Flooding is a natural phenomenon that occurs when water overflows or soaks land that is normally dry. It can be a devastating natural disaster, causing loss of lives and property. Flooding can also affect the environment, contaminating soil and damaging wildlife and plants.
Floods often happen slowly and give residents time to evacuate. However, there are also cases of flash flooding that develop suddenly and without warning. The speed and intensity of flooding depends on the rainfall, topography, ground conditions, and if dams or levees have failed.
People living in low-lying areas or regions that are prone to flooding have a higher risk of flood. This includes people who live in single-storey bungalows, below-ground homes, caravans and tents. Floodwaters can be contaminated with sewage and other pollutants. These pollutants can cause illness in people who touch them or consume contaminated food and drink. Floodwaters can also damage infrastructure and make it difficult to access services such as schools, hospitals, government offices and aged care centres.
A flood can be triggered by weather events such as heavy rain or storms, or changes to the environment such as building construction or fire debris from wildfires. In urban areas, it is important to reduce the amount of water that flows into streets and buildings by improving drainage systems or through measures like greening streets, porous paving and wetlands.
People living in areas that have experienced flooding in the past are more likely to be at risk, as are communities where people have moved into formerly flood-prone areas and not rebuilt or upgraded their homes and infrastructure to be able to withstand flooding. Communities that experience frequent floods are also at greater risk, as the environment does not have time to recover between flooding events.