TAKING CAUTIOUS STEPS IN THE USE OF WATER FOOT-PRINTING
CIWEM's latest policy position statement welcomes the
role that concepts such as water foot-printing can play in raising
awareness of the volumes of water required for the production of
goods, but urges caution over the use of such terms, which ignore
the complexity of a number of factors such as the situation and
source from which water is abstracted and returned.
Highlighting the size of water footprints has been extremely
beneficial in focusing public attention on the volume of water
required to produce food and goods at source and to deliver them to
end users thus drawing attention to these hitherto overlooked
issues. Water footprints determined in this 'all things
included' way can be surprisingly large. On average 140
litres of water are said to be required to produce one cup of
coffee, and it is estimated that 17,000 litres of water are needed
to produce one kilogramme of beef (EBLEX, 2010). A
typical UK adult's diet is said to have a water footprint of around
3,400 litres/day, compared to a direct drinking water requirement
of ten litres/day and an overall direct use (for domestic drinking,
cooking, washing, watering and sanitation purposes) of around 150
litres/day.
However, CIWEM urges caution and care must be taken not to use
the concept too simplistically. A water footprint is not a
direct measure of environmental impact. The timing and
location of the associated resources are vitally important aspects.
The impact of water resource use on society and the environment is
unlike the impact of carbon use and emissions in this respect,
because whilst carbon emissions impact globally, water resource use
impacts are confined to a local area or region, even when knock-on
consequences are taken into account. Selecting between goods
(or services) solely on the basis of the volumes of water involved
in their production can therefore be very misleading.
The establishment of a definition which reflects impact rather
than volume would avoid such problems but the complex interplay
between the range of different factors make this difficult.
Chair of CIWEM's Water Resource Panel, Colin Fenn, said: 'It is
a myth to suggest that the water footprint is a measure of
environmental impact. So far, water footprints only measure the net
volume of water associated with the manufacture of products and
delivery of services. More work needs to be done to assess and
determine the indentation of the footprint and its effects on the
environment.'
Back
