Bawei delivers huge gift: Reservoir's catchment inflow equals full capacity

Typhoon Bawei delivered a substantial gift to the Shihmen Reservoir catchment area, bringing 421.8 millimeters of rainfall. The total inflow reached approximately 201.4 million tons, a volume equivalent to the entire storage capacity of one Shihmen Reservoir. As of Sunday evening, the reservoir's water level was at about 244.57 meters, with a storage capacity of 202.36 million tons, reaching a 98.5% storage rate.

To manage the influx, Shihmen Reservoir commenced controlled releases using its sand-flushing tunnel, power generation conduits, and PRO facilities. This operation aims to continuously remove sediment carried by the inflow, with adjustments to the release facilities planned based on future inflow conditions to achieve a full reservoir level.

The typhoon's heavy rains caused the reservoir's spillway to open fully for the first time in 618 days. Water was released through six gates of the spillway, along with the sand-flushing tunnel, power generation pipes, and the Amuping silt-clearing tunnel. This multi-pronged approach helps regulate the rate of water level rise and maintain the structural integrity of the dam.

The Amuping silt-clearing tunnel, a project supported by the Forward-looking Infrastructure Development Program, began construction in November 2017 and was completed in February 2023. Its function is to create an outlet at the bottom of the reservoir, facilitating the removal of sediment during flood discharge operations. This extends the reservoir's effective storage capacity and lifespan. Yesterday marked the seventh activation of the tunnel's silt-clearing operation, with a cumulative discharge of 1.125 million cubic meters.