Wanli Creek landslide dam overflow delayed to July 20 amid increased seepage

Authorities in Taiwan are closely monitoring the Wanli Creek landslide dam in Hualien County, where the anticipated overflow has been delayed. The Central Disaster Response Center convened a meeting to assess the situation, with the Forestry and Nature Conservation Agency reporting that increased seepage has led to reduced inflow, consequently postponing the overflow. The new estimate for the dam reaching its crest and overflowing is now set for approximately midnight on July 20.

Current monitoring data indicates the dam's water level stands at 1086.4 meters, just 1.1 meters below the crest of 1087.5 meters. While drone footage shows continuous seepage from the natural dam's lower slope and an increase in seepage from the upper slope, officials believe this is currently surface erosion, not internal erosion. They assess that even if internal erosion were to occur, the flood's impact downstream would likely remain confined to the river channel.

Despite the delay, a red alert remains in effect. The command center has urged local governments to continue managing public sentiment and to allow citizens freedom of movement within controlled areas. The Forestry and Nature Conservation Agency is intensifying its monitoring efforts, including frequent drone surveillance, to track water level changes. The reduced inflow, stemming from unstable water supply and lower rainfall, contributes to the uncertainty surrounding the exact timing of the overflow, though the dam structure itself shows no significant damage.