Taiwan's Matanxi River Faces Risk of Second Landslide Lake Formation

Experts warn of potential new landslide lake due to remaining debris, prompting government action to reinforce defenses.

Following the severe flooding caused by a landslide lake in Taiwan's Matanxi River, which heavily impacted Guangfu Township in Hualien, water resource experts have raised concerns about the potential for a second landslide lake. Li Hongyuan, a water resource expert and former Minister of the Interior, has warned that approximately 250 million tons of sediment remain on the mountain. He cautioned that heavy rainfall or earthquakes could trigger another collapse, forming a new landslide lake.

In response to these concerns, Li Mengyan, Deputy Chief Coordinator of the Central Forward Coordination Office, confirmed the existence of this risk. He stated that the Water Resources Agency is currently reinforcing embankments to enhance protection. Professional teams are also developing plans for spillways or drainage facilities to significantly reduce flood volume and sediment flow in the event of another collapse.

Li Hongyuan noted on the 3rd that the remaining water in the current Matanxi River landslide lake is around 5 to 6 million tons, posing no immediate danger. However, out of a total of 320 million tons of sediment involved in the initial event, only 70 million tons have been released, leaving 250 million tons on the mountain. He further pointed out that the left mountainside is unstable, and another heavy rainfall could cause it to collapse again, creating a second landslide lake.

Lin Yuanpeng, Director of the Water Resources Agency, added that the first phase of constructing a 3-meter high earth dike is expected to be completed by the 4th. Unless there is extremely heavy rainfall, water flow will not re-enter Guangfu Township. The subsequent second phase will involve raising the dike by an additional 2 meters and strengthening its waterproofing, with completion anticipated by the 11th.