel, we’re working with a Chinese manufacturer to develop a version for mass production. Next week, I’m visiting the factory to finalise material choices before production begins. And in a year and a half? We aim to have fully rolled out the concept in Zambia and be ready for international expansion.”

Indonesia and the Netherlands share a deep-rooted history of cooperation in water management, formalised through a Memorandum of Understanding (MoU) on Water between the Ministry of Infrastructure and Water Management (MIW) in the Netherlands and Indonesia’s Ministry of Public Works (PU). This Water MoU serves as the basis for bilateral collaboration. The Indonesian government has asked Ivo van der Linden on behalf of the Dutch government to structure and synergise the joint efforts between the two countries, particularly in water management.

Alongside Simon van Meijeren, Programme Advisor for the Partners for Water programme at RVO, van der Linden explains how they are working together with Indonesia, combining expertise and planning for the country’s water management challenges on multiple levels.

Priorities in a changing landscape

The Water MoU has been drafted to address Indonesia’s critical challenges: strengthening urban water resilience, protecting vital agricultural lands and achieving independent food security. It emphasises three interconnected focus areas: integrated water resilience for Northern Java, lowland development and irrigation and knowledge exchange focusing on engaging younger generations and preserving expertise. The Water MoU will analyse problems, develop solutions and embed them in national policies and frameworks, ensuring long-term impact through collaboration among governments, financial institutions and local communities.

Integrated water resilience for Northern Java

Coastal cities like Jakarta and Semarang face severe land subsidence, with areas sinking by 15 to 20 centimetres annually. “In Indonesia, the scale of subsidence is unparalleled compared to the Netherlands, where we see only a few centimetres each year,” Van der Linden points out. “Groundwater extraction,” says Van Meijeren, “leads to severe land subsidence and consequent flooding, so we need to look beyond quick fixes like draining water and instead map out the root causes and address them.”

This long-term approach is illustrated by a project in Semarang, where a team of experts supports the Indonesian government in preparing an integrated vision for what a resilient city could look like by 2045.

“Relationships are very important. Fortunately, we work with many champions,” says Van Meijeren, “who also support an integrated approach, going beyond mandates and short-term visions.”

The goal is to create integrated solutions that combine traditional engineering with Nature-based Solutions (NBS). Examples of this approach include projects such as Water as Leverage in Semarang and the integrated river basin management initiative in the Welang area. The Welang River project near Surabaya used a compartmentalised strategy, responding to challenges at upstream, midstream and downstream levels with targeted interventions like small dams and sediment traps to improve water retention and reduce sedimentation.

Integrated solutions: From policy to practice

Van der Linden says that to implement NBS in Indonesia, you must start from scratch. “Conventional methods for infrastructure development heavily rely on the use of concrete – so-called grey solutions. Nature-based Solutions, often referred to as green solutions, can be an alternative option. However, NBS cannot be applied anywhere, anytime and should be assessed case by case. Green where possible, grey where it should be. Together with the Indonesian authorities and the Asian Development Bank, we are looking into how a gradual shift can be made towards more hybrid construction. Achieving a ratio of 80% grey and 20% green would already be a great success.”

Seeking a balance between grey and green infrastructure is also central to President Prabowo’s ambition to construct a giant seawall along the North Coast of Java. In addition to infrastructure, this process also seeks to balance socio-economic and environmental impacts.

While these efforts show promise, there is political uncertainty, budget constraints and the entrenched reliance on conventional approaches that can all hinder progress. Van Meijeren reflects on the need for clear policy frameworks: “Applying NBS is not common practice and the ‘how to’ from a planning, governance and implementation perspective is still largely unclear. Without a metaphorical coat rack to hang these solutions on, it’s difficult to take steps towards implementation and long-term adaptation.”

Nevertheless, the first steps are underway, adapting to Indonesia’s pace, by introducing ideas that can make a lasting impact. In partnership with the Netherlands, Indonesia is exploring these pathways to implementation with support from the Asian Development Bank, which seeks to invest in environmentally sustainable projects and become the ‘climate bank’ of the region.

Water management and food security

Lowland development and irrigation are also important focuses for the collaboration, particularly as Indonesia seeks to boost agricultural productivity and achieve food independence. By optimising water management in existing lowland areas, farmers have the potential to increase “the crop per drop”. “The focus of the Water MoU isn’t just about technology,” says Van Meijeren. “It’s also about ensuring that younger Indonesians are equipped with practical knowledge on how to effectively maintain and operate water management systems in the lowlands. Currently this knowledge is held by older professionals – grey men, both in the Netherlands and in Indonesia”. To optimise agricultural production, you need good water management. That knowledge exchange is one of the pillars through which the RVO want to engage young people in these partnerships and give them a central role under the Water MoU. “We need to combine forces and look ahead to the future,” says Van der Linden.

Both Van Meijeren and Van der Linden emphasise that: “This is not just about helping Indonesia. It’s about working together to create solutions that bring mutual benefits to both countries in addressing some of the most pressing challenges of our time.”

Conclusion

The collaboration between the Netherlands and Indonesia aims to strengthen urban areas and vital agricultural lands, particularly in coastal regions such as Jakarta and Semarang, where subsidence and flooding pose significant threats. Enhanced water management in agricultural zones further contributes to improved food security by boosting higher productivity and reducing dependence on imports.

Key initiatives such as Water as Leverage, coastal protection in Jakarta and the integrated water management of the Welang River are setting the stage for a new way of tackling water-related challenges. These projects take a balanced approach, combining modern engineering with natural based approaches to protect communities and the environment.

In addition, efforts in lowland development and irrigation underscore the importance of intergenerational knowledge sharing – passing from older generations to younger ones, while also improving water management. These efforts are crucial for maintaining the health and productivity of critical agricultural areas for years to come.

“The water sector plays a critical role in Indonesia’s well-being and is fundamental for development across multiple dimensions,” stated Royhan Wahab, Minister Counsellor for Economic Cooperation at the Indonesian Embassy in The Hague. Speaking about the longstanding Dutch-Indonesian water cooperation, he outlined key priorities for future collaboration: establishing a national roadmap for sustainable water management; building Indonesia’s giant seawall system; creating Centres of Excellence for Water Management; improving drinking water systems through lake and seawater conversion and strengthening existing partnerships.

The counsellors’ enthusiasm and ambitious words set the tone for the Platform Meeting, which reflected on past achievements and future opportunities and through focussed break-out sessions explored themes such as Nature-based Solutions (NBS), the BlueDeal, Lowland Development and Irrigation and the Welang River Basin Transformation Project.

Deep dive sessions

Nature-based Solutions: Turning theory into practice

“Indonesia has demonstrated a strong commitment to implementing NbS, incorporating them into their national midterm development plan for 2025-2029 and is one of the focuses under for the Dutch-Indonesian water collaboration,” begins Tom Wilms from Witteveen + Bos during his breakout session on NbS implementation guidelines for the Indonesian government. “Despite this enthusiasm and political backing, the Indonesian government faces challenges in practical implementation of NbS.”
To bridge this gap between theory and practice, Dutch and Indonesian experts will support the Indonesian Ministries of National Development Planning (Bappenas) and Public Works (PU) by integrating NbS into two guideline documents: a strategic guideline for flood risk management and a technical guideline for establishing river planning criteria. The support is the result of an ongoing fruitful collaboration between the Asian Development Bank and the Netherlands Enterprise Agency and will be provided by experts from Witteveen + Bos, Deltares and Royal Haskoning DHV.

However, translating these guidelines from theory into practice remains a challenge. During the plenary discussion, several key points emerged to support implementation:

• Create synergies with existing local NbS projects to benefit from their experiences and avoid reinventing the wheel.
• Recognise that whilst government guidelines provide the framework, local communities, farmers and the private sector have been implementing NbS for generations.
• This requires rethinking traditional partnership models to better support small-scale, community-driven initiatives alongside larger governmental programmes.
  Invest time in building strong political relationships, as these connections often prove crucial for turning plans into reality.

Welang River Basin Transformation

In East Java, the Welang River serves as a vital water source for local communities. However, urban growth has introduced significant challenges, including flooding, erosion, pollution and water distribution issues. Maarten Onneweer, from AidEnvironment, spoke about the Welang River Basin Transformation Project: an Indonesian-Dutch collaborative project demonstrating how grassroots participation can effectively address these water management challenges. “By uniting local residents, government officials, the private sector and environmental specialists, we have successfully implemented NbS through an integrated, participatory approach,” shared Onneweer. “Now it’s time to scale up to other watersheds in Java. Opportunities for follow-up were discussed with the local authorities, the Asian Development Bank and the World Bank.”
During the plenary discussion, a common dilemma for scaling up such projects was identified: quantifying the impact of NbS. Whilst these small-scale interventions collectively appear to significantly improve catchment water management, the evidence often remains anecdotal. To justify similar approaches elsewhere, it’s crucial to turn practice into theory and learn from implemented examples, incorporating these lessons into a scaling-up strategy for other watersheds across Indonesia.

Blue Deal Indonesia

The Blue Deal, running from 2018 to 2030, brings together Dutch Water Authorities with local governments around the world in providing 20 million people access to clean, safe water. “Since 2023, the Blue Deal has officially become part of the water cooperation between the Netherlands and Indonesia,” explains Robin Bos from Dutch Water Board Hoogheemraadschap Hollands Noorderkwartier. “We currently focus on flood risk, coastal zone and wastewater management in Tangerang, Pekalongan and Semarang, but we’re also open to collaborations in other regions connected to our projects,”

The programme operates across three layers of water governance— knowledge, institutional and relational—whilst providing advice, training and facilitating the implementation of practical solutions. One example is a demonstration project in the Batik industry to address water pollution. “Drawing from past experiences, we observed that local governments often struggle to manage large-scale wastewater treatment facilities,” notes Bos. “In response, we’re initiating a small-scale and low-tech pilot project using NbS to treat Batik industry wastewater.” This initiative complements a recently funded Partners for Water subsidy scheme project, which also tackles water pollution in the Batik industry.

A key factor to their success? Bos emphasizes the importance of working simultaneously at different scales, combining top-down and bottom-up approaches. “Strong relationships with relevant officials and stakeholders are essential. If they don’t know your project, if they don’t know you, it can be very difficult to take steps with the local government.”

Lowland development and irrigation: knowledge exchange

Irrigated lowland areas play a crucial role in Indonesia’s journey towards the national priority of food independence. The Netherlands, with its historical expertise in water management, has been a key partner in this quest. However, valuable knowledge of lowland development resides primarily with experienced older professionals both countries. To prevent this expertise from being lost, it is critical to actively transfer it to the next generation of water managers.

During this breakout session, Sur Suryadi from IHE Delft shared historical initiatives in lowland development, providing insights into the ongoing collaboration in Dadahup, Kalimantan and discussed knowledge exchange strategies. A lively discussion took place among the participants on strategies for effectively transferring essential lowland expertise to future water managers. This topic will be further developed in the coming year with the Ministry of Public Works and local knowledge institutions.

Building relationships for the future

The day’s deep dive into Dutch-Indonesian water collaborations concluded with networking and drinks, underscoring a key insight: sustainable water management is achieved through genuine relationship-building across all levels. Success requires bringing together diverse voices—from local communities to government officials. While this inclusive approach may be more complex, it yields more sustainable and far-reaching results, creating the foundation for lasting impact.

The Welang River in East Java, Indonesia, is a vital resource for the nearby communities providing water for daily use and supporting local agriculture. However, as cities expand and populations grow, the river has faced increasing problems such as flooding, erosion and pollution. In response, the Governments of Indonesia and the Netherlands, through its Partners for Water programme have initiated the Welang River Basin Transformation Project to tackle these challenges and protect both the river and the people who depend on it.

Nature-based solutions (NbS) are increasingly recognized as an essential strategy to address water and erosion challenges in watersheds. These solutions harness natural resources to tackle various water and soil issues. In areas where traditional infrastructure may be expensive, NbS offers a sustainable and cost-effective alternative that is easily replicable by local governments and communities.

In the upstream area of Welang Watershed, East Java, Indonesia, the NbS approach was applied through co-construction with the local community by employing a 3R methodology (retention, recharge, and reuse of water) through creation of simple gully plugs. These structures made from locally available materials like bamboo, stones and branches, serve to collect and temporarily store water during high rainfall flows, retain sediments and materials washed into the channel, and slow down small, concentrated flows.

Utilizing natural materials available in the area as gully plugs (left: bamboo, right: stone)

1. In Surorowo, the upstream area of Welang on the side of Mount Bromo, the project marked the communities’ first experience participating in an international project. Village officials played an important role in encouraging broad community participation. Two Focus Group Discussions involving various stakeholders were held to explain the value of the project and the interventions, to build trust and gain commitment of the community. Over two months of activities, at least 28 different gully plugs and gabions were installed on community land and initiated directly by the community.
2. The project location in Wonosari, the upstream area of Welang on the side of Mount Arjuno, is directly managed by the Wonosari Tea Plantation, making it easier to mobilize and cooperate with the workers. In just 12 working days, a total of 145 simple gully plugs made of stones, tree branches, and bamboo of various sizes were constructed.

Stakeholders involvement in demonstration activities

Institutional support
A Memorandum of Understanding (MoU) on sustainable water resources management in East Java was signed between the East Java Provincial Natural Resources and Public Works Agency (PUSDA), the government implementing agency of the project, and Perhutani, a state-owned enterprise managing the implementation site. This ensured stakeholder alignment and paved the way for replicating NbS across the province.

Monitoring and evaluation
Once implemented, effective monitoring becomes essential for tracking the progress of the installed structures and demonstrating their effectiveness. Field observations conducted by the State University of Malang assess the condition of the gully plug installations, their impact on sediment capture, erosion control, and soil stability. These insights help identify the most effective structure types, ensuring informed recommendations for future implementations.

The monitoring showed that series of gully plugs made sequentially following the channel from upstream to downstream are effective in retaining heavy water discharge and capturing sediment. On average, a 10-20 cm thick layer of sediment was found behind the installed gully plug structures, with the greatest accumulation of sediment occurring behind gully plugs with bamboo barricades filled with soil or grass and dense shrubs.
The other type of gully plug made of branches, was observed to have grown densely, providing a natural barrier to the heavy water discharge and sediment flowing along the channel.

Recommendation for replication
For replication, bamboo gully plugs and branch-made gully plugs are identified as the most effective, affordable, and easy-to-implement structures. These options are chosen based on their proven ability to capture sediment, ease of installation, support for vegetation growth, and the accessibility of materials, making them suitable for small-scale community implementation across diverse land uses.
On the other hand, gully plugs made from stone or even gabions tend to be more difficult for communities to implement without assistance from the government or third parties in procuring materials, but are structurally more robust and durable.

Miniseries on the Welang River Basin project

This is the second article in the miniseries on the Welang River Basin project, highlighting the role of youth in sustainable waste management. Below you can find the links to other articles in the series:

Article 1: The role of trusted advisors
Article 2: Practical implementation of Nature-Based Solutions
Article 3: Empowering youth for sustainable waste mangement
Article 4: A participatory design approach