Urban Stormwater Harvesting
What does an urban stormwater harvesting scheme look like?
Urban stormwater harvesting schemes can be defined as the collection, treatment, storage and use of stormwater runoff from urban areas. It differs from rainwater harvesting as the runoff is collected from drains rather than roofs.
If you are planning to harvest urban stormwater, heres what a typical urban stormwater harvesting scheme might look like (Note: Each scheme will vary in characteristics but will have common elements):
Stages in a stormwater harvesting scheme:
- Harvest stormwater is collected from a source usually a drain. The source will either be a Melbourne Water or Council asset.
- Storage stormwater is temporarily held in above or below ground storages to balance supply and demand. Sometimes this can be a constraint on a scheme as storage can be a significant cost and space may also limit the volume of storage available.
- Treatment captured water is treated to reduce pathogen and pollution levels. It is up to the proponent to ensure that water quality is fit for purpose and to manage the risks to public health and the environment.
- Distribution the treated stormwater is distributed to the area of use.
Hydrological modelling may be required to determine the appropriate storage means and capacity for the scheme. Sometimes a study may need to be undertaken to ensure that environmental impacts are assessed at both the source and receiving waterways downstream. A successful stormwater harvesting project requires input from several specialist sectors including stormwater management, environmental management and public health to name a few.
If the source of your stormwater is from a Melbourne Water stormwater drain you will need to apply for a licence to harvest stormwater. See: How do I get a licence to harvest stormwater?
Using stormwater
Before it can be used, stormwater may need treatment, depending on the requirements of the end use. Treatment can be in the form of natural systems such as wetlands, or mechanical water treatment plants.
Although there are no specific laws that dictate what stormwater can be used for or what quality standards stormwater must meet, individuals and organisations responsible for stormwater schemes do have a duty of care to make sure their scheme will not place people or the environment at risk. The quality of stormwater and the associated management controls need to be proportional to the level of risk - the more likely it is that stormwater will place people or the environment at risk, the higher the water quality and more stringent the management controls need to be.
The Australian Guidelines for Stormwater Harvesting and Reuse establish the standards and best practice for protecting public health and environment and managing risks that may be associated with stormwater use. These guidelines should be the basis for developing and managing a stormwater use scheme.
Stormwater can be used for many purposes including watering sporting ovals, golf courses, industrial uses and to replenish wetlands. There are many stormwater harvesting projects in operation around Melbourne.
More information:
Projects with a primary focus on improving stormwater runoff quality, reducing peak flows and protecting waterways. According to the key principles of WSUD, as stated in the Urban Stormwater - Best Practice Environmental Management Guidelines, the main aims are to:
- Protect natural systems
- Integrate stormwater treatment into the landscape
- Protect water quality
- Reduce runoff and peak flows
- Add value while minimising development costs.
Also see:
If you have a stormwater harvesting project you would like to share, please visit our Water Sensitive Urban Design Case Studies web page to register your project.
Urban stormwater boundary
You can apply to harvest stormwater from within the Urban Growth Boundary. The document below shows the urban growth boundary in relation to our drainage and waterways boundary. For a more detailed view, including which planning zone a property is in, go to the Department of Planning and Community Development website.