Expert Explains Causes of Jakarta Road Subsidence

JAKARTA, KOMPAS.com - A section of Lenteng Agung Main Road in South Jakarta subsided on Thursday evening (28 May 2026), causing severe traffic congestion on Friday morning (29 May 2026).

The road subsidence measured approximately 3 metres deep, 3 metres wide, and 16 metres long. Similar incidents have occurred in other areas.

Road expert Purnomo explained that road subsidence is typically caused by issues with the drainage system beneath the road surface. He stated that water flow under the asphalt can gradually erode the soil, creating voids beneath the road until the surface loses support and subsides.

“There is water flow from right to left or left to right, eroding the soil. Eventually, voids form due to erosion, leading to subsidence,” he said.

Purnomo added that such incidents usually relate to poorly functioning drainage systems, with weak or damaged culverts also being a contributing factor.

Regarding mitigation, Purnomo said repairs should involve filling the voids and fixing damaged water channels or culverts.

“Fill the hole, replace any damaged culverts, then backfill,” he added.

He noted that the risk of further subsidence depends on the quality of the drainage system and culverts used.

For the Lenteng Agung case, Sartono, Head of the Jagakarsa District Water Resources Agency (SDA), said his office received initial reports of road issues starting Thursday evening (27 May 2026), with initial information about a hole in the road.

“On Thursday evening we received the report, but for SDA it was just a hole, which was then referred to Bina Marga regarding the road,” Sartono said in Jakarta on Friday (29 May 2026), according to Kompas.com.

On Thursday morning, SDA and Bina Marga conducted a site survey. The road, which had begun to undulate, was patched to reduce risks for drivers.