Weather bureau warns of downpours, floods
Bambang Nurbianto, The Jakarta Post, Jakarta
The Meteorology and Geophysics Agency (BMG) has warned residents about taking measures over the next two weeks to anticipate possible flooding in major parts of the city, as heavy rains are expected to hit in early January.
Meteorologist Endro Santoso revealed on Thursday that rainfall would reach up to 600 millimeters by January, enough to cause serious inundations across the city.
"Unfortunately, we have no predictions as to the exact time of high rainfall next month. Therefore, we must be prepared to face any possibilities at any time," Endro told The Jakarta Post on the sidelines of a seminar on flood anticipation.
BMG has five classifications for cumulative monthly rainfall: very light for rainfall measuring 10 mm to 15 mm; light, 70 mm to 85 mm; medium, 250 mm to 295 mm; heavy, Rp 400 mm to 545 mm; and very heavy for 510 mm to 845 mm.
During the floods of early 2002, which inundated nearly one- third of Jakarta's 660 square kilometers for few days, monthly rainfall averaged 800 mm.
Endro forecast that worse floods would occur in several areas, including Kapuk and Cengkareng Barat in West Jakarta, Kedaung Kali Angke and Kelapa Gading Barat in North Jakarta, as well as Utan Kayu Selatan, Kayumanis, Kampung Melayu, Pisangan Baru and Cipinang Melayu districts in East Jakarta.
"Heavy downpours would not be the only cause of floods ... major parts of the capital have been filled with concrete and therefore cannot absorb the water," he said.
Bambang Warsito, an official at the Ministry of Public Works tasked with monitoring rivers in Greater Jakarta, revealed that the capital's present-day water absorption capacity was 10 percent, compared to 40 percent in the 1970s.
"This means that 90 percent of rainwater flows directly into the rivers, which, in their poor condition, can no longer hold the excess water," he said.
Bambang said the rivers of Greater Jakarta were continually narrowing and silting up due to sedimentation and squatters occupying their riverbanks.
He cited the width of the Cipinang River in East Jakarta, which had narrowed to only six meters from the original 30 m, while the Ciliwung River in Bidara Cina, South Jakarta, was now only 10 m wide from an original width of 165 m.
"The government doesn't have the money to dredge the rivers, not even to remove the garbage that had clogged them," Bambang added.
Project development head at the City Public Works Agency Leo Sianturi acknowledged that the lack of comprehensive measures had reduced the efficacy of the city's flood prevention projects and facilities for 78 flood-prone areas.
"We can only ease the floods, not prevent them," he said.