Maria Gabrielle, Jakarta – Concerns over coastal defenses in Jakarta have intensified after a video showing seawater seeping through a seawall in Pantai Mutiara, North Jakarta, went viral on social media this week. The footage renewed public anxiety about the capital's vulnerability to tidal flooding, especially as the city faces both rapid land subsidence and mounting population pressures.
A Beritasatu.com visit to the site on Friday found that seawater was receding at midday, making the leak less visible. Residents said the seepage often becomes more pronounced during high tide and that similar incidents have occurred before.
Local residents have long carried out makeshift repairs themselves, patching weak points in the seawall with available materials to prevent seawater from entering the neighborhood. They are urging the Jakarta Provincial Government to provide a permanent solution, noting the high-risk nature of coastal infrastructure facing strong sea pressure.
The Jakarta government said coastal defense upgrades remain a priority, particularly in densely populated areas. Strengthening seawalls is considered crucial to reducing the risk of tidal flooding and preventing broader social and economic losses.
"About 390 meters of seawall have been completed, while another 530 meters are in the bidding process for work scheduled between 2025 and 2027," the city's water resources agency said on its official social media account on Friday.
Jakarta Deputy Governor Rano Karno also responded to reports of leakage in Pantai Mutiara, confirming that the city will follow up on the incident according to existing procedures. Officials said regular inspections of seawall conditions will continue to prevent similar problems from escalating.
The urgency of repairs is growing as parts of Jakarta sink at alarming rates. The National Research and Innovation Agency (BRIN) reports that areas of the city are subsiding by 10 to 30 centimeters each year due to natural soil compaction and decades of excessive groundwater extraction. The pace of land subsidence is among the fastest recorded in any major global city.
These environmental challenges come as Jakarta's population density reaches unprecedented levels. The United Nations recently ranked Jakarta as the world's most densely populated metropolitan area, projecting its population at 42 million – surpassing Tokyo for the first time in decades. Dhaka follows with nearly 40 million residents, while Tokyo has dropped to third place amid Japan's demographic slowdown.
Jakarta also rose three spots to 71st place in Kearney's 2025 Global Cities Index, reflecting its growing resilience despite the compounding threats of sinking land, coastal flooding, and extreme density.