Land Conversion Increasingly Cripples Jabodetabek

JAKARTA, KOMPAS - The Greater Jakarta area continues to face an increase in the frequency and intensity of hydrometeorological disasters, such as floods and landslides, due to population growth and infrastructure development that disregards spatial planning. Without effective environmental management, major floods that typically occur every five years could happen again sooner.

The Head of the Meteorology, Climatology, and Geophysics Agency (BMKG), Dwikorita Karnawati, urged the government not to overlook issues related to spatial planning development that affect environmental and climate sustainability. Sustainable spatial planning is crucial to reducing the impact of hydrometeorological disasters in the future.

"Please do not disregard spatial planning that takes environmental changes into account. This must be discussed immediately," said Dwikorita during a webinar themed Reflection on Jabodetabek Floods: "Spatial Planning Strategies and Extreme Weather Mitigation," Monday (24/3/2025).

Dwikorita stated that hydrometeorological disasters such as floods are not solely caused by high rainfall. There are other significant contributing factors, such as environmental conditions, land use planning, and climate change.

"We observed the flooding that occurred in early March 2025 in Jabodetabek. The impact was very severe, even though the cloud clusters there were the smallest compared to other regions," said Dwikorita.

Based on satellite data, there are two larger cumulonimbus clouds in Palembang, Lampung, and West Kalimantan. However, the flooding in these regions is not as intense as in Greater Jakarta.

Dwikorita also compared rainfall data in Bekasi in January 2020, which at that time exceeded 300 mm and fell into the extreme category. However, even though the rainfall was higher then, the impact of the flooding was not as severe as what occurred in early March 2025 with rainfall of only around 200 mm.

He is also concerned that the condition of the Ciliwung River Basin (DAS) and urbanization factors may contribute to more severe flooding. The rapid growth of urbanization in the Greater Jakarta area (Jabodetabek) has reduced water absorption capacity, which can worsen conditions during heavy rainfall.

"Land use changes and local warming also play a role. Open land is decreasing year by year, which contributes to rising temperatures and changing hydrological patterns," Dwikorita said.

Understanding the potential for disaster, BMKG continues to strive to improve weather prediction capabilities and provide early warnings. However, the major challenge faced by BMKG is the complexity and limitations of the weather prediction system in densely populated areas such as Jabodetabek.

Then, weather prediction in urban areas is very complex. Changes in land use, river flow, and rainfall patterns influenced by local factors make predictions more challenging.

In areas like Jakarta, which are low-lying and have many drains that are often clogged, flooding often occurs even after moderate rainfall.

"The flood in Jabodetabek or what is known as the five-year flood, if it is not mitigated now to protect the environment, it will no longer be a five-year flood, but could be sooner," he said.

Dwikorita also invited the public to be more active in accessing weather information through the official BMKG channel, so that preventive measures can be taken earlier.

In areas like Jakarta, which are low-lying and have many drains that are often clogged, flooding often occurs even after moderate rainfall.

"With close collaboration between local governments, BMKG, and the community, it is hoped that the impact of disasters due to extreme weather can be minimized," said Dwikorita.

Meanwhile, BMKG noted that data on extreme weather phenomena in Indonesia from January 1 to March 17, 2025 reached 1,891 events. With details, 43 tornadoes, 400 strong winds, 1,182 heavy rains, 55 lightning, and 11 hail events.

The impacts caused by the extreme weather have resulted in 721 floods, 371 fallen trees, 374 landslides, 553 damaged buildings, and 567 transportation disruptions.

Coordinating Minister for Infrastructure and Regional Development Agus Harimurti Yudhoyono or AHY also emphasized the importance of balanced spatial development. This is to prevent flooding like what has happened in several areas of Jabodetabek recently.

According to AHY, currently natural conditions are full of uncertainty as climate change increases the potential for natural disasters.

"We must comply with spatial planning which has actually been planned proportionally to maintain the balance of nature," said AHY.

The development of infrastructure, housing, and other needs, said AHY, must still pay attention to natural factors. The goal is to avoid environmental damage that has long-term impacts.

AHY also said that the water reservoir capacity must be increased and river normalization must continue to be carried out. However, AHY reminded that the use of clean water sourced from groundwater can be reduced.

Greenpeace Indonesia Forest Campaigner M Iqbal Damanik said that the floods that occurred in Jabodetabek were indeed triggered by land conversion. He gave an example, Babakan Madang and Sukamakmur Districts in Bekasi which are the upstream of the Bekasi River Watershed, many of which have been converted into settlements and built-up areas.

"In the Bekasi River watershed, there are Sentul City, Summarecon, Hambalang, Indocement. The remaining forest is only on Mount Pancar," said Iqbal.

Currently, the area of the Bekasi river basin (DAS) is 147,000 hectares but the forest is only 1,700 hectares. The landscape has changed a lot into built-up areas so that water absorption is greatly reduced.

In fact, according to Greenpeace data, deforestation of the green area of the Bekasi River watershed from 1990 to 2022 reached 23,600 hectares.

"Currently, there are 1,700 hectares left. DAS is a watershed/catchment area. Not just the right and left of the river. If the DAS is bad, the water overflows directly into the river," he said.

Ideally, 30 percent of the watershed area should be covered by forest. Iqbal proposed that the government comply with the regulation on 30 percent cover in watershed flows.

Because, supervision of housing development must be in accordance with the carrying capacity of the capacity. Infrastructure development, especially housing in the DAS area, has a different impact than non-DAS areas, so it must be stricter.

In this regard, the West Java Provincial Government has ensured that it will restore the function of protected areas in its territory. It has appointed a team that will monitor and ensure the return of protected areas to their original function.

Head of the West Java Provincial Government's Economic Bureau Yuke Maulina said that protected areas in West Java are facing great pressure due to growing development. Many areas that previously functioned as water catchment areas or conservation forests have turned into built-up areas.

"One of them is the upstream area which is often the cause of flooding in the downstream area. Changes in the upstream have a big impact on the downstream area which often experiences flooding," said Yuke who was also present at the webinar.

Yuke also emphasized the importance of the community's role in protecting the environment. To that end, he invited the community to be more concerned about protecting water catchment areas and lands that function as disaster buffers.

According to Yuke, in the long term the West Java Provincial Government will also update the regional spatial planning and optimize land use.

"It is hoped that this can reduce the impact of natural disasters in the future," he said.

Meanwhile, in facing urban challenges, Jakarta Governor Pramono Anung emphasized the importance of a comprehensive strategy. Jakarta as an area crossed by 13 rivers is very vulnerable to flooding and disasters caused by extreme weather.

Pramono said there were factors that worsened the situation, such as changes in land use upstream, land subsidence, and climate change.

For that, Pramono explained, the Jakarta Provincial Government has set five main focuses for Jakarta's development. Some of them include decent housing, a sustainable environment, and a digital-based city.

Strengthening the city's resilience to climate change is also a priority in the Governor's policy. Pramono said that Jakarta will continue to collaborate with the Jabodetabek area to overcome the impact of disasters.

In addition, the Jakarta Provincial Government together with BMKG is improving the technology-based early warning system, namely BMKG Signature specifically for the Jakarta area. This technology has several advantages that will later provide accurate and timely weather information to the public while also being able to design more adaptive spatial planning policies.

"We want the community to be able to deal with potential disasters more quickly and accurately. The DKI Jakarta government continues to use BMKG data to anticipate flooding, whether due to upstream, local rain, or tidal flooding. We also carry out weather modification operations to redistribute rainfall," Pramono said.