Silting of the navigation channel hampered Black Rock Harbor in the late 19th century, and then the Japanese colonial administrators opened a rail line to Yi-lan. As a result, shipping volume at the harbor gradually declined.
19 世紀末期，洪水帶來泥沙淤積河道，加上日治時代宜蘭鐵路已經開通，烏石港逐漸失去運輸功能。