Loss of Lakes Blamed for Worsening Flooding in Greater Jakarta

JAKARTA – The Balai Besar Wilayah Sungai Ciliwung Cisadane (BBWSCC), Indonesia’s Ciliwung Cisadane River Basin Authority, has stated that the disappearance of situ (lakes and ponds) due to land conversion has become one of the key factors exacerbating flooding in the Greater Jakarta region encompassing Jakarta, Bogor, Depok, Bekasi, and Tangerang (Jabodetabek).

“Indeed, one of the causes of flooding is land conversion (of lakes and ponds),” said David Partonggo Oloan Marpaung, Head of the Ciliwung Cisadane River Basin Authority (BBWS), in a statement received on Sunday (1 March 2026).

According to data from the Water Resources Data Center (WRDC), from thousands of lakes previously recorded, only 187 situ now remain under management by the BBWS Ciliwung Cisadane. Meanwhile, the Jakarta provincial government manages 16 additional lakes, bringing the total to 185 situ still existing in the authority’s service area.

Marpaung expressed regret over the gradual annual reduction in the number of lakes across Greater Jakarta. He noted that many lake areas have been converted into developed zones and are no longer capable of optimally storing and absorbing water. Yet lakes perform two critical functions.

First, they serve as water conservation areas. Lakes store water, facilitate absorption processes, and maintain groundwater reserves for the long term.

Second, they function as natural flood control infrastructure. Lakes temporarily retain rainwater to prevent it from flowing directly into rivers or overflowing into residential areas.

It is therefore unsurprising that flooding in Greater Jakarta has become increasingly severe in recent times, particularly when heavy rainfall occurs over short periods.