A Comprehensive Introduction to Water Footprints Arjen Hoekstra Professor in Water Management – University of Twente – the Netherlands Scientific Director

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


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)


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)


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



[Aldaya & Hoekstra, 2009]








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)


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


Global water footprint of the Netherlands

82% of the Dutch water footprintis outside its own borders


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


< 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


< 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

Documents

A Comprehensive Introduction to Water Footprints Arjen Hoekstra Professor in Water Management – University of Twente – the Netherlands Scientific Director