Whilst what you say Crazy guy is perfectly true this is not the direction to go if you are attempting to interpret a myth.
If one were familiar with Quaternary geology i.e. the prevailing geological period, or more specifically the Holocene epoch which covers the last twelve thousand years; it is simply a matter of normalcy that rivers flood. I have hands-on experience of describing flood events in a proto river Thames at 230,000 years before present. Any of these events could have caused deaths and folk with boats could survive an inundation. It could also create local legends of survival and renewal. However I suggest that the Biblical Flood is not one of these but does nevertheless describe the consequences of a literal global event. (It takes more than a quick post to explain convincingly!) Evidentially determined Earth- sciences do not allow for the possibility of a global flood within the last 2.6 million years of the Quaternary... and local flood events are legion.
As you say CalebinF there are a number of different
types of myth which is an important distinction to make when discussing a folk
tales, legends or traditional stories etc.