On average, flooding costs the UK economy £1.1 billion a year. The cost of the 2015 floods alone was £5 billion. One in six properties in the UK is now at risk of flooding. But this need not be.
The evidence, both in the UK and abroad, is incontrovertible: naturalising rivers and rewilding river catchment areas prevents flooding. It is far cheaper, safer and more resilient than engineering hard flood defences. And it brings with it other huge economic benefits in terms of water purification, soil restoration, drought resistance and wildlife.
Healthy soils also store huge amounts of water as opposed to cultivated, anaerobic soils. According to the Soil Association, a 20% increase in soil organic matter increases the holding capacity of one hectare by between 40 – 100 thousand litres. Leafy scrub helps intercept heavy rainfall and alleviates flash floods, too.
We are already seeing this effect at Knepp, thanks to our restored soils and increased vegetation cover and, in particular, the restoration of our section of the river Adur and surrounding floodplains.
Of course, beavers – the ultimate hydrological engineer – are experts at restoring natural wetland systems and storing water. We look forward to seeing how these keystone species increase water storage on our land – and hopefully biodiversity, too – after their introduction in 2022.