Stormwater is the rainwater that runs across gardens, roads and parks and into stormwater drains, creeks, the harbours and the ocean. It picks up significant pollution as it does so.
Harvesting some of this water can help to save drinking water and also reduces water pollution. However, while there are frequent calls to capture all the water running down our gutters, this is not as easy as it sounds.
The costs of large-scale storage and treatment can be high. Capturing a significant amount of water would require a large number of water storages across Sydney, each the size of approximately 500 to 1,000 Olympic-length swimming pools. For each of these, a recycled water treatment plant and an expensive distribution system would be needed.
Such costs for large-scale schemes can rarely be justified, so stormwater harvesting is most efficient at a local scale, where the costs of storing, treating and distributing the stormwater are low. Most stormwater pipes and channels are owned by local councils and councils manage most stormwater recycling schemes.
To date, over 80 stormwater projects that include harvesting have received financial support in the greater Sydney and Central Coast areas. These schemes will save about two billion litres of water a year. Many more such schemes will eventually build to a sizeable total.
The NSW Government is promoting an integrated approach to stormwater harvesting, focussing on smaller, local schemes which provide an alternative water source but also deliver river health, water quality and flood mitigation benefits. The combined value of the water and environmental improvements makes this approach a better use of funds than schemes that focus only on delivering water.
Further funding is available under the $80 million Urban Sustainability Program to help councils undertake stormwater management projects, including harvesting and reuse.
- Water sensitive urban design
- Integrated water cycle management guidelines
- Managing urban stormwater – harvesting and re-use
- Three Ministerial Councils (Natural Resources, Environment Protection and Heritage, and Health) are jointly developing Australian Recycled Water Guidelines. Phase 2 of the project includes stormwater recycling.
- Stormwater Industry Association of NSW