Some rainfall is collected in rainwater tanks or other storage systems for further use. Stormwater is rainwater that enters the drainage system either by being collected off roofs in gutters and pipes, or by falling on paved areas such as driveways, roads and footpaths and easily becomes polluted by chemicals and litter.
In the past, stormwater has been considered wastewater because of contamination. It has mainly been managed by local councils as runoff into the sea.
Information about
stormwater pollution and
monitoring of stormwater can be found on the Adelaide and Mount Lofty Ranges (AMLR) NRM Board website. The board has also undertaken
floodplain mapping of the various catchments in the Adelaide area.
Patawalonga Lake
At the Patawalonga Lake, additional infrastructure has been constructed to ensure the lake is kept clean and healthy with seawater and to also manage stormwater to avoid local flooding. For more information, view the Patawalonga Lake page.
Stormwater harvesting
Harvesting stormwater is now seen as a way to improve water quality and produce a significant, if irregular, non-drinking water resource that is particularly useful for sports grounds, parks and gardens, agriculture and flushing toilets.
South Australia leads the nation in stormwater capture and reuse. In the future, new developments will need to include water-sensitive designs that optimise the use of recycled water.
With local council involvement, the
Stormwater Management Authority (SMA) has estimated that up to 60 billion litres of water per year can be harvested from Adelaide's stormwater using retention ponds and re-created urban wetlands.
Stormwater strategy
On 5 July 2011, Minister for Water Paul Caica released the Stormwater Strategy, a high-level ‘road map’ for the future of stormwater management in South Australia.
The Stormwater Strategy includes nine actions to improve stormwater management in Adelaide in a way that integrates it with other urban water resources. Under the Strategy, the South Australian Government will develop a ‘blueprint for urban water’ to bring together stormwater and wastewater alongside other water resources in the Adelaide region, guide future infrastructure investment and policy requirements across Adelaide, and assist transition to a water sensitive city.
Stormwater projects
Information about stormwater projects in South Australia can be found in the
Urban Stormwater Harvesting Options Study and the
Water for Good Plan.
Constructed wetlands provide opportunities for improved pollution control and temporary storage, and this increases the potential for reusing stormwater. In Adelaide stormwater reuse can be enhanced by the technique of
aquifer storage and recovery (ASR) and constructed wetlands. This involves stormwater or even highly treated wastewater being stored below ground for later extraction and reuse.
The ASR approach is particularly useful in urban areas with suitable aquifers as the cost of land for above-ground storages can be extremely high. A number of large schemes using ASR have been developed in the Adelaide and Mount Lofty region:
More information about the use for stormwater management can also be found on the
Water Proofing Northern Adelaide and
Waterproofing the South websites.