The rivers around Hualien are usually dry, but heavy rainfall in the mountains brings flash floods, and so it was decided in 1971, when the tracks were being widened, to tunnel under two of the riverbeds.
花蓮的溪流屬於荒溪型，平常沒什麼水，一下大雨卻山洪暴漲。民國六十年間東線鐵路拓寬時，就決定改建河底隧道。