What is virtual water? Virtual water is the water used to
create the goods and services that we consume and use. The embodied
water concept is illustrated in the diagram with a bowl of pasta,
which may hypothetically contain 200 litres of virtual water,
although only two litres of boiling water is used to produce it at
home.
By Mike Muntisov
Thinking about virtual water can make us look at our water
management systems in completely different ways. A detailed
analysis of Victoria’s virtual water cycle shows that:
- Victorians harvest around 25 per cent of the state’s total
historic average stream flows;
- Of this harvested water, around 40 per cent (2000GL) is
exported out of the state as virtual water, mainly embodied in food
products;
- Victorians each consume about 0.8 ML of virtual water each year
which is about eight times our direct water use
A breakdown of the virtual water consumption of Victorians is
shown in the pie chart. Dairy products and red meat together
represent more than a quarter of our total virtual water
consumption. Indeed, Victorians’ virtual water consumption in the
form of dairy products exceeds the state’s total direct household
consumption of water.
A recent UNESCO funded study also found that Australia, the
world’s driest inhabited continent, was the largest net exporter of
virtual water in the world.
Why do Victoria and Australia export so much virtual water? The
answer is that there is a lot of water embodied in our food export
products. In comparison, our imports are dominated by manufactured
products that generally have a low virtual water content; hence we
are a large net exporter of virtual water. This tells us that water
management and use is dependent on total economic activity, not
just direct household water use.
As the economy grows so too will water use in the “business as
usual” scenario. A simplistic 3 per cent per annum growth (The
Australian average over the last 30 years has been 3.2 per cent per
annum) would result in the need to harvest 100 per cent of the
state’s historic average stream flows by 2050 (even earlier with
climate change). So our water management paradigms and the balance
of Victoria’s and Australia’s economic sectors will need to
change.
We will need to ask ourselves whether the nation is getting the
best value it can from its water resources. This may involve
starting to look at strategic aspects of virtual water trade
including reviewing our export product mix, importing virtual
water-rich products from water-rich nations such as New Zealand, or
moving the growth of water-intensive industries such as irrigation
to the water-rich parts of Australia. An appropriate pricing policy
and market framework will facilitate these changes.
Finally, thinking in terms of virtual water also shows that
lifestyle choices at the household level can influence water
management within the whole economy. For example, our diet choices
affect virtual water consumption. Foods which some dieticians
recommend eating in moderation have a high virtual water content
(eg. dairy products, red meat, sugar). While those that are often
recommended for increased consumption (eg. fruit, vegetables,
grains, seafood) tend to be lower in virtual water. Indeed, a
vegetarian diet has half the virtual water content of a standard
meat-rich diet. And to answer a frequently asked question, beer has
the lowest virtual water content of the common alcoholic
beverages.
Ultimately, we may reach a stage where this is “watersmart”
labelling on all household products. In a water conscious
environment this will put pressure on producers across the whole
production chain to reduce water consumption. “Low water use”
products may appear beside “97% fat free” products on the
supermarket shelves!
Thinking in terms of managing virtual water sources and demands
provides an eight-fold greater impact on overall water management
than simply focusing on household water consumption. It also
provides a strong link between irrigation use and personal
lifestyle – in other words, water management is not a problem for
farmers alone.
Please click the link here to read the full report.
This article was published in Water – the journal of the
Australian Water Association
For further information, contact:
Mike Muntisov
Tel: 61 3 8687 8222
Email: Mike Muntisov