Hualien Landslide Lake Downgraded to Yellow Alert, River Channel Remains Red

Hualien County's Wananxi River landslide-dammed lake has seen its yellow alert lifted, as authorities downgraded the warning to a general alert level. The lake reached its full capacity on the afternoon of the 20th, with its water level at 1089 meters and accumulating 5.7 million cubic meters of water. Despite reaching the monitoring benchmark, no overflow has been observed.

Aerial surveillance conducted at noon revealed that while the water level neared the spillway and seepage from the dam body showed an increasing trend, there was no overflow. The dam structure itself remains stable, with no immediate signs of damage. However, the steep slopes near the dam crest have experienced landslides, which may have contributed to the rising water level. The volume of stored water continues to rise, calculated by the inflow minus seepage.

Based on weather forecasts and current monitoring data, the weather in the upper reaches of the Wananxi River is stable, and the lake's water level is expected to remain steady. Experts estimate that the dam crest is currently 13 to 14 meters from the horizontal distance of the reservoir. The potential for a breach remains uncertain and depends on cumulative rainfall, inflow, seepage rates, and the stability of the remaining dam material.

Despite the downgrade of the lake's alert status, the Wananxi River channel remains under a red alert, with entry strictly prohibited. Bridges crossing the river will continue to be closed preventatively after 10 p.m. due to difficulties in nighttime aerial observation. The agricultural department and Hualien County government are maintaining a Level 3 emergency response. Future alert levels will be determined by the remaining storage capacity and predicted rainfall, with specific thresholds set for issuing warnings and potentially mandatory evacuations if rainfall exceeds 200 millimeters within 24 hours.