Agency warns of possibility of massive flooding during next rainy season

Bambang Nurbianto, The Jakarta Post, Jakarta

The Meteorological and Geophysics Agency (BMG) has warned of the possibility of huge floods during the next rainy season, which will peak between late December and the middle of January, when the frequency and intensity of rainfall will be significantly high.

Chief of BMG's weather forecasting division Achmad Zakir told The Jakarta Post on Thursday the next floods would not be as severe as those in January and February this year, but rainfall would be heavier than normal.

He said that the cumulative rainfall in January and February this year was around 600 millimeters (mm), while the equivalent for the peak of the next rainy season would be around 500 mm. The cumulative rainfall at the peak of the rainy season in Jakarta was normally about 400 mm.

According to Zakir, during the peak of the next rainy season the frequency of rain could reach five consecutive days, which could cause serious flooding in several locations in the city.

"It is possible that incessant rain over five consecutive days, with downpours of around 100 mm, could occur in early January. If that happens, flooding will be significant in several parts of the city," Zakir told the Post on Thursday.

The city administration has acknowledged that no significant action to alleviate flooding has been taken in the city this year.

Head of the Public Works Agency IGKG Suena said that if rainfall was normal in the next rainy season, 73 areas in the city would be liable to flooding. If it were higher, then the number of such areas would increase. Unfortunately, the agency had only about Rp 224 billion available for tackling flooding in just five areas.

Zakir said that the possibility of heavy rainfall was the result of a prolonged dry reason, as the rainy season would start early in December instead of in September as usual.

According to Zakir, November would not experience much rain as it would still be in the transitional period from the dry to the rainy season.

"As the rainy season is shorter than usual, namely only two months -- December and January -- the amount and frequency of rainfall will be higher than usual," said Zakir.

He added that the city administration should begin to make contingency plans for people resident in areas liable to serious flooding.

The floods in January and February, which inundated 168 subdistricts in the city, resulted in 30 fatalities, 300,000 people being evacuated from their homes and financial losses estimated at about Rp 10 trillion.

He also warned of the increased possibility of landslides in Jakarta and other areas such as the Puncak in Bogor, West Java, during the next rainy season. He added that during the dry season from May to October, soil molecules expanded, making the land less stable.

"Landslides are no less dangerous than floods as they can also kill many people," said Zakir.