How much water is necessary to produce what we eat?

Discover how much water is necessary to produce food and why the water we consume has different colors depending on its source and use, as well as its impact on the environment.

Water is the basis of life on our planet. More than three quarters of the Earth's surface is made up of it, but only 2,5% is fresh and much of it is frozen or trapped in hard-to-access aquifers. If we only consider the quantity available for human consumption, the quantity available is not even 0,01% of the total quantity and the distribution throughout the world is very uneven.

The need for water cuts across all aspects of our lives. It is essential for agriculture and livestock, industry, energy production, health and hygiene, tourism and entertainment, without forgetting of course its importance for direct consumption.

The colors of water and the water footprint

The evaluation of the water footprint of any product or activity is carried out through classification, which assigns different “colors” to water based on its origin and intended use.

Blue water

It is water from surface and underground water bodies, such as rivers, streams, lakes, lagoons, reservoirs and aquifers, which is reusable and has a "blue water footprint" when it evaporates or is incorporated into products that use it. Examples of its uses include irrigation of crops and consumption of livestock.

Green water

It is stored in the soil, absorbed by the roots of plants and retained in the plant tissue. Unlike blue water, this is only used in agriculture. The "green water footprint" refers to the amount that plants lose through transpiration or added to products derived from them, such as textiles or livestock feed.

gray water

Gray, on the other hand, is defined as the amount necessary to dilute a contaminant to a safe level. It includes many different forms of pollutants and although the ISO standards that regulate the water footprint do not officially mention it, its consideration is important in research. The gray footprint is usually associated with industrial wastewater.

There are also two types that are not included in the concept of water footprint because they are not suitable for use.
On the one hand, there are white water, which evaporate immediately after rain and are never used for any other process, neither environmental nor artificial.

The opposite extreme is sewage, highly contaminated, incapable of being purified by conventional methods.

Saving water depends on what we eat

Ecological disasters caused by human activities are a complex reality, in which the causes and consequences are unevenly distributed on a global scale. A small number of countries, companies and lifestyles are responsible for most of the consequences, while ordinary people actually bear very little responsibility.

However, this does not exclude the possibility that ordinary consumers can make a positive contribution. While the individual impact may seem small, widespread adoption of more sustainable daily consumption practices could have a significant impact on reducing water use.

These practices include consciously choosing foods that use less water, favoring foods produced locally, in season or grown in areas of abundance.

Reducing meat consumption is often suggested as an effective strategy due to its higher water demand compared to agricultural products. However, it should be noted that the water footprint should not be judged solely by the weight of the product. Directly comparing foods by weight, while useful, can be misleading due to differences in nutritional value. For example, although half a kilo of chicken requires almost twice as much water as half a kilo of asparagus, the nutritional value and calorie content of each is very different. So in terms of water and energy efficiency, animal foods like chicken may be more efficient than some plant foods like asparagus.

Similarly, there are food products whose water footprint, although large, does not fully reflect its impact on daily consumption because the amount of water used is very small. For example, a roasted coffee with a water consumption of almost 19.000 liters/kg or a vanilla coffee of more than 125.000 liters/kg may seem extremely water intensive at first glance, but the actual amount of water used each day is very small. For example, a cup of coffee with milk requires about 4 grams of coffee and about 150 grams of milk. In this case, the water content of coffee with milk is estimated at about 230 liters, of which almost 70% is milk. .

It is important to evaluate the water footprint of a product in a comparable context. It is reasonable and consistent to compare the water footprint of similar foods, such as different meats, fruits, vegetables and spices. Directly comparing products from different categories lacks scientific rigor.

From this perspective, we can make more informed and sustainable decisions by focusing on practical changes that truly promote water conservation.

How much water is consumed worldwide?

According to a report by the Food and Agriculture Organization of the United Nations (FAO), it is estimated that global food production consumes approximately 70% of the fresh water available on the planet. This is equivalent to about 1,5 billion liters of water per year. But how much is consumed in the production of these foods?

La meat production Worldwide, it consumes around 20.000 liters of water for every kilogram of water. meat produced. This data includes how much water is used in the production of livestock feed, such as water used in the process of raising, transporting and processing meat.

The amount used in the vegetable production Worldwide it can vary depending on factors such as the type of crop, climate, agricultural practices, technology used, among others. In general, it is estimated that vegetable production consumes around 237 liters per kg of harvested product.

how much water

As examples of how much water is consumed, let's look at some:

Values ​​for how much water is consumed can vary significantly depending on regional factors and specific agricultural practices. For example, crops like corn and rice may require a very high amount compared to other types of vegetables.

La production of coffee Worldwide, it consumes around 140 liters for every cup of coffee produced. This includes the water used in the production of coffee beans, in the roasting process and in the preparation of the final drink. It is estimated that the coffee industry is responsible for consuming approximately 20.000 liters for every kilogram of coffee produced.

And how much is needed so that we can eat a chocolate? The chocolate production consumes approximately 24,000 liters for every kilogram of chocolate produced. This is due to the process of growing cocoa, producing cocoa butter and making the chocolate itself.

It is estimated that the production of one liter of milk requires around 1,020 liters of water, considering the amount used to irrigate crops to feed livestock, the amount consumed by animals and the amount necessary for cleaning and operating production facilities.

How long does the olive oil production? Worldwide it can vary depending on various factors, such as climate, type of crop, irrigation practices, among others. However, it is estimated that each liter of olive oil produced may require between 2,000 and 6,000 liters, depending on the specific conditions of each region.

In general terms, the production of olive oil is considered a crop that requires a significant amount of water, which can have an impact on the availability of this resource in regions where this product is cultivated intensively. Therefore, it is important to implement sustainable water management practices in olive oil production to reduce your water footprint.

The importance of saving water in food production

Water is a limited and essential resource for life, becoming aware of how much we consume is key. Agriculture is one of the most consuming sectors worldwide, so it is essential to look for ways to reduce the excessive use of this resource.

Some ways to save water in food production include implementing more efficient irrigation systems, collecting and reusing rainwater, using drought-resistant crops, rotating crops, and applying water conservation practices. floor. In addition, it is important to raise awareness among farmers about the importance of using it responsibly and sustainably.

Saving water in food production not only contributes to the conservation of this vital resource, but can also help reduce production costs and increase farmers' profitability. Therefore, it is essential to promote sustainable practices in food production to ensure long-term food security.


  • Hughes, D. 2009. State of the resources. In Water in a changing world. UNESCO.
  • Ibidhi, R. et al. 2020. Water footprint of livestock products and production systems: a review. Animal Production Science. DOI: 10.1071/AN17705
  • Mekonnen, M. et al. 2010. The green, blue and gray water footprint of farm animals and animal products. American Journal of Hematology - AMER J HEMATOL.
  • Mekonnen, M. M. et al. 2011. The green, blue and gray water footprint of crops and derived crop products. Hydrology and Earth System Sciences, 15(5), 1577-1600. DOI: 10.5194/hess-15-1577-2011
  • Mekonnen, M. M. et al. 2012. A Global Assessment of the Water Footprint of Farm Animal Products. Ecosystems, 15(3), 401-415. DOI: 10.1007/s10021-011-9517-8
  • Moreno-Ortega, G. et al. 2019. Yield and fruit quality of avocado trees under different regimes of water supply in the subtropical coast of Spain. Agricultural Water Management, 221, 192-201. DOI: 10.1016/j.agwat.2019.05.001

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