Hualien Landslide Lake Stable with Steady Overflow After Typhoon Hongxia

The Wanli Creek landslide lake in Hualien County continues to maintain a stable overflow status, even after being affected by the outer bands of Typhoon Hongxia. The Forestry and Nature Conservation Agency's Hualien Branch reported that the upstream catchment area received 32.5 millimeters of rainfall between Thursday and Friday.

As of Friday noon, the lake's water level was recorded at an elevation of 1091.02 meters, holding an estimated 6.1021 million cubic meters of water. Despite a slight increase of 52 centimeters compared to previous measurements, this rise is attributed to increased inflow from rainfall. The agency assessed that the dam body has experienced only minor localized erosion and undercutting, with its overall structure remaining intact.

Aerial footage captured on Friday midday revealed that the landslide debris on the right side of the dam crest continues to slide along the slope, but this movement is being closely monitored. The agency concluded that the current overflow volume is insufficient to cause significant erosion or undercutting of the dam. Based on water level monitoring and downstream CCTV river level data, the rate of dam undercutting remains slow, and the risk of a breach has not significantly increased. Downstream impacts are currently limited to the river channel.