The Sinking City: Exploring Jakarta’s Vulnerability From Above And Below

Venice typically springs to mind when discussing the topic of sinking cities. However, it is the capital of Indonesia that is now subsiding at increasingly alarming rates. Channel News Asia has reported that “Jakarta is the world’s fastest sinking city,” and has recently recorded rates “as fast as 10 centimetres per year.” Other Asian metropolises such as Vietnam’s Ho Chi Minh City and Thailand’s Bangkok have also experienced surface level subsidence. Cities with more resources, such as Tokyo, have managed to effectively manage and manage this problem.

Subsidence Explained

Whilst sinking is an alarming concept, technically it is known as subsidence – referring to the gradual horizontal shifting of an area of land. It is actually a common feature of many coastal cities. It is commonly due to the shifting of sediments that a city’s infrastructure is built on. Here, it can also be affected by other additional factors such extractive industrial activities or even tectonic plate movement in that geographical area.

Nonetheless, in Jakarta there is a growing consensus that subsidence rates are increasing, because ground water is still being drawn at dramatic levels from beneath the city streets. This water is an essential commodity. Due to a continuously growing population, the demand for this essential commodity is high. Numbers have grown to over 9.6 million residents (which swells to above 11 million with migratory workers during the day). Further pressure is generated by another 30 million total people living in the area around Jakarta. Despite plans to build a giant $40 billion floodwall, named the Jakarta Bay Reclamation project, there has been a lack of policy attention to address the city sinking. Calls to ban ground water extraction have been, thus far, resisted.

Climatic Complications

Jakarta is also vulnerable to rising sea levels and storm surges – which have all increased in annual probability, due to the current global climate trends. The JBA Risk Management corporation cited that this unique set of vulnerabilities is because “Jakarta lies on a deltaic floodplain on the north-west coast of Java, at the mouth of the Ciliwung river on Jakarta Bay.” Carefully identifying and responding to these risks presents a difficult challenge, particularly since it has higher rates of inequality than anywhere else Indonesia.

The Indonesian Meteorology, Climatology and Geophysics Agency (BMKG) cited record-setting floods at the beginning of 2020. These saw levels of precipitation of 377mm in a single day, far higher than the previous record set by devastating floods in 2007. Adam Prana and Fakhridho Susilo for The Jakarta Post critique that ‘in general flood control has been centred around rehabilitating and rebuilding flood control infrastructure, like canals and waterways”, since such a focus is outdated. Specifically, this limits flood management to “the use of hard infrastructure” rather than addressing more complex socio-economic issues.

These physical forms of climatic control are increasingly hard to justify, especially when they do not solve the issue for the long term. Peter Guest, reporting for Wired in, cited that the President Joko Widodo even announced that “a public search for a new capital for Indonesia” has begun due to Jakarta’s “environmental problems.”

One thing is beyond doubt. In this South-East Asian megacity, the race is on to identify and manage this risk, with the effects of climate change raising the stakes. Other urban coastal centres should take heed. Preemptive action must be taken for those on the front line in the fight against global warming.