Recently I calculated my water footprint.  It's 1086 gallons a day, quite low.  We can only reduce water used if it's one of the things in our conscious mind.  Be happy and thankful for water and just use what we need.

My friends and I will ring up the water department when we see leaking pipes in public areas.  Some time back, one friend received a letter to attend a meeting and was told that prizes would be given.  But he was rather late and didn't have the privilege to pick up a numbered token.  He glanced around at all the prizes.  There were many electric appliances to be given away from hair dryers to the grand prize, a large plasma TV.

After a short speech of thanks for public contribution, the MC drew the numbers from a cloth bag.  To Mr Lee's surprise, he won the plasma TV for helping the water department to conserve water.  I hope you find this simple narration an encouragement to conserve water in the home and out of the house. Thanks.

Research in this area is rapidly developing worldwide and a broadening base of Water Footprint Assessment applications are being initiated across all sectors of the economy, in many countries of the world. The footprint is not confined to agricultural and industrial uses. It covers any sort of water use. Footprint assessment are initiated, across all sectors of economy and covering all continents. Water footprint assessment’ refers to the full range of activities to: (i) quantify and locate the water footprint of a process, product, producer or consumer or to quantify in space and time the water footprint in a specified geographic area; (ii) assess the environmental, social and economic sustainability of this water footprint; and (iii) formulate a response strategy. Broadly speaking, the goal of assessing water footprints is to analyse how human activities or specific products relate to issues of water scarcity and pollution, and to see how activities and products can become more sustainable from a water perspective.

WF like any other footprint, assesses the impact of products/processes. Systems approach (like LCA) -sets a boundary through which you quantify the impacts-quantity & quality. On the other hand, WFN approach was developed by hydrologists- where there "footprint" definition is primarily based on agricultural produce and estimation of ideal water requirements of crop growth-based on FAO's Cropwat & Climwat data.

Thus, whether you consider LCA approach (which is complete framework but cannot assess complete boundary) or WFN approach (which is also based on systems thinking, but doesn't go beyond crops and refrains from impacts beyond nitrogen/phosphorous use) you can measure total contribution of nature, more so a mid-point indicator. To assess true impact on an environment, you need to put a background, like water availability in the local environment. Using both estimations (availability and use), one can determine absolute impact on a spatial scale.

So following above reasoning, WF assessments determine -how much you withdraw, consume or pollute.

Green water is defined as water used by biomass, so it applies to crops not supply chain of agricultural systems.

For details about LCA, refer to ISO 14040 and read WFN assessment manual for distinction between green, blue and gray.

Once comprehensive nature of impacts is determined, one can explores pathways wherein total impact of production can be reduced.

I hope this answers your query.

I agree whole-heartedly with Mr. Karbassi's statement. I would go even further and say we should ask every product on sale to indicate its water footprint (of course we need to set up some norms on how we assess it). The consumer can then make a conscious decision on what product to support. The same goes with the energy footprint. Now we check the level of sugar or fat in a product to safeguard our health. Why not we check on water and energy footprints of a product to safeguard the health of the mother nature?

Thank you all of you professionals for adding comments. I will try at my best to keep in touch with you to progress towards my research. Thank you again.

Sorry for coming late. Th essence of this discussion is that measurement leads to better appreciation of related supply and demand conditions and when conducted at different scales of decision-making such as household, firm, industry, sector and national it will provide useful information for formulating strategies for more sustainable utilisation of a resource. Given water was a free good that was available to people as a natural right, development of policies cannot proceed without creating conflict. Information such as water foot print, albeit difficulties in defining accurately, provides useful input in that debate. Also it provides guidance for technological development and innovation. In Australia, after the Millenium Drought, we introduced Water Acounting and the Australian Water Account (www.abs.gov.au) provides an official assessment periodically based on best available data. 

Green water Green water availability Green water footprint Green water footprint impact index Green water scarcity

The precipitation on land that does not run off or recharge the groundwater but is stored in the soil or temporarily stays on top of the soil or vegetation. Eventually, this part of precipitation evaporates or transpires through plants. Green water can be made productive for crop growth (although not all green water can be taken up by crops, because there will always be evaporation from the soil and because not all periods of the year or areas are suitable for crop growth).

The evapotranspiration of rainwater from land minus evapotranspiration from land reserved for natural vegetation and minus evapotranspiration from land that cannot be made productive.

Volume of rainwater consumed during the production process. This is particularly relevant for agricultural and forestry products (products based on crops or wood), where it refers to the total rainwater evapotranspiration (from fields and plantations) plus the water incorporated into the harvested crop or wood.

An aggregated and weighed measure of the environmental impact of a green water footprint at catchment level. It is based on two inputs: (i) the green water footprint of a product, consumer or producer specified by catchment and by month; and (ii) the green water scarcity by catchment and by month. The index is obtained by multiplying the two matrices and then summing the elements of the resultant matrix. The outcome can be interpreted as a green water footprint weighed according to the green water scarcity in the places and periods where the various green water footprint components occur.

The ratio of green water footprint to green water availability. Green water scarcity varies within the year and from year to year.