Rescue workers from the Trenggalek Disaster Mitigation Agency evacuate a senior citizen suffering from a shortage of breath using a rubber dinghy amid flooding in Kelutan subdistrict, Trenggalek district, Trenggalek regency, East Java, on Dec 16, 2024. The flooding has cut access to Trenggalek city centre. — Photo The Jakarta Post/ANN

JAKARTA — Floods and landslides triggered by extreme weather have struck various regions across the archipelago in the past week, as millions of people prepare to hit the road and flock to popular tourist destinations for the Christmas and New Year holidays.

At least 12,000 people living near the northern coastline of Jakarta were affected by tidal floods, locally known as rob, since last Friday, with floodwaters reaching a depth of up to 1 metre in several areas.

The tidal floods hit residents in Pademangan, Penjaringan, Cilincing and Tanjung Priok, all in the North Jakarta municipality.

Hundreds of houses around the Muara Angke harbor in Penjaringan have been experiencing coastal flooding every morning for over a week.

An overflow of seawater between 25 and 100 centimetres deep has inundated the area for several hours every day, disrupting traffic and Commuter Line services.

The North Jakarta administration has deployed dozens of personnel and several water pumps to alleviate the flooding. The Meteorology, Climatology and Geophysics Agency (BMKG) has also carried out weather modification efforts to reduce rain intensity by between 13 and 67 per cent.

Acting Jakarta governor Teguh Setyabudi said that the coastal flooding in the northern part of the city was caused by multiple factors, including extreme weather, rising sea levels amplified by the new moon phase and land subsidence.

“According to the BMKG estimate, tidal flooding is likely to continue to hit North Jakarta until Friday,” Teguh said on Thursday, adding that regions that were affected by the recent tidal flooding were those that have yet to be protected by a new sea dike.

The Jakarta administration and the central government have been constructing around 22 kilometres of sea dike in North Jakarta in the past few years to prevent coastal flooding. However, Teguh said authorities still needed to build around 16km of additional sea dike to protect all residents of the coastal area from high tides.

Tidal flooding has also hit thousands of homes in Karawang regency, West Java, since last week, with floodwaters reaching a depth of around 20-40cm.

At least 5,400 families in nine districts are affected, including in Tirtajaya, Cibuaya, Cipedes, Cilebar, Tempuran, Pakis Jaya and Batujaya districts.

According to the Karawang Disaster Mitigation Agency (BPBD), the tidal floods inundated two schools, three mosques and around 1,000ha of coastal fishponds in the regency.

The flooding has also caused residents in the area, who mostly work as fishermen or manage coastal fish farms, to lose their source of income.

Hydrometeorological disasters

Meanwhile, torrential rain triggered a flash flood that impacted several villages in the Tano Tombangan Angkola and Batang Angkola districts of South Tapanuli regency, North Sumatra, on Wednesday.

Floodwater carrying large logs, sand, mud and stones from the Aek Mardua River struck hundreds of houses in the regency at around 2pm, injuring 10 people and forcing 350 others to leave their homes.

The flood left 50cm of thick mud in several areas and shut down power to the affected districts.

At least four houses were swept away by the flashflood. The disaster also damaged a church, two mosques and some 200 residential dwellings.

A day prior, heavy rainfall caused flooding and landslides in Temanggung regency, Central Java, killing one person and injuring another.

The BMKG has warned that the majority of regions of the country are entering the rainy season and forecast a 20 per cent increase in rainfall intensity due to a weak La Niña, which typically brings a wetter rainy season with heavier rainfall to the country.

The rainy season was expected to peak in late December for most parts of Sumatra and southern Java, while the peak would likely arrive in January to areas of central and northern Java. — THE JAKARTA POST/ANN