Jakarta. Indonesia is accelerating construction of a 575-kilometer sea wall along the northern coast of Java, spanning five provinces, to mitigate escalating risks from land subsidence and rising sea levels, a senior official said on Monday.

Coordinating Minister for Infrastructure and Regional Development Agus Harimurti Yudhoyono said the project can no longer be delayed, given the high stakes, including the safety of millions of residents and the potential economic fallout if coastal cities are inundated.

The northern coast of Java is home to around 55 million people across 20 regencies and five cities, with approximately 26% living directly along vulnerable coastal areas.

Agus noted that the region contributes about 27.53% of Indonesia’s gross domestic product (GDP), equivalent to roughly $368.37 billion annually, underscoring its strategic economic importance.

The urgency of the project is driven by severe environmental pressures, including land subsidence of up to 20 centimeters per year and sea level rise of around 1.2 centimeters annually.

“This is double pressure. Rising sea levels are triggering recurring coastal floods that damage property, destroy homes, and risk escalating into more severe and potentially fatal disasters,” he said.

The most acute conditions are currently observed in northern Jakarta --Indonesia’s largest city -- and in Semarang, the capital of Central Java.

Agus warned that without decisive intervention, projections for 2050 point to widespread property damage and heightened disaster risks. A looming freshwater crisis in northern Java could further compound the challenges facing coastal communities.

He added that the region serves as a national economic epicenter, hosting 70 industrial estates, five major industrial growth hubs, and five Special Economic Zones.

“We must act decisively to prevent economic disruption and, more importantly, to avoid loss of life if no action is taken today,” Agus said.