Various factors such as population growth, urbanisation and climate change are causing water shortages in many places around the world. Lack of safe and reliable water causes millions of human deaths a year. There are a number of ways that people can manage water better to minimise water ‘stress’ and help the environment.

Why save water

Water is a finite and irreplaceable resource.

Water is essential for life. Adequate safe water is crucial for healthy ecosystems as well as being fundamental to human well-being. It is vital for reducing disease and improving the health, welfare and productiveness of human populations. It is also at the heart of adaptation to climate change, serving as the link between the climate system, human society and the environment.

In the world today a total of 748 million people do not have access to a safe and reliable water source. To achieve the right to access safe drinking water requires real improvements for several billions of people.

Water management is a serious challenge, but if it’s done efficiently and equitably, it can play an important role in boosting the resilience of social, economic and environmental systems.

Why save water

It is good to manage and conserve water use, even in places where there is plenty of water,  like New Zealand, because of:

1. Less resources used

Water uses resources such as land, energy, metals and plastics to build the infrastructure to collect, treat, pump, drain and treat again. Water infrastructure includes water collection, reservoirs, pump stations, treatment plants and pipes, plus all of the wastewater infrastructure.

New reservoirs cause the loss of high quality agricultural land and displacement of people. Reservoirs are also very expensive. Maintaining infrastructure for water supply includes the costly upgrades and maintenance of pipes, sewers and treatment facilities. As well as the fuel consumption to distribute water around the network.

2. Saving the environment

Building reservoirs has a large environmental effect including altered streamflows, destruction of wilderness, changes in local erosion patterns, and generally degraded ecological health. Many of our rivers, wetlands and bays have been degraded by human water use. This is due to the high levels of water extracted, as well as polluted surface runoff and stormwater flushed into them.

Humans divert water from ecosystems. Protecting our natural eco-systems from further damage is critical, especially for the survival of some endangered species. The earths oceans, streams and lakes that are the lifeblood of local eco-systems are used as waste water dumping grounds, hurting everything that relies on these water sources.

Water consumption for agriculture affects the natural water cycle. This degrades production areas and intensifies other environmental problems such as land-clearing and eutrophication.

3. Resilience and self-sufficiency

With the escalating effects of population growth, climate change and environmental degradation it is prudent to establish ways to manage water use in the home – even collecting rainwater and use grey water water on site.

Main uses of water


Agriculture is by far the biggest consumer of water globally, accounting for 70% of withdrawals worldwide, although this figure varies considerably between countries.

Industry and energy

Industry and energy together account for 20% of water demand. More-developed countries have a much larger proportion of freshwater withdrawals for industry than less-developed countries, where agriculture dominates.

The water used in agriculture, industry and energy is called virtual water (see below), because the end consumer doesn’t actually see the water.


Domestic use accounts for 10% of the total. And yet, worldwide, an estimated 748 million people remain without access to an improved source of water and 2.5 billion remain without access to improved sanitation.

Virtual water

The information above highlights the fact that most of the water we use is not actually water itself. The water content of the goods and services we use, which is an indirect water use, is called virtual water. The table below shows how much water is used in the production of some everyday goods. Read more about Virtual Water here »

ItemVirtual water (litres)
1 glass of beer (250 ml)75
1 glass of milk (200 ml)200
1 cup of coffee (125 ml)140
1 cup of tea (250 ml)35
1 slice of bread (30 g)40
1 slice of bread (30 g) with cheese (10 g)90
1 potato (100 g)25
1 apple (100 g)70
1 cotton T-shirt (250 g)2000
1 sheet of A4-paper (80 g/m2 )10
1 glass of wine (125 ml)120
1 glass of apple juice (200 ml)190
1 glass of orange juice (200 ml)170
1 bag of potato crisps (200 g)185
1 egg (40 g)135
1 hamburger (150 g)2400
1 tomato (70 g)13
1 orange (100 g)50
1 pair of shoes (bovine leather)8000
1 microchip (2 g)32

Managing water in the home

As well as all the virtual water people use indirectly, water is also used directly in the home for things like drinking, cooking, toilets, baths, showers, laundry, cleaning and in the garden.

Click here to learn about managing home water use.