At least 14 dead, 46 missing after Maitai’an Creek barrier lake overflow, Taiwan
At least 14 people were killed and 46 remain missing after the Maitai’an Creek barrier lake overflowed in Hualien County, Taiwan, on September 23, 2025. The flood, triggered by extreme rainfall from former Typhoon Ragasa, released about 60 million tonnes of water downstream, inundating Guangfu Township and nearby areas.
A barrier lake on Maitai’an Creek in Hualien County, eastern Taiwan, overflowed twice on September 23 after extreme rainfall brought by Super Typhoon Ragasa, releasing huge amounts of water downstream and causing severe flooding.
The National Fire Agency revised the death toll from 17 to 14 on September 25, after duplicate counts were removed, and updated the number of missing from over 100 to 46. More than 30 people were injured.
The lake, formed by earlier landslides, held an estimated 91 million tonnes of water. About 60 million tonnes were released during the surges, overwhelming defenses and sweeping into downstream communities.
Guangfu was one of the worst hit areas by the flooding, with water rising to the second floor of homes in some places.
The lake had overflowed twice that day, with the initial overflow occurring at 14:50 local time on September 23, bringing it down and washing away the embankment.
Officials had expected it would take the floodwater two hours to reach inhabited areas downstream, and only people living near the river would be affected.
The force of the water unleashed by the lake burst could be compared to a tsunami, said Chen Wen Shan, a professor of geology at National Taiwan University.
But within an hour, vast quantities of water were pouring into Guangfu Township, with a population of 12 000. The floodwater swept away multiple vehicles, including military trucks, along Provincial Highway 9. A second, larger surge occurred around 16:30 LT, prompting additional evacuation warnings for nearby areas.
Rescue teams from Taipei, New Taipei, and Taitung County, along with private search-and-rescue units, had been dispatched with boats and water-rescue equipment.
The Guangfu Station and nearby railway lines were also flooded, halting train operations and causing the temporary closure of some bridges and roads in the area.
“The kinetic energy could even be greater than that of a tsunami. The flow speed can exceed 100km/h [62mph] per hour,” said Shan. “Although the energy decreases once it reaches the plains, it still remains powerful and fast – far beyond what a typical river embankment can handle.”
Survivors in Guangfu said they received no warning from the authorities immediately before disaster struck.
But Prof Chen said the academic community had sounded the alarm bell before, as universities were closely monitoring the water level of the barrier lake and worked with authorities on the emergency plans.
The Matai’an Creek barrier lake is about 11 km (7 miles) away from downstream communities from where arounf 10 000 people were evacuated on September 22 due to risk of overflow.
“With the typhoon approaching, we could estimate the rainfall. We knew the water could overflow the lake this time. Part of the dam also collapsed, which caused a large volume of water. But even this volume was within our estimates,” he said.
“Failing to evacuate residents properly is one of the factors why the disaster became so severe.”
But the evacuation was “not mandatory” and local officials only called on the public to go to higher ground, Hualien county councillor Yang Hua-mei told the BBC.
He said he’d just finished lunch at around 15:00 when he heard the lake had burst its banks.
“Within 10 minutes, water spread to the campus from the street. The 400-sq-mile sports ground was submerged,” he said. Chairs, tables, refrigerators, and even cars were soon floating.
“If I’d still been on the street, I wouldn’t have been able to reach higher ground. There were lots of objects floating in the water. I could have been hit or even electrocuted.”
The administrator said officials might have underestimated Ragasa’s impact as the lake had not breached its banks when a weaker typhoon hit last month.
Ragasa battered much of China and Philippines before finally weakening and dissipating after its second landfall in Yangjiang, China on September 24.
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Feature image credit: CNA Focus Taiwan
I am an Assistant Editor and Severe Weather & Science Journalist at The Watchers, specializing in real-time severe weather coverage, geophysical event reporting, and research-driven scientific analysis. You can reach me at rishav(at)watchers(.)news.
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