A flash flood occurs when the amount of rainfall overwhelms our natural and man-made drainage systems or low-lying areas. Generally, one inch of rain per hour will cause flash flooding.
Development doesn't cause flooding but can make flooding worse
|Extra water has to go somewhere
There is a limit to how much water our creeks can hold. If enough rain falls in a short amount of time, creeks naturally overflow onto the floodplain.
Floodplains are designed by nature to
flood. For that reason, floodplains are part
of a healthy creek system.
Rain-swollen creeks naturally overflow
onto the floodplain
Although flooding is a natural occurrence, man-made changes to the land can also be a factor. In cities and suburbs, pavement and rooftops prevent some rainfall from being absorbed by the soil. This can increase the amount of runoff flowing into low-lying areas or the storm drain system. And eventually, that excess runoff flows into our creeks.
While flooding cannot always be prevented, the risks can sometimes be reduced. Storm Water Services: