Denpasar, Bali. The Bali provincial government is using the devastating floods and landslides in September as a lesson to prepare for the upcoming rainy season.

“Last September’s flooding should serve as a learning moment for disaster readiness. At that time, rainfall reached unprecedented levels even before the official start of the rainy season, so a similar event could happen again,” said Bali’s Regional Secretary, Dewa Made Indra, on Tuesday.

The September disasters killed 17 people. Environment Minister Hanif Faisol Nurofiq attributed the tragedy to poor waste management and unregulated construction of hotels, villas, cottages, and housing on former rice fields and hillsides. Rapid conversion of green space, he said, has weakened Bali’s resilience to extreme rainfall.

Government data shows Bali has lost roughly 400 hectares of forest to commercial and residential development since 2015. In response to the deadly floods, Governor I Wayan Koster announced a halt on permits for converting productive farmland into commercial zones, though the legal framework to enforce this is still under development.

On Tuesday, the provincial government conducted a hydrometeorological disaster drill in Denpasar. The exercise aimed to ensure cross-agency coordination, with Dewa Made Indra personally inspecting the readiness of personnel and equipment.

“The goal is that, in a large-scale disaster like the September floods, all elements are prepared and can respond quickly to protect the public,” Dewa Made Indra said. “I have reviewed personnel strength, operational vehicles, and logistics, and everything is in good condition.”

The heightened preparations follow the deadly floods and landslides in Sumatra in late November, triggered by Cyclone Senyar and reportedly worsened by deforestation. The disasters claimed at least 604 lives, left 464 people missing, and displaced more than 570,000, according to the National Disaster Mitigation Agency (BNPB).

Bali Disaster Management Agency (BPBD) Chief I Gede Agung Teja Bhusana Yadnya added that the agency has mapped areas prone to hydrometeorological hazards. He said landslides could even occur in Denpasar, despite the city lacking steep cliffs. He urged residents to familiarize themselves with the disaster risks in their areas, including landslides, flooding, and falling trees.

Authorities are also preparing for the upcoming Christmas and New Year holidays, when population movement and tourist traffic increase significantly. BPBD officials are prioritizing disaster preparedness along tourist routes, transport corridors, and hilly or sloped areas.

Bali’s BPBD has identified 14 types of potential disasters in the province, nine of which are considered high risk. The rainy season is projected to continue until April 2026, peaking in February. However, officials caution that extreme rainfall events, like those in September that saw daily totals of 380–390 mm, remain unpredictable.

“Extreme rainfall, over 150 mm per day, cannot be predicted precisely. In September, we had three days with 380–390 mm of rain, which triggered major flooding,” Gede Teja said.