Stormwater
In this section:
- What is stormwater?
- Why is stormwater harvesting important?
- What does an urban stormwater harvesting scheme look like?
- Examples of stormwater harvesting projects
- How do I get a licence to harvest stormwater?
Important!
For information on the location of underground assets at your site, please phone Dial Before You Dig on 1100, or visit the Dial Before You Dig website.
What is stormwater?
Stormwater is rainwater that runs off all urban surfaces such as roofs, pavements, car parks, roads, gardens and vegetated open spaces. Stormwater can be collected (harvested) and reused for many purposes. In urban areas, the best quality water is rainfall captured from roofs before it meets up with other stormwater at ground level or in drains.
Also see:
Why is stormwater harvesting important?
Did you know stormwater pollution is the biggest threat to our urban rivers and creeks? Each year about 500 billion litres of water containing litter and other harmful pollutants such as heavy metals, oil, organic matter and excess nutrients enters our rivers, creeks and bays via stormwater drains.
Excess nutrients such as nitrogen can cause vigorous growth of algae, which leads to reduced oxygen levels in water. Algal blooms threaten animals, plants and fish living in our waterways.
The quantity of stormwater (i.e. how much water enters our waterways after heavy rainfall) is also a problem, leading to erosion of river beds and banks and providing unfavourable conditions for many plant and animal species.
Stormwater pollution becomes a bigger challenge the more Melbourne grows. More urban areas mean more roads, concrete, roofs and paving where a natural environment used to be. When it rains the amount of water that is able to soak into the ground is reduced, so more water runs into stormwater drains. This means that there is a faster build-up and greater volume of stormwater going into the rivers and creeks when it rains.
Stormwater harvesting can help by reducing the volume and speed of flow of water in the drainage system and by reducing the amount of pollution reaching our waterways.
Stormwater also offers an alternative water source to drinking water. However, because it can become polluted from such things as atmospheric pollution, litter and industrial runoff, stormwater may need to be treated before it can be used.
Raingardens are another form of stormwater treatment which treat stormwater from roofs and other hard surfaces like driveways. Raingardens remove excess nutrients and other pollution from stormwater before it flows into drains and into our rivers, creeks and bays.
More information:
- Other water supplies
- Urban stormwater harvesting
- EPA Victoria – Stormwater Harvesting and Use
- Australian Guidelines for Water Recycling
- Raingardens Program
What is rainwater collection?
In the urban environment, the best quality water during rainfall is captured before it becomes stormwater. This water is collected directly from roofs and stored in tanks, before it has the chance to become polluted from the ground or other mixed sources discharging to the drainage system.
Rainwater collected in tanks from domestic or commercial roofs can be used for many different purposes. Rainwater collected in this fashion does not require a stormwater harvesting licence from Melbourne Water.
Rainwater is only suitable for some purposes e.g. watering your garden. For more information on using rainwater read the Dept of Health and Aging Guidance on use of rainwater tanks.
If you would like more information about installing a rainwater tank, please contact your retail water company: