A flood (홍수, hongsu) inherits water's generally favorable associations in Korean tradition but pushes them past the point of comfort — the same water that blesses as rain becomes a problem once there's simply too much of it, arriving faster than it can be absorbed.
Some interpreters read a flood surprisingly close to a money dream taken to an extreme — wealth or opportunity arriving in genuine overflow, more than expected, which can be read favorably if the dream's overall tone stays calm rather than frightening. This mirrors the same "too much of a good thing" logic that shows up in some money-dream readings.
Floodwater entering your own home specifically shifts the reading toward personal overwhelm — financial, emotional, or practical matters spilling into your private life in a way that's hard to contain. This variant is read more seriously than a flood observed at a distance, since the water is now inside the space that's supposed to be safest.
Floodwater receding, especially cleanly and without leaving lasting damage, follows the same reassuring pattern as clearing rain or melting snow — a difficult, overwhelming period passing through and leaving things intact, even if it was frightening while it lasted.