Beavers' hydrological engineering helps to back water up, so that it slowly filters down to the rivers which prevents floodwaters from rushing downstream to flood our villages, towns and cities.
Over Christmas 2007, a Eurasian beaver quietly escaped from its Gloucestershire nature reserve and set up a territory on the River Thames in Oxfordshire.
It remained there unnoticed for over three months and did not build any dams. I discovered its existence myself in March 2008.
During a wildlife survey in the area, I was taken to look at a landowner's large pond to determine what had been making the marks on his willow tree.
"As incredible as this will sound, these marks were made by a beaver gnawing on the bark", I remarked!
Absolutely no beavers had been licensed for release, so my remark sounded unbelievable and I could not quite believe what I had seen! But that evening the beaver returned to finish the job and fell the tree. Its arrival was signalled by the security lights going on.
Undetected for three months
The beaver had happily lived on a main, canalised river and had been no problem whatsoever for over three months. It was recaptured sometime afterwards and sent to live in captivity in another part of the country.
As the great debate has continued to rage over beaver reintroductions, another beaver escaped in Devon during a flash flood two years ago. Sightings have been reported since its escape, then in July last year it established territory on the River Otter alongside farmland which it ventures into.
The beaver has "been doing a bit of damage but nothing major" reported the farmer. The damage is most likely felled trees which will create an open habitat.
As a rough guide, one beaver family may need a 500m length of stream or river in optimum habitat, and ten times more in poor habitat.
Vital to a thriving wetland ecosystem
Beavers create areas of natural habitat such as wetlands, pools and ponds with marginal vegetation, which enable other wetland species such as otters, fish, bats, water voles, frogs, dragonflies, water fowl and birds such as Reed Warblers to move in. The beaver is a vital part of a thriving wetland ecosystem.
Their hydrological engineering helps to back water up, so that it slowly filters down to the rivers which prevents floodwaters from rushing downstream to flood our villages, towns and cities. Which is just what we need in this wet winter of 2014!
When you remove a species from the ecosystem, as we removed the beaver over 400 years ago by hunting it to extinction, it is going to have consequences.
Building on floodplains across the UK has added to the loss of wetland area. It may not be immediate, but over time the result becomes glaringly obvious: flooding and on a massive scale, aided even more by climate change.
They know what they are doing, and why
The sight of a beaver slowly gliding down or upstream is a calming and beautiful sight to behold.
It is also beneficial to allow beavers to fell the trees, rather than people with intrusive chainsaws, or to leave the land until it becomes so over-shaded by too many trees that the ecosystem loses its biodiversity.
There are a number of misconceptions about beavers. They are not carnivores, so don't threaten fish stocks - in fact they probably encourage fish and their growth. They are a native species unlike the Grey Squirrel, so are unlikely to spread disease to a native cousin.
Strange as it may seem to humans, a beaver knows exactly what it is doing and why. Maybe part of the problem in our reluctance to re-wild lies in our gradual disconnection with the wild over generations: recently termed as 'shifting baseline syndrome'.
Reconnecting with nature
The land of wildflower meadows, water meadows and roadsides verges filled with flowers such as Oxeye Daisy, Bird's-foot trefoil, Cowslip and Meadow Cranesbill and water voles in our streams and rivers that were common during my childhood in the 50's and 60's are now a national rarity.
So much so that many 20-somethings have never encountered them and do not know what a wildflower meadow or water meadow is. It is not their fault: wildlife has been tidied away by overzealous land management just about everywhere.
Neither is it their fault that they do not know what a beaver is, how big it is or the habitat it requires. Similarly a water vole.
There is a drastic need for reconnection with Nature and the realisation of our need to co-exist with wildlife who manage ecosystems which enable human existence.
Humans, back off!
There also needs to be the realisation that wildlife can manage ecosystems without the help of humans. It is what bears, bison, wolves, lynx and deer are still doing in the Carpathian Wolf Mountains.
And it's what the bears, wolves, bison and many other species are doing in Alaska and Yellowstone.
You might think that wildlife needs to be placed back into large expanses of wilderness, but beavers are moving successfully into heavily populated areas in Holland. And now they are trying to do the same in England.
England is their home
As D. J. Halley observes: "Most beaver conflicts with man occur in a very narrow riparian zone: 75% within 20m, and almost all within c. 100m, of the water's edge.
"Current moves throughout Europe to conserve and regenerate the riparian zone around rivers, for other conservation and flood control motives, have the side effect of both creating beaver habitat, and reducing the scope for conflict with many human activities."
We should welcome the return of beavers to our ecosystems to re-wild our lands and ourselves. We need to start rethinking our whole approach to environmental management - and rely more on freely provided natural processes, and less on human interference.
Also in The Ecologist: Louise Ramsay on 'Time to bring back Nature's flood management engineer - the beaver'.
Jo Cartmell is a wildlife photographer, conservationist, amateur ecologist and natural historian with a particular interest in water voles. She has been involved in the recreation of several wildflower meadows and is co-warden of a local nature reserve.