ABSTRACT
Sidoarjo is geomorphologically located between two tributaries of the Brantas River, named as the Porong River and the Mas River. Because of the fertile soil, the Dutch East Indies Government built many sugar industries and sugarcane plantations. Additionally, the river streams in Sidoarjo's can lead to ecological problems, such as flooding. This research tries to find more about the flood disasters that have occurred frequently in Sidoarjo, especially in the Southern Sidoarjo, since the 20th century. The research uses historical methods that have five steps: topic selection, heuristics, source criticism, interpretation, and historiography. The research conclusion is that flooding is caused by geographical position and the frequency of high rainfall and land changes.
