The United Nations warns that water use is growing at twice the rate of population growth. Unless this trend is reversed, two-thirds of the global population will face water “stress” by 2025. In light of this, sharing water fairly and sustainably amongst so many of us is one of the greatest challenges we face in the 21st century.

Margaret Catley-Carlson, Vice-Chair, World Economic Forum

A nation’s water footprint can be viewed from two perspectives: production and consumption.

The water footprint of production is the amount of local water resources that are used to produce goods and services within the country. This includes the water footprint of agriculture, industry and domestic water use and tells us the total volume of water and assimilation capacity consumed within the borders of the country. This can also be measured for any administrative unit such as a city, province, river basin or even the whole world.

We can also view the water footprint from the perspective of consumption. In this case, the water footprint is calculated for all the goods and services that are consumed by the people living in a country. This water footprint may be partly inside the country and partly outside of it, depending on whether the products are locally produced or imported. The water footprint of consumption can also be measured for any administrative unit.

Together, the water footprint of production and consumption tell an important story about a nation’s water use and dependence on external water resources, which can be used to help governments manage their water resources as well as understand the links between their economic development, food security and international trade relations and water.

The water footprint of production measures the amount of pressure that is being put on local water resources and forms the basis for determining whether they are being used in a sustainable way. The water footprint of consumption reflects the standard of living and lifestyle choices of the country’s residents. Understanding how much of that water footprint is within its borders and the amount and location of the water footprint that is elsewhere is a first step toward assessing the country’s external water dependence and its influence on food and other forms of security.

There are large differences in the water footprint of consumption of nations. In the USA, the average water footprint per year per capita is as much as the water needed to fill an Olympic swimming pool (2 842 cubic metres), that is an average of 7 786 litres of water per person per day. In China, the average water footprint is 1 071 cubic metres per year per capita, or 2 934 litres of water per person per day.

Differences in the internal and external water footprint of consumption are also large. In the Netherlands, 95% of the water footprint of consumption lies somewhere else in the world through imported goods, whereas in India and Paraguay only 3% of the national water footprint of consumption is external.

The water footprints of the products consumed depends on the circumstances in the places of origin. For example, very low agricultural yields and associated large water footprints per unit of harvested crop in some developing countries explains why they can have a relatively large water footprint of national consumption.

Find out more about the water footprint of your country and how it compares to others by using our free National Water Footprint Explorer tool.

Governments, along with all societal stakeholders, can work towards managing water for sustainable development, for thriving economies and the well-being of their citizens and the environment.

To promote sustainable development, governments will need to form coherent cross-sectoral policies – with respect to the environment, agriculture, energy, economy, trade, foreign affairs and development cooperation – that will improve integrated water resources management and governance. For example, agricultural policies and plans for economic development need to be coherent with goals for water resources protection.

Achieving a sustainable national water footprint, means working both in the country and outside its boundaries.

Governments can engage with businesses and establish mechanisms encouraging companies to be resource efficient and transparent in their water use. Creating legislation or voluntary agreements per sector to promote product transparency and disclosure on water footprint is one example of this. Governments can also engage with their citizens raising their awareness of the water footprint of their consumption and ways to reduce it.

Outside their borders governments can focus foreign aid on improving the sustainable management of water resources in locations where the external water footprint lies, work with trade partners to ensure sustainable production of goods that are imported and exported and ultimately, can work towards the promotion of international agreements on maximum sustainable water footprint limits and equitable sharing of the water footprint of consumption.

Governments can secure long-term sustainability of freshwater resources use by:

Extending water use statistics beyond what is traditionally accounted will provide governments with the information needed to manage their water resources and external water dependence in a comprehensive way. Traditional national water use accounts only refer to the water withdrawal within a country. They do not distinguish between water use for making products for domestic consumption and water use for producing export products. They also exclude data on water use outside the country related to the water footprint of consumption.

In addition, they include blue water use only, excluding green and grey water footprints. In order to support broader analyses and to better inform decision-making, the traditional national water use accounts need to be extended.

Extending water use statistics to include all aspects of the water footprint will broaden the basis for the formulation of integrated water resources management plans and policies, improved water governance and sustainable development.

By looking only at water use in their own country, governments tend to overlook the question of whether national consumption is sustainable. Many countries have significantly externalised their water footprint without assessing whether the imported products are related to water depletion or pollution in the producing countries. Few countries that have externalised their water footprint fully understand their resultant dependency on foreign freshwater resources and overlook the potential risks this might incur.

If you would like to go beyond the statistics and use them to develop policies that secure water, food and energy and regulations that support integrated water resource management, please contact us.

The concept of virtual, or embedded, water was first developed as a way of understanding how water scarce countries could provide food, clothing and other water intensive goods to their inhabitants. The global trade in goods has allowed countries with limited water resources to rely on the water resources in other countries to meet the needs of their inhabitants. As food and other products are traded internationally, their water footprint follows them in the form of virtual water. This allows us to link the water footprint of production to the water footprint of consumption, wherever they occur.

Virtual water flows help us see how the water resources in one country are used to support consumption in another country. See our FAQs page to clarify the difference between water footprint and virtual water.

As nations work toward securing food, water, energy and other essential inputs for people’s well being, livelihoods and the country’s economic development, most countries rely on imports as well as exports of goods and services. A country may aim to be self-sufficient by relying primarily on goods that can be produced within its borders. Or a country may choose to reduce the burden on the natural resources within its borders by importing water intensive products.

A country may select energy security by using its natural resources to produce electricity in exchange for food security by importing food. The water footprint and its translation into virtual water can illuminate these choices and their inter-dependencies. Virtual water helps us understand the dependencies our economies have on others’ resources.

Coupling this with the water footprint enables us to map out the dependencies and to identify when and where risks may lie, in terms of scarcity and pollution. This has implications for food security, economy and diplomacy.

For water-scarce countries it can sometimes be attractive to import virtual water (through import of water-intensive products), thus relieving the pressure on the domestic water resources. This happens, for example, in Mediterranean countries, the Middle East and Mexico. Northern European countries import a lot of water in virtual form (more than they export), but this is not driven by water scarcity.

Instead it results from protection of their domestic water resources, land availability and land uses. In Europe as a whole, 40% of the water footprint lies outside of its borders.

Legend: Virtual water imports into Europe. Source: Mekonnen, M.M. and Hoekstra, A.Y. (2011) National water footprint accounts: the green, blue and grey water footprint of production and consumption, Value of Water Research Report Series No.50, UNESCO-IHE, Delft, Netherlands.

Countries can both import and export virtual water through their international trade relations. Globally, the major gross virtual water exporters are USA, China, India, Brazil, Argentina, Canada, Australia, Indonesia, France and Germany and the major gross virtual water importers are the USA, Japan, Germany, China, Italy, Mexico, France, the UK and the Netherlands. The largest net exporters of virtual water are found in North and South America (the USA, Canada, Brazil and Argentina), Southern Asia (India, Pakistan, Indonesia and Thailand) and Australia. The biggest net virtual water importers are North Africa and the Middle East, Mexico, Europe, Japan and South Korea.

Legend: Global map showing countries with net virtual water import related to import of agricultural and industrial products from Latin American countries (green) and countries with net virtual water export due to agricultural and industrial exports to Latin American countries (red) over the period 1996-2005. Only the biggest gross virtual water flows (over 10 billion cubic meters per year) are shown. Source: Mekonnen, M.M., Pahlow, M., Aldaya, M.M., Zarate, E. and Hoekstra, A.Y. (2015) Sustainability, efficiency and equitability of water consumption and pollution in Latin America and the Caribbean, Sustainability, 7(2): 2086-2112.

Many nations save domestic water resources by importing water-intensive products and exporting commodities that are less water intensive. National water saving through the import of a product can imply saving water at a global level if the flow is from sites with relatively high water productivity (i.e. commodities with a small water footprint) to sites with low water productivity (commodities with a large water footprint).

The total amount of water that would have been required in the importing countries if all imported agricultural products were produced domestically is 2 407 billion cubic meters per year. These products are, however, being produced with only 2 038 billion cubic meters per year in the exporting countries, saving global water resources by 369 billion cubic meters per year (Mekonnen and Hoekstra, 2011). This saving is equivalent to 4% of the global water footprint related to agricultural production (which is 8 363 billion cubic meters per year).

National policy makers in water-scarce countries are likely to be more interested in national water savings than in global water savings. There are many examples of water-poor countries that save their domestic water resources by importing water-intensive goods. Mexico, for example, imports maize and, in doing so, it saves 12 billion cubic meters per year of its national water resources. This is the volume of water that it would need domestically if it had to produce the imported maize within the country.