Seven bridges could collapse, city to handle only two
Irawaty Wardany. The Jakarta Post, Jakarta â€“ 10/02/2011
The city administration said that it would only reinforce two bridges out of seven in North Jakarta where their structure had been compromised by land subsidence.
Bridge Division at the Public Works Agency head Novizal said that the city would only pay for the reinforcement of two bridges in North Pluit and Muara Angke, which were already in critical condition.
The city has earmarked Rp 19 billion (US$2.1 million) for the reconstruction project.
A researcher from the Bandung Institute of Technology, Heri Andreas had warned the city administration that due to land subsidence, at least seven bridges in Kamal Muara, Pluit, Pantai Mutiara and Ancol in North Jakarta, Mangga Dua and Mangga Besar in West Jakarta and Gunung Sahari Bridge in Central Jakarta had their structures compromised. Novizal insisted that land subsidence only affected the two bridges.
“We expect to raise the two bridges up by 2 meters,” Novizal told reporters.
The project on the Muara Angke bridge had in fact started in early 2010. For the North Pluit Bridge, the city government would auction the project later this year.
The North Pluit Bridge project is estimated to cost Rp 15 billion while the Muara Angke is to cost Rp 4 billion.
Jakarta is located on a low-lying coastal area with 13 rivers running through it. Chances of inundation increases from the fact that 40 percent of Jakarta’s land is below sea level.
A study conducted by the Bandung Institute of Technology discovered that the sea level in Jakarta Bay area had been rising at a rate of 5.7 millimeters per year.
The ITB also found that land subsidence in Jakarta had accelerated at an alarming rate over the past four decades.
The north coastal region of Jakarta will sink by 60 centimeters in 2020 the study says.
If no action is taken to mitigate land subsidence, flooding and high tides are to contribute to 5,100 hectares of land in North Jakarta submerging by 2020 and another 6,000 hectares in 2050.
A worst-case scenario, however, put the figures at 16,200 hectares in 2020 and 18,100 hectares in 2050.Anticipating a worsening rate of land subsidence and rising sea levels, the Jakarta administration is considering a plan to construct a giant seawall surrounding the city’s northern coast.
Jakarta Governor Fauzi Bowo has said that a feasibility study on the project was started in December and will be completed in two or three years.
“In 2025, we are expecting to have a giant seawall protecting the capital from flooding,” Fauzi said.
Jakarta has already partnered with the city of Rotterdam in the construction of the seawall. Rotterdam is expected to send expertise on the construction project.