Maybe, however we have recent flooding events that are almost biblical. There are the recent in my lifetime floods in the Mississippi valley 1993 and 2011. Not to mention the 1927 flood. Ohio River flood of 1937 which I think is mythologized in the Johnny Cash song 5ft high and rising.
In the Great Flood of 1862 the California Central Valley flooded, 6000 square miles, some of which was still under water 6 months later.
While I suspect such floods don't occur in the Euphrates and Tigris basins now, 5000 years ago when the climate was wetter, perhaps such floods similar to the Great Flood of 1862 did occur every few hundred years.
In the Great Flood of 1862 the California Central Valley flooded, 6000 square miles, some of which was still under water 6 months later.
While I suspect such floods don't occur in the Euphrates and Tigris basins now, 5000 years ago when the climate was wetter, perhaps such floods similar to the Great Flood of 1862 did occur every few hundred years.