...It will be our plates, not our rates, that bear the brunt of water shortage. As today's report from WWF spells out, the amount we spew out of taps is piddling compared with what it takes to make stuff and, especially, to grow our food.

The volumes involved are staggering: the 200 billion litres a second it takes to grow the world's food is like gulping down the Amazon day in, day out. In the UK, we use about 58 bathtubs full of water every day, both directly and in the food we eat and the clothes we wear, and 62% of that comes from other countries. We're eating dry Lake Naivasha in Kenya and Australia's Murray River, as well as running down our own reserves.


But our water problem isn't just about the amount we use. Quality is as crucial as quantity. Whether water is clean, dirty or briny, comes from groundwater or from rainfall, and its whereabouts, can make all the difference.

To tackle water scarcity we need to remind ourselves why it is a problem. The most obvious reason is that we just can't keep using water at current rates. In practice, running low on a resource can mean that rich places like the UK barely notice while poor people take the hit.

But we've been there already with water – other countries have suffered from scarcity for decades – and we're now at the point where even the big-name companies that feed us are feeling the squeeze and getting seriously worried about the security of their supply chains.