Zengwen Reservoir storage rate returns to 30% after receiving water equivalent to Sun Moon Lake

Continuous rainfall in the catchment area has significantly boosted the water levels of Zengwen Reservoir, Taiwan's largest. The reservoir's water level has climbed above 206 meters, reaching the height of the spillway intake platform. This substantial inflow has brought the reservoir's storage rate back to 30%, marking a significant turnaround in water conditions.

Since early June, the reservoir's catchment area has received over 580 millimeters of rain. This sustained precipitation has resulted in an inflow of more than 126 million cubic meters of water. This volume is nearly equivalent to the capacity of Sun Moon Lake, another major reservoir. Authorities noted that the inflow coefficient has increased to 0.57, indicating efficient water collection from the rainfall.

As of the afternoon of June 11, 2026, Zengwen Reservoir's water level stood at 206.67 meters, with a storage rate of 30.82%. Combined with the effective storage capacity of Wushantou Reservoir, the total available water exceeds 180 million cubic meters. Despite the improved water situation, the Water Resources Agency's Southern Region Water Resources Branch is still appealing to the public to continue practicing water conservation in Tainan.

The rainfall is expected to continue, with the reservoir receiving nearly 60 millimeters on June 11 alone, suggesting further replenishment is likely. The recent improvement in water levels is attributed to the combined effects of a weather front and the southwest monsoon, demonstrating the significant impact of these weather systems on reservoir replenishment.