Figures are not obvious. Too many data have circulated on water and livestock farming. They have, once again, stigmatized the entire profession. Therefore, let’s set the record straight regarding water in farms.

What are the different types of water ?

Depending on the method used, figures vary from 50 to 15 000 litres for the production of 1 kilo of meat and from 3 to 1 000 litres to produce 1 litre of milk…

It is necessary to define words used to differentiate several types of water and therefore evaluate water management :

GREEN WATER : rainwater stored in the soil and then evaporated during plants growth 

BLUE WATER : real consumption by withdrawal (watering, irrigation, cleaning). This is “tap” water or water coming from well and/or drilling

GREY WATER : water necessary to dilute pollutants and obtain a quality complying with the regulation.

What is the water use ? 

Figures of 1 000 litres and 15 000 litres come from this calculation method. These were strongly conveyed by the media… but what is behind it?

In fact, water use sums the blue water, the green water and the grey water. This is referred to as virtual water flow but not as real consumption.

90% of water footprint used is therefore rainwater

TRUE sif we talk about water flow taking into account rain water that represents already 90% of this figure

FALSE if we talk about withdrawn water, the one from the tap, our well known blue water

50 litres is the quantity of withdrawn water to produce 1 kilo of meat

3 litres is the quantity of withdrawn water to produce 1 litre of milk

Geographical area and water resources should also be taken into consideration.

It is always good to compare… let’s take the example of a French family: its average consumption is 350 litres of water per day.

And for our simple comfort (far from food needs): each time that we flush the toilet, 9 litres of water are used, and 200 litres for a bath…

Sources : Gaël Cheleux, Chercheur Universitaire, Université de Liège – INRA Productions Animales, 2013