Rainwater and stormwater
Rainwater is increasingly being collected in household tanks to supplement household water supplies. On a larger scale, stormwater is a resource that offers environmental, economic and social benefits to our urban areas.
Collecting rainwater
Rainwater tanks have a long history of use in Australia, especially in many rural areas that often depend upon them for household water. In recent years, there has been an upsurge in rainwater tank installations in towns and cities as water availability and government policies have changed.
While rainwater collection can boost the volume of water available to households and reduce the amount of stormwater flowing into gutters and local waterways, the costs and reliability of tanks for households vary dramatically depending on location and individual household circumstances.
Stormwater harvesting
Just as rainwater tanks can offer a supplementary water supply option for households, larger-scale stormwater harvesting and re-use can augment the normal water supply for urban communities.
Stormwater collects on paved areas, such as driveways, roads and footpaths, or non-residential roofs. This water usually flows into stormwater drains, creeks and rivers; sometimes reaching the sea.
The volume of stormwater runoff from a city is often greater than its entire combined household water use, and has the potential to provide water for irrigating parks, gardens and ovals, as well as replenishing groundwater supplies. Use of stormwater for these purposes can help to take pressure off the potable (drinking) water supply. It can also reduce the level of stormwater pollution in our waterways and alleviate flooding reoccurrence in high-risk areas.
Harvesting stormwater involves monitoring, collecting, storing and treating the water before it is distributed. With highly variable rainfall, and urban areas with little space for constructing storage facilities, this is not as straightforward a task as it first appears. On top of this, stormwater carries pollutants and pathogens that need to be treated to a level fit for the intended use of the water.
Stormwater harvesting is a real option for easing pressure on our urban water supplies and stormwater asset management, and stormwater harvesting opportunities are being investigated through the National Water Initiative.