Drought across swathes of Australia, highlights our need for water conservation in addition to seeking new sources of water (demand and supply-side resource options). Water conservation or efficiency improvement is currently a non-systematic process along the lines of ‘if we do such and such then we will save so much water’. Such an approach is ad-hoc and only has the appearance of being ‘quantitative’. We would class it as qualitative, or maybe advanced qualitative water conservation. True quantitative or structured water auditing of non-domestic water consumption is an iterative, systematic and documented process of obtaining reliable use data, validated by a closure approach. Opportunities are identified for water use reduction, water reuse, recycling and for water resource substitution. Financial assessment of savings in cost against cost of measures will provide a payback period. A water management strategy or Water Management Plan (WMP) as it is known in Victoria, Australia, is devised which is consistent with legal requirements, the enterprise's environmental policy and its movement towards sustainable development. Regulators have legislated for mandatory WMPs and audits in Victoria, but this is the only state so far to do this. Mandatory water auditing should be an uncontested choice as it can only provide a win:win situation regulation to the private sector.
We argue that only the systematic process provided by structural water auditing constitutes quantitative water conservation. Further, statutory obligation for water users to engage in the water auditing process will give the broad, systematic quantitative information, and based upon which optimal water management strategies or WMPs can be devised. This will ensure a rational approach to our future water needs and the needs of our environment. It is anticipated that voluntary auditing in the arenas not mandated will increase in the long term if this is done.