Why water footprinting should be used with caution as a regulatory tool

Water footprints provide interesting information, but they should not be used as a tool for decision-making. Shutterstock

It seems logical that crops and goods that need lots of water should not be produced in water-scarce countries. If consumers, companies and governments know how much water is used, they could then make the right decisions about what to make and buy. Instead of using their own limited supplies, water-scarce countries could import “virtual water”. This is the water used to produce the goods elsewhere.

The water footprint is a tool proposed by researchers and environmental activists to measure how much water is used to grow different crops and produce different goods. The idea is based on that of carbon footprints, which measure how much carbon dioxide, or CO2, an activity emits. As with CO2 and other greenhouse gases, the idea is that households, companies and countries should reduce their water footprints. Groups like the Water Footprint Network encourage governments and companies to adopt this approach.

The risk is that applying water footprints could leave poor people poorer and more vulnerable. This almost happened in Kenya, where environmental activists threatened a boycott of the roses that Kenya exports to Europe for Valentine’s Day. They believed that flower production was using too much water from Lake Naivasha and damaging its ecosystem.

But those flower farms produced far more livelihoods per drop of water than any other water use. At a time when Kenya was experiencing a wave of political violence, the last thing the country needed was a sudden increase in unemployment and less taxes for public services. And the flower farmers are leading the effort to sustain life in the lake.

Generally, farmers don’t try to grow rice in the desert (or flowers in Kenya) unless there is a good reason to do so. Aside from water, they consider many other factors. Most important is whether there will be a market for their products.


The danger is that, while water footprints are interesting and can be informative, they can lead to bad decisions. They could be used to encourage companies and countries to avoid – and even ban – products from places that don’t meet their standards.

The water footprint measures how much water is used to produce different crops and goods. Shutterstock

Knowing how much water is needed to make your jeans is unlikely to help you make a better buying decision. The sugar in your coffee could come from rainfed cane in KwaZulu-Natal in South Africa or Brazil, both of which have little impact on local rivers. Or it could come from irrigated fields in the Sudanese desert, which depend on a network of dams and canals and reduce flows downstream.

Southern African countries illustrate the complexities. They import more virtual water in food that has been produced elsewhere than they export. The region buys water-intensive cereals like rice from places like Thailand. Then it exports water-efficient crops like fruit and tobacco to the USA, Europe and China that earn more dollars and create more jobs. But the virtual water in agricultural trade does not always flow from water-rich to water-poor countries.

South Africa and Malawi have less water per person than most of their neighbours. Water footprinting would suggest that they should use less water for agriculture while other countries produce the region’s food. Yet South Africa, in particular, is an exporter of virtual water in the food it sells to other Southern African Development Community countries. And Malawi is an intensive agricultural producer because its people have few economic options.

In the long term, production may shift to other countries. At the moment, however, most of the southern African countries lack the finance, technology, infrastructure and institutions to fill the gap. That is why South Africa, the most water-scarce country, exports food to countries with more water, land and labour.

What’s not being measured

Southern Africa’s agricultural trade shows how decisions on water use are actually taken and why water footprinting can be very misleading. Economists point out that virtual water and water footprints can only reveal the absolute advantage the countries may have in water. It is the comparative advantage and the opportunity cost – or what else the water could be used for – that determines where production happens. Access to capital, technology, infrastructure and markets rather than lots of water and land is what drives trade between southern African countries.

These issues are important because decisions on the way water is used should be made in the countries concerned. That can happen through national and regional planning. It also happens through individual decisions of farmers, big and small, who change the crops they plant when they see new opportunities or when water is short.

The problem is that some people believe that producing tools to show where water use has a negative impact could be a good business. This creates many problems. Morgan Gillespy of the Carbon Disclosure Programme told a recent meeting in Johannesburg that 30 different water assessment tools are being used or considered by the programme’s members because there is no agreement on what should be measured.

Part of the problem is that different countries and regions have different standards. Europeans don’t want to allow changes to their water environment. Meanwhile, African leaders want to increase the use of water on the continent eightfold in the next few decades, which will require extensive infrastructure investment.

The conclusion is that, since the impact of water use and management is local, decisions on water development should not be taken by people in other countries with different priorities. Water footprints may provide interesting information, but their interpretation often just muddies the waters. They should not be used as a tool for decision-making.