The Public Works and Housing Ministry’s (PUPR) Ciliwung Cisadane Flood Control Office (BBWSCC) head Bambang Heri Mulyono said that the river normalization project would resume  according to its previous design, which was mainly building concrete embankments, in 2023.

“We cooperate with the Jakarta Administration that provided the land on which we will build river embankments on,” Bambang told The Jakarta Post on Tuesday.

However, he said that river normalization did not mean only by building river embankments, as some parts of the river might need to be dredged of sediments depending on their physical situation.

The river normalization project, which was under the BBWSCC purview, was initiated in 2013 along a designated 33-kilometer stretch of the Ciliwung River in Jakarta. However, as of 2017 only about 16 km of the river had been normalized. 

Heru’s predecessor Anies Baswedan halted the project during his tenure from October 2017 to October 2022

The halt in 2017, Bambang said, was due to unavailability of lands procured by the Jakarta administration.

“The administration had already procured quite a lot of land. However, building river embankments to mitigate floods needs to be on contiguous plots. If there were some plots of land that had not been procured or purchased [from their previous owners], then we can’t start construction,” Bambang said.

According to the Public Works and Housing Ministry, this year about 1.2 km of the Ciliwung River would be normalized. However, only about 500 meters had been on the works, as several plots of land still needed to be procured.

Bambang said that the BBWSCC was currently studying to decide which part of the Ciliwung River would be normalized next year and how much of the National Budget (APBN) would be allocated to the PUPR budget.

 

Interim’s target

Interim governor Heru said that to procure lands for the Ciliwung River normalization project he earmarked about Rp 700 billion (US$44.76 million) from the 2023 City Budget Draft (RAPBD).

He aims to complete about 4.8 km of the river normalization section during his tenure, which will last until 2024. 

For the river normalization project, the city administration prioritized land procurements in four subdistricts in the city to be completed by next year, according to Jakarta Water Resources Agency head Yusmada Faizal.

The four locations to be prioritized are Rawajati in South Jakarta (a total of about 1.5 hectares) and Cililitan (0.8 ha), Cawang (2.25 ha) and Kampung Melayu (1.95 ha) in East Jakarta, all totalling about 6.5 ha.

Trisakti University urban analyst Nirwono Joga said that resuming the normalization on the Ciliwung River would help in mitigating floods especially those that were caused by influx of water from upstream.

“The solution for that kind of flood is by cleaning up the rivers, dredging to deepen the river’s depth and to widen the river to increase the capacity of the river,” Nirwono said on Wednesday.

If all 13 rivers running through Jakarta were cleaned up, 109 lakes and ponds in Jakarta revitalized and the construction of four new reservoirs in Jakarta as well as the Ciawi and Sukamahi dams in Bogor, West Java, were finished by the end of this year, the impacts from floods caused by upstream influx could be reduced by up to 30 percent, he said.

However, Gadjah Mada University hydrologist Agus Maryono said that river normalization by installing concrete embankments while increasing water discharge would also hasten sedimentation downstream, which could contribute to larger flooding.

“The solution [to flooding] should not be speeding up water discharge but by [increasing] water retention to reduce the amount of water flowing downstream,” Agus said.

He said that increasing water retention could be done by building retarding basins to contain rainwater before going into rivers, revitalizing lakes and reservoir especially in upstream areas such as Depok and Bogor, as well as installing rainwater catchment especially on large buildings in the city to not allow water to be immediately absorbed into the ground.