Floodplains
A floodplain is the low lying land bordering a creek, river, lake, sea coast or artificial channel. In Victoria floods are usually caused by heavy prolonged rainfall.
This produces surface runoff which flows overland into rivers and streams. When there is a large amount of runoff, water overflows the river banks onto the adjacent floodplain causing land to flood.
Built up urban land can be affected by overland flows that occur during severe storms when the capacity of drainage systems is exceeded.
For planning purpose the 1% probability (one in a hundred years) flood is used to identify land which is liable to flooding. This is determined from data obtained from previous floods and from flood studies.
This produces surface runoff which flows overland into rivers and streams. When there is a large amount of runoff, water overflows the river banks onto the adjacent floodplain causing land to flood.
Built up urban land can be affected by overland flows that occur during severe storms when the capacity of drainage systems is exceeded.
For planning purpose the 1% probability (one in a hundred years) flood is used to identify land which is liable to flooding. This is determined from data obtained from previous floods and from flood studies.