How much water do we really use?

There is no shortage of data and analysis showing the world’s deteriorating water supply. What has been harder to measure, however, is the full and actual quantity of water currently being used at the individual, industry and country level. Water foot printing is a new methodology that exposes the true measurement of water usage. How this information can be converted into better water policy and programming is yet to be seen.

The World Water Security Risk Index, developed to enable businesses and investors to identify countries where water supply will be limited or interrupted in the future, rates 18 countries at ‘extreme risk’, with 15 of these countries located in the WANA region. The water security ranking measures many aspects of countries’ water use including water stress, population rates, reliance on external water supplies, government effectiveness, and virtual water use. Importantly, virtual water trade - the water embedded in traded goods and services – has provided the first step in measuring the full water footprint of humanity.

The water footprint, first introduced by Professor Arjen Hoekstra through a UNESCO-IHE research programme, is an indicator of freshwater use that looks at both direct and indirect water use of a consumer or producer. The water footprint of an individual, community or business is defined as the total volume of freshwater used to produce the goods and services consumed by the individual or community or produced by the business. 

The idea is to trace processes of production and consumption and express them in a specific quantity of water, called the virtual water content. This approach provides a more holistic measurement of water usage and also allows for consumers and governments to better understand the water usage of activities or sectors that might have otherwise slipped under the radar. The agriculture industry, for example, is the biggest water using sector, with a global average water footprint of a kilogramme of boneless beef measured at 15,400 litres.

Until recently, issues of freshwater availability, use, and management have been addressed at a local, national, and river basin scale for planning, analysis and institutional arrangements. The quantification of global virtual water trade has revealed the actual water footprint of countries and regions throughout the world, as well as specific industries. The West Asia – North Africa (WANA) region is an example for the need of international governance structures, because only few countries in the region have sufficient water available to theoretically achieve self-sufficiency. Trade among these countries is therefore not helping to address water scarcity, making the region highly dependent on external water resources.

Green, blue and grey water

Distinguishing between different types of water resources is important for the purposes of water management, especially in regions with a growing scarcity of this vital resource. It makes a difference – on an economic, social and environmental level – if an agricultural products has a high blue water footprint (ground or surface water, pumped and conveyed for irrigation) or a predominantly green water footprint (water contained in soils from precipitation). In a third category, the grey water footprint quantifies the degree of water pollution through the freshwater needs for dilution of pollutants to an environmentally acceptable standard.

Returning to the example of beef, this distinction will result in one piece of beef being very different from another. The precise water footprint of beef strongly depends on the production system from which it is derived (grazing, mixed or industrial), as well as the composition and the origin of the feed. Because cattle grows faster when fed concentrates, beef from industrial systems often has a lower total water footprint than beef from mixed or grazing systems. But due to the larger fraction of concentrates in industrial feed and the fact that concentrates have a larger water footprint than roughages, industrial beef generally has larger blue and grey water footprints than beef from mixed or grazing systems.

Freshwater problems in the WANA region mostly relate to blue water scarcity and water pollution and, to a lesser extent, to competition over green water. Thus, grazing systems are preferable over industrial production systems from a water resources perspective.

Informing decision makers and stakeholders

Green, blue and grey water footprints are summed up to a total water footprint of consumption and/or production. This single-unit indicator and the three categories of water footprints provide the major advantage of the concept, as it translates diverse and complex patterns into a strikingly communicable and comparable figure. A wonderful example is the work of Angela Morelli in her inforgraphic and book on the water footprint of humanity.

In order to inform policymakers, water users and non-governmental organisations, water footprint assessments must be detailed. Local level water use data for all sectors offer the chance to decide on and implement benchmarks, as well as link blue and grey water footprints to export values of products and social and environmental costs. Investors can be informed about the sustainability of an enterprise in a certain locality where water is a critical resource. It can even incentivise reuse and treatment through pricing or taxing of pollution levels.

It has been argued that the calculation of water volumes and their assessment do not contribute to water policy formulation or to setting goals, monitoring or other methods of evaluation. This is because water footprints consider only water volumes consumed, instead of other inputs, and do not consider opportunity costs for production input. Nevertheless, it must be recognised that many products are produced in places different to where they are ultimately consumed, and that the export and import of such products plays a significant role in the socio-economic development of nations.

This is particularly true for arid and semi-arid countries such as those found in the WANA region. The import of agricultural products in the region will not only replace large volumes of water in local production, it will also free water resources to be used in domestic, industrial and service sectors, which generally contribute a much larger share of gross domestic product and thus improves the important purchasing power for agricultural imports.

Overall, the important advantage of water footprint assessments is that they can show trade flows in different economic sectors and different places in volumes and kinds of water. Provided the spatio-temporal scale of water footprint assessments is focused on local levels, this can generate detailed data. Dealing with volumes and different qualities of water is existential for countries like Jordan, Yemen and most others in the WANA region. Additionally, local NGOs can get further involved in demand management activities, with more focus on water reuse and pollution.

Today, ISO standard 14046:2014 provides a model for assessing water footprints and is designed to support governments and non-governmental entities alike. If you wish to measure your own personal water footprint of consumption, you can use the quick calculator provided by the Water Footprint Network. A more detailed and precise calculation of your water footprint can be done if you take some more time to consider your individual consumption patterns.

The water footprint of national consumption includes two components: the part of the footprint that falls inside the country (internal water footprint) and the part of the footprint that presses on other countries in the world (external water footprint). You can find information about the water footprint of your country of interest by using the global water footprint calculator. 

A sustainable or resilient future is certainly not only about water. Water footprint assessments can only be an additional tool for decision makers, the public and the international community to find ways to cope with emerging and existing environmental, economic and social challenges. Combined with design and visualisation, however, the water footprint concept helps to communicate and raise awareness about one of the most pressing future challenges for humanity.