Will Giant Sea Wall plan sink or swim in Jakarta?

Will Giant Sea Wall plan sink or swim in Jakarta?

Reuters

Indonesia’s bustling capital, Jakarta, is sinking faster than any city in the world. An ambitious plan, however, to build a giant wall to keep out the encroaching sea has come under fire from fishermen who fear for their catches and homes and from water experts who say it doesn’t do enough to tackle the sinking land, also known as subsidence.

The city’s northern areas have sunk 4 meters in the past 40 years, Japanese experts say, while some “hot spots” are said to be dropping as much as 20 centimeters a year.

The 10 million residents of the low-lying coastal city, built on a swampy plain, are exposed to tidal and seasonal flooding. In 2013, parts were submerged under nearly
2 meters of water after a heavy monsoon storm.

Jakarta’s vulnerability to floods, already exacerbated by population growth, urbanization and changing land use, rises with every centimeter the ground falls.

Experts and residents agree that overextraction of groundwater for drinking and commercial use is largely responsible for the land subsidence. What they don’t agree on is how to tackle it. An iconic infrastructure project that is supposed to ease Jakarta’s flooding woes is mired in uncertainty.

The Dutch, regarded as the foremost authorities on the concept of “living with water,” are lending their expertise via the flood prevention plan involving a giant sea wall that will close off Jakarta Bay, which could cost up to U.S. $40 billion.

Critics, however, say the National Capital Integrated Coastal Development (NCICD) program does not address land subsidence, the underlying reason for flooding.

At the same time, “the government is throwing away access to the sea” for tens of thousands of people in the bay who rely on fishing and fish processing, said Ahmad Marthin Hadiwinata of the Indonesia Traditional Fisherfolk Union.

He worries that residents will be evicted from their homes to make way for the new infrastructure.

Unveiled in 2014 and better known as the “great garuda” or “giant sea wall,” the project involves raising and strengthening the existing onshore embankment of Jakarta Bay, as well as constructing a 24-kilometer outer sea wall and developing real estate on artificial islands reclaimed from the ocean.

Seen from the air, the mega construction project was initially shaped like a garuda, the bird-god of Hindu mythology that is Indonesia’s national symbol.

The design was changed in response to opposition and a government request to incorporate another project led by private developers to build 17 artificial islands, said Victor Coenen, Indonesia representative for Witteveen+Bos, a Dutch engineering consultancy leading the NCICD consortium.

Its partners, which also include South Korea, are now awaiting the government’s decision on the final plan, he added.

A June 2017 document outlining an updated NCICD master plan confirmed the new design and emphasized the importance of stopping land subsidence, as well as addressing water and sanitation issues.

Many, including Hadiwinata, hope Anies Baswedan, who won a hard-fought election for the post of Jakarta governor in April 2017, will stop or modify the project when he takes office in October 2017. Officials suspended work for several months in 2016 amid regulatory and environmental concerns.

Coenen said stopping land subsidence is important but could take 15 to 20 years, meaning Jakarta should work on flood prevention at the same time. The future of the crowded city’s flood protection lies offshore because it has no space for flood basins, he added.

“It’s only a question of how far offshore you go, how big you want to build, and how long you want it to last, because the smaller the scheme, the shorter the lifetime will be,” he said.

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