What’s a Water Footprint?

water footprint?I was reading an article over the weekend about how the coffee industry needs to address water usage. How they need to promote things such as responsible farming practices. One example given was of a group of farmers from Hama, Ethiopia. For years they had been discarding the pulp part of the coffee cherry in the local river. The pulp would then decompose giving off toxins which polluted local water supplies. It wasn’t until a team from Nestle met them and explained that the pulp shouldn’t be wasted, as it actually makes a very good compost, that they stopped.

The article certainly provides food for thought. I know a lot of micro roasters are already working hard with farmers to improve growing and processing techniques; even helping out by buying equipment. The Speciality Coffee Associations of both America and Europe are also helping. But maybe more multinational roasters should be following Nestle’s example.

One thing that puzzled me in the article was a quoted statistic from the ‘Water Footprint Network’: a 125ml cup of coffee has a water footprint of 140 litres. What does this mean and how could they have possibly calculated this?

Yes I get that there saying that to go right from the beginning of the process, growing the coffee; to the end of the process, actually brewing a cup of coffee, uses 140 litres of water. But how is this relevant? It’s not as if the majority of these 140 litres of water are being taken from a water source. Crops in general aren’t watered by humans, farmers rely on the gods i.e. rainfall. In years where there’s little rain, there’s little coffee too.

Now I get carbon footprints. You can easily measure the amount of electricity, gas or petrol that something uses and then make a relatively accurate estimate of how much carbon dioxide that produces. I’m sure there are flaws to the system, but as an analytical tool it works quite well. If I cycle to work instead of using the car, I save x amount of carbon dioxide.

But for a water footprint how is it measured? How can you allocate x amount of rainfall to a specific plant? Yes you could probably grow a plant in a lab and work out how much water it needs to produce a health crop. But that’s under controlled conditions. What happens outdoors, with varying amounts of sun, wind, shade and nutrients? And you certainly can’t think, if I don’t have this cup of coffee I’m saving 140 litres of water, so no one goes thirsty in Brazil tonight (hero high-five).

I’m not knocking the concept that we need to save water. I agree with that. I just don’t understand the water footprint. Maybe someone out there could explain it to me?

Here’s how other drinks shaped up:

Beverage Footprint for 125ml drink
Coffee 140 ltr
Tea 15 ltr
Milk 125 ltr
Beer (from barley)  37 ltr
Wine 120 ltr


By the way, avoid chocolate at all costs. 100g has a footprint of 2400 litres!