(Updates with Widodo’s former role in paragraph above “Better Drainage” subheadline. Click here for a map. For Cities columns, click here.)

Nov. 12 (Bloomberg) -- If you worry that rising sea levels may one day flood your city, spare a thought for Michelle Darmawan. Her house in Jakarta is inundated several times a year -- and it’s 3 kilometers (1.9 miles) from the coast.

Whenever there’s a particularly high tide or heavy rain, the Ciliwung River and its network of canals overflow, swamping thousands of homes in Indonesia’s capital. In January, a muddy deluge washed over Darmawan’s raised porch, contaminating her fresh-water tank and cutting off electricity for three days.

“We were sitting on the second floor, looking down at the floods, calling out to neighbors to make sure they’re OK,” said Darmawan, 27, a marketing executive whose family had to store drinking water in buckets.

Jakarta, a former Dutch trading port, is one of the world’s megacities most at risk from rising sea levels. That’s because parts of the metropolis of almost 30 million people are sinking by as much as 6 inches a year, more than 10 times faster than the sea is rising.

The Indonesian capital ranks eighth among the 30 biggest cities in the 2015 Climate Change Vulnerability Index compiled by Bath, England-based risk-assessment company Maplecroft. The index is led by Dhaka, Lahore in Pakistan, and Delhi.

$40 Billion

The government’s solution: a $40 billion land-reclamation project unveiled last month. It includes a 32-kilometer (20- mile) sea wall, a chain of artificial islands, a lagoon about the size of Manhattan -- and a giant offshore barrier island in the shape of the national symbol, the mythical bird Garuda.

The first pile for the initial stage of the program -- a barrier to strengthen existing sea defenses along 32 kilometers -- was sunk at the Oct. 9 opening ceremony.

“The whole city is sinking like Atlantis,” said Christophe Girot, principal investigator of the Jakarta Study at the Future Cities Laboratory research group in Singapore. “You see the absolute most miserable and poorest population living right by the river, and they know they’re going to get flooded and may be killed three or four more times a year.”

The central and municipal governments will split the 3.2 trillion rupiah ($263 million) cost for the first 8 kilometers of the wall. Developers would put up the remaining 24 kilometers by 2030 in exchange for the right to build on reclaimed land.

Breached Defenses

Drenched by tropical downpours in the October-to-March rainy season, Jakarta is no stranger to flooding from its rivers, which flow into the coastal plain from the mountains of Bogor to the south. A new urgency arose in 2007 when, for the first time, the sea flowed over the embankments and levees in the north.

Records of a settlement at the mouth of the Ciliwung date to the 4th century. The area rose to prominence when the Dutch East India Company developed the city of Batavia in the early 17th century. As the port expanded, a Flemish military engineer, Simon Stevin, designed a walled city modeled on a traditional Dutch town, including canals to drain the Ciliwung delta into the sea. Today, the metropolis is home to almost 30 million people, making it the second-most-populous urban area in the world, after Tokyo-Yokohama, according to urban-policy research company Demographia in Belleville, Illinois.

Now the Dutch are back to help, with the new master plan drawn up by engineering and consultancy companies Witteveen+Bos and Grontmij.

Below Sea Level

“When a third of the city is under sea level and there’s nowhere else to put people, the only option is to go the Netherlands route,” said Paul Rowland, a Jakarta-based political consultant. “It’s just going to get worse.”

The works can’t come too soon. In October 2013, the sea rose to just 10 centimeters below the top of the defenses, threatening 4 million people, according to Deventer-based Witteveen+Bos. Global sea levels may increase by as much as 82 centimeters this century, according to the United Nations Intergovernmental Panel on Climate Change.

Meanwhile, North Jakarta is sinking by between 7.5 and 17 centimeters a year because of decades of pumping out groundwater to supply homes and businesses.

Coastal cities have been building barriers against the waves since Herod the Great sank barges full of concrete to protect the harbor of Caesarea Maritima in modern Israel before the birth of Jesus Christ. With the rise of sea levels accelerating, ocean defenses have become more popular -- from London’s Thames Barrier, opened in 1982, to Venice’s 5.5 billion-euro ($6.9 billion) MOSE project, scheduled for completion in 2016.

New Business

For local companies such as PT Agung Podomoro Land, Indonesia’s seventh-largest property developer, the Garuda project opens up a whole new area that has traditionally been blighted with run-down colonial structures and shanties, sandwiched between an airport and the nation’s largest port.

Podomoro is marketing a planned 160-hectare (395-acre) man- made island called Pluit City with apartments, a shopping mall, offices, an international school and a “floating” opera house.

“The sea level keeps rising while Jakarta is sinking, so without a wall the flooding will get worse,” said Wibisono, Podomoro’s head of investor relations, who, like some Indonesians, uses one name. “Development is happening across Jakarta, from East, West and South, but in the North it’s constrained by lack of land.”

15 Years

The company is awaiting a license to begin reclaiming the land, he said. The island city would take 10 to 15 years to complete.

The sleek images of the future contrast with the patchwork of slums, docks and walled compounds today. The first piles for the new sea wall are being erected in Muara Baru, near the sprawling Dunia Fantasi amusement park. On the shore, fishermen work on their boats next to a 3-meter sluice gate with pumps that keep the land from submerging.

Nearby, antique cars are parked in the driveway of a mansion in a walled compound and an Azimut motor yacht is tethered to its private dock.

In the narrow streets of Muara Angke to the west, the evening air is filled with the smell of salted fish, laid out to dry in front of crowded concrete houses. These streets have sunk more than 4 meters -- the height of the houses -- since records began in 1975, according to a report for the Jakarta Coastal Defence Strategy study in 2012. They wind down to the sea where Warkin, a fisherman sits in his wooden boat, mending his net before heading out for the night’s catch.

Fishermen’s Worries

He’s worried the project will disrupt fishing grounds and block the boats. “How will small people like us go out to sea if they build a wall?” said Warkin, who made almost a week’s wages in a single day during a flood last year by ferrying fresh fruit and vegetables to the rich neighborhoods. “How will we be able to keep fishing?”

That’s not the only potential problem. Skeptics are concerned about the amount of garbage and silt the city’s rivers would spew into the proposed lagoon, the corruption such a large project would attract and the danger posed by the fact that Indonesia is one of the most earthquake-prone countries in the world.

The city’s acting governor, Basuki “Ahok” Tjahaja Purnama, said the first stage -- strengthening the existing defenses -- will go ahead, while further studies need to be done before proceeding with the plan for the land reclamation and Garuda island. Purnama took over running the city in June from Indonesia’s new President Joko Widodo.

Better Drainage

Darmawan, the marketing executive whose house is near a canal that joins the Ciliwung, is doubtful about the benefit.

“I’m not going to get my hopes up that it will get better, knowing how Jakarta is,” she said. “I’m not that optimistic about the sea wall. I think they should improve the drainage system.”

She said the government brought in dredging equipment after the January floods to remove garbage from the canals, but it hasn’t made much difference.

“The difficulty in widening and improving drainage along the Ciliwung River lies in entrenched practices of pumping ground water and dumping of human and industrial waste,” said Girot, who is also a professor at the Swiss Federal Institute of Technology in Zurich. “Building the wall of course would guard against the rising seas very well, but we should first take care of the river.”

Residents caught between the rising sea and the flooding Ciliwung aren’t holding their breath.

“The giant sea wall is only a project to earn more money for government officials and give more land for real-estate developers,” said Charli Soegono, 38, who lost his red Honda Civic and whose prized Arowana fish swam away when water flooded his house up to the second floor last year. “It was like in that movie Titanic, where the ship is sinking and you have to rush to get all your valuables out of the water.”

(A previous version of this story incorrectly stated the cost of Venice’s MOSE project.)

--With assistance from Neil Chatterjee in Jakarta and Sharon Chen in Singapore.

To contact the reporters on this story: Yudith Ho in Jakarta at yho35@bloomberg.net; Rieka Rahadiana in Jakarta at rrahadiana@bloomberg.net To contact the editors responsible for this story: James Hertling at jhertling@bloomberg.net Adam Majendie

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