Staying in Jakarta: Will a great sea wall protect Indonesia's capital from coastal flooding?

Stania Puspa Channel NewsAsia 29 Jun 19;

JAKARTA: For those living in North Jakarta, regular coastal flooding is a fact of life.

Entire communities are inundated, usually in the middle of the month, as the sea level rises around the full moon period. Residents of Kaliadem in Penjaringan, North Jakarta, simply refer to coastal flooding using the Javanese word “rob”.

“(A) big cycle (of flooding) comes once every three months,” said local citizen Bani Sadar when interviewed by CNA.

“Sometimes, it’s a moderate flood, sometimes it’s a big flood. We have (in the past) experienced five days of flooding in a row.”

In the middle of May this year, seawater flooded Mr Sadar’s house. The water level was up to his ankle.

He recounted how the seawater seeped in through the backfill soil beneath the living room’s floor, before making its way to the other rooms.

Other residents in the neighborhood like Mr Eko Budianto, have similar experiences.

His house, three by six metres in size, is constructed with wood. The seawater has damaged the wood in the lower part of the structure, leaving it a greyish colour.

The various urban challenges in Jakarta, including flooding and traffic congestion, have been under the spotlight since the Joko Widodo administration announced in April that it will relocate the capital outside Java.

The new capital will likely be in Kalimantan, said planning minister Bambang Brodjonegoro, noting that it has the least potential for natural disasters compared to other parts of the country.

The government is expected to make an announcement on the location of the new capital city at the end of this year.

Jakarta is the fastest sinking city in the world, say experts. The continuous construction of new buildings and excessive groundwater extraction have triggered land subsidence.

At the same time, around 40 per cent of the city, particularly the northern areas, is below sea level and prone to coastal flooding. With rising sea levels, it is expected that around 95 per cent of North Jakarta will be submerged by 2050.

Residents in Penjaringan, including Mr Ahmad Hadi, have been making adaptation plans in light of the rising sea levels.

He told CNA that the villagers have raised the base of their houses to guard against coastal flooding.

“If there are no villages here (serving as bulwark), the seawater (moving inland) from Kaliadem might trigger a much bigger flood in the area.”

To keep out the seawater and prevent flooding, the area that borders the North Javanese Sea has been peppered with sea dikes. These dikes form the Giant Sea Wall of Jakarta project, which is part of the National Capital Integrated Coastal Development (NCICD) masterplan.

The Giant Sea Wall – when completed will be 32km long - is part of a bigger plan for a flood-free Jakarta. After a feasibility study, the master plan was finalised in 2008, and construction of the initial wall began in 2014.

It began by constructing an 8 km part of the sea wall along the coast. This will be integrated with a water reservoir and other land reclamation works involving 17 artificial islands. The project is expected to be completed in 2025.

Under the NCICD, Jakarta Bay would become a water reservoir enclosed in the Giant Sea Wall and would eventually become a source for clean water for the entire city.

President Joko Widodo (who was Jakarta governor during the early days of the initiative) named the Giant Sea Wall as “Project Garuda” as it is built in the form of the country’s mythical bird symbol.

Inside the wall, large lagoons are constructed to buffer outflow from the 13 rivers in Jakarta. The project is funded by the government, state-owned corporations and private sectors.

The NCDID is projected to be a centre of urban development equipped with facilities such as airport, harbour, toll road, residential areas, industrial areas, waste treatment and green areas, among others, on a space of about 400ha.

The Ministry of Public Works has earlier said that the NCDID is a coordinated effort between the governments of Jakarta, Banten and West Java.

Mr Budianto, who lives near the sea wall said the dikes have generally reduced the flooding time.

“Every year, flooding will come from January to March. It (used to take) two or three days before the water receded. But now, the water recedes in several hours.”

EFFECTIVENESS OF SEA WALL QUESTIONED

The project however, is not without its detractors.

Current Jakarta governor Anies Baswedan has suggested that the Giant Sea Wall project be reviewed, claiming that many studies have questioned the project’s effectiveness.

While he did not elaborate on the studies, Mr Baswedan had expressed his concerns back in September 2018 that the sea wall might turn into a “giant pond” (kobokan) that collects dirty water.

He said with the sea wall in place, water would not be able to flow into the open sea.

Weighing in on the issue, Trisakti University urban expert Nirwono Yoga said what the government has done to tackle coastal flooding is not enough.

The government should clarify the policy towards affected residential areas near the coast – whether the areas will need to be reorganised and whether the residents need to be relocated to other places, he said.

A questionnaire survey of local inhabitants by researchers from the Tokyo Institute of Technology in 2017 revealed that seawater is already breaching coastal dikes and flooding vulnerable communities along Jakarta’s waterfront.

Mr Yoga also pointed out that the residential areas near the sea wall is prone to be submerged if the dikes are damaged. Coastal replanting of mangroves is also required in North Jakarta so that it can act as a buffer flooding zone.

More preparation can also be done at the community level, which includes villagers' initiatives to provide community pumps and growing greens in their neighbourhood. Traditional stage houses built on stilts should also be encouraged, while people should be asked to voluntarily move to areas that are safe and liveable, he added.

TRADITIONAL SOLUTIONS NO LONGER SUFFICIENT: PUBLIC WORKS MINISTRY

Dismissing the concerns, Special Staff for the Minister of Public Works and Public Housing, Dr Firdaus Ali noted that the sea wall project is the collective work of multinational urban and water science experts from the Netherlands, South Korea, Japan and Indonesia.

“The problem is already massive, we can’t expect traditional ways to overcome flooding anymore… This project aims to save Jakarta for the next 50 to 100 years, not (just) 5 years,” he told CNA.

Commenting on the need for more green spaces, he said Jakarta is already experiencing land shortage. “We only have 662 sq km of land with roughly 13.5 million people ... There is simply not enough room to add effective green spaces to prevent flooding if done occasionally,” he said.

He also said that traditional stage houses are not the solution as they need a lot of space to house extended families. Dr Ali said that the housing strategy for highly urbanised Jakarta is vertical housing, not traditional architecture.

“The problem of Jakarta land subsidence and seawater increase are complex and massive. It can’t be solved sporadically through community initiatives at a small scale,” he said.

“The government needs to handle this with expertise solutions. It’s no longer about the need for preventive action, but a requirement for a curative solution.”

Given the uncertainties, are residents thinking of moving? Most of those interviewed said they plan to stay put, so as not to risk their livelihoods.

North Jakarta resident Taufik Ismail says he plans to stay put. (Photo: Stania Puspa)
Villager Taufik Ismail said he has spent the past two years adapting to life working in a modern fish market in North Jakarta.

“Where else we can move? We make a living here. Our sustenance is here,” he said.

Source: CNA/aw