Hualien: A deadly natural disaster struck eastern Taiwan as a barrier lake in Hualien County burst its banks on September 23, unleashing a massive flood that has claimed at least 15 lives and left 124 people missing. The catastrophic event was triggered by Super Typhoon Ragasa, one of the most powerful storms to hit the region this year, which brought relentless rainfall and widespread instability to the mountainous terrain.
The barrier lake, located above the town of Guangfu along a tributary of Matai'an Creek, was formed when previous landslides, exacerbated by heavy rains and seismic activity, blocked a valley and trapped millions of cubic meters of water behind a natural dam. Satellite monitoring in July 2025 revealed the lake’s dimensions to be nearly 120 meters in height, containing approximately 91 million tonnes of water. When the natural dam gave way, an estimated 60 million tonnes of water surged downstream, wiping out homes, infrastructure, and sweeping away roads and bridges in its path.
Authorities faced significant challenges in attempting to mitigate the threat posed by the barrier lake. The remote and unstable location, combined with the aftereffects of a 7.2 magnitude earthquake the strongest Taiwan has experienced in 25 years hampered rescue operations and preemptive interventions. Despite early warnings, the scale and suddenness of the overflow overwhelmed local disaster management teams, leaving residents with little time to evacuate safely.
The town of Guangfu bore the brunt of the flooding. Approximately 60 percent of the town’s 5,200 residents were forced to flee to higher ground, while others were trapped or swept away by the torrent. The floodwaters left behind thick layers of mud and debris, severely complicating ongoing rescue and relief efforts. Emergency teams continue to search for missing residents, with the government mobilizing additional personnel and resources to assist in recovery operations.
In response to the disaster, Taiwan’s Premier Cho Jung-tai announced a full inquiry into the evacuation failures and preparedness lapses. Public outcry has intensified, with residents criticizing the lack of timely warnings and insufficient preventive measures. Experts emphasize that the incident underscores the vulnerability of mountainous and remote regions to sudden natural hazards, particularly in the context of increasingly volatile weather patterns linked to climate change.
The barrier lake burst serves as a grim reminder of nature’s unpredictable power. As Taiwan works to recover from Super Typhoon Ragasa, officials and communities are urged to reassess disaster preparedness strategies, implement stronger early warning systems, and ensure that vulnerable areas receive adequate attention before tragedy strikes again.