A Hundred-Year Flood Can Happen Twice in a Decade
A flood is an overflow of water onto dry land. The phrase hundred-year flood describes a probability, not a schedule.
A flood is an overflow of water onto land that is normally dry. The term *hundred-year flood* is widely misread: it means a flood with a one per cent chance of occurring in any given year, not one that arrives on a century-long timetable. Two can happen in successive years without contradicting the definition, exactly as two sixes can follow each other on a die. *Flood* also means the incoming tide, the opposite of *ebb*.
- An overflow of water. *Flash flooding.*
- A large quantity. *A flood of applications.*
- The rising tide. *Flood and ebb.*
- Floodlight — a broad lamp. *Under floodlights.*
- Floodplain — land beside a river. *Built on a floodplain.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | flood | A severe flood. |
| Plural | floods | Winter floods. |
| Verb | flood | The river flooded. |
| Adjective | flooded | A flooded field. |
| Old English | flod | A flood, a tide. |
- The river flooded three villages.Water.
- A flood of complaints followed.Figurative.
- A hundred-year flood is a one per cent annual chance.Statistics.
Flood terms explained
- Flash flood — sudden, from intense rain, often in dry ground
- Fluvial flood — a river overtopping its banks
- Surface water flood — drains overwhelmed by rainfall
- Storm surge — sea level pushed up by wind and low pressure
- Floodplain — land a river naturally floods, and a poor place to build
Old English *flod*, a flowing of water or a tide, from a Germanic root related to *flow* and *float*.
Can a hundred-year flood happen twice in a decade?
Yes. The term describes a one per cent annual probability, not a fixed interval between events.
What does flood tide mean?
The incoming tide, when the sea is rising. The outgoing tide is the ebb.