Does Jakarta Really Have a 5-Year Flood Cycle?

Ronna Nirmala & Lenny Tristia Tambun Jakarta Globe 14 Jan 13;

The claim that Jakarta’s floods follow a five-year cycle has been a persistent one, perpetuated by people ranging from occupants of high public office to bakso sellers plying their trade on the streets of the city.

Major floods in 2002 and 2007 prompted fears that either last year or this one would herald particularly nasty wet seasons, but now an academic at the Netherlands’ Utrecht University has debunked the claim as a myth.

“The probability of flooding occurring each year [in Jakarta] is 20 percent,” post-doctoral student Edwin Husni Sutanudjaja explained. He added that the so-called five-year cycle “is actually a bad interpretation ... of this statistic: flooding does not occur every five years, but every year, with a different quantity.”

Edwin said the city must conduct routine dredging to reduce the sediment of rivers running through Jakarta.

“Dredging needs to be done routinely each year; not just when the sediment is visible [above the water level],” he said.

Jakarta Governor Joko Widodo on Saturday instructed the city’s public works office to conduct dredging along the Kali Muara River in Penjaringan, North Jakarta, to save the local fishing community, which is hit by flooding annually.

Joko said he found many problems associated with the annual floods after visiting the area, and formulated plans to alleviate the problem.

“Starting with the overflow of streets, they should be raised by another 40 centimeters,” Joko said. “The Kali Muara must also be dredged, its sediments reduced so [fishing] boats can dock [in the river].”

Joko also noted problems with the area’s drainage system, which seems to not work during the flood season.

“So there are many problems. These problems are affecting their daily lives and must be solved,” he said. “These are [temporary] solutions, but to overcome the problems [in the long term] there must be a grand design. There must be other efforts.”

Jakarta has been hit with days of heavy rains sweeping across the area. The rain has caused water in some areas to overflow their drainage systems, creating crippling traffic in other parts of the capital.

The Jakarta public works agency also noted that the rain and overflow have damaged roads in more than 6,400 locations covering 2.7 kilometers in length.

The agency’s head of road and bridge maintenance, Maman Suparman, said his team has been collecting data of the severity of the damage the roads sustained including for the so-called “national roads.”

National roads are major streets or highways constructed and maintained by the Ministry of Public Roads.

Maman said that is would be useless to fix the roads during the rainy season.

“If it’s raining the asphalt won’t dry,” he explained. “Or the roads will get holes in them again if vehicles pass over the repaired areas.”

Among those people to previously voice the five-year claim was Coordinating Minister for People’s Welfare Agung Laksono, who in December told the Jakarta government to be vigilant of the cycle and take preventive measures.

“We hope the city can act quickly,” he said. “Bad weather and high-intensity rain is part of a five-year cycle and it is predicted that January or February will be marked by continuous heavy rains.”

Floods paralyze Indonesian capital, heavy rains continue
Fergus Jensen and Rieka Rahadiana PlanetArk 18 Jan 13;

Floods paralyze Indonesian capital, heavy rains continue

Heavy monsoon rain triggered severe flooding in large swathes of the Indonesian capital, Jakarta, on Thursday, bringing the city to a halt with many government offices and businesses forced to close because staff could not get to work.

At least 20,000 people were forced from their homes in the capital and weather officials warned the rain could get worse over the next few days.

"Rain will continue to fall in the greater Jakarta area ... the potential for flooding remains," a spokesman for the Meteorology Climatology Meteorology and Geophysics Agency told Reuters. He said rain was expected to remain heavy in mountains above Jakarta, often the source of floodwater.

Four people were reported to have been killed, according to the National Disaster Prevention Agency, which urged residents to stay at home to reduce traffic congestion on blocked roads.

Torrential rain was reported across much of the country, including the main island of Java and heavily agricultural area of southern Sumatra.

However, officials said there had been no reports of any serious damage to key crops such as rice, sugar and palm oil.

An estimated more than 175 mm (7 inches) of rain fell in one part of west Jakarta between 7 a.m. and midday.

"In 30 years of my life here it has never flooded, ever. This is the very first time," said Ninuk, 30, a resident of central Jakarta.

Floods even forced the country's anti-corruption agency to move some of its most prominent prison inmates, including a former deputy head of the central bank, to a notorious women's prison, Pondok Bambu, in east Jakarta, a spokesman said

The flooding will put pressure on the capital's popular new governor, Joko Widodo, who came to office last October with promises to work to fix a huge array of basic infrastructure problems that bedevil the city of about 10 million people.

"The government has to do something to prevent floods ... If it needs to build stronger dykes, then build them," said Syaiful Bakhri, a taxi driver whose car was stuck in the flood.

In the centre of Jakarta, where streets are jammed at the best of times, long lines of idled cars waited for waist-deep water to recede. An inflatable dinghy provided by emergency services ferried people to safety across water dividing the heart of the city.

The city's main airport was open but many roads leading to it were reportedly blocked. Most commuter trains and buses were suspended.

The Jakarta Stock Exchange did open but trading was light.

Flooding was even reported at the presidential palace, forcing the postponement of a meeting between President Susilo Bambang Yudhoyono and his visiting Argentine counterpart, Cristina Fernandez.

(Additional reporting by Michael Taylor and Janeman Latul; Writing by Jonathan Thatcher; Editing by Robert Birsel)