Yishuitu Introduction
The overflow spillway is used to discharge excess water from Sun Moon Lake to the Shui Li Creek. Residents near Sun Moon Lake refer to it as the "Tianjing." The spillway has a circular tower shape, as water flows most quickly in a circular form; the circular tower-shaped spillway is set to a fixed water level. When the water level is normal, water from the lake does not flow into the tower, but if it exceeds the full water level, it will automatically flow into the spillway for discharge. The spillway is a funnel-shaped structure with a diameter of 24.39 meters, tapering downwards, leading into a tunnel with an inner diameter of 3.48 meters, and a total length of 219.93 meters. To accommodate the complex terrain and landscape, the tunnel and channel change in many shapes, which is one of the reasons it constituted Sun Moon Lake's hydroelectric power project, once regarded as the "largest hydroelectric project in the East," and it remains a spectacular attraction to this day. Visitors walking along the Shuishe to Xiangshan Trail should not forget to stop and take a look.
