Timbulsloko in Demak Chosen as Pilot Site for North Java Coast Protection Programme

Timbulsloko village in Sayung sub-district, Demak regency, has been chosen as a pilot site for coastal protection along Java’s northern coast. The approach, known as a Nature-based Solution (NbS), combines mangrove restoration with modular HexBRIck breakwaters.

“We planted mangroves this morning, and this is certainly part of a Nature-based Solution,” Didit Herdiawan Ashaf, head of the North Java Coast Management Authority (BOPPJ), told reporters at Timbulsloko Beach on Monday (19 October 2026).

The programme began with a symbolic mangrove-planting event at the beach on Monday morning. Didit then opened a discussion with local residents about the programme.

Coordinating Minister for Infrastructure and Regional Development Agus Harimurti Yudhoyono (AHY), deputy head of the National Peatland and Mangrove Management Agency (BPGMN) Sriyanto Muntasram, and Central Java Governor Ahmad Luthfi also attended.

Didit said that coastal management along Java’s northern coast would not rely solely on concrete and heavy machinery. He also stressed the importance of ensuring that the project’s development is aligned with local natural conditions.

“Building the giant sea wall does not mean using heavy machinery simply to construct concrete structures or sand embankments. The work must also take a hybrid approach, integrating the project with the natural conditions of each area,” Didit said.

The BOPPJ plans to manage and develop 15 coastal segments from Serang to Gresik, using a hybrid approach that includes mangrove breakwaters, coastal embankments and sea walls.

The NbS pilot in Timbulsloko combines mangrove restoration with modular HexBRIck breakwaters, an innovation developed by the National Research and Innovation Agency (BRIN). However, the same combination will not necessarily be used across all areas of the northern coast.

“Given the conditions, this morning we are establishing a demonstration plot to assess the natural conditions in Central Java, particularly in segment 12 in Timbulsloko, Sayung, Demak,” Didit said.

“We hope that nearby affected areas and places with similar characteristics can receive the same intervention. Other locations may not use this approach because each area has different characteristics. We need to study that together,” he added.

Didit said the coastal protection plan had been discussed with local communities. He assured residents that the programme would not disrupt the work of fishers and fish farmers.

“It will not close off all the areas used to support people’s livelihoods and economic activity, whether at sea or in the fish farms,” he said.

Timbulsloko was selected as an NbS demonstration site because the average rate of coastal erosion there is 279 metres a year, reportedly the highest along Java’s northern coast.

The extreme erosion has destroyed thousands of hectares of fish farms, settlements and mangrove forest, and submerged several villages in Sayung. The threat has been compounded by land subsidence of 10–20 centimetres a year in parts of the sub-district.

Without intervention, cumulative subsidence in the worst-affected areas could exceed one metre over 15–20 years. Tidal flooding and river flooding also frequently occur at the same time, worsening environmental conditions and threatening local communities’ living space.

Coordinating Minister for Infrastructure and Regional Development AHY said combining hard infrastructure with natural measures was one solution to the problem. He cited mangrove planting as a way to reduce erosion.

“President Prabowo Subianto’s vision and priorities include building a giant sea wall, understood as a hybrid approach combining hard infrastructure, in the form of coastal embankments and sea walls, with natural solutions,” AHY said.

“We have just planted mangroves together. They are intended to reduce the energy of sea waves, helping to lessen severe coastal erosion,” he added.