Jakarta sinks as citizens tap groundwater

JAKARTA, Oct 7 (Reuters) - It's one of the fastest-growing megacities in Asia. But some doomsters predict large parts of Indonesia's coastal capital could be under water by 2025.

The reason? Unchecked groundwater mining.

"Goundwater extraction is unparalleled for a city of this size," Almud Weitz, regional team leader of the World Bank's water and sanitation programme, said in an interview for Reuters Environment Summit.

"It's like Swiss cheese. People are digging deeper and deeper and so the city is slowly, slowly sinking. That is why tidal floods are occurring in poor areas on the coast."

Jakarta is one of Asia's more densely populated cities, but experts say it has one of the least developed piped water networks, pushing many residents as well as mushrooming megamalls and skyscrapers to increasingly suck out groundwater.

According to some estimates, Jakarta has a water deficit of about 36 million cubic metres (1.28 billion cubic feet) a year and much of the groundwater is contaminated with faecal matter because of leaky septic tanks.

As the city of around 10 million sinks and sea levels rise because of climate change, Jakarta has become more vulnerable to flooding and the threat of severe tidal surges remains grave.

In recent years, Jakarta, a city criss-crossed by 13 rivers and many canals built by its former Dutch rulers, has been devastated by massive flooding triggered by tropical rains and the incursion of sea water.

A study by a Dutch consultant for the World Bank showed that by 2025, the city could be between 40 and 60 centimetres lower than it is now, if nothing is done to check the crisis.

"An ever-growing population, densely populated residential areas, rapid infrastructural development, a diminishing number of green areas and catchments, plus six months of near-constant rain --- you have a recipe for flood disasters which literally paralyse the city," the World Bank said in a statement when the study was released in April.

The Bank is supporting a flood management initiative with the local government.

Swathes of the teeming city were swamped and Jakarta's main airport was shut for hours earlier this year following heavy flooding caused by the combination of unusually high tides and the effects of subsidence from excessive extraction of groundwater.

More from Reuters...