These are normal disasters which happen along rivers with Floodplains, which includes rivers on all terrain types except Tundra. The level of the water rises, flooding all Floodplains tiles found along the river, and then recedes on the next turn.
- Damages or destroys Districts, improvements and units on the Floodplains tiles near the river. This may also include a City Center, in which case it loses some HP and Defenses (if it has them).
- May kill some Citizens in a nearby city.
- Can fertilize affected tiles, adding Food and/or Production potential.
- A Dam built along the same river will mitigate floods there. Fertilization rates will drop about 50%, but there will be no destruction anymore.
River floods have three levels of severity, starting with Moderate and ending with 1000 years Flood. The Disaster Intensity setting of the game controls what levels of flooding will occur more often, but climate change may also contribute to their severity.
The Egyptians' civilization ability allows them to receive full fertility from Floods yet suffer no damage from them.
The table below lists the percentage chance of all effects happening at each different severity level.
|50%||100%||15%||15%||30-50 HP||30-50 HP|
|1000 Years||Pillaged: 100%;
|80%||100%||25%||25%||50-70 HP||50-70 HP|
It is interesting to note that floods fertilize each type of Floodplains differently; the exact percentages are listed in the table below. Each expresses the chance of a tile to gain +1 of the given yield, and note that a single tile may gain both yields from the same flood!
|Severity||Yield type||Plains Floodplains||Grassland Floodplains||Desert Floodplains|
The second type of floods happen on coastal lowland tiles, and are a direct result of melting ice caps (which in turn is a result of climate change). Coastal flooding will start occurring as climate change progresses to certain phases, and will affect first the 1-meter tiles (that is, the lowest-lying flatlands), then the 2-meter tiles, and finally the 3-meter ones.
As climate change progresses further, coastal lowland will become Submerged. Submerged tiles are irrecoverable and become permanent Coast tiles; all districts there are lost. The tiles, however, may be worked as normal Coast tiles; they may also receive any applicable improvements (such as an Offshore Wind Farm).
In-game disaster descriptions
|Flood||Moderate||Rising waters overflow the banks of the river and spill into the land beyond.|
|Major||Surging, murky water rushes over the land around the river during an intense flood.|
|1000 Years||The river bursts its banks, and rising water covers the land for miles around. Not for a thousand years has the river flooded to such an extent!|
|Civilization VI Disasters |
|Comet Strike1 2 • Drought • Flood • Forest Fire1 • Meteor Shower1 • Nuclear accident • Solar Flare1 2 • Storm (Blizzard • Hurricane • Sand storm • Tornado) • Volcanic eruption|
|1 Requires a DLC • 2 Apocalypse mode only|