Japan will support Indonesia in addressing the pressing issue of subsidence, as Jakarta’s land sinks 18 centimetres annually, triggering widespread flooding.

A master plan to normalise the ground level in Indonesian capital city is under way, said Kunihiro Moriyasu, water resources policy advisor at the Japan International Cooperation Agency (JICA).

According to Moriyasu, excessive consumption of ground water by industries and households is responsible for subsidence in the city. Without prompt measures, by 2100, 10 percent of Jakarta will be submerged.

Rescue work after a subsidence in Indonesia.

Japan experienced a similar phenomenon between 1920 and 1970 when Tokyo’s ground surface dropped by 4 metres due to overuse of ground water, Moriyasu said.

Back then, local authorities constructed dams and opted for alternative water supply sources, such as sewage treatment and rivers, among others. Some industries were relocated to other cities to reduce water demand. Once alternative water supplies met demand, residents and businesses were banned from digging wells or using groundwater.

These measures helped Tokyo restore its original ground level, but the plan may need alterations to be applied in Jakarta, said Moriyasu.

(Source: VNA)