Giant sea wall 'must be built quickly' to stop Indonesian capital sinking into sea, president says

Areas in northern Jakarta already four metres below sea level, collapsing 20cm each year

Indonesian president Joko Widodo urged the imminent construction of a giant sea wall to save northern Jakarta from sinking into the ocean (AP Photo/Achmad Ibrahim)

A giant sea wall around the sinking capital of Indonesia must be built quickly to prevent swathes of the city being submerged, the country’s president warned on Friday.

Joko Widodo’s comments lent renewed urgency to a meandering and politically contested mega project, which the government first considered a decade ago and is expected to cost £34bn.

Experts estimate one third of Jakarta, home to millions of people, could sink beneath the sea by 2050 – an unforgiving timeframe fuelled by longstanding structural problems and rising seas.

The existential crisis facing the city, parts of which are sinking by 20cm a year, is the culmination of decades of unfettered development of vast skyscrapers on swampy ground, almost nonexistent urban planning and misrule by city politicians serving private interests

Lacking a comprehensive water network, industry and homeowners have dug into the city’s natural underground water supplies, causing rapid collapse in the city’s north.

“This huge project will need to be done quickly to prevent Jakarta from sinking under the sea,” Mr Widodo said.

The president, re-elected in May for a final five-year term, addressed other ambitious plans for Jakarta – a forward-looking, but polluted, sprawling metropolis of 30 million, when counting those living in the outer limits.

Mr Widodo promised to be less constrained by politics, saying he’s determined to push through key projects and reforms, even if unpopular.

He also reiterated his desire to build a new capital, suggesting it should be outside Indonesia’s main island of Java, where 57 per cent of the country’s nearly 270 million people are concentrated.

“We want to separate the capital, the centre of government and Jakarta as a business and economic centre,” he said. “We don’t want all the money existing only in Java. We want it to be outside Java as well.”

Jakarta’s vulnerability to flooding and earthquakes is also a factor, Mr Widodo said. “We need to make sure our capital is safe from disasters,” he said, without naming the location for the new capital.

The threats facing Jakarta are most visible in Muara Baru, a waterfront slum.

A sea wall along the shore is meant to protect the area’s makeshift homes against the Java Sea, but the concrete barrier has developed cracks.

A half-submerged mosque on the bay side of the wall serves as a stark reminder of what could be in store for the entire area.

Two women in the neighbourhood said their homes are flooded frequently.

Heri Andreas, an earth scientist at Indonesia’s Bandung Institute of Technology, said that in some parts of northern Jakarta, the ground is already two to four metres below sea level.

“Jakarta keeps sinking. If subsidence continues at the same rate, 95 per cent of northern Jakarta will be underwater by 2050.”

Mr Andreas said it took time for his alarming forecasts to be taken seriously by Indonesian government officials.

The project – known as the “Great Garuda” for its shape reminiscent of Indonesia’s national symbol – envisions three stages, starting with strengthening 30km of existing coastal dams and creating 17 artificial islands.

This would be followed by building giant sea walls on the western and eastern sides of Jakarta Bay.

However, implementation has been delayed by political arguments over the project’s cost and fears of harm to the local fishing industry.

Andreas, who is occasionally consulted by the authorities, said he expects a scaled-back version of the giant sea wall to be built for less than the initial budget.

In this scenario, a wall stretching 20km would enclose only part of the bay to protect the most vulnerable area, rather than a loop intended to be three times as long.

This would buy time for the government to deal with the other areas later, but local fishermen view the idea with suspicion, fearing it will rob them of their livelihood.

In Muara Angke, a small fishing port in northern Jakarta, 63-year-old Pandi dismissed the warnings by scientists, arguing that occasional flooding is part of life on the waterfront.

Pandi, who uses a single name, catches mussels for a living, in an operation that provides a livelihood for about 30 people.

He said land reclamation already underway in the bay forced him to sail farther away from shore in search of mussels. He fears a giant sea wall could drive him out of business for good.

“If we can’t work, we will suffer for a long time,” he added. “Sinking below water is just part of the risk.”

Additional reporting by AP