The figure comes from an annual Environment Agency (EA) study into the health of ‘water bodies’ – segments of river divided into comparable sections – using a Europe-wide classification system called the Water Framework Directive (WFD). Each water body is graded across various ecological and chemical categories as either bad, poor, moderate, good or high.

However, much of the difference can be explained by a tightening of rules across the whole continent. ‘It’s more than likely there hasn’t been an actual change compared to last year in the rivers, it’s more that monitoring systems are now more sophisticated,’ explains Rose O’Neill, water policy manager for WWF. ‘The EA doesn’t actually know if things have got worse, but what it has done is make a significant improvement to its monitoring system, which means it now has a much better idea of the health of rivers.’

‘After considerable investment, rivers in England are the healthiest for 20 years,’ claimed an EA spokesperson. It pointed out that for the individual tests done on the water bodies, 74 per cent were graded either good or high. ‘EU legislation means the assessment criteria has just got even tougher.’

Nevertheless, O’Neill highlights that most other European countries are still performing much better when it comes to river health, with an average of 53 per cent of water bodies across the continent graded either good or high. ‘There has been quite a bit of progress over the last five or six years on tackling water company pollution and over extraction,’ she says. ‘The other major pressure on our rivers is pollution running off of farms. When it rains you get all of the water that falls on the farmlands taking all the minerals, fertilisers and nutrients and washing it into rivers. That agricultural pollution is responsible for about a third of our rivers failing.’