Jabodetabek Floods, Upstream Fragile and Downstream Congested

On Sunday night (2/3/2025), Atik Nurhayati (48) had just returned from Tarawih prayers when muddy water inundated her home in Tugu Selatan Village, located in the Puncak area, Bogor Regency, West Java. This was not the first time flooding occurred, but she felt this time was far worse. The water not only came from the overflowing river but also surged from underground, damaging the foundation of her house.

Since living in the area 13 years ago, Atik said disasters have come more frequently and more severely. "Now the water comes from all directions, above, in front, even from under the floor of the house," Atik told Kompas.

A few hours later, downstream, hundreds of residents in Bekasi, West Java, were evacuated after water more than two meters high submerged their neighborhoods. The Bekasi River overflowed after upstream areas in Bogor were hit by extreme rainfall. Jakarta, Depok, and South Tangerang experienced similar conditions. In one night, floods struck several areas in Greater Jakarta.

This massive flood repeats a pattern that experts had already predicted. According to Abdul Muhari, Head of the Data and Disaster Information Center at the National Disaster Management Agency (BNPB), this flood was not solely triggered by extreme rainfall. Cumulative factors such as environmental damage upstream, land-use changes, and the lack of absorption areas in downstream regions have significantly contributed to the widespread disaster.

"From year to year, the ecological carrying capacity of Jabodetabek has become increasingly critical; this is the accumulation of decades of mismanagement in spatial planning," said Abdul.

Puncak, as an upstream area, has become a primary focus. The massive land-use conversion has transformed thousands of hectares of forests and plantations into villas and tourist attractions. According to data from the Watershed Management Agency (BPDAS) Citarum-Ciliwung, critically degraded land in the Puncak area reached 4,600 hectares in 2018. The latest report from the Ministry of Environment and Forestry (KLHK) as of March 2025 states that the extent of land-use conversion in the upstream area of Ciliwung has already surpassed 2,065 hectares.

Deputy for Pollution Control and Environmental Damage at KLHK, Rasio Ridho Sani, stated that the figure is equivalent to 30 times the area of Bogor Botanical Gardens. As a result, rainwater falling upstream is no longer absorbed by the soil but instead flows rapidly into the river.

However, blaming Puncak alone is insufficient to explain the complexity of flooding in the Greater Jakarta area (Jabodetabek). Brutal urbanization in downstream areas exacerbates the impact. According to records from the Regional Development Planning Agency (Bappeda) of DKI Jakarta, more than 95 percent of the land in Jakarta is currently covered by buildings. Green open spaces account for only about 6 percent of Jakarta's total area, far below the minimum requirement of 30 percent as stipulated by the Spatial Planning Law.

Bekasi, Depok, and Tangerang face a similar situation to DKI Jakarta. The conversion of swamps, reservoirs, and riverbanks into residential and commercial areas has occurred without effective control.

IPB University hydrologist Hidayat Pawitan emphasized that the Jabodetabek flood is a product of collectively damaged upstream-downstream ecosystems. Hidayat said the contribution of water runoff from upstream to Jakarta is only around 8 percent. The rest comes from the middle and downstream areas that are no longer able to absorb water due to massive development.

"The peak is indeed problematic, but don't forget from Katulampa downstream it's all urban, the absorption capacity is almost zero. All factors intertwine to create a major flood," said Hidayat.

Climate change is making matters worse. According to a study by the Meteorology, Climatology, and Geophysics Agency (BMKG), although total annual rainfall in Jakarta tends to stagnate or decrease, the intensity of extreme rain in short durations has actually increased drastically.

Head of the BMKG Applied Climate Information Working Group Team, Siswanto, explained that heavy rain that used to last an average of 6-8 hours, now falls in just 2-3 hours. This kind of rain pattern is much more difficult to handle because the drainage does not have enough time to drain the water out of the city. "This is a classic characteristic of the impact of climate change in tropical urban areas," said Siswanto.

The problem downstream is getting worse because the rivers in Jakarta, Bekasi, and Depok have lost their water parking space. According to the Director General of Land and Spatial Control and Regulation of the Ministry of ATR/BPN Budi Situmorang, many lakes and swamps that should have been water pockets have disappeared or narrowed due to land conversion. Research by Kompas Research and Development in 2024 found that more than 60 percent of land on riverbanks in Jabodetabek has changed function to become settlements.

Amidst all the damage, Jabodetabek's flood control policy is still fragmented. The central government is focused on building dams, local governments are busy dredging rivers, while the spatial planning of the agglomeration area actually relaxes land conversion for investment.

Deputy Chairman of Commission V of the House of Representatives Syaiful Huda criticized that the flood control project so far has only touched the surface of the problem. "Flooding will not be resolved as long as spatial planning in Jabodetabek is managed sectorally and passes authority to each other," said Huda.

In other countries, the approach to water management is much more integrative. China has implemented the concept of a “sponge city” that restores the city’s natural absorption capacity by increasing city parks, biopores, and micro reservoirs. The Netherlands lives side by side with water through spatial planning that prioritizes ecology. However, in Jabodetabek, ideas like this are still just discourse.

If development patterns and water management do not change, BNPB estimates that in the next 20 years, Jabodetabek flooding could double, with economic losses reaching IDR 30 trillion per year. Moreover, the threat of tidal flooding on the coast of Jakarta is increasingly real due to rising sea levels.

The Jabodetabek floods are a collective product of careless spatial planning, reckless urbanization, and the acceleration of the impacts of the climate crisis. The city no longer provides enough space for water, both upstream and downstream. Blaming one party, whether Puncak, Jakarta, or Bekasi, will not solve the root of the problem. Real solutions can only come from a total redesign of the Jabodetabek spatial plan that takes into account ecological carrying capacity, not just investment targets.

We need to learn from the history of Jakarta floods that have been recorded since the 17th century. The Dutch once understood that controlling water was the key to controlling Batavia. Now, with the population of Jabodetabek reaching 30 million people, managing water is no longer just a matter of technical infrastructure, but also a matter of the sustainability of the entire region.

If we fail to build this awareness, then every rainy season will always bring the same threats: increasingly widespread flooding, increasingly severe disasters, and increasingly thin hopes for the future of Jabodetabek.

Note: This summary is compiled from a number of articles that have been published in Kompas.id in the last month. The articles were compiled with the support of generative artificial intelligence (AI) technology. However, before being published, the articles went through a verification and editing process by the Kompas editor. Here are a number of articles that are sources: