What is the water footprint and how does it impact the environment?

The water footprint is the total volume of fresh water used, directly and indirectly, to produce a good or service across its entire life cycle. It is a key indicator for understanding the environmental impact of water consumption and for managing this resource sustainably.

This article explains what the water footprint is, its three components, how it is measured and how it can be reduced in companies and activities.

What is the water footprint?

The water footprint measures the water used at every stage of a product's life, from growing or extracting the raw materials to manufacturing, transport and final use. It counts not only the water used visibly in the factory, but also the water embedded across the whole value chain. The concept was developed by Arjen Hoekstra and the Water Footprint Network.

The water footprint is classified into three components:

1. Blue water footprint: the surface water or groundwater consumed, that is, the water that evaporates, is incorporated into the product or does not return to the same water body.
2. Green water footprint: the rainwater stored in the soil that plants consume during their growth.
3. Grey water footprint: the fresh water needed to assimilate the discharged pollutants until quality standards are met.

To this classification by colours we can add another distinction that is useful for companies: the direct and indirect footprint, depending on whether the water is consumed within the facilities or in the supply chain through virtual water.

Why is the water footprint important?

A high water footprint can deplete water sources, degrade ecosystems and expose companies to supply restrictions, penalties and market risks. Fresh water is a limited and unevenly distributed resource, and the pressure on it increases with population growth, industrialisation and climate change.

Main impacts

• Degradation of aquatic ecosystems: the over-exploitation of rivers, lakes and aquifers reduces flows, damages habitats and affects biodiversity.
• Competition for water: when resources are scarce, tension increases between agricultural, industrial and urban uses, especially in areas with water stress.
• Risk for companies: interruptions due to lack of water can halt production and drive up the cost of raw materials in the most intensive sectors.

If you want to know how the environmental impact of a product is assessed, we recommend our article on life cycle assessment (LCA).

How is the water footprint measured?

Two main frameworks are used to measure the water footprint: the ISO 14046:2014 standard, with an impact-oriented approach, and the Water Footprint Assessment methodology of the Water Footprint Network. The latter is structured in four phases:

1. Setting goals and scope: what is being assessed and within what boundaries.
2. Accounting: quantify the blue, green and grey footprint (in m³).
3. Sustainability assessment: interpret the volumes in terms of scarcity and pollution, according to the context of each basin.
4. Response formulation: design and implement reduction strategies.

The key difference is that ISO 14046 translates the volumes into impact indicators (for example, of scarcity) through life cycle assessment, while the WFA emphasises accounting by colours and its sustainability at the basin level.

The importance of measuring the water footprint

Measuring the water footprint makes it possible to identify where water consumption is concentrated and to prioritise reduction actions. In the textile industry, for example, large volumes of water are used to grow cotton, dye fabrics and process them, so improvements must cover all stages.

For companies, knowing the water footprint helps to optimise processes, reduce costs and strengthen resilience against scarcity. If you want to go deeper, you can read our article on how to measure the corporate water footprint.

The water footprint and sustainability

Sustainability is not limited to reducing the carbon footprint: it also involves the responsible use of water. Adopting sustainable water management is essential to guarantee access to this resource in the future.

In agriculture, efficient water use has a direct impact on food production and on the health of ecosystems. To go deeper, see our article on the water footprint in agriculture.

How to reduce the water footprint?

There are strategies to reduce the water footprint at both the personal and corporate level:

• Efficient water use: technologies that reduce consumption in production processes.
• Reuse and recycling: systems that allow water to be reused at different stages.
• Efficient irrigation: techniques that reduce water consumption in agriculture.
• Effluent treatment: treat wastewater to reduce the grey footprint.
• Supply chain: work with suppliers that can demonstrate good water practices and apply ecodesign with materials that have low water demand.

If you are interested in this approach, you can read our article on strategies to reduce the water footprint of companies.

The water footprint, a key indicator of water consumption

The water footprint is an essential indicator for understanding the impact of water consumption on the environment. Measuring and managing it helps to reduce costs, lower risks and improve a company's reputation. With standardised tools and proven strategies, any organisation can move towards a more efficient and resilient use of water.

Frequently asked questions about the water footprint

What is the difference between water footprint and water consumption?

Consumption measures the volume of water used directly, while the water footprint also includes the indirect water from the value chain (virtual water) and the associated pollution (grey footprint).

Can water footprint measurement be certified?

Yes. The water footprint can be assessed in accordance with the ISO 14046 standard and verified by accredited certification bodies.

Which sectors have the largest water footprint?

Agriculture is, by far, the largest user of fresh water (around 70% according to the FAO), followed by sectors such as textiles, food and mining.

How does climate change affect the water footprint?

It intensifies the variability of rainfall and the frequency of droughts, which alters water availability and can increase the pressure on surface and underground sources.

To measure and reduce your organisation's water footprint with traceable data, you can rely on Manglai's water footprint solution.