November 24, 2011
Despite ongoing efforts to prepare the city for flooding, Jakarta is ill-equipped to deal with a “hundred-year flood” on the scale of the one that has inundated neighboring capital Bangkok, a leading expert says.
The Jakarta government can learn some lessons from the Bangkok disaster that has killed at least 600 people, said Upmanu Lall, an expert on flood risk and mitigation with the Columbia Water Center in New York. Focusing on early warning systems, minimizing electrical dangers and, most importantly, prioritizing long-term weather forecasting are chief among them, he said.
“From a climate perspective, the potential for flooding is similar in Indonesia and Thailand,” Lall said, speaking a week after significant surface flooding hit Jakarta’s streets.
In a number of ways, however, Jakarta is actually more vulnerable to flooding than Bangkok was, he said.
Both cities have reservoirs designed to hold rainwater in reserve for drought conditions. Usually, they are kept partially full, with the remaining space intended to hold surplus water in the event of flooding.
“If floods come as an individual event, this is what you design for,” Lall said from New York. “The problem in Thailand this year and last year is it kept raining for three straight months.”
It’s a tricky tightrope for authorities to walk. If they release too much water ahead of time and it turns out to be a dry year, then they will have contributed to a drought.
“It’s double jeopardy,” Lall said. “If they were looking ahead, they should have been releasing the water all along. What they really needed was a better capacity for long range forecasts than what they have.”
The lack of green space in the capital and the amount of development and deforestation in the upstream highlands around it have seriously reduced the city’s water catchment capacity, something that residents learned all too well during the floods of 2007, when 54 people died and hundreds of thousands were displaced from their homes.
City officials, responding to criticism over Jakarta’s flood-readiness in recent weeks, have offered reassurances that there are no indications this rainy season will cause flooding on that scale despite the much talked-about five-year flood cycle. The height of the current rainy season, in early 2012, will mark the fifth year since the 2007 floods.
“Even if inundations do take place, we are well prepared,” Arfan Arkili, the head of the regional disaster mitigation office, said last week.
Jakarta Governor Fauzi Bowo said on Wednesday that residents share some responsibility for preventing flooding, highlighting the large amount of domestic waste clogging waterways in Greater Jakarta.
The government, he said, will utilize lands belonging to the Jakarta administration to make way for flood control reservoirs.
Jakarta this year purchased 9,000 square meters of land, which Fauzi said would be dedicated for the construction of reservoirs. “Next year we will add another 8,000 square meters,” he said.
Fauzi said that warning systems intended to signal problems at dams around the city were being expanded and that the rivers were being dredged to boost their capacity to handle flood runoff.
Lall agreed that short-term warning systems and evacuation plans were crucial, but warned that flooding in itself is not the only danger.
“Many electricity transformers are close to the ground,” he said. “The potential for loss of life greatly enhanced if the electricity is interacting with the water, and they could also lose power. So I think this is something they should take care of.”
(read in the JG)
zo 27 nov 2011 - 3:57