Hualien barrier lake water levels drop, but evacuations continue: CEOC

Taipei, Sept. 24 (CNA) The Matai'an Creek Barrier Lake in Hualien County overflowed again Wednesday following a massive breach a day earlier, but water levels have since dropped sharply, easing though not removing the threat to downstream communities, officials said.

Aerial surveys by the Ministry of Agriculture showed the lake's volume had fallen by about 75 percent, leaving an estimated 23 million cubic meters of water. Despite the reduction, the Central Emergency Operation Center (CEOC) maintained red-level debris flow alerts for Guangfu and neighboring townships, making continued evacuations necessary.

Tuesday's overflow, triggered by Typhoon Ragasa, unleashed torrents of silt-laden water and debris that devastated Guangfu Township, killing 17 people, injuring 32 and leaving 17 unaccounted for as of 5 p.m. Wednesday, according to the CEOC.

Most of the injured and missing are in Hualien, the CEOC said.

Deputy CEOC commander and Deputy Agriculture Minister Huang Chao-chin (黃昭欽) said the barrier lake, formed by a landslide dam roughly 200 meters high, 2 kilometers long, and 600 meters wide, released about three-quarters of its water and sediment in Tuesday's disaster.

Authorities are continuing to monitor conditions with drones while reinforcing embankments, dredging river channels, and deploying sandbags to limit further risk, Huang added.

With rainfall forecast to ease by Thursday, officials said they expect any additional overflow to be minor compared with Tuesday's surge.

Meanwhile, the Forestry and Nature Conservation Agency said it is revising disaster-warning protocols to reflect the lake's reduced size, dam stability and downstream conditions. Officials stressed that alerts will only be lifted after careful evaluation of water levels and structural risks.