Flooding and stormwater
Floods occur from heavy or sustained rain, and stormwater is the runoff.
In this section
Flooding and stormwater can be a risk to property and life.
Flooding occurs when water flows over land that is normally dry. This can occur after heavy or prolonged rainfall. This type of flood water is fresh and usually full of sediment and other pollutants. Flooding can also occur from storm tides, often caused by tropical cyclones or east coast lows. This type of flood water is mostly marine and salty.
Stormwater is runoff from rainfall that flows overland. It causes short-term flooding across roads, parks and sports grounds. Stormwater travels through our urban stormwater network of underground pipes and open drains. It is sometimes stored in basins and later released to rivers or creeks.
We need to manage stormwater to protect the health of our community and our waterways. It's often polluted with litter, oils, chemicals, heavy metals and sediment. As a result, we capture and treat stormwater runoff before its released or reused.
We remove stormwater litter using gross pollutant traps. Then, we can treat it using natural processes, such as wetlands and bio-retention basins.