A recent ABS report revealed that in 2001, 25 per cent of water consumption in NSW was for outdoor or external purposes (Table C1). This was approximately the same as the proportion used in the bathroom (26 per cent) and for toilets (23 per cent). Kitchens and laundry uses accounted for the remaining 26 per cent. One of the paradoxes facing water managers is that although they have been successful in providing a reliable supply of drinking water, little of it is actually drunk (approx 1 per cent). The volume of potable water actually consumed, used in food preparation or cleaning cooking equipment and utensils, cutlery and crockery is about 10 per cent of household consumption.

Derived from Tables 9.6 and 9.7 in ABS 2004

No regional breakdown of this consumption within NSW is offered in the ABS report (2004), but given that the great proportion of this consumption is accounted for by households in Sydney, the NSW figure can reasonably be taken as a close proxy for the Sydney Metropolitan Area at that time. Recent research shows that water restrictions on garden watering and car washing, the main targets of these restrictions, at best impacted on a minority of Sydney residents; namely, those who had gardens and bothered to water them, or those who regularly washed their cars at home. These turned out to be minority pursuits across households in Sydney, even before the introduction of restrictions.

The other key fact to note here about water consumption, as evidenced in several recent studies (IPART 2004a; Troy et al. 2005; Eardley et al. 2005), is that the size of household is a key determinant of domestic water consumption. A number of studies indicate that on a per-capita basis Sydney households in different forms of accommodation have, for all practical purposes, similar annual demand for water, at approximately 100kL (IPART 2004a & b; ABS 2004; Troy et al. 2005). Research also indicates that there were considerable economies of scale in domestic water consumption in Sydney. This implies that, per-capita water consumption is not dependent on the residential built form. Falling household size is likely to be accompanied by an increase in average per-capita consumption.

Given that the current restrictions on external water use have probably reduced such use as far as is possible, then it is only by reducing the consumption of potable water inside the home that real gains in winding back the growing demand for water services in Sydney can be made.

Whatever the cause of the increasing inability of the water-supply system to meet current demand, whether it is due to growth in demand exceeding the supply, the need to maintain environmental flows, reduced runoff in the dam catchments due to long-run climatic cycles or to global climate change, there is an urgent need to re-examine Australian cities’ water-services systems. This is needed to make the cities more water independent without at the same time creating unacceptable stresses on the regions from which water is abstracted or of creating environmental stresses in the water bodies around them into which wastewaters are discharged.

City water corporations have undertaken major exercises in demand management which significantly reduced consumption, most of which has been achieved mostly through improved efficiency in commercial and industrial activities. Mandatory restrictions on domestic water consumption, with severe penalties for those breaking the restrictions, have also been used to reduce consumption. The totality of these measures, however, remains insufficient to be able to rely on dams as the major supply.

A variety of alternative sources of water have been proposed in each city. In Sydney these include increased extraction from the Shoalhaven River south of Sydney (a river which is already stressed), large-scale recycling, extraction from aquifers in the Sydney region and building a major desalination plant. All proposals also imply continuation of the nineteenth-century solution to meet the demand for water by increasing supply. Before adopting any of these ‘solutions’ it would be apposite to review the nineteenth-century decision-making to try to understand how Sydney has reached the current crisis and to explore alternative methods of providing essential water services. The same could be said of other large cities such as Brisbane where a significant proportion of the consumption of water is used for cooling water flows in power stations and where the basic demands for water have not been reviewed. The draft water plan for SE Queensland (QWC 2008) nonetheless proposes five desalination plants and recycling of sewage (without public consultation) to maintain water services. In the case of the desalination plants, little consideration appears to have been given to the increase in greenhouse gases and therefore increased climate change pressures to which their operation would lead.

Many of the proposals to increase supply by exploiting wastewater flows assume that the waste streams are available to be sold. However, in Chapter 7 Gray and Gardner advance a compelling argument that waste may be seen as belonging to those who create it. This raises several considerations, including whether or not those discharging body wastes can object to their wastes being sold to others without their approval or of being used in recycling systems without their approval.

The development of reticulated water supply and sewerage systems in Australian cities in the late nineteenth century led to improved personal hygiene and improved sanitation, which was reflected in dramatic improvements in the health of communities. This success has coloured the approaches to water supply and management ever since and has raised community expectations that the present water-services systems can continue to do so. Unfortunately, they cannot.

Rather than simply increasing supply, a different strategy is now required to significantly reduce consumption of potable water. The strategy must acknowledge that the need to supply potable water for drinking and basic health reasons remains but that for other purposes individual and community expectations have to change. The question is: how can this be achieved at the same time as the use of potable water for purposes and activities that do not need to use water of drinking quality is reduced in an equitable manner? The current ‘drought’ provides the need for short-term measures to begin the process of re-educating people, of changing their patterns of consumption, of reshaping some of their behaviour and attitudes. The increasing acceptance of the reality of climate change and, with it, the increased variability in rainfall provides opportunities to change expectations and cultural norms that affect the patterns of consumption in potentially a more profound way.

Two basic approaches suggest themselves:

Currently about a quarter of the per-capita average annual consumption of potable water is used to clear the toilet basin but this is not sufficient to transport the approximately 500 kilos of urine, faeces and paper ‘produced’ per capita annually (note that this is about twice the amount estimated to have been ‘produced’ at the time of the Chadwick report on sanitation. One of the problems was that while the Chadwickian solution to sanitation was based on water-borne transportation of wastes it assumed a relatively low flow of water. The sewers themselves had relatively high gradients.

Changes in water-using behaviour increased the wastewater flows, which had two consequences.

The first was that with higher flows the sewerage lines could be laid at lower gradients, leading to significant economies in the construction and operation of sewerage systems. One consequence of this approach is that currently the sewers need water in addition to that required to flush toilets to transport wastes to the treatment plants. This means that there is a tendency for sewerage-system managers to be less enthusiastic about measures to reduce ‘wastewater’ discharges to the sewer. The problem of dwellings ‘producing’ less sewage and wastewater flows on average thus lead to tendencies for sewers to ‘block’. This has necessitated the release of potable water directly to the sewers to ensure that the system functions. Examples of this ‘problem’ may be seen in holiday and retirement areas that have rapidly expanded or where only small proportions of the dwellings serviced by a sewerage system are occupied at one time.

The second was that sewage treatment plants are required to treat ever-increasing volumes of water to increasing standards to minimise the environmental stresses from the urine, faeces and other wastes discharged to the sewer. The fact that approximately 40 per cent of the potable water delivered to dwellings (some of it being bathroom and laundry discharge) is now used to transport toilet wastes should itself cause questions to be raised about the efficacy of the present approach to sanitation services.