Coastal restoration in Java

In March 2015 the Dutch and Indonesian governments launched a public-private partnership aimed at strengthening Java’s north coast by combating the rapid erosion that affects the area. This coastal restoration project is one of the leading initiatives in the ‘Building with Nature’ programme set up by Ecoshape and its partners.

Witteveen+Bos is a participant in the ‘Building with Nature’ programme and is also contributing to the project in Java. In the past few decades, large parts of the mangrove forests on the north coast of Java have been cut down to make way for fish ponds. This has led to extensive erosion because the coast is no longer properly protected by vegetation. Local communities have been forced to abandon roads, schools, homes and fish ponds and have it taken over by the sea. Many residents have lost their source of income. Near the town of Demak alone, the affected area covers approx. 1,000 hectares. ‘Building traditional dikes is not a financially feasible option at these sites,’ explains Eveline Buter, engineer at Witteveen+Bos. ‘Instead we construct small dams that break the waves and are permeable to silt flows. If the area behind the dam is left undisturbed, the silt gradually accumulates so that the mangrove forests can grow back and coastal protection is restored.’ Mangrove-friendly fish ponds will be created to foster sustainable aquaculture, so that the mangrove forests no longer have to be cut down. In this way, the economy can benefit optimally from the natural environment. ‘For this project we combined our technical expertise with local knowledge and local networks,’ says Eveline Buter. ‘No matter how wonderful your design, you also need to convince local residents to support it. In our plans we try to make sure that the local population can continue to earn a living.’ The pilot site at Demak covers twenty kilometres of coastline. The aim is for the project to be rolled along other sections of Java’s north coast. The long-term goal is to inspire coastal management authorities throughout the world to embed the ‘Building with Nature’ approach into their policies and landscape planning activities.