PRE-EMPTIVE MEASURE
About 200 people from seven villages have been evacuated and bridges to the areas have been closed as a precaution, FANCA said
The Forestry and Nature Conservation Agency’s (FANCA) Hualien Branch yesterday announced that seven communities within the outwash area of a newly formed barrier lake upstream in the Wanli River (萬里溪) have been pre-emptively evacuated as the lake filled toward overflowing.
A yellow alert for the area was initially lifted on Friday afternoon, but as rainfall continued, the FANCA reimposed a yellow alert in the area at 7:25am yesterday, saying that the barrier lake could overflow within 48 hours.
The agency upgraded the alert at noon yesterday, warning of the possibility that the barrier lake could overflow within 24 hours instead.
Photo: Hua Meng-ching, Taipei Times
Authorities evacuated about 200 residents from about 70 households in seven villages across the county’s Wanrong (萬榮) and Fenglin (鳳林) townships, FANCA said.
Those who have been evacuated are temporarily quartered in public buildings, such as schools, hospitals and locations with assembly halls or amphitheaters, it said.
Three bridges to the areas have been closed as a precaution, it added.
The alerts were issued as estimated rainfall could reach 58mm within the next 24 to 48 hours, based on the weather forecast from the Central Weather Administration and the local measurements taken from the barrier lake, it said.
Pre-emptive evacuations were necessary, because the forecast showed no sign that the rain might let up in the area, it said.
Reconnaissance flights of the barrier lake could not be launched at the moment due to heavy cloud conditions, but the lake is estimated to be between 40 and 60 percent capacity, the agency added.
FANCA urged emergency response departments to continue monitoring the barrier lake, and remain alert and safeguard the well-being of their communities.
The Wanli River barrier lake is roughly 7km north of where a barrier lake on the Mataian River (馬太鞍溪) burst in September last year. The breach killed 19 people and flooded more than 1,600 homes in Guangfu Township (光復), which is south of Wanrong Township.
Minister Without Portfolio Chi Lien-cheng (季連成) on Tuesday said the barrier lake is about 20km upstream from Wanrong Township, at an elevation of about 1km.
Its estimated capacity is 6 million cubic meters of water, and an overflow could erode the natural dam and trigger a breach, Chi said, adding that as little as 1.5 million cubic meters of water could cause a significant downstream impact.
