Challenge

As families in Senggarang prepared to welcome relatives for Hari Raya, nearly half the households in the coastal community still lacked adequate sanitation. For residents of its stilt houses, this was not merely an infrastructure gap. It shaped privacy, dignity and whether people felt comfortable inviting loved ones into their homes.

The consequences travelled beyond each household. Waste entered the surrounding water, affecting the marine environment on which many residents depend for small-scale fishing. Meanwhile, the loss of mangroves threatened habitats for fish and crabs and left the shoreline more exposed to waves.

Previous sanitation initiatives had not lasted. This time, the solution needed to fit homes built both on land and above water, earn the trust of residents and recognise that the wellbeing of the village and the coast were inseparable.

Solution

Witteveen+Bos brought those needs together in one community-led project.

Working with Safe Water Gardens and Universitas Maritim Raja Ali Haji, with funding from the Magnuson Trust, the team installed decentralised sanitation systems adapted for Senggarang’s unusual landscape. The low-maintenance design draws inspiration from a traditional system used in Bintan, making it practical for local households.

Residents were trained to operate and maintain the systems. Through social agreements, participating families also committed to caring for the infrastructure and supporting the restoration of the nearby mangroves.

Along the shoreline, residents and local builders planted more than 2,000 mangrove seedlings across 1.1 hectares of mudflat. Two native Rhizophora species were chosen to strengthen diversity and resilience.

To give those young trees a fighting chance, the team installed 300 metres of semi-permeable dams made from locally sourced wood, built with the help of the local community. The structures soften wave energy without cutting the shore off from the sea. As sediment gathers behind them, new ground can form for mangroves to take root and spread naturally.

Impact

By early 2025, 92 families had received sanitation systems. Senggarang Besar and Tanjung Seboak subsequently became officially open-defecation-free.

The change could be felt inside people’s homes. Families gained greater privacy and could welcome visitors with renewed confidence, while cleaner sanitation reduced the amount of waste entering the coastal environment.

Outside, the ecological story is only beginning. The mangroves that were planted between September and October 2025 have been recognised as a designated protected area by Indonesia’s Ministry of Maritime Affairs in late 2025. The first ecotourism visitors have also arrived, offering an early glimpse of how a healthier coastline could support new livelihoods alongside fishing.

Future Outlook

Monitoring will continue through November 2026, aiming to reach well above the global average mangrove survival. The partners will also study changes in sanitation, biodiversity and livelihoods before taking the model further.

Over the next five to seven years, they aim to expand into five additional villages, restore five hectares and reach more than 500 households. Future projects may draw on village budgets, microloans and ecosystem-related finance to reduce dependence on philanthropy.

In Senggarang, renewal began with two deeply practical acts: giving families dignity at home and helping a living coastline grow beyond their doors.