Climate refugees: How extreme weather is forcing people to move

Semarang is sinking - 'all has become sea' for its tiny neighbour

Mr Agus Salim, 34, recalls when as a child the villages on the outskirts of Semarang made a living from rice paddy and fish farms. For years, villagers throughout this regency of Demak sucked up groundwater for their thirsty enterprises, depleting aquifers and prompting the ground to sink.

Now two years into his first term as village chief of Bedono, Mr Agus must cope with an exodus of villagers, while coaxing those who remain into new lines of work such as boat tours of the dwindling mangroves.

The enormity of the work ahead is not lost on Mr Agus. Roughly half of the 7,000 people who used to live here have been forced to move. Nearly a dozen villages have been inundated.

"This used to be paddy and fish farms. It wasn't sustainable" Mr Agus told The Sunday Times.

"All has become sea."

Irreversibly, Java's northern shore is sinking owing to a perfect storm of urbanisation, poor planning and treacherous geology. Add to that rising sea levels owing to climate change - and the outlook for this place is dire. But Bedono is the cautionary tale of what awaits its bigger neighbour to the west, the port city of Semarang, population 1.6 million.

There, the stakes are higher. Reclaimed land in Semarang's northeast, including its port which handles about 635,000 containers a year, is at risk. It's here, where modest livelihoods and industry co-mingle, where the city is sinking fastest: about 13cm a year. Factor in rising sea levels and the roughly 5,200ha of the city - more than a tenth - will be under water by the end of the next decade.

And this may be an underestimate. Dutch water management consultancy Deltares has estimated that the sea could rise as much as 70cm by the end of the century in North Java, which includes Jakarta.

But Mr Peter Letitre from Deltares says that as summers become hotter and weather more extreme, the upper limit may need to be ratcheted up: "There are indications the high scenario needs adjustment to become higher."

In Kampung Bahari, not far from the port, residents are already feeling the squeeze as houses sink into the soft soil. Some houses have sunk so deeply they resemble something from the Shire in Lord Of The Rings. Fishermen and labourers, those without the means to rebuild, must duck under roofs that start at about shoulder level. The main road into the neighbourhood has been raised twice during the past five years. This could be Semarang's future, too.

Much of the problem has to do with geology. Semarang, like most cities along northern Java, is built on sand and clay laid down by rivers emptying out into the ocean. Extracting water from the aquifers that puff up this mushy concoction will cause the sand and clay to sink, bringing homes and even container terminals down with it.

Mr Letitre says the root of the problem is the city's rapidly disappearing groundwater.

A 2010 study by Bogor Agricultural University suggests the city's homes and businesses were sucking up 6.3 million cubic m of water a year from the aquifers. Within four years that tally jumped to 9.6 million. At the current rate, there won't be enough groundwater to meet the city's needs by 2030.

Proof of the link between subsidence and uncontrolled groundwater use can be found in the case of a very thirsty ice factory in northern Jakarta, Mr Letitre says.

In 2010, alarmed municipal authorities closed down the facility located in the capital's Muara Baru area, when it became clear the business was sucking up so much water that the area around it was sinking 20cm a year. Within five years of the factory's closure, rates of subsidence had halved, according to Deltares. "The only way to stop subsidence is to add more water to aquifers," Mr Letitre says.

In the fishing community of Kampung Bahari, in northern Semarang, houses like this one may sink but owners lay down a new floor because they don't have the means to rebuild or move. PHOTO: JEFFREY HUTTON

Semarang mayor Hendrar Prihadi has vowed to step up monitoring of groundwater use. "This problem is quite serious. There is already seawater seeping into low-lying areas in the centre of city," Mr Hendrar says through a spokesman.

Experts like Professor Wiwandari Handayani, a lecturer in city planning at Universitas Diponegoro, worry that since groundwater will always be cheaper than piped alternatives, residents will always be tempted to tap it.

Much is at stake. According to a 2014 report published in the Indonesian journal Forum Geografi, at the current rate of subsidence, more than 5,000ha - over a tenth of Semarang - will be flooded by 2030. The dislocation and strain on business will total about 29 trillion rupiah (S$2.7 billion) in economic damage as firms and people bear the hardship of adapting or moving.

Back in Bedono, Mr Zainuri, 57, is a stark reminder of the hardship that may be in store. On a recent weekday, he and a dozen other men vie to ferry the few tourists by motorcycle from the mainland, roughly 1km away, to the tomb of a local hero of the war of independence. By midday, he's only had one fare, paying 10,000 rupiah. Mr Zainuri says: "It's not enough."

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A version of this article appeared in the print edition of The Sunday Times on November 04, 2018, with the headline Semarang is sinking - 'all has become sea' for its tiny neighbour. Subscribe