The Water Delusion

Why what you've probably heard about how much water it takes to produce beef is pure fantasy.

We’ve all had that friend who hates “the system” and believes that interest rates, Tony Blair and socks are all part of some global conspiracy trying to keep him in a little box – stopping him from realising his true, authentic, genius potential. If you think back for a sec, you might remember an instance he went off on one about how bad eating beef is for the environment – probably citing some gazillion of litres it takes to produce one steak.

Without a doubt, one of the most popular figures tossed around in these kinds of discussions comes from the research of an agronomist called David Pimental – let’s call him Dave. Dave argues that it takes 100,000 litres of water to produce every Kilo of beef we consume. This number sounds so astronomically ginormous and shocking that your gut probably tells you it surely can’t be true, right? Well, that’s because it’s not.

Using these numbers, the total water used to produce our appetite for 60 million tons of beef every year is greater than the total freshwater reserves of the planet. So, let’s figure out how Dave came up with this number!

A relatively small cow can produce about 125 Kg of beef having been pasture raised for around 16 months. According to Dave, that would mean that in total, it took 12,500,000 litres of water to produce that small cow, or about 26,000 litres a day. Let’s break this down.

From our experience as farmers, we know that everyday a cow this size would drink about 50 litres of water and eat about 50 kilos of grass or forage. Let’s say – and this is heavily rounded up – that the water content of that grass/forage comes to about 50 litres. This brings the cow’s daily water consumption up to about 100 litres a day. Most of this water is either … but let’s imagine for a moment that that’s not the case. Where does the rest of Dave’s 25,900 litres of daily water come from?

A little bit of digging into his research and the references he uses will quickly tell you that Dave’s calculation includes all the rain that falls on the land that a cow roams around on – ignoring the fact that the rain would fall regardless of whether the cow was there or not! If it wasn’t, the grass would still grow but instead of the cow eating it, it would be rabbits, deer or other wildlife which would eventually consume the same (theoretical) amount of water!

What’s more, you’ll also find that Dave very cheekily uses the biggest rainfall figures he could find – those for American ranch (yes, think cowboys) cattle that roam over much, much more land than British cows do.