The term 100-year flood is a statistical term. It is not a recurrence interval. From your reading, "Simply put, the 100-year flood is a statistical device used for insurance purposes . . .it is a statistical projection of what that flood might be. The unfortunate name implies that such a flood happens at 100 year intervals, but that is not the case." Additionally, the term 100-year flood means that there is a 1% chance of a flood of similar magnitude each year. You could also state that the term 1,000-year flood means there is a .1% chance of that flood occurring on a given year. Somewhere in the answer there should be a conversion from x-year flood to percent chance. From your reading, "Because a 100-year flood is the biggest one that happened only once in the past 100 years, statisticians would say that it has a 1% chance of happening in a given year." Just because there was a recent 100-year flood and 200-year flood, that there is no guarantee that there will not be a similarly sized flood in the near future. Floods don't have to follow any regular spacing like 100 years. It may be a 1,000 years before another magnitude 100-year flood. From your reading, "Communities often do not understand that they can experience several "hundred year floods" in a matter of weeks or even days and that if a property has flooded once, it will flood again." It is not a safeguard, it is a statistic.