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									A Comprehensive Introduction
    to Water Footprints

                     2009 Arjen Y. Hoekstra

   Professor in Water Management – University of Twente – the Netherlands
                Scientific Director – Water Footprint Network




                       www.waterfootprint.org
Overview Presentation

1. The water footprint of products

2. The water footprint of a nation
    The relation between national
    consumption, trade and water

3. The water footprint of a business

4. From concept to practice
    Water footprint impact assessment
    Reducing water footprints

5. Conclusion

6. The way forward
     1
The water footprint
   of products
                 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.
                        Components of a water footprint



                         Direct water footprint    Indirect water footprint




                                                                                consumption
                           Green water footprint     Green water footprint




                                                                                   Water
              Water withdrawal

Non-consumptive water
   use (return flow)
                           Blue water footprint       Blue water footprint




                                                                                pollution
                                                                                 Water
                           Grey water footprint       Grey water footprint
The traditional
  statistics
on water use

                                                                              [Hoekstra, 2008]
      Assessing the water footprint
      of crop and animal products




Water footprint of a crop
 Crop water use (m3/ha) / Crop yield (ton/ha)


Water footprint of an animal
 Sum of water for feed, drinking and servicing


Water footprint of a crop or livestock product
 Distribute the water footprint of the root product over its derived
  products
               Crop water requirement




1. Calculate reference crop evapotranspiration ET0 (mm/day)
   e.g. Penman-Monteith equation

2. Calculate crop evapotranspiration Etc (mm/day)
   Etc = ET0  Kc where Kc = crop coefficient

3. Calculate crop water requirement CWR (m3/ha)
   CWR = Σ Etc [accumulate over growing period]
              Irrigation requirement




Irrigation requirement = crop water requirement – effective rainfall
                      Crop water use




Green water use by crop =
   min (crop water requirement, effective precipitation)

Blue water use by crop =
    min (irrigation requirement, effective irrigation)
                Grey water footprint




•   volume of polluted freshwater that associates with the production of
    a product in its full supply-chain.
•   calculated as the volume of water that is required to dilute pollutants
    to such an extent that the quality of the water remains above agreed
    water quality standards.
                                                                                           0.16                             1.07          Cotton seed oil,
Production chain                                                                           0.47
                                                                                                     Cotton seed oil        1.00              refined


cotton                                                   Cotton seed
                                                                               Hulling/    0.51       Cotton seed
                                                                              extraction   0.33          cake

                                               0.63
                                               0.18                                        0.10
                                                                                           0.20
                                                                                                     Cotton linters
               Harvesting
Cotton plant                  Seed-cotton      Ginning
                                                                                                                    0.05
                                               0.35                                                                 0.10
                                                                                                                                    Garnetted stock
                                               0.82


                                                                       1.00          Cotton, not           Carding/
                                                         Cotton lint   1.00       carded or combed         Spinning


                                                                                                                    0.95            Cotton, carded or
                                                                                                                    0.99             combed (yarn)

                                                                                                                                        Knitting/
                                                                                                                    0.95
                                                                                                                                        weaving
                                                                                                                                                             0.05
                                                                                                                    0.99                                     0.10

                                                                                                                       Grey fabric                  Yarn waste


                                                                                                                  Wet processing

                                                                                                                    1.00
                                                                                                                    1.00

                                                                                                                           Fabric
    Legend
                                                                                                                        Finishing

     0 .35                  Product fraction                                                                        1.00
                                                                                                                    1.00

     0 .82                  Value fraction                                                                             Final textile
[Hoekstra & Chapagain, 2008]
Water footprint of EU’s cotton consumption (blue water)


                                                                                       421
                                                                                      Mm3/yr
                                                                             2959M
                                                                              m3/yr
                                                                     581
                                                                    Mm3/yr
                                                                803
                                                               Mm3/yr


                                                       450
                                                      Mm3/yr
                                              533
                                             Mm3/yr
                                     690
                                    Mm3/yr

                        2459
                       Mm3/yr




Blue water footprint
Million m3/yr




                                EU25's impact on blue water resources




                                                                                               [Hoekstra & Chapagain, 2008]
Water footprint of EU’s cotton consumption (green water)


                                                               485
                                                              Mm3/yr


                                                           165
                                                          Mm3/yr


                                                      325
                         186
                                                     Mm3/yr
                        Mm3/yr

                                       283
                                      Mm3/yr




                                                          3467
                                                         Mm3/yr




Green water footprint
Million m3/yr




                                 EU25's impact on green water resources




                                                                          [Hoekstra & Chapagain, 2008]
Water footprint of EU’s cotton consumption (grey water)



                                                                                               92
                                                                                    310       Mm3/yr
                                                                                   Mm3/yr
                                                                           635
                                                                          Mm3/yr
                                                                  102
                                                                 Mm3/yr
                                                         398
                             83                         Mm3/yr
                            Mm3/yr



                                               409
                                              Mm3/yr


                                      697
                                     Mm3/yr




Dilution water footprint
Million m3/yr



                           EU25's impact on global water resources due to pollution




                                                                                            [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




Endangered Indus River Dolphin
                                              [Photo: WWF]
This is a global average and aggregate number. Policy decisions should be taken on the basis of:
1. Actual water footprint of certain coffee at the precise production location.
2. Ratio green/blue/grey water footprint.
3. Local impacts of the water footprint based on local vulnerability and scarcity.




                                                                                                   [Hoekstra & Chapagain, 2008]
[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, 2009]
     2
The water footprint
   of a nation
                 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
                  National water accounting framework

                   Internal             External            Water
                                  +                    =
                     water                water            footprint   Consumption
                   footprint            footprint
                     +                        +                 +
                  Water use           Virtual water        Virtual
                  for export +        import for re-   =   water       Export
                                          export           export

                     =                    =                 =

                  Water use              Virtual           Virtual
                                  +                    =
                    within                water             water
                   country               import            budget
                     Production



                                           Import




The traditional
  statistics
on water use
Regional virtual water balances
        (only agricultural trade)




                   Arrows show trade flows >10 Gm3/yr


                                      [Hoekstra & Chapagain, 2008]
                                                       Water footprint per capita
                              3000
                                             Domestic water consumption                Industrial goods     Agricultural goods

                              2500
Water footprint (m /cap/yr)




                              2000
3




                              1500      Global average water footprint

                              1000


                              500


                                 0
                                                                                                   Mexico
                                                                Pakistan




                                                                                                            Russia




                                                                                                                                Thailand
                                                                                          Brazil




                                                                                                                                                   USA
                                                                                                                                           Italy
                                                                           Indonesia




                                                                                                                     Nigeria
                                     China


                                               India


                                                        Japan




                                                                                                                               [Hoekstra & Chapagain, 2008]
Major determinants of a water footprint


1.   Consumption characteristics

         Consumption volume
         Consumption pattern


2.   Production circumstances

         Climate: evaporative demand at place of production
         Agricultural practice: water use efficiency
       3
The water footprint of a
      business
Why businesses are interested



•   corporate social responsibility
•   corporate image / marketing perspective
•   business risks related to
     - freshwater shortage for own operations
     - freshwater shortage in supply chain
•   anticipate regulatory control
Water footprint of a business



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.
                       The virtual water chain




             Virtual                   Virtual                 Virtual
             water                     water                   water
              flow        Food          flow                    flow
Farmer                  processer                Retailer                Consumer




green grey               blue grey               blue grey               blue grey
 and water               water water             water water             water water
 blue                     use                     use                     use
water
 use




                                                                                 [Hoekstra, 2008]
         The water footprint of a consumer




             Virtual                  Virtual                 Virtual
             water                    water                   water
              flow       Food          flow                    flow
Farmer                 processer                Retailer                Consumer




green grey              blue grey               blue grey                blue grey
 and water              water water             water water              water water
 blue                    use                     use                      use
water
 use

                       Indirect WF                                      Direct WF




                                                                                 [Hoekstra, 2008]
             The water footprint of a retailer




              Virtual                    Virtual                 Virtual
              water                      water                   water
               flow        Food           flow                    flow
Farmer                   processer                 Retailer                   Consumer




green grey                blue grey                blue grey                   blue grey
 and water                water water              water water                 water water
 blue                      use                      use                         use
water
 use

       Supply chain WF                        Operational WF               End-use WF of a
                                                                               product



                                        The traditional statistics
                                        on corporate water use
                                                                                       [Hoekstra, 2008]
       The water footprint of a food processor




                  Virtual                  Virtual                 Virtual
                  water                    water                   water
                   flow       Food          flow                    flow
   Farmer                   processer                Retailer                Consumer




   green grey                blue grey               blue grey               blue grey
    and water                water water             water water             water water
    blue                      use                     use                     use
   water
    use

Supply chain WF        Operational WF                    End-use WF of a product




                The traditional statistics
                on corporate water use
                                                                                     [Hoekstra, 2008]
Water footprint – Carbon footprint


Water footprint                        Carbon footprint
•   spatial and temporal               •   no spatial / temporal
    dimension                              dimension
•   actual, locally specific values    •   global average values
•   always referring to full supply-   •   supply-chain included only in
    chain                                  ‘scope 3 carbon accounting’
•   focus on reducing own water        •   many efforts focused on
    footprint (water use units are         offsetting (carbon emission
    not interchangeable)                   units are interchangeable)

Water footprint and carbon footprint are complementary tools.


                                                               [Hoekstra, 2009]
Water footprint – Life cycle assessment


Water footprint                    LCA
•   measuring freshwater           •   measuring overall
    appropriation                      environmental impact
•   multi-dimensional (type of     •   no spatial dimension
    water use, location, timing)
•   actual water volumes, no       •   weighing water volumes based
    weighing                           on impacts
•   WF accounts offer basis for    •   LCA offers basis for comparing
    impact assessment and              products with respect to
    formulation of sustainable         overall environmental impact
    water use strategy


                                                          [Hoekstra, 2009]
       4
From concept to practice
From water footprint accounting to policy formulation


                      Vulnerability of local water systems

                       Current water stress in the places
                      where the water footprint is localised




    1                           2                              3
    Spatiotemporal-             Impacts of the                 Reduce and
    explicit water              water footprint                offset the
    footprint of a              • environmental                negative impacts
    • product                   • social                       of the water
    • individual                • economic                     footprint
    • community
    • business




                                                                            [Hoekstra, 2008]
Water footprint impact assessment


      Global map of where              Global map of where
       the water footprint              water systems are
           is located                       stressed



                             Overlay



                    Global hotspot map
    Impact assessment – hypothetical example
Global water footprint of a business                        Environmental water scarcity
    located 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
            Main producing regions
            Producing countries




                                       Hotspots
                                                                           Water stress
                                                                           (withdrawal-to-availability)
                                                                                 < 0.3

                                                                                         Hotspots are spots where
                                                                                 0.3 - 0.4
                                                                                 0.4 - 0.5
                                                                                 0.5 - 0.6
                                                                                           (1) the business has a
                                                                                 0.6 - 0.7
                                                                                 0.7 - 0.8
                                                                                           substantial water footprint
                                                                                 0.8 - 0.9
                                                                                 0.9 - 1.0   (2) water is stressed.
                                                                                 > 1.0



                                                  Main producing regions
                                                  Hotspots
Reducing and offsetting the impacts of water footprints



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]
Consumer perspective


Reduction of the direct water footprint:
   water saving toilet, shower-head, etc.


Reduction of the indirect water footprint:
   substitution of a consumer product that has a large water footprint
    by a different type of product that has a smaller water footprint;
   substitution of a consumer product that has a large water footprint
    by the same product that is derived from another source with
    smaller water footprint.


Ask product transparency from businesses and regulation
  from governments


                                                                  [Hoekstra, 2008]
Business perspective


Reduction of the operational water footprint:
•   water saving in own operations.


Reduction of the supply-chain water footprint:
•   influencing suppliers;
•   changing to other suppliers;
•   transform business model in order to incorporate or better control
    supply chains.




                                                            [Hoekstra, 2008]
Business / product transparency



Water footprint reporting
Shared standards
Labelling of products
Certification of businesses
Benchmarking
Quantitative footprint reduction targets
Government perspective

Reduction of own organizational water footprint:
   Reducing the water footprint of public services.


Embedding water footprint analysis in legislation

Supporting / forcing businesses:
   to make annual business water footprint accounts;
   to implement measures that reduce the impacts of business water
    footprints.


Promoting product transparency
   through promoting a water label for water-intensive products;
   through water-certification of businesses.
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.
   6
The way forward
                    www.waterfootprint.org




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



Partners
   partners from six continents
   •   research institutions
   •   governmental institutions
   •   non-governmental organisations
   •   large companies from different sectors
   •   branche organisations
   •   consultants
   •   international institutions

								
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