Java needs seawall, mangrove restoration to protect northern coast

BOGOR, West Java – Indonesia’s Environmental Ministry is pushing for a hybrid coastal defence along the northern Java coast, consisting of estuary protection, groundwater control, tight spatial planning and mangrove restoration.

Northern Java currently faces a serious threat of coastal abrasion, tidal floods and land subsidence. Although the construction of a giant seawall has value in protecting economic activities along the coast, the concrete structure is not the sole solution, Environmental Minister Jumhur Hidayat said on June 2.

“If groundwater is extracted excessively, spatial planning is also needed for coastal ecosystem damage to be controlled,” he said.

He emphasised the importance of reactivating natural protections because mangroves form a natural barrier. Mangrove forests can reduce wave height by 13 per cent to 66 per cent in 100, while at the same time restoring fish habitats and the local economy.

Jumhur was speaking at Sultan Agung Islamic University in Semarang on June 2 in an event titled “Giant Sea Wall as a Strategic Solution to Mitigate Abrasion and Tidal Flood in Central Java’s Northern Coast”.

During the public lecture, Jumhur dissected the root causes of the coastal crisis.

He said that the environmental crisis had a huge impact, directly affecting residential areas, industrial zones and port activities, as well as the agriculture and fisheries sectors, which are the region’s backbones.

He said the public must understand that the crisis in Central Java has severe domestic consequences.

“The root causes of tidal waves are not only about raising sea surface, but also land subsidence. Water levels increase by 2.1mm a year, while land subsidence from Semarang to Demak could reach 0.01m to 0.150m a year,” he said.

“With a land subsidence rate of 10cm to 15cm a year, mitigation measures can no longer use the usual way.”

In addition to technical and ecological aspects, Jumhur assured the public that his ministry, as the regulator, would not tolerate environmental degradation.

Every giant seawall construction plan must go through a strategic environmental study, or KLHS, and a strict environmental impact analysis, or AMDAL. Both mitigation processes must be science-based policy, involve transparent public transportation, and guarantee full protection for fishermen, aquaculture farmers, coastal women and other vulnerable groups.

“A giant seawall can help to solve the Pantura (northern Java coast) defences, but cannot be the sole solution,” Jumhur said.

“The Environmental Ministry emphasises a hybrid approach, that its physical infrastructure must be combined with groundwater control, mangrove restoration, strict spatial planning and protection for coastal communities.”

Through this hybrid commitment and approach, the ministry expects coastal abrasion and tidal floods in the northern coast to be defended from environmental threats and, at the same time, maintain the economic sustainability of communities that depend on coastal areas as living space and sources of their livelihoods. THE JAKARTA POST/ASIA NEWS NETWORK