Other ways of indirectly reducing demand for potable water include developing local-area harvesting of stormwater runoff for use in public parks and gardens. This will become more important as climate change proceeds because it will be even more important to encourage and support the growth of trees and shrubs to help manage the production of CO2 emissions. More energetic encouragement of the use of greywater for the maintenance of trees and shrubs around dwellings would have a similar effect.
Separating the water-supply services from the sanitation services would lead to significant reductions in water consumption and sewage flows. The new approach would require dwellings to install a rainwater tank, a greywater-recycling system and a storage tank for the treated greywater. These components would increase the cost of dwellings but there would be significant savings in the dwellings’ plumbing and in their water-supply system.
Installation of a new waste-management system would lead to significant reductions in sewage flows, which would lead to economies in the development and operation of the sewerage system. Reduction in the sewage discharge from dwellings would lead to smaller volumes requiring to be treated at sewage treatment plants and, in turn, smaller volumes to be discharged into receiving ecosystems.
The installation of dry-composting toilets would greatly reduce the need for sewerage services, as well as reducing water consumption. Such toilets would be cheaper to install than the present water-based flushing systems; moreover they would greatly reduce the environmental stresses currently experienced in the water bodies into which sewage is discharged.
The significant savings in the water-supply, sewerage and stormwater-management systems could be used to subsidise the installation of the new approach to water services. The reduction in the volume of potable water supplied by the water-supply network would leave more water to be applied to maintain environmental flows and to provide a more secure supply in dry periods.
Securing a similar degree of water independence for households in multi-unit developments would, in principle, be no different from those in traditional housing, although the collection of rainwater and the processing and storage of recycled water would present slightly different challenges.
As discussed above, water authorities were originally created as public-health agencies and they have been successful in that mission. Water consumption is now more a result of the commodification of water and changes in behaviour. One consequence of the need to encourage more local responsibility for water services is that the health standards of the community would need to be protected. Local water storage and waste management would need to be regulated and compliance with the regulations checked regularly to ensure that the water supply was of a high standard. Checking the quality of household and other supplies could become part of the obligations of the meter readers who visit consumers monthly to record their consumption.