During the Japanese Colonial Period, the Japanese had the Chianan Canal constructed. The Japanese Government at the same time worried that Wushantou Reservoir would not be able to receive enough water and the Japanese Government then had the engineer, Yoichi Hatta, build a 4 kilometer long aqueduct to direct the Tseng Wen River at Dongkou, passing through Sikou, flowing unto Wushantou Reservoir. Because there is a huge drop, the water quickly gyrates down in cascades out of the hole and that makes a peculiar scene " Tian Jing Syuan Wou" (which literally means that the whirl comes from a well above).