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A Comprehensive Introductionto Water Footprints
Arjen Hoekstra
Professor in Water Management – University of Twente – the Netherlands
Scientific Director – Water Footprint Network
www.waterfootprint.org
1. The water footprint of products
2. The relation between consumption, trade and water
3. The water footprint of a business
4. From concept to practiceWater footprint impact assessment
Reducing and offsetting water footprints
5. Conclusion
6. The way forward
Overview Presentation
The water footprintof products
1
Water footprint of a product
► the volume of fresh water used to produce the product, summed over the various steps of the production chain.
► when and where the water was used:a water footprint includes a temporal and spatial dimension.
► type of water use:green, blue, grey water footprint.
Water footprint of a product
Green water footprint
► volume of rainwater evaporated.
Blue water footprint
► volume of surface or groundwater evaporated.
Grey water footprint
► volume of polluted water.
HarvestingCotton plant Seed-cotton
Cotton seed
Cotton lint
Cotton seedcake
Cotton seed oil
Grey fabric
Fabric
Final textile
Cotton linters
Cotton, notcarded or combed
Cotton, carded orcombed (yarn)
Hulling/extraction
Garnetted stock
Carding/Spinning
Yarn waste
Knitting/weaving
Wet processing
Finishing
Cotton seed oil,refined
Ginning
18.0
63.0
82.0
35.0
47.0
16.0
33.0
51.0
20.0
10.0
00.1
07.1
00.1
00.1
99.0
95.0
10.0
05.0
00.1
00.1
00.1
00.1
99.0
95.0
10.0
05.0
82.0
35.0
Legend
Value fraction
Product fraction
Production chaincotton
[Hoekstra & Chapagain, 2008]
Blue water footprint Million m3/yr
2959Mm3/yr
690 Mm3/yr
421 Mm3/yr
2459 Mm3/yr
803 Mm3/yr
581 Mm3/yr
533 Mm3/yr
450 Mm3/yr
EU25's impact on blue water resources
[Hoekstra & Chapagain, 2008]
Water footprint of EU’s cotton consumption (blue water)
283 Mm3/yr
485 Mm3/yr
3467 Mm3/yr
165 Mm3/yr
Green water footprint Million m3/yr
186 Mm3/yr
325 Mm3/yr
EU25's impact on green water resources
Water footprint of EU’s cotton consumption (green water)
[Hoekstra & Chapagain, 2008]
Dilution water footprint Million m3/yr
409 Mm3/yr
310 Mm3/yr
92 Mm3/yr
102 Mm3/yr
635 Mm3/yr
83 Mm3/yr
398 Mm3/yr
697 Mm3/yr
EU25's impact on global water resources due to pollution
Water footprint of EU’s cotton consumption (grey water)
[Hoekstra & Chapagain, 2008]
The water footprint:making a link between consumption in one place and impacts on water systems elsewhere
Shrinking Aral Sea
The water footprint:making a link between consumption in one place and impacts on water systems elsewhere
[Photo: WWF]
Endangered Indus River Dolphin
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Aldaya & Hoekstra, 2009]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
Water footprint of biofuels from different crops [litre/litre]
[Gerbens-Leenes, Hoekstra & Van der Meer, 2008]
The relation between consumption, trade and water
2
Water footprint of a nation
► total amount of water that is used to produce the goods and services consumed by the inhabitants of the nation.
► two components:• internal water footprint – inside the country.• external water footprint – in other countries.
Water footprint of a nation
► National water footprint =national water use+ virtual water import– virtual water export
Export
Consumption
Impo
rt
Pro
duct
ion
Virtual water import for re-
export
Water use for export
Virtual water export
External water
footprint
Internal water
footprint
Water footprint
+
+
=
=
Virtualwaterimport
Water use within
country
++
= =
Virtual water
budget
+
+ =
=
National water accounting framework
The traditional statisticson water use
Arrows show trade flows >10 Gm3/yr
Regional virtual water balances(only agricultural trade)
[Hoekstra & Chapagain, 2008]
0
500
1000
1500
2000
2500
3000
Chi
na
Indi
a
Japa
n
Pak
ista
n
Indo
nesi
a
Bra
zil
Mex
ico
Rus
sia
Nig
eria
Thai
land
Italy
US
A
Wat
er fo
otpr
int (
m3/c
ap/y
r)
Domestic water consumption Industrial goods Agricultural goods
Water footprint per capita
Global average water footprint
[Hoekstra & Chapagain, 2008]
Global water footprint of the Netherlands
82% of the Dutch water footprintis outside its own borders
[Hoekstra & Chapagain, 2008]
Environmental Water Scarcity Index
[Smakhtin, Revenga & Doll, 2004]
Water stress(withdrawal-to-availability)
< 0.3
0.3 - 0.4
0.4 - 0.5
0.5 - 0.6
0.6 - 0.7
0.7 - 0.8
0.8 - 0.9
0.9 - 1.0
> 1.0
The impact of the water footprintof the Netherlands: hotspots
External water footprint for agricultural products (106 m
3)
0 - 10
10 - 100
100 - 1000
> 1000
Hotspots
Main product category in hotspot
Fruit, nuts and wine
Oil crops and oil from oil crops
Coffee, tea, cocoa and tobacco
Livestock and livestock products
Cotton products
The water footprint of a business
3
Operational water footprint• the direct water use by the producer – for producing,
manufacturing or for supporting activities.
Supply-chain water footprint• the indirect water use in the producer’s supply chain.
Water footprint of a business
bluewateruse
greywater
Farmer RetailerFood
processer
Virtualwaterflow
Virtualwaterflow
Virtualwaterflow
greenandbluewateruse
bluewateruse
greywater
greywater
Consumer
bluewateruse
greywater
The virtual water chain
[Hoekstra, 2008]
The water footprint of a retailer
bluewateruse
greywater
Farmer RetailerFood
processer
Virtualwaterflow
Virtualwaterflow
Virtualwaterflow
greenandbluewateruse
bluewateruse
greywater
greywater
Supply chain WF Operational WF
Consumer
bluewateruse
greywater
End-use WF of a product
[Hoekstra, 2008]
From concept to practice
4
From water footprint accounting to policy formulation
1
Vulnerability of local water systems
Spatiotemporal-
explicit water
footprint of a• product• individual• community• business
Current water stress in the places where the water footprint is localised
Impacts of the
water footprint• environmental• social• economic
Reduce and
offset the
negative impacts
of the water
footprint
2 3
[Hoekstra, 2008]
Global map of where
the water footprint
is located
Overlay
Water footprint impact assessment
Global map of where
water systems are
stressed
Global hotspot map
Hypothetical example
Main producing regions
Producing countries
Global water footprint of a businesslocated in the Netherlands
Water stress(withdrawal-to-availability)
< 0.3
0.3 - 0.4
0.4 - 0.5
0.5 - 0.6
0.6 - 0.7
0.7 - 0.8
0.8 - 0.9
0.9 - 1.0
> 1.0
Environmental water scarcity
Water stress(withdrawal-to-availability)
< 0.3
0.3 - 0.4
0.4 - 0.5
0.5 - 0.6
0.6 - 0.7
0.7 - 0.8
0.8 - 0.9
0.9 - 1.0
> 1.0
Main producing regions
Hotspots
Hotspots
Hotspots are spots where
(1)the business has a substantial water footprint
(2) water is stressed.
Reduction: all what is ‘reasonably possible’ should have been done to
reduce the existing water footprint; do not undertake water-using
activities if better alternatives are available.
Offsetting: the residual water footprint is offset by making a
‘reasonable investment’ in establishing or supporting projects that
aim at a sustainable, equitable and efficient use of water in the
catchment where the residual water footprint is located.
[Hoekstra, 2008]
Reducing and offsetting the impacts of water footprints
Shared responsibility and an incremental approach
Consumers or consumer or environmental organizations push businesses and governments to address water use and impacts along supply chains.
Some businesses act voluntarily in an early stage.
Governments promote businesses in an early phase and implement regulations in a later phase.
The way forward
6
Mission: Promoting sustainable, equitable and efficient water use through development of shared standards on water footprint accounting and guidelines for the reduction and offsetting of impacts of water footprints.
Network: bringing together expertise from academia, businesses, civil society, governments and international organisations.
www.waterfootprint.org
Status today: 29 partners from six continents
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