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.

The Welang River in East Java, Indonesia, is a lifeline for the people who live nearby, 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 invest in the Welang River Basin Transformation Project to tackle these challenges and protect both the river and the people who depend on it.

The project is built around a central idea: collaboration. Local communities, government officials, and environmental experts are all working together to develop smart water management solutions that address the river’s problems. What makes this project unique is its focus on local ownership by involving everyone in the process, ensuring that solutions are created by listening to the needs and ideas of the people who live near the river.

The Welang River Project adopts a collaborative, step-by-step approach to co-create practical and sustainable solutions that meet community needs. It begins by engaging with local residents to understand their issues, such as flooding or limited access to clean water. With these insights, local residents, government officials, and experts work together to develop solutions. After initial testing, community feedback is used to refine these ideas, enhancing their effectiveness. The final, improved solutions are then implemented in coordination with government plans to ensure they can be scaled for broader impact.

Partners for Water recently sat down with Fauzy Nasruddin, the Secretary at the Water Resources Agency of East Java Province (Indonesia) and spoke about the collaboration with the Netherlands on managing the floods in the Welang river basin in East Java.

Fauzy Nasruddin has significant expertise and experience in water management, and visited Delft in September to accompany his staff members on a short course at the Institute for Water Education (IHE) which also allowed him to join his wife’s graduation. Just like him, she studied at the Institute for Water Education (IHE).

Long-standing collaboration

For the last decades, Fauzy Nasruddin has been deeply involved in collaborative water management projects, including those funded by Partners for Water, predominantly addressing issues like flooding, drought, and water pollution in East Java. The challenges of having too much, too little, or too polluted water should eventually be replaced by the 3 Rs of sustainable water management: Recharge, Retention, and Reuse.

The partnership with the Dutch government formally began in 2020, but its roots date back to 2015. That year, the former Dutch minister Stef Blok came to East Java to visit the grave of his grandfather, an engineer who built a dam in the region during the colonial period. This dam still functions today, symbolizing the historical connection and shared expertise between the two countries.

Early dialogue and exploration

In 2018, a delegation from East Java, including Fauzy Nasruddin himself, visited the Netherlands. They travelled to Zeeland and were invited to the University of Applied Sciences to explore potential areas of collaboration and discuss cases of mutual interest, including flood and water quality issues in East Java. In 2020, the collaboration was strengthened during a royal visit to Indonesia.

The Minister of Infrastructure and Water Management visited Surabaya, where Nasruddin’s office is located. She decided that the Welang River could be a pilot project for further cooperation in water management. The river basin is experiencing great problems with flooding and has been the subject of various water management and flood control projects, including collaborative efforts between Indonesia and the Netherlands.

The Welang river’s challenges

The Welang River floods between eight and ten times a year during the rainy season, which lasts from December to March. These floods have significant impacts on local communities, especially the poorer populations who are more vulnerable to natural disasters. While past infrastructure projects, such as building levees and reinforcing riverbanks with stones and concrete (grey infrastructure), have been undertaken, these solutions proved temporary. The floods returned, indicating a need for more sustainable and integrated approaches.

A new approach: the Welang River Master Plan

As part of the collaboration with the Netherlands, a Master Plan for the Welang River has been developed, followed by several pilot projects that focus on integrated and participatory water management, design and implementation. The goal is to manage floods by slowing down and absorbing water in the watershed rather than simply diverting it as quickly as possible. In upstream areas, solutions that use local materials and labour are being found, so they are not only cost-effective but also sustainable and scalable, as local communities can maintain and replicate them, Nasruddin says.

“Early results indicate that these methods are effective at a pilot scale, but scaling them up across more locations, midstream and downstream, is still work in progress,” he adds. The collaboration in Welang is a showcase of integrated planning and implementation, involving a diverse set of local stakeholders. In the midstream and downstream locations, the collaboration is taking a participatory design approach to jointly identify and agree upon interventions that improve water management in critical flooding areas.

A concrete example of such a pilot project is the construction of simple water barriers in the upstream part of the Welang River. These structures, made of bamboo, wood, and local stones, retain water and reduce sedimentation. While some early attempts were unsuccessful – some bamboo structures collapsed during heavy floods – the project has provided valuable insights. It underscores the importance of designing structures that are strong enough to withstand extreme weather conditions while fitting the local context and capabilities.

Challenges

One of the biggest challenges Nasruddin mentions is the complexity of the administrative and political landscape in Indonesia. Political changes can lead to shifts in priorities and budgets, hindering the continuity of long-term projects. He compares this to the situation in the Netherlands, where a Delta Act and a fixed Delta Budget ensure consistent funding and planning, regardless of political changes. He sees the lack of a similar legal framework in Indonesia as an obstacle to sustainable water management initiatives.

Another issue is the involvement of multiple stakeholders with different interests. In the upstream area of the Welang River, for example, forestry agencies, water companies, environmental organizations, and local communities are all active. Each of these parties has its own priorities, making it difficult to arrive at a joint action plan. Nasruddin stresses the importance of stakeholder engagement and co-creation, where all involved parties are included in the process from the start. This not only promotes collaboration but also ensures that solutions better fit the needs and context of the local community.

The economic aspects are also a challenge. Investments in water infrastructure, especially in flood control and upstream conservation, are often seen as less profitable compared to projects like toll roads or commercial developments. This makes it harder to secure funding for crucial water management projects that may not provide immediate financial returns but are essential for the sustainability and safety of communities.

Personal motivation

Nasruddin’s personal motivation stems from his passion for water management and the realization that well-managed water can improve lives and make communities more resilient. He sees water as a common good that, when effectively managed, can have tremendous positive effects on society. His experience in the Netherlands has broadened his perspective, particularly in understanding the importance of process management and stakeholder involvement alongside technical solutions

Future hopes

In the future, he hopes that Indonesia can develop a legal framework similar to the Dutch Delta Act, enabling long-term and stable investments in water management. However, he acknowledges that this is a complex process, given the political dynamics and the diverse interests of stakeholders. Nonetheless, he remains committed to improvement and innovation in water management, with the ultimate goal of improving the quality of life for the people of East Java and making the region more resilient to the challenges of climate change and population growth.​