Going with the flow of stormwater and drainage

What are stormwater and drainage?

Stormwater is the runoff that comes from rainfall in urban areas. This includes rain on your rooftop and water that travels from roads and footpaths into stormwater drains. Water from your rooftop can be stored in a water tank or flow from your gutters into the stormwater drain on the street. This water then travels through pipes to local waterways, or sometimes directly into the sea.

Unlike water that’s piped to our homes or wastewater, stormwater is often not treated. This means it can carry pollutants like car oil and litter into waterways and the sea.

Our drainage systems are normally designed to carry stormwater away as quickly as possible. This reduces local flooding when it rains. Without proper design it can lead to flash flooding events and is what often leads to urban flooding. Using water sensitive design in cities and towns can reduce the damage that stormwater does to the environment. Water sensitive design can treat stormwater to remove pollutants, mimic the natural water cycle and capture stormwater for reuse. Reusing stormwater conserves valuable drinking water.

What can help?

Some examples of what helps stormwater and drainage include:

raingardens
constructed wetlands
swales and infiltration trenches
porous driveways and pathways
rainwater tanks
passive street tree irrigation
stormwater harvesting to water sporting ovals.

In urban areas, stormwater can be a valuable water source for wetlands so they don’t dry out. Like all waterways, it is also important they don’t get polluted. To help keep waterways clean and healthy you should put your rubbish in a bin and pick up after your pets. At home, washing cars on the lawn rather than in the driveway means soapy water can soak into the ground, rather than running down the drain.

Case study

Wetlands like the Edithvale-Seaford wetlands in Melbourne’s south can act as natural drains for stormwater runoff. This series of videos, including the Drainage Story of the Wetlands from Melbourne Water explain their story including the impact of drainage.

Watch the video

Drainage story of the Edithvale and Seaford wetlands (2 min 43 sec)

Meet the expert

Emily Plymin is a Senior Policy Officer in the Stormwater Policy team at the Department of Energy, Environment and Climate Action (DEECA). Here she discusses how stormwater and its infrastructure affects us every day and ways these change cities and your own home.