I suggest the reason that there were myths myth of floods found in all inhabited continents was because of the need to explain the reason why it began to rain so much after the last ice age. There was no Noah’s Flood; it is just one of the myriad folk tales found in the earliest literature as an echo of the phenomenon of global warming and its natural consequence; the new experience of voluminous rain which had not occurred even within folk memory of earth’s inhabitants twelve thousand years ago. During the last global thermal minimum between twenty thousand and eleven thousand years ago, a large amount of the earth’s free water had been bound up frozen in the arctic and Antarctic ice sheets.
With the melting of the enlarged ice-caps (beginning about 14,000 years ago) which had accumulated during the arctic freeze of the last ice age, the sea levels began to rise dramatically as the ice evaporated and water vapour became airborne. Floods most definitely occurred and land bridges were drowned including the connection between northern France and England which existed up till about 8400 years ago if memory serves right.
To get a proper handle on anything: stop believing in the truthfulness of the Bible. The Bible is pre-scientific superstition. The question of " how much sediment" makes no sense unless there was a Noachian flood...which was both physically impossible and for all the catastrophic impact it would have had is not recorded at all by the earth sciences. Further to that , it happened so the Bible says, in historic time and as others have said;there is no mention of it. It's a myth!