Building With Nature: How Demak Uses Mangroves Against Erosion

Demak, on the northern coast of Java, has faced serious erosion, flooding and land loss. Mangroves that once helped protect the shoreline were reduced by aquaculture, development and other changes. [1][3]

The Building with Nature project tried a different approach from simply building a concrete seawall. Teams placed permeable, fence-like structures along parts of the coast. These structures slow waves and trap sediment. [1]

As more mud collects, the seabed can become suitable for mangroves to return naturally. The project therefore focused on creating the right conditions for trees instead of planting large numbers of seedlings in places where they might not survive. [2]

The UN Decade on Ecosystem Restoration reports that about 119 hectares were under restoration through the initiative. The project also used about 3.4 kilometres of permeable structures. [1]

Local livelihoods were part of the plan. Fish and shrimp farmers learned more sustainable aquaculture methods, while recovering mangroves provided habitat for fish and other coastal species. [1][2]

The approach has attracted international attention because it combines engineering with natural processes. It has also been copied in other Indonesian districts. [1]

Demak's experience suggests that coastal protection does not always have to mean creating a harder barrier between land and sea. In some places, slowing the water and giving an ecosystem room to rebuild may offer another path.