Jakarta Will Never be Free of Flooding, Expert Warns

Arientha Primanita

The opening of the East Flood Canal this year is no reason for Jakartans to feel safe from the threat of flooding, as heavy inundations in the past few days have demonstrated.

“Jakarta will never be completely free from floods,” said Sutopo Purwo Nugroho, head of disaster-flood mitigation at the Agency for the Assessment and Application of Technology (BPPT).

Jakarta has been flood-prone since the Dutch colonial era and the risk has grown with the rising population, he said. About 24,000 hectares of flood plains in North Jakarta have now been developed into residential and industrial areas.

Besides being on low-lying land, with some of it below sea level, the city also has 13 rivers running through it. The rivers’ ability to channel water is very low, their flow impeded by settlements along their banks, garbage, and sedimentation, Sutopo said.

Their capacity to channel water ranged from 17.5 percent to 80 percent of what it should be, with the main Ciliwung River being at the lower end, he said.

“That causes the rivers to easily overflow,” he said.

Sutopo said the Rp 4.9 trillion ($592.2 million) East Flood Canal (BKT) had not been fully completed but said even if it had been, it would only be able to reduce flooding in East Jakarta by about 30 percent.

“The BKT’s reliability has not been proved because we are not yet at the peak of the rainy season. There are already floods although the rainfall was only one-third of 2007’s rainfall,” he said, referring to the last time Jakarta suffered major floods.

Sutopo said that officials’ recent claim that the floods subsided faster than before because of the BKT was misleading because the floods were only local and located near the Cipinang River that drained the area.

Slamet Daryoni, chief of urban environmental education at the Indonesian Green Institute, said the government should adopt a more pro-environment policy to control floods. “The green space in Jakarta is very minimal due to the city’s development. There is no flood-prevention program from upstream to downstream,” Slamet said, adding that Jakarta’s green space, at 9.3 percent of the city’s area, was far from the 30 percent required.

Slamet said there should be an integrated flood program involving Jakarta and its surrounding areas. Those areas must be able to hold the water upstream so that the runoff will not be as bad in Jakarta, he said.

Downstream areas should also be better managed, he said, adding that only 200 hectares of mangrove remained in Jakarta, from an original 1,444 hectares.

Pitoyo Subandrio, the head of the Public Works Ministry’s Ciliwung-Cisadane Agency, said that the BKT had not been able to accommodate the runoff from the Ciliwung because there was no connecting channel. The channel was planned for 2014, he said.

Jakarta Governor Fauzi Bowo said he aimed to improve coordination on flood mitigation between Jakarta, West Java and Banten.
“West Java and Tangerang maybe also have funding issues. Therefore, we ask the central government to help rehabilitate the dams and water-catchment areas,” he said.