Jakarta resident Ardi Yanto remembers that the water levels and land were much higher when he was younger.

His mother Isahwati's corner shop in the Indonesian capital has also sunk several meters below sea level over the past 20 years.

They are not the only ones affected, as Jakarta has become one of the fastest sinking cities in the world.

If left unchecked, parts of the megacity, home to 10 million people, could be entirely submerged by 2050.

This is according to a recent finding by the Bandung Institute of Technology, which showed that the city is already sinking at least 15 centimeters per year. 

Floods are frequent in Jakarta as the city sits on swampy land, with 13 rivers running through it.

But it is sinking faster than any other major city on the planet, due to ongoing extraction of groundwater, leading to land subsidence.

In the past 10 years alone, northern Jakarta has sunk 2.5 meters, double of what experts had predicted. 

"I think they realize what the problem is. But many private developers are still building high-rise buildings using groundwater resources. These developers are still not getting the point," said Peter Letitre, a groundwater expert at Dutch institute Deltares, an independent institute for applied research in the field of water, subsurface, and infrastructure. 

Experts say the only way to prevent the city from sinking is to stop all groundwater extraction, and fully rely on other water sources such as rain or piped water from man-made reservoirs.