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What the water footprint is

The water footprint is the indicator that quantifies the total volume of freshwater consumed, directly and indirectly, by an organisation, product, process or activity throughout its life cycle or supply chain. Unlike simple water consumption measured on a bill, the water footprint also incorporates water used indirectly in the production of raw materials, energy and contracted services.

The calculation is governed by the international standard ISO 14046, which sets out the principles, requirements and guidelines for assessing the water footprint under Life Cycle Assessment (LCA) methodology.

The three components of the water footprint

The methodology distinguishes three types of water, each with a different environmental meaning:

• Blue water footprint — consumption of surface or groundwater, i.e. water extracted from a water body that does not return to the same system (through evaporation, incorporation into the product, or discharge into another basin).
• Green water footprint — rainwater stored in the soil and consumed by crops or vegetation, particularly relevant in agricultural and forestry activities.
• Grey water footprint — the volume of freshwater required to assimilate the pollutant load discharged, calculated from the maximum permissible concentrations under water quality regulation.

Why calculating it matters

Calculating the water footprint adds concrete value in several contexts:

• Water risk management in water-stressed areas, identifying the exposure of facilities or supply chains to water scarcity.
• Corporate sustainability reporting, complementing the carbon footprint in sustainability reports and ESG disclosures.
• Agricultural and industrial projects with intensive water consumption, where authorities or financiers may require justification of efficient resource use.
• Eco-labelling and product environmental communication, when demonstrating the water consumption of a specific product to clients or consumers.

How it is calculated

The process follows the phases of Life Cycle Assessment adapted to ISO 14046:

1. Definition of the goal and scope: whether the footprint is calculated for the whole organisation, a specific product, or a production process.
2. Inventory of water consumption, both direct (extraction, abstraction) and indirect (water embedded in raw materials, energy and contracted services).
3. Characterisation of the water environment, identifying whether the source basin or aquifer is under water stress using tools such as the Water Risk Filter or WRI Aqueduct.
4. Calculation of the three components (blue, green, grey) based on activity data and discharge concentrations where applicable.
5. Interpretation of results and proposal of reduction measures: water reuse, changing supply sources, improving treatment processes.

Common calculation mistakes

The most common issues we find when reviewing water footprint studies are:

• Confusing water consumption (volume extracted) with the water footprint (which also includes water embedded indirectly across the supply chain).
• Omitting the grey water footprint due to lack of discharge quality data or applicable maximum permissible concentrations.
• Failing to contextualise the result against the water stress level of the basin, which prevents a real assessment of impact severity.
• Calculating only blue water, ignoring the green footprint in agricultural activities where it can be the most significant component.

Why choose Ideas Medioambientales

We calculate the water footprint of organisations, products and processes under ISO 14046, integrating the result with our other corporate sustainability services: carbon footprint, sustainability reports and environmental assessments. Our knowledge of Spain's territory and water resources allows us to contextualise the result with real data from the affected basin or aquifer, not just generic figures.

Tell us about your activity and we'll advise you on whether you need an organisational water footprint, a product water footprint, or both.