Giant sea wall, islet project off Jakarta coast could cause more harm than good

Giant sea wall, islet project off Jakarta coast could cause more harm than good

INDONESIA - Experts have expressed their concern over the building of 17 artificial islets and a giant sea wall off the northern coast of Jakarta, arguing that the reclamation project would not address the real problem of the city sinking.

Elisa Sutanudjaja, an analyst with city planning watchdog the Rujak Center, said over the weekend that the islets and the giant sea wall - part of the Coastal Defence Strategy to prevent seawater inundating the capital city - would not be effective.

"Subsidence is a natural process but the rate at which it is happening here in Jakarta and other big cities in Indonesia is rapid," she said, adding that it was due to the over-exploitation of groundwater.

Therefore, Elisa said, the central government and city administration's plan, which would "solve" the issue with a giant sea wall, would only "exacerbate the problem".

Elisa said the islets might even trigger new problems as they could alter the sea's current, which would cause abrasion along other coasts.

"I am also worried that the islets would only cater to the interests of businesses and affluent communities," she said, adding that she was afraid that the promise to provide public access to the islets was mere lip service.

It is reported that the city is sinking by 7 centimeters (cm) every year and that seawater intrusion into freshwater has currently reached Lapangan Banteng square in Central Jakarta and Blok M in South Jakarta.

Analysts predict Jakarta may face a groundwater scarcity in 10 to 15 years should the administration overlook the uncontrolled use of groundwater for household and industrial purposes.

Governor Joko "Jokowi" Widodo previously announced that he wanted the project, initially scheduled to kick off in 2020, to start next year.

The project may cost Rp 280 trillion (S$30.8 billion).

The islets would be built by city-owned companies and private entities and include housing, entertainment and open green spaces.

The Indonesian Traditional Fishermen's Association (KNTI) supervisory board chairman, M. Riza Damanik, warned of issues that would occur if the current was disrupted.

"The islets will change the pattern of the current and wave," he said, adding that it would also affect the sediment.

He said if the sedimentation was not in balance, the constructing of the islets would result in siltation.

Riza said although the permits had been signed off, the governor should revoke the plan as it went against laws on environmental sustainability.

According to him, land reclamation should not be for land expansion.

"I am afraid that many parties have misused the environmental crisis in Jakarta Bay to support the construction of property," he said.

Riza said if the islet project was really aimed at reclaiming the highly-polluted coast, the city should simply turn the area into open green space, which would be "cheaper than building islets".

Trisaksi University urban analyst Nirwono Yoga said instead of building the islets, it would be better for the city to focus on greening the mainland and revitalizing drainage and rivers.

"We have 13 rivers and 40 dams and water reservoirs that need to be restored immediately," he said, adding that these projects would be cheaper than building the giant sea wall and the islets.

Nirwono said the project would also be useless if the cause of the problems were not solved such as residents throwing garbage to the rivers without a second thought.

For the next few years, the city administration plans to dredge and revitalize 12 lakes, 160 connecting waterways and 18 sub-macro waterways; construct 1,958 percolation pits in flood-prone areas; and repair 73 pump houses to prevent floods.

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