SDA Reveals Cause of Rapid Water Flow Beneath Subsided Lenteng Agung Road
Head of the Water Resources Agency (SDA) in Jagakarsa District, Sartono, explained the cause of the fast-flowing water beneath the subsided road on Lenteng Agung Main Road in South Jakarta. He stated the water was previously held back upstream.
Sartono said previous road damage had caused water to be blocked and accumulate upstream. The flow has now resumed following repairs downstream.
“Before yesterday’s repairs, the hole was large after the collapse. The road subsided halfway, causing water to be held back. Because of the subsidence, the water was trapped upstream, leading to a backlog,” Sartono told reporters on Saturday (30 May 2026).
Sartono noted the strong current at the hole’s end was due to the installation of box culverts for the channel. However, as work remains incomplete, the water flow has intensified.
“After yesterday’s work on the bridge end and crossing, the box culverts were partially replaced. Once opened slightly, the water began to flow, reducing the buildup,” he explained.
Sartono said upstream water levels are now receding, according to officials monitoring the channel.
“I received updates from my colleagues upstream that the water has started to recede,” Sartono said.
“It’s a slow process, but the water is receding. The crossing repairs are not yet complete, so there’s still some obstruction,” he added.
He also confirmed the strong current is eroding the hole, making it larger. Sartono hopes favourable weather will aid repairs.
“Over time, the water level should recede further. We hope for no extreme weather or rain,” he said.
Regarding repair work, Sartono said major construction is being carried out at night to minimise traffic disruption.
“Work will continue tonight. Daytime repairs pose significant traffic risks, whereas night-time reduces congestion. We’ll work overnight, with daytime only for precautions,” he explained.
SDA teams remain on standby to monitor the situation and coordinate with other agencies to secure utility poles and infrastructure.
“Tonight, workers from various departments, including the Transportation Agency (Dishub) and Public Order Police (Pol PP), will manage traffic. We’re collaborating with all teams,” he concluded.
Previously reported, fast-flowing water beneath the subsided road on Lenteng Agung Main Road in South Jakarta’s Jagakarsa district had forced authorities to narrow traffic lanes for safety.
Detikcom’s observation on Saturday (30 May 2026) showed the subsided road section covered with steel plates to allow vehicle passage, but a hole on the roadside revealed water flowing beneath the asphalt.
Muddy water was rushing beneath, carrying soil and rock debris along with it.
Near the water flow hole, several internet and electricity poles were secured with red ropes by Public Infrastructure and Facilities Handling (PPSU) officers to prevent collapse.