At that time, the Japanese used the natural valley of Kuan Tien Hsi for building a dam near Wushantou to impound water for the irrigation of the farmland of the Chianan plain.

• 水库兴建于民国九年，当时日本人利用官田溪的自然溪谷，在乌山头附近筑坝截流，以供嘉南平原的灌溉用水。