New suburbs could disconnect from city drinking water supplies and wastewater collection systems, easing fears of future water shortages in Australia's cities, according to a study on sustainable urban water supply by the Commonwealth Scientific & Industrial Research Organisation (CSIRO).
Dr. Grace Mitchell of CSIRO Urban Water explained: "Introducing rainwater tanks, dry toilets and domestic fire sprinklers are among a range of measures that offer a self-sufficient water future for new home owners. In Australia's self-sufficient suburb there is no reticulated potable water to homes and factories. All residential, commercial and industrial wastewater is collected, treated and recycled by a local wastewater treatment plant and stormwater is managed locally."
A less radical scenario envisions a reticulated water supply that is maintained and supplemented by domestic rainwater tanks, and stormwater collection for commercial users and sports ground watering. "In this socially acceptable scenario," Dr. Mitchell explained, "demand for potable water piped to the suburb is reduced by 62% and the output of treated wastewater is cut by 88%." Contaminants such as nitrogen and phosphorus are reduced by, respectively, 37% and 66% due to reduced wastewater discharges.
The study found that this model could provide water supply, drainage and sanitation services to a greenfields development in a manner that is cost neutral in comparison to traditional water servicing and significantly reduces its effect on the total water cycle.
