The water footprint has gained a global foothold since its introduction a decade ago. These days it is not uncommon for people to know exactly how much water it takes to produce a glass of red wine (about 120 l), a kilogram of rice (2 500 l) or even an average-sized pizza (1 260 l).

The so-called water footprint concept, first introduced in the Netherlands in 2002, is now used internationally to create awareness around the water consumption and pollution of consumer products, within catchments and even countries.

Like similar tools which raise awareness around water use efficiency, the water footprint is becoming increasingly important, especially for South African corporations as they find themselves having to share an increasingly scarce resource with the socio-economic needs of a growing population as well as having to meet ecological requirements.

But what is the water footprint and how does it work? According to a new Water Research Commission (WRC) report on the applicability of water footprints in South Africa, a water footprint is an indicator of freshwater use that considers the direct and indirect water required to produce a project, measured over the full supply chain. The report, authored by Elizabeth Hastings and Dr Guy Pegram forms part of a larger WRC project led by Pegasys Strategic Management into adapting water footprints for South Africa.

“The water footprint concept was developed to raise awareness that for inclusive sustainability management beyond direct water use as the only impact on a process, product, producer or consumer has on the water cycle,” explains Dr Valerie Naidoo, WRC Research Manager for Industrial Water Use. “As such the water footprint includes the consumption of surface and groundwater (so-called ‘blue’ water), evapotranspiration of rain water (‘green’ water), as well as the effect of effluent (‘grey’ water).”

According to Hastings and Dr Pegram, water footprints have the potential to bring new and important decision making into the water debate in a way that is intuitive and cuts across sectors. “Additionally, water footprints create an opportunity for companies to join a global process of disclosure, understand risk and integrate an understanding of water into planning decisions. With this potential, the concept of water footprints has gained significant traction in the past ten years in the private and public spheres across a variety of sectors.”

Dr Valerie Naidoo adds, “Most of the corporates that use water in their operations may face water risk in terms of physical limitations, reputational risks, social risks or regulatory risks. Water footprint adds another dimension to this in that it highlights the importance of supply chain water risk, as it indicates not only direct water use but also indirect water use such as that required by raw materials for example, cotton that needs to be grown to manufacture jeans. Companies are now beginning to understand that the most significant water risk may fall outside of their internal operations and instead be located in their supply chains”.

At present, the food and beverage and textile sectors are most active with water footprint assessments, as the tool helps to understand significant upstream supply-chain risks. These are industries with a large reliance on agricultural inputs, which use significant volumes of water. Consumer products and the cosmetics sector, which have significant downstream water implications, are also becoming interested.

One of South Africa’s international players to have their water footprint assessed recently is SAB Miller. The company teamed up with WWF to determine where water is being used in its businesses as well as the context of water use. The total net water footprint for the brewer’s South African operations (excluding grey water) was found to be 421 billion litres – equivalent to 155 l of water for every litre of beer produced. The local cultivation of crops was found to be the dominant water consumer at 84, 2% while another 14, 1% of the water footprint was derived from the cultivation of imported crops. This means that 98, 3% of the water footprint of the company is related to the growth of crops. SAB Miller is now considering how it can reduce its risk by exploring water savings initiatives for barley farming.

The WRC report notes that the water footprint concept has not found traction to date in industries such as chemicals or mining. This is mostly likely due to the fact that direct water use and wastewater from operations are the most significant concerns, rather than water use elsewhere in the supply chain.