TAIPEI (Taiwan News) — The Forestry and Nature Conservation Administration said Sunday that a barrier lake on the Wanli River in Hualien County has reached 82.6% capacity, with a red alert downstream evacuation order remaining in effect.
The agency said aerial monitoring was completed at 7:20 a.m. Sunday showed that the lake level had risen slightly following rain from Typhoon Bavi, but the overall structure of the landslide dam remained stable. No significant changes in the shape of the lake or dam were detected, per a press release.
Monitoring data showed that as of 10 a.m., the water level had reached 1,080.78 meters, with the lake holding about 4.2 million cubic meters of water out of a maximum capacity of 5.1 million cubic meters.
The agency said it will continue monitoring water levels, the surrounding area, and the dam structure around the clock. As the typhoon’s impact weakens, officials will conduct rolling assessments to determine whether the red alert should remain in place or be lifted.
FANCA Hualien Branch Director Huang Chun-tse (黃群策) said the current water level is about 7.5 to 8 meters below the overflow, adding that the lake’s storage capacity increases as water rises closer to the top.
The lake is currently gaining about 140,000 to 160,000 cubic meters of water per day. Huang said that without additional rainfall, the lake would take an estimated seven to nine days to overflow, per CNA.
Huang said authorities must assess both rainfall levels and water inflow to make a more accurate estimate of when overflow could occur. The agency is working with National Cheng Kung University’s Disaster Prevention Research Center to monitor water storage levels and improve overflow predictions.
The current red alert requires mandatory evacuation for downstream communities and allows for possible road and bridge closures. If the alert were downgraded to yellow, authorities would warn that overflow could occur within 48 hours, with preventive evacuations recommended and emergency personnel, shelters, and road closure measures placed on standby.
