One of the Causes of Flooding, Land Conversion in Upstream Reaches 2,000 Hectares

JAKARTA, KOMPAS – In addition to the extremely high intensity of rainfall, land-use conversion in upstream areas has become one of the main causes of flooding occurring in various regions of Jakarta, Bogor, Depok, Tangerang, and Bekasi over the past few days. This land-use conversion has even reached more than 2,000 hectares.

Deputy for Pollution Control and Environmental Damage at the Ministry of Environment/Environmental Control Agency (BPLH), Rasio Ridho Sani, on Wednesday (5/3/2025), stated that environmental damage leading to flooding occurs in upstream areas.

The analysis results by BPLH indicate that environmental destruction due to land clearing or land-use conversion in upstream areas has reached 2,065.50 hectares, or 30 times larger than the Bogor Botanical Gardens, which covers only 87 hectares. It is recorded that there are 3,203.24 hectares of critical land and 7,811.08 hectares prone to erosion.

The estimated data on land-use conversion from BPLH is calculated using the Normalized Difference Vegetation Index (NDVI), an index that indicates the level of greenness, density, and health of vegetation. This data is also processed using satellite imagery from 2024, combined with high rainfall data.

The estimated area of land-use conversion from the BPLH analysis is even twice as large as the data held by the West Java Provincial Government. In his statement on Monday (3/3/2025), West Java Governor Dedi Mulyadi stated that more than 1,000 hectares of tea plantation land in Puncak have been converted and must be immediately stopped.

Meanwhile, based on the mapping conducted by the Citarum-Ciliwung Watershed Management and Protected Forest Center in 2018, severely critical land has covered nearly half of the Puncak area, encompassing the districts of Cisarua and Megamendung, with a total area of 4,600 hectares.

The increased role of the Jakarta Provincial Government and regional governments in Jabodetabek in repairing damage in upstream areas becomes highly significant.

Another analysis from Forest Watch Indonesia (FWI) revealed that 5,700 hectares of natural forest were lost in the Puncak Area between 2000 and 2016, leaving only 21 percent of natural forest remaining from the total upstream area of the Ciliwung River Basin (DAS). The extent of natural forest loss is estimated to continue increasing to this day.

Regarding critical and erosion-prone land locations, Ratio said that they would be rehabilitated including through a tree planting movement involving various stakeholders. Meanwhile, regarding land conversion, it will be investigated through supervision and disciplined and enforced by the law if violations are found.

"The Deputy Team for Pollution and Environmental Damage Control and the Deputy for Law Enforcement of the BPLH are currently in the field monitoring field conditions and supervision," said Rasio.

The ratio emphasized that increasing the role of the DKI Jakarta Government and regional governments in Jabodetabek in repairing damage to areas in the upstream area is very important. This is because the impact of land conversion, critical land and high levels of erosion in the upstream area increase the risk of flooding in the downstream area.

Professor of Regional Development Planning at IPB University Ernan Rustiadi said that the Puncak area is actually part of the Cibodas biosphere reserve so that its development aspects need to be controlled. However, in reality, development has continued to grow massively since decades ago.

"Since the Dutch era, then President Soekarno until now, Puncak is an area that is relatively regulated, including in laws and regulations. However, growth control seems ineffective so that this area continues to experience environmental degradation and is vulnerable to various disasters," he said.

Ernan views that development control in upstream areas is less effective because local governments, especially at the sub-district and village levels, do not have adequate authority. Meanwhile, at the district level there are also limitations, especially in sectoral aspects such as access to certified forest and plantation areas.

"At the central level, there is also a division of authority in each ministry. The regional spatial planning at the district, provincial, and national levels has indeed been revised several times. However, I see the trend of revisions increasingly loosening or accommodating market mechanism processes," he said.

As an effort to overcome this condition, in the short term, Ernan encouraged the government to strengthen the early warning system related to the potential for flooding and landslides in vulnerable areas, including along river basins. Meanwhile, in the long term, the government needs to be firm in controlling development in upstream areas.