Giant Sea Wall: New Solutions Or Problems For Pantura Java?

JAKARTA c

The Indonesian government, in this case President Prabowo Subianto, is also planning the construction of GSW which stretches from Jakarta to Gresik. This project is referred to as a solution to the threat of tidal flooding and land subsidence on the North Coast (Pantura) of Java.

Yes, the Pantura area of Java does face serious threats due to climate change. Land subsidence in this area reaches 1 25 centimeters per year, exacerbated by sea level rise of 115 centimeters per year. Cities such as Jakarta, Semarang, and Demak witnessed how the coast continued to erode, forcing thousands of families to lose their homes.

For example, in Demak Regency, Central Java. In September 2024 more than 800 houses in three sub-districts were destroyed by abrasion and tidal flooding. Meanwhile, in Semarang, abrasion has eroded 1,764.5 hectares of land in the last two decades. In Jakarta, the large floods in 2007 proved that the coastal embankments built in 2002 were not enough to protect the capital city from the combined impact of climate change and mismanagement of spatial planning.

This crisis also threatens the economic sector. Throughout Pantura Java there are 70 industrial areas, five special economic zones, and other economic growth centers that are prone to tidal flooding. Ironically, the government's excessive focus on the industrial sector often ignores coastal communities, those most affected by this crisis.

The question that arises is, will this government's ambitious project really address an increasingly severe crisis, or is it just a patch solution that has the potential to cause new problems in Pantura, Java?

Executive Director of Rujak Center for Urban Studies, Elisa Sutanudjaja revealed, problems in coastal areas, such as Jakarta, Semarang, Demak, and Pekalongan are not merely abrasion and tidal waves, but a problem of land subsidence, which cannot be handled by embankments or giant walls.

According to him, the embankment will not last long if the government does not first address the main problem of tidal flooding, namely land subsidence or land subsidence. "If the land subsidence is not fixed, then the wall will go down or break like what happened in Muara Baru in December 2019," he said.

Elisa explained that a report from one of the UN agencies, the Intergovernmental Panel on Climate Change (IPCC) in 2022 states that flood management solutions in the form of infrastructure development can be 'maladated' if implemented in the long term.

In the report, IPCC describes a number of cases, one of which is the Jakarta sea embankment project which aims to reduce the risk of flooding, which is estimated to increase the risk of flooding for the poorest urban population.

The embankment has the potential to trigger flooding because GSW will close the bays and mouths of the river, so it will accelerate sedimentation. This sedimentation slows down the flow of rivers into the sea. GSW in Jakarta itself has been declared by the IPCC as maladaptive infrastructure, having a negative impact on society, especially those throughout Java," he said.

Not only that, a number of observers also consider the narrative of the government to provide a "safe feeling" with the construction of this embankment actually "sesat".

In a research journal released in 2017, researcher who graduated from Ocean University of China, Elisabeth Augustina Issantyarni assessed, the narrative that the construction of GSW aims to provide a sense of security for the Pantura Jawa region will 'insist' the public and investors who will invest in coastal areas.

The reason is, coastal land is usually formed from alumcial soil or river deposits for hundreds of years, so that the structure is softer than the area in the middle of the island. Therefore, the more heavy building structures that stand in coastal areas, the physical vulnerability of the land is increasing.

"This increase is manifested in the speed of rapid and deep land subsidence. Flood disasters have become a necessity, and this is only a matter of time," he said.

Elisabeth also called the construction of this embankment a paradox. On the one hand, the embankment provides a sense of security for a while, even though the vulnerability of coastal areas has increased. According to him, the losses incurred will be greater than when a disaster hit the area before the embankment construction.

"Reactive actions by the government and the private sector to build embankments are not merely aimed at protecting humans and living spaces, but rather to maintain the capital that has been invested so that it can continue to grow," he said.

Coastal Coastal Crisis Needs Holistic And Sustainable Handling

A different opinion was put forward by ITB Water Resources Engineering expert, Dantje Kardana Natakusumah, who said that the construction of GSW, which is part of the National Capital Integrated Coastal Development (NCICD) as a way to protect the capital city from flooding.

He explained that there are three main components in the NCICD project, namely, the construction of coastal embankments and river embankments funded by public or government funds, giant sea embankments (Giant Sea Wall) and the Coastal Reservoir.

However, there are several problems in NCICD Beach Reservoir Design, such as the construction of Giant Sea Wall that will not stop flooding from rivers, unconventional and untested flood control approaches, excessive hydraulic burden on beach reservoirs, and failed replication of designs in Shihwa Lake, South Korea. GSW can't stop flooding from rivers, if it's from the sea it can," he added.

Dantje sees that the construction of GSW is very important, especially in Pantura, Java, which has experienced land subsidence, such as in Jakarta, Semarang, and Pekalongan. However, the construction of GSW must be accompanied by the concept of the construction of the Beach Reservoir.

"The integration of the Beach Reservoir to GSW is seen as a solution to the problems of the coastal areas of certain Pantura Java, starting from Jakarta. So we do not take groundwater because in the future there will be a freshwater reservoir on the beach," he explained.

Apart from the pros and cons regarding the construction of GSW, the coastal crisis in Indonesia requires a holistic and sustainable approach. Natural-based solutions such as restoration of mangroves, rehabilitation of coral reefs, and termination of land conversion in coastal areas must be a priority. Mangroves, for example, not only protect coasts from abrasion, but also absorb large amounts of carbon. Likewise, restoring forests and wetland can help reduce carbon emissions while strengthening environmental resilience.

Likewise with very urgent spatial reforms. The government must stop development in vulnerable areas, manage groundwater wisely to prevent subsidents, and strengthen regulations that protect coastal areas. Investment in low-emission public transportation and reducing dependence on fossil energy must also be part of climate change mitigation strategies.

The GSW project can be said to reflect the government's big ambitions in dealing with coastal crises, but this project is not enough to answer the root of the problem. Indonesia's coastal crisis is the result of a combination of climate change, poor spatial planning, and unsustainable development policies.

This is because a true solution requires changes in the paradigm, as well as touching the root of the problem, prioritizing sustainability, and prioritizing the people most affected. Without these steps, no matter how high the embankment is built, it will not be able to withstand the wave of crisis that continues to come.