JAKARTA IS SINKING

 

With more than 10 million inhabitants the Indonesian megacity is facing the effects of land subsidence and sea level rise . A lethal combo that along with the Indonesian climate facilitates floods .

"The potential for Jakarta to be submerged isn't a laughing matter," says Heri Andreas, who has studied Jakarta's land subsidence for the past 20 years at the Bandung Institute of Technology.

"If we look at our models, by 2050 about 95% of North Jakarta will be submerged."

North Jakarta has sunk 2.5m in 10 years and is continuing to sink by as much as 25cm a year in some parts, which is more than double the global average for coastal megacities.

 

This is the Waladuna mosque, last time people prayed here was in 2001 , when it was above the ground

One of the biggest floods occurred in 2007 when 70% of Jakarta's total area was submerged with water up to 4 meters deep in some parts of the city . 80 people were killed and at least 190.000 have fallen ill . Damages amounted to at least 5,2 trillion rupiah (572M dollars ).

Now let me explain the reason behind land subsidence .

Jakarta sits on a swampy plain, on low coastal land . It has 13 rivers that run through it . But the reason the city is sinking is actually that most people here don't have enough water .

Most Jakarta's inhabitants lack access to clean , piped water .Thus they get their water by digging wells . The pumps go deep into the ground to extract the water stored in aquifers , underground layers of rock that hold groundwater . The porous spaces of the rock are filled with it so you have to think of the rock as a soaked sponge , the more water is extracted the more it deflates , causing the soil to compact and collapse and the ground above it to sink . Pumps alone shouldn't be able to do this . While some layers of earth will never recover their water , aquifers are usually refilled naturally when it rains . But in Jakarta it's becoming increasingly rare . For decades the city has been developing at a fast pace , and it's now covered in concrete . So the rainfall that would usually fill up the aquifers isn't being absorbed .The use of groundwater is so common because Jakarta's water infrastructure still doesn't serve the majority of the city. In 1959 only 12 % of people had access to pipe water and to date we are around 40% ( that is like 4 million people out of 10 millions ). So these six million people without access to piped water have no other choice but to keep pumping groundwater to survive and the city continues to sink .

 

The people in the fishing community of Muara Baru have built makeshift floating-bridges to move through their neighborhoods

The situation has gotten so bad that the Indonesian government has talked about moving the capital , from Jakarta , to the neighboring island of Borneo , but that won't help the millions of people living in Jakarta .

So to save the city in 2014 the government announced a project , in collaboration with Dutch architecture firm , to build and reinforce 120 km of seawalls to stop the water from flooding the lands as it sinks , but so far only 10 kilometers have been reinforced . But the problem is that just like the rest of Jakarta , the seawall is sinking .Besides the reinforcement , the project includes an ambitious 40 billion dollars plan to build a 38 km wall , shaped like a massive bird to protect the coast from flooding however the project could take up to 30 years to complete and by then Jakarta could have lost most of its coastal land . 

So the truth of the matter is that Jakarta will continue to sink until the groundwater stops being pumped and groundwater will continue to be pumped until the government provides an alternative .

Giordano C., 4sc