T

he heavy rains that poured down throughout the capital several times during this year’s rainy season may have inundated several areas suffering from land subsidence and bad drainage systems, but data from the Meteorology, Climatology and Geophysics Agency (BMKG) show that precipitation would not be as bad as experienced before.

The data show that rainfall in Greater Jakarta during the peak of the rainy season that runs from February to March would measure around 300 milimeters per month, far lower than the 500 mm precipitation recorded in 2017, when nearly 3,400 houses along the banks of the Ciliwung River along with Cawang and Cililitan in East Jakarta were swamped by floods triggered by downpours in Bogor, West Java. Five people were killed during the floods that year.

The BMKG categorizes 0 to 100 mm per month as low rainfall intensity, 101 to 300 mm as medium and anything above 400 mm as very high.

However, BMKG spokesperson Harry Tirto said he would not conclude that floods were out of the picture this year as the rainy season would run until March.

“Heavy rain followed by flooding can still happen,” Harry told The Jakarta Post on Sunday.

Jakartans have regularly suffered from major flooding when floodwaters reached the center of the capital, even inundating the Hotel Indonesia traffic circle.

In 2007, when rainfall intensity was almost 700 mm in February alone, floods inundated about 60 percent of the city. At least 80 people died in the floods, while 320,000 people were displaced and Rp 4.3 trillion (US$344 million) in losses were recorded because of the damage to property and infrastructure.

In 2013, 20 people died in floods and 15,000 people were displaced. Transportation, power and other essential services were disrupted.

In 2014, over 89,000 people were displaced while 23 were killed during the floods, which hit around 100 subdistricts. At that time, over 1,000 mm precipitation was recorded in January and over 600 mm in February.

During Saturday night’s downpour, the disaster mitigation agency recorded that up to six subdistricts and 19 thoroughfares in all municipalities except Central Jakarta were inundated with rainwater ranging from 20 to 70 centimeters in depth. The rainwater subsided by 2 a.m. on Sunday.

No casualties or displacement have been reported by far.

The heavy rainfall also alarmed residents of coastal areas in fear of floods caused by rainfall or tidal floods, with the Pasar Ikan sluicegate on alert level siaga 2 from 5 to 10 a.m. Sunday with up to 225 cm in depth.

Aside from possible floods, the rainy season also brings the threat of a dengue fever outbreak.

As of early this month, the city has recorded almost 900 dengue fever cases. However, the administration has yet to declare the outbreak an extraordinary occurrence.

To curb the spread of dengue, which is carried by Aedes aegypti mosquitoes, the administration has carried out several measures such as deploying thousands of jumantik (volunteers) to carry out on-site monitoring, as well as spraying insecticide, commonly known as fogging, to kill mosquitoes.

The administration also joined hands with the BMKG to create a website named DBDklim that aims at raising awareness about dengue fever and serve as an early warning system for potential outbreaks. It can be accessed at dbdklim.bmkg.go.id.

The website shows forecasts of potential increases in dengue fever cases in the city’s five municipalities based on rainfall and humidity in each area, as well as data received from the health agency.

In addition to the efforts by the administration, residents in Marunda subdistrict chose a more organic method of preventing the spread of dengue fever. The residents planted 2,000 lavender plants and placed chopped lemongrass in different corners of their homes to get rid of mosquito.

Marunda subdistrict head Hilda Damayanti said the residents deliberately took home preventive measures in January to avoid fogging as insecticide spraying was usually conducted only after a dengue case had been confirmed in an area.