内水氾濫 ないすいはんらん Meanings Noun flooding within the confines of a levee (i.e. caused by surface runoff, drainage failure, etc.) See also: 外水氾濫 (がいすいはんらん). Kanji 内 inside. Read as ナイ. 水 water. Read as スイ. 氾 overflow. Read as ハン. 濫 indiscriminate. Read as ラン. Jinuma: Japanese Dictionary · Word lists