But what many people do not know is that in 1941 Kukeng experienced another major earthquake, which struck the Chiayi-Tainan area. The western face of a 1200-meter high mountain collapsed and fell into the Chingshui River. It formed a natural dam 100 meters high, and created a new lake, Lake Tsaoling, with a volume of 12.86 million cubic meters.
然而許多人卻不知，早在日據時代昭和十六年，古坑鄉就曾因為嘉南大地震，導致境內草嶺西側標高一千二百公尺的山石頃刻崩坍，下洩入清水溪，除了堆積成一道高約一百公尺的天然堰堤之外，也造成蓄水量約一千二百八十六萬立方公尺的天然巨潭「草嶺潭」。