Also in Tempo English February 4th, 2013.
The flood in Jakarta on January 17, 2013 is a wake-up call. It has two new features: long inundation of the coastal Pluit and gushes that overwhelmed central Thamrin Avenue. The cause for both is infrastructure failure. In Pluit some pumps did not work. Near Thamrin a segment of the canal embankment along Latuharhary Street collapsed. The rain intensity on January 16-17 is only half the peak in 2007. The structural approach has failed. It is time for conservationist alternatives.
One can always say that there should be more infrastructure to channel excess water. This statement is faulty for seeing only one third of the equation: F = Sr – (Q1+Q2); where F is flood, Sr is surface run-off, Q1 is capacity of natural drains and Q2 is capacity of man-made drains. To reduce F we need to reduce Sr and increase (Q1+Q2). Normalizing rivers and building canals only increase (Q1+Q2). This will not solve the problem without reducing or stabilizing Sr, as the (Q1+Q2) will always be overfilled by increasing Sr.