Fixing a dripping tap can save an average of 528,000 litres of water in a year – enough to fill half an Olympic swimming pool. It will also, typically, save a company several hundred pounds in water bills, making it worthwhile to send someone in with a wrench.

In large swathes of Europe and the US, as well as south America, drought has encouraged formerly carefree companies to pay more attention to water efficiency. Businesses already have a good financial incentive to save water, and in time of drought they also face moral pressure and the threat of regulatory enforcement.