Building with Nature to Prevent Coastal Floods in Java, Indonesia

The Indonesian and Dutch governments have launched a comprehensive five-year project to enhance coastal safety and flood prevention along Java’s north coast in Indonesia.

It aims to build stable coastlines with reduced erosion risk through a unique integration of mangrove restoration, small-scale hard-engineering and sustainable land use. The initiative is to be financed by the Dutch Sustainable Water Fund.

Natural Protection for Coastlines

This project aims to stimulate sustainable coastal engineering approaches that make use of the natural protection provided by ecosystems like mangroves and salt marsh habitats.

Announcing the project, Wetlands International said that it represents the transition of traditional infrastructure designs that typically fight against nature, towards solutions that work with and alongside nature.The latter are often more cost-effective, they say, while bringing more prosperity to the local economy such as through enhanced fisheries and carbon storage.

The initiative is said to be the leading international case of the “Building with Nature Innovation Programme”.

Eroded Coastline Leads to Flooding

Millions of people in northern Java are at risk from coastal erosion and flooding. Wetlands International say that the increase in risk is a result of the removal of mangrove belts for aquaculture development, the development of unsustainable coastal infrastructures, and groundwater extraction.

In some places more than 3 km of land has already been taken by the sea and entire villages have been engulfed. The consequences can often be devastating. Many people experience a major loss in income, reaching up to 60-80% in some villages. The agri- and aquaculture sectors, key economic engines in Indonesia, also suffer multi-billion losses.

Demak, Central Java

The five-year programme will focus on the most affected coastline in Demak, where a successful pilot of the program was carried out 2014.

In Demak, sea level rise is projected to cause flooding 6 km inland by 2100, inundating 14,700 hectares of land, affecting over 70,000 people and the loss of 6,000 hectares of aquaculture ponds.

The partners in the project will construct a 9 km strip of permeable dams made of brush wood and sediment nourishment to trap silt, regain lost land along this eroding coast and support rehabilitation of 90 hectares of mangrove buffer.

In parallel, the initiative will introduce sustainable aquaculture along the shoreline and support income diversification. This will lead to the transition from a mangrove-conversion model to a mangrove-based economic model.

The aim is to inspire coastal zone managers of government and the private sector to scale up and replicate the approach in Indonesia and worldwide and to embed the approach in local and regional policies and planning.

mangroves - natural coastal protection
Mangroves – Photo: Eustaquio Santimano

Reducing Disaster Risk through Nature Based Solutions

The Building with Nature approach will be promoted by Wetlands International at the Third World Conference on Disaster Risk Reduction, which will seal a post-2015 global UN Framework on Disaster Risk Reduction in the city of Sendai in Japan in March. Reducing disaster risk through nature based solutions has for the first time become a cross-cutting theme in this framework.

For more information, see the Wetlands website here.