Floods are a natural part of the Australian landscape. The play an important role in certain ecosystems and help fill our dams to get us through drier times. However, at disaster-scale, they can also be very destructive.
Severe flooding can result in loss of life, long-term physical and mental health impacts, widespread damage to homes, buildings, roads and bridges, and disruption of vital services such as water and electricity. They are the most costly natural disasters in Australia, with South East Queensland bearing the brunt of an enormous burden of these costs over many years.
Flood impacts depend on how much, how long and where rain falls on our catchments and no two floods are alike. However, one thing we do know is that we are likely to see an increase in the frequency and severity of floods as the climate changes.
Floods have long-lasting impacts on communities and the environment.
Floodwater is often contaminated with sewage which can lead to illness and reduce access to clean drinking water. Power outages can result in businesses and other important services such as hospitals and public transport being forced to shut down. The transport network can be affected, and infrastructure such as bridges, roads, railways can be damaged cutting people off. The economic consequences, such as the loss of livelihoods, a decrease in purchasing power, and a loss of land value can leave communities economically devastated. Flooding in key agricultural areas can cause widespread damage to crops and fencing and the loss of livestock, leading to supply shortages and increased food prices. Furthermore, for the victims, these traumatic events can be leave some people with a deep and lifelong impact on a psychological level.
Many natural systems rely on floods to maintain key functions and biodiversity. Floods connect waterways with surrounding land and other nearby aquatic habitats, recharge groundwater supplies, fill wetlands, help to cycle nutrients and sediment, and trigger important animal lifecycle events such as breeding and migration. However, floods can also have very damaging effects, including habitat loss, increased weeds, increased pollution, loss of wetlands function, reduced fish production, and loss of recreational areas. Impacts are often worse for already degraded ecosystems, such as urban waterways, where the loss of riparian vegetation has led to massive erosion and changes to the channel which further increase the impact of future floods. Floods also have a negative impact on marine and coastal environments by introducing increased sediment, nutrients, and pollutants that damage aquatic ecosystems.
Click to see by threats & pressures