Bali Floods Expose Risks of Overdevelopment and Waste Mismanagement

Standing where her family home once stood, Ruth Deidree Boelan closed her eyes in silent prayer for her missing relatives—victims of the devastating flash floods that tore through Bali earlier this year. The deluge, which claimed at least 18 lives and left four people missing, was described by Indonesia’s Meteorology, Climatology and Geophysics Agency (BMKG) as the worst flooding event in a decade.

While the catastrophe was partly caused by record-breaking rainfall, experts say it also represents a reckoning for years of unchecked development and a waste management system stretched to breaking point.

Once known for its verdant southern landscapes of paddy fields and coconut groves, Bali’s scenery has been rapidly transformed by a tourism boom that has brought both economic growth and environmental strain.

The Nusantara Atlas Project by conservation start-up The TreeMap has visually documented these dramatic shifts by pairing Cold War-era US spy satellite images of Bali with current high-resolution imagery.

“All this land is now turned into roads or buildings. The soil no longer has the same capability to absorb water,” explained David Gaveau, founder of The TreeMap.

Between January and August 2025, Bali welcomed over 4.6 million foreign visitors, surpassing its native population of 4.4 million. According to Made Krisna Dinata, Executive Director of WALHI Bali (Indonesian Forum for the Environment), the influx has fuelled “land conversion, chaotic urban management, and lax enforcement of planning laws.”

Authorities have begun demolishing illegal beachfront structures and cracking down on construction along rivers and hillsides. Yet Krisna warns that the haphazard expansion has already placed “Bali in a very disaster-prone situation.”

For Ruth Boelan, the flood’s devastation was personal and absolute. Her family’s riverside home, built in 2020, was swallowed by raging waters.

“I am still in shock,” she said. “My brother, father, and mother were swept away by the flood—and when it was over, the house and everything inside had vanished.”

Another resident, I Wayan Dibawa (52), described how his dog’s frantic barking woke him amid the torrential downpour:

“I stepped outside and saw water rising around my house in minutes. It was terrifying—so horrific that we were speechless.”

According to government data, record rainfall was logged across several areas, including Badung District, on 9 September, just a day before the floods.

“There has never been such high rainfall,” admitted Bali Governor I Wayan Koster, while conceding that poor infrastructure and illegal construction worsened the disaster’s impact.

Koster announced that the government would:

• Review all construction along four major rivers,
• Enforce zoning laws more strictly, and
• Introduce new regulations to protect rice paddies from urban sprawl.

“If rules are violated, there will be enforcement,” he vowed.

Beyond overdevelopment, Bali faces another mounting threat: waste mismanagement.

A 2019 study found that the island generates 4,200 tonnes of waste daily, but less than half reaches official landfills. The rest often ends up clogging waterways and drains, worsening the flood risk.

“We are all struggling with waste because we lack an effective waste management system,” said I Gede Hendrawan, an associate professor at Udayana University who studies Bali’s waste issues.

The local government plans to construct a waste-to-energy facility, but officials admit it will take time to materialise.

Meanwhile, a planned second airport—intended to spread tourism to Bali’s north—has sparked fresh concerns.

“When today we see overtourism in south Bali, then we will see overtourism in north Bali in the future,” warned Krisna of WALHI Bali.

Scientists caution that climate change is amplifying such disasters. A warmer atmosphere holds more moisture, making record-breaking rains like this year’s increasingly common.

“If we cannot fix the waste and infrastructure problems,” Hendrawan warned, “then in December and January, when the rainy season peaks, an even bigger disaster could occur.”

Bali’s tragedy underscores a painful truth: the island’s natural beauty—once its greatest asset—is now at the mercy of uncontrolled development, failing infrastructure, and environmental neglect.

The flash floods serve as a grim reminder that the island’s pursuit of tourism prosperity must urgently reconcile with environmental preservation, before paradise is permanently washed away.