Overflow Well Introduction
The spillway is used to discharge excess water from Sun Moon Lake into the Shui Li Creek, and nearby residents refer to it as the "Tianjing." The spillway has a circular tower shape because circular water flow is the most efficient. The circular tower-shaped spillway is set at a fixed water level; when the water level is normal, the lake water does not flow into the tower, but once it exceeds the full water level, it automatically flows into the spillway for discharge. The spillway is a funnel shape with a diameter of 24.39 meters, narrowing from the top down, connecting to a tunnel with an inner diameter of 3.48 meters, and a total length of 219.93 meters. To adapt to the complex topography, the tunnel and channels change many shapes, which is one of the reasons why it constituted the Sun Moon Lake hydropower project, once regarded as the "largest hydropower project in the East," and it remains an incredible attraction to this day. When visiting the Wusi to Xiangshan Trail, don't forget to stop and take a look.
