Want to Really Know Why Jakarta Is Sinking? Blame Your Tap

The white colonial-era building sitting in Jakarta's old town stands a little shorter than it did back when the Indonesian capital was still called "Batavia." That's because the art-deco building, now named Gedung OLVEH, is actually sinking into the earth—about one centimeter every single year.

“The ground has sunk 95 centimeters,” Lin Che Wei, executive director of the Kota Tua Revitalization, told local media.

And it's a bigger problem than just one building. Jakarta itself is sinking, in some coastal areas by as much as 25 centimeters a year, under the weight of new construction and an increasingly unstable foundation. The existing sea wall, a four-meter-high embankment that runs parallel to the shoreline in North Jakarta neighborhoods like Muara Baru and Pluit is no longer enough.

The reason why the capital is sinking so much all comes down to water. But it's not an issue too much water. The problem is that there's not enough. The flood-prone city lacks anywhere near enough connections to public water lines, a long-standing issue that has forced many residents to dig down for their own wells. The problem here is that these wells have destabilized the city, causing it to sink at a time when global sea levels are already rising.

An estimated 65 percent of all Jakarta residents rely on ground wells for water. There are at least 10 million people living in the Indonesian capital, and when more than half the population relies on private household wells to draw their water, each well has a multiplier effect. The capital's shallow aquifer (the space underground where clean water lives) keeps dropping. So homeowners keep digging deeper, and, eventually, the ground itself starts to pay the price.

And so do the taxpayers. Indonesian officials are now floating a Rp 500 trillion ($37 billion USD) solution that some have experts likened to an extremely pricey band-aid. The solution, dubbed the Giant Sea Wall, will run for more than 500 kilometers along the Jakarta coastline in a bid to literally hold back the sea waters as the city sinks slower.

But it's this problem, the fact that city itself is sinking, that officials really need to fix, explained Adang Saf Ahmad, a special staff member with the Ministry of Public Works and Public Housing and the head of the Giant Sea Wall project.

"The key is to stop groundwater extraction completely," Adang said. "We need law enforcement. If Jakarta can’t stop the rapid sinking, then the Giant Sea Wall project needs to be sped up."

Indonesian officials are currently working with civil engineering firms for South Korea and the Netherlands to develop a timeline for the sea wall. If the city can stop sinking, then the wall will be built sometime around 2028, Adang said. If not it will have to start construction a lot sooner.

The reality here is that no one can do anything to reverse the sinking. All officials can hope for is slowing it down enough that it's not as pressing a problem as it is today. But that's easier said than done. The government imposed a tax scheme in 2009 that was meant to convince businesses to stop using groundwater. The Jakarta Water Works Department reported that groundwater use dropped 30 percent since then, but some experts have doubted this claim, asking if the use of groundwater actually dropped that much, shouldn't we see a sizable increase in piped water connections?

The city's current public water network, which, until recently was actually privately owned, only services about 40 percent of the city's households. To provide service to the rest of the city, water operator PD PAM Jaya would need 7,800 kilometers of new pipes—or enough pipes to run the entire length of Java eight times over.

Increased enforcement is also needed. The city, with the help of the Corruption Eradication Commission (KPK), discovered at least 10,000 illegal wells during a survey of the capital. Meanwhile, the Jakarta Waterworks Department found another 4,475 instances of commercial properties illegally using groundwater wells. But even that is likely only the tip of the iceberg. That survey of corporate offenders totaled only 9.143 million cubic meters of that.

But experts estimate that there is currently 140 million cubic meters of water being pulled from wells ever year, or enough water to fill 56,000 olympic sized swimming pools.

Then there's government buildings, which are exempt from the law and allowed to pull as much water as they want from private wells—all totally tax free, explained Janjaap Brinkman, a consultant based in the Netherlands.

“The government doesn’t set a good example for the industrial sector," Brinkman said. "It’s simply not fair. It all should start from the government."

So, until the government can stop groundwater extraction, the solution seems to be the Giant Sea Wall. But the project is not without its controversies. For one, there's the price. It's an extremely expensive project. Then there's the fishermen who already live in communities along the North Jakarta coast. They complain that building a sea wall to hold back the waters also shuts them out from the Jakarta Bay—and their source of income.

And that's not even mentioning the Jakarta reclamation project, a totally different proposal to build new islands of the coast and let big-name builders turn the land into a lux. development. This project has nothing to do with the sea wall, but it's often linked to the project in the domestic press, which confuses the public and creates further dissent.

So the government is left with two options, Brinkman explained, either stop all groundwater extraction and clean up the river system so the rainwater runoff has somewhere to go, or evacuate everyone living along the northern coast of Jakarta. But even then, either one of these options is probably too little, too late, he said.

The longer government officials spend mulling their options and not enforcing a strict ban on groundwater extraction, the lower buildings like Gedung OLVEH will sink.

“The solution is right in front of us,” Brinkman said of the groundwater well ban. “But we’re too busy looking in another direction.”