Mia Wannewitz & Veronika Zwirglmaier

Jakarta’s 13 rivers have their source and catchment area south of the city. To get an impression of the catchment, its topography, land use and population, TRANSCEND team members Mia and Veronika travelled towards Bogor, which is located in the upstream area of the Ciliwung catchment. The importance of understanding the catchment’s current management practices and potential future development scenarios is crucial to understanding the fluvial flood situation in the city area of Jakarta.

During our visit, we had a look at the Bendung Katulampan. Currently, the weir in Katulampan regulates the river and thus influences the discharge and the resulting flooding from the Ciliwung in the downstream area. It was built at the beginning of the 20th century to assist flood management and warning, but the retained water is also used to irrigate adjacent agricultural land.

Formal and informal early warning messages leave from the Katulampan area to inform Jakarta’s flood-prone residents about upcoming flooding. Once a warning has been issued, flood-exposed residents along the rivers have two to three hours to secure their belongings.

We got the impression that the current land use upstream is shaped very much by agricultural use. However, there is a high potential for further urbanisation and development. This would change the run-off processes within the Ciliwung catchment and most likely increase the flood risk for the city of Jakarta. Therefore, careful and integrated planning of further development is inevitable to prevent related negative consequences.

Currently, the area along the river is characterised by rural settlements and roads. Furthermore, along the course of the Ciliwung upstream of the Bendungen Katulampa, recreational activities like bathing and biking seem to play an important role for the population.