Virtual Water is the volume of
water needed to produce a specific quantity of
good or services. For agricultural products, it
is calculated on the basis of a country’s specific
crop water requirements estimated in cubic meter
per ton of products (< see chart for comprehensive
calculation >). This water is said to be virtual
as it is not anymore present in the good or service.
For instance, an egg needs 135 liters of water
to be produced a 150 grams hamburger needs 2400
liters of water to be produced, a cotton tee shirt
and a pair of (bovine) leather shoes respectively
2000 and 8000 liters.
These observations reframe our
perception of water in a totally different dimension.
of relativity… once and for all
The importance of absolute terms
gives us goals in terms of increasing water productivity
(i.e. is the amount of water for a specific amount
of production or crop water requirements).
The analysis must also consider
the comparison between countries and the origin
of the production of goods or services. Depending
on climatic, land, geographical and hydrological
characteristics, a country uses more or less water
to produce certain goods. Put differently, countries
have specific water productivities for each of
its agricultural production:
a country can have an advantage over others to
produce certain products in terms of water content
as a production factor. This does not mean that
Morocco should stop growing wheat or maize and
import them from other countries. Firstly because
countries have the right to implement national
food security policies, secondly because what
matters is the relative advantage of producing
a good so that a country can always gain from
producing a basket of good depending on its relative
Water that crosses borders
Water is bulky – of course, water
cannot be transported as easily as goods can be.
It is far more interesting to export virtual water
embedded into the good.
Water crosses borders – it does
so in a virtual way through international trade.
A virtual water map can then be drawn as a subsequent
layer of international trade flows. Right after
NAFTA (North American Free Trade Agreement) was
signed, Canada began to have concerns about its
water falling into the agreement’s constraint.
A text from the NAFTA statement of September 1993
"Unless water, in
any form, has entered into commerce and become
a good or product, it is not covered by the
provisions of any trade agreement including
the NAFTA. And nothing in the NAFTA would oblige
any NAFTA Party to either exploit its water
for commercial use, or to begin exporting water
in any form."
Let’s recall that the concept
of virtual water was put forward at first in 1994.
Mostly addressing the question of water bottles,
did Canada knew at the time the amount of Canadian
virtual water that would cross its border through
agricultural trade? Last evaluations show that
nearly 13% of all water consumed for agriculture
globally is being exported as virtual water.
On going research
Water GAP will try to contribute
to the debate on whether international trade can
save water or not, by:
- determining the impact of
selected agricultural trade policies on virtual
water flows and on how trade policy can affect
water depletion or water savings;
- determining how water can
be a side-factor for agricultural trade negotiations
in particular in the context of World Trade
Organization or regional trade agreements;
- determining the impact of
agricultural products subsidies and water uses
subsidies on virtual water flows.
Le Vernoy, Alexandre, "Water
and Trade in Agriculture: Investigating Virtual
Water Hypothesis in the Euro-Mediterranean Region",
Policy brief. May 2006. English,
Le Vernoy, Alexandre, "L’eau,
une chance pour l’agriculture française: La libéralisation
des échanges agricoles pourrait donner l’avantage
aux pays utilisant plus parcimonieusement le précieux
liquide", Le Monde, January