Sinking cities: Over-extraction of ground water


Mushfiqur Rahman   | Published: August 28, 2019 20:38:10


Indonesia President Joko Widodo delivers a speech in parliament in Jakarta on Friday: He formally proposed to parliament on Friday a plan to relocate Indonesia's capital from Jakarta to Kalimantan on the island of Borneo            —Photo:  Reuters  

Indonesian President Jokowi Widodo announced his plan on August 26, 2019 to relocate the country's capital city from Jakarta, home to more than 10 million residents, to a new location in East Kalimantan. Indonesian parliament has to pass a law to confirm the President's plan and to give legal basis for shifting the country's capital.

If approved by parliament, the administrative capital will be shifted from Jakarta to the new location between KutaiKartanegara regency and Penajam Paser Utara regency in East Kalimantan. The present capital Jakarta is located on Java island, home to approximately 54 per cent (150 million) population of the Indonesian archipelago of 17,000 islands.  Kalimantan is nearly four times bigger than Java island and has a population density 38 times lower than that of Java despite having a few major cities there. Kalimantan is in the Borneo Island shared by eastern Malaysia and Brunei and famous for its minerals and mining industries, large rainforests accommodating the Orangutan's natural habitat. Indonesian government intends to build a smart, green city and 'not to disturb any existing protected forests'.

After the relocation, Jakarta will continue to be the commercial capital of south-east Asia's largest economy. Several governments of Indonesia suggested for such a shifting of capital in the past. However, president Jokowi Widodo finally took concrete action plans to move the capital to a new city to be built in Kalimantan, approximately 1000 km away from the present capital. As per the statement of Indonesian President, the government has conducted in-depth studies during last three years for shifting the capital from Jakarta and the planning started immediately with the objectives to commence construction works for the new capital city next year so that the relocation of government offices can happen in 2024.

It looks like that the Indonesian leader has been inspired by its South-East Asian neighbours Malaysia (who shifted its administrative capital from Kualalumpur to Putrajaya) and Myanmar (shifted its capital from Rangoon to Naypyidaw. Indonesian senior officials wanted to assess the experience of shifting capitals from others including from Malaysia, Australia, Brazil while planning and developing the new capital city. As reported by The Jakarta Post on August 26, 2019, President Widodo considered that the new capital would be a symbol of the nation's identity, development and  it was needed 'for the sake of realising an equitable and just economy.'

Apart from the concerns for equitable development, Indonesia has a major concern for the flood-prone capital Jakarta as it remains the fastest sinking cities of the world. Researchers have concerns that part of Jakarta may be submerged by 2050. As reported, Jakarta has been sinking by about 25 centimeters every year. Experts fear that 95 per cent of the northern part of Jakarta will be submerged under water which already suffered nearly 2.5 meters subsidence in last 10 years. Thirteen rivers flow through Jakarta and almost half of the city now sits below the sea level. North Jakarta houses one of the busiest sea ports of Indonesia, Tanjung Priok, on the river Ciliwung that flows into the Java bay.

The rapid sinking rate of Jakarta has been linked partially to the excessive ground water extraction for its use as drinking water, bathing, industrial uses and other everyday purposes of the city dwellers. Also, climate experts consider that Jakarta faces growing challenges of sea level rise supplemented by ground sinking due to excessive ground water extraction and land subsidence.

Jakarta is not the only city that is sinking fast. Bangladesh capital Dhaka, Italian city of Venice, Thai capital Bangkok, Dutch city Rotterdam, Egyptian city Alexandria, US cities Miami, New Orleans, Huston or part of them are sinking. Research reports confirm that Dhaka is sinking nearly 14 millimeters (half an inch) a year on average because of excessive ground water extraction and inadequate recharging. Some parts of Dhaka experience faster rate of ground subsidence. Dhaka dwellers' life and economic activities have been so far dependent mainly on ground water as 75 per cent water supply comes from the deep tube wells. Experts have been reporting that the surface water sources in and around Dhaka have been severely polluted. Therefore, more and more reliance on ground water is inevitable.

To tackle the problem of ground subsidence, underground water pumping has to be significantly reduced. At the same time recharging of ground water needs to be accelerated. There are good examples of ground water recharging and limiting withdrawal rates of the same in Shanghai and Tokyo cities. But to attain that, surface water sources should be preserved to maintain them as reasonably clean sources of water. The way open water bodies and rivers in and around Dhaka city have been polluted, surface water has been losing its economic treatment capacity. It is not the problem of land subsidence only, clean water scarcity can make a mega city like Dhaka unlivable.

Mushfiqur Rahman is a mining engineer and writes on energy and environment issues.

mushfiq41@yahoo.com

 

 

 

 

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