Access to clean accessible water is coming under pressure worldwide. While New Zealand is relatively fortunate in its supply of water, it should not be complacent. Despite a widely held belief to the contrary, water supply is constrained especially in some parts of New Zealand while at the same time there is a combination of increasing and competing demands for this increasingly valuable (in dollar terms) resource.
Water services are a major component of council expenditure, generally in the region of 30-40% and councils are increasingly aware of the benefits of water conservation and water use efficiency. Some of the key reasons to consider water conservation in the home are as follows:

• Capital cost savings through delaying or eliminated infrastructure development.
• There are significant cost savings to be made in wastewater management through reducing the water that goes through the system.
• There is a large and growing body of robust scientific evidence that shows existing water supply systems cause profound changes to the water cycle and do not operate in harmony with natural water cycles and water catchments. They are in fact inherently unsustainable being designed at a time when both the human population and economy was considerably smaller and less resource intensive than the present day
• The need to address climate change issues and the need to improve the resilience of our supply system to cope with unforeseen change and greater variability in climate patterns
• Reducing the contribution of leaks and spills from wastewater on declining water quality in New Zealand
• There are energy savings to be had through reducing in-house water use.
• There are energy savings in both the treatment of water to a potable standard and its reticulation.
• There are further energy savings to be made in the reticulation and treatment of wastewater.
• The customer benefits to be had from lower water and power costs.
• The expectation from consumers that alternatives will be investigated when a major new water supply source has been signalled as required.
• Within New Zealand there is a requirement under the Local Government Act (LGA 2002), for councils to think sustainably across the four pillars of wellbeing – cultural, environmental, social and economic. Existing reticulated water supply systems on their own do not adequately meet sustainability objectives across any of these four well-beings.
• Worldwide demand for water is doubling every 21 years – developed countries in particular have a social and ethical obligation to reduce the amount of water their societies use (and waste) in the same way that emissions reductions are now actively being sought to limit the effects of climate change.

Water use efficiency can be built into new homes in a variety of ways, through their design; selection of taps and appliances; incorporating supplementary water supply or recycling water within the home and garden.

Good design can also help to minimise the impact of removing water from a house and section. Reducing the demand or re-using water limits wastewater volumes in the mains sewage system. Wastewater typically costs twice the amount to treat and dispose of than water costs to supply. Stormwater, the rain that lands on impervious surfaces on a developed section, can be drastically reduced through detention or absorption on site, reducing infrastructure costs and environmental damage.

It must be acknowledged that council rules and restrictions relating to water aspects of the home are not uniform across the country and some do not always favour optimising water use efficiency. However it is important to explore all feasible options to make a home water efficient and to give a well reasoned rationale as to why they are not incorporated in the home if that is the case.