When the Ciawi and Sukamahi dam could not prevent floods in Jakarta

TIRTO.ID – At the beginning of March 2025, some parts of JABODETABEK were affected by generalized floods. In some regions, it has become the worst flood in recent times. The public highlighted this event as a five -year flood cycle.

The severity of the impact of the jabodetabek flood then raised a great question concerning the effectiveness of the flood control infrastructure that has been built by the government so far.

One of the most highlighted flood control projects is Ciawan-Sukologis. The two dams located in Bogor Regency were part of the Jakarta and the surrounding flood control system which was inaugurated by former president Joko Widodo at the end of 2023.

The Ciawi and Sukamahi dams should be able to accommodate the excess water upstream of the ciliwung sunga and sank it downstream downstream.

The CIAWI dam has a capacity of 6.05 million cubic meters and a flacquer area of ​​39.49 hectares. The dam which started to be built in 2016 can also reduce the water flow from the Ciliwung river before reaching Jakarta with a capacity of 111.75 cubic meters per second.

Meanwhile, the Sukamahi dam began to be built in 2017. This dam has a capacity of 1.68 million cubic meters and a 5.23 hectare puddle area. It can reduce the water flow by 15.47 cubic meters per second. This dam is used to reduce the flow of several tributaries flowing in the Ciliwung river, such as the Sukabirus river.

Ciawi and Sukamahi dams are certainly working, but it turns out that big floods occur. This shows that the function of the two dams is far from optimal to overcome the floods.

The meteorological phenomenon changes

Infrastructure and town planning experts, Yayat Superriatna, said that the technical planning of the Ciawi and Sukamahi dams was undoubtedly uncontrollable. Because the government is only focused on a single place with a high intensity of precipitation, in this case the region of Puncak Bogor.

Thus, perhaps the government's calculations provide that there is strong precipitation at the top. And which was prepared by the Ciawi-Sukamahahi dam scenario to use as aquatic potential controller, said Yayat when he was contacted TirtoTuesday (11/3/2025).

If high intensity precipitation occurs in the region upstream or in puncak, the Ciawi and Sukamahi dam can indeed play an optimal role in the adaptation and regulation of the water discharge. The problem is that, according to Yayat, the weather phenomenon can change.

One thing we have to accept is that there are things that may not be read so far when the meteorological phenomenon has changed, Yayat said.

This is what has escaped from the government's calculation. Because the floods that struck the Grand Jakarta region at the start of Ramadhan yesterday were due to high precipitation in the city of Bogor, Katulampa, Sentul and surrounding, not in the Puncak region.

When it rains, it is extraordinary high and there is no dam or embankment in the middle of Ciliwung. Thus, water still goes down, said Yayat.

In the city of Bogor, there is always a Katulampa dam. Part of the ciliwung water through which takes place through the valves in Kali Baru Timur. However, downstream, there is no dam that can control water flow from the Ciliwung river.

In Katulampa, there is no dam. This caused eastern Jakarta, Kalibata, then at Kebon Pala around him, Yayat said.

Meanwhile, the Director General (Dirjen) of Water Resources (SDA) of the Ministry of Public Works, Lilik Retno Cahyadiningsih, said that the Ciawi and Sukamahi dams had really worked and showed good performances.

According to Lilik, the Ciawi dam is able to contain up to 2 million cubic meters of water, while the Sukamahi dam accommodates 0.3 million cubic meters of water. This success shows the effectiveness of the existing water management system.

[Bendungan] Ciawi and Sukamahi have shown their performance, said Lilik when confirmed TirtoTuesday (11/3/2025).

However, his party cannot deny that he cannot be a single solution to extreme precipitation that have caused floods in the Grand Jakarta region.

Yesterday, what happened in the extreme rain of Ciawi and Sukamahi, he added.

The Center of Researchers Associated for the Research and Innovation Research Agency in Limnology and Water Resources (FRUD), Yus Budiono, has agreed that floods in Jabodetabek in recent years show an increase in the intensity of extreme events. Global climate change causes more extreme rain, as happened on January 1, 2020 and at the end of January 2025, when precipitation reached more than 300 mm well above normal.

In addition, Yus explained that floods in Jabodetabek could be classified into three main types, namely the floods due to local rain (Torrential rain flood), the floods due to the overflow of the river (river flood), as well as the floods due to the tides (coastal flood).

“The deluge that occurred some time ago was more dominant as river floodwhere the rain occurs more intensely upstream and causes the water overflow in the big rivers, “was cited in Yus StrandTuesday (11/3/2025).

What to do?

To anticipate the recidivism of disasters in the future, the Ministry of Public Works plans to make a retention basin at several times. However, the financing of the project was not included in this year's budget.

“And also in the short term is that we do emergency manipulation,” said Lilik.

According to urban planning experts, Nirwono Yoga, the Ministry of Public Works should ideally assess the efficiency of Ciawi and Sukamahi dams which are not as planned. This evaluation aims to assess its impact on flood control and water flow from the Ciliwung river.

The existence of sodedan towards the flood of the oriental canal (BKT) is also one of the objectives of the best water management efforts, Nirwono declared TirtoTuesday (11/3/2025).

In addition, the flow of the Ciliwung river should ideally be free from buildings. The arrangement and use of green land or vacant land for the construction of new tanks, lakes or tanks are also one of the important stages to reduce the flow of river water and accommodate the overflow of water.

In the long term, the government must also strengthen efforts to control spatial planning and land conversion along the river downstream from Ciliwung. This step is a response to the threat of floods that have more and more hit the Jabodetabek region during the rainy season.

The transfer of land functions and uncontrolled space changes is one of the main factors causing floods in Jabodetabek. The construction of housing, commercial areas and other infrastructure in watersheds and along the flow of the river reduced the capacity of the river to collect water.

In addition, the existence of development in critical areas also causes the navigable paths that aggravate the flood potential.

The government must also demolish buildings that violate and move colonies that subscribe to the floods in Rusunawa, Nirwono said.

With spatial planning control and strict supervision of land conversion, the Jabodetabek region should be able to avoid the threat of flooding which is increasingly putting the infrastructures of the community and the city in danger. This effort should reduce the risk of flooding and improve the quality of life of the affected community.