THEY were made popular by the character Ratty in the much-loved children’s book, Wind in the Willows.

But while Ratty in the classic novel by Kenneth Grahame enjoyed messing about in boats and having adventures with Mole and Mr Toad, the UK’s real water voles have faced a crisis.

Across the country, the population of the mammals has crashed by 90% in the last 20 years with Essex even harder hit, losing 94% of its water voles.

Now the endangered animal, whose plummeting population has been blamed on being eaten by Minks, looks set to flourish again in the picturesque River Colne as part of a major relocation project.

Hundreds of the water voles were introduced to their new home yesterday after being transported from the site of a major new container port in south Essex.

The creatures were moved to make way for the deep sea port at the London Gateway site in Thurrock owned by terminal operators DP World.

In total more than 50,000 animals have been moved so far including lizards, snakes and newts.

Yesterday’s release at Fordham Hall estate just outside Colchester was thought up and organised by Darren Tansley, Essex Wildlife Trust’s water for wildlife officer.

Last year he moved a colony of water voles which were under threat at Abberton Reservoir to a specially created habitat elsewhere on the site.

The project proved successful with the water voles breeding and surviving the winter, and was the blueprint for the River Colne relocations.

One in ten of the water voles, which had been cared for at the Wildwood wildlife sanctuary in Kent before release, will be radio-tracked by Essex Wildlife Trust, providing important information for future projects.

During the summer and autumn, the progress of the colony will be monitored by a BSc student in conjunction with Essex Wildlife Trust’s water for wildlife project.

This will provide useful data about the voles’ response to their new habitat, how quickly they breed and expand their range.

The area will be regularly surveyed over five years to establish how successful the project has been.

Mr Tansley, said: “Water vole numbers are now improving across the Essex water vole recovery area and I am confident the River Colne translocation will be as successful as our other work to restore this species to its former range.

“Many organisations have been involved and it is great we have found such good habitat at Fordham Hall, under the management of the Woodland Trust, to translocate a significant proportion of the London Gateway water voles.

“DP World has been exemplary in its environmental management of relocation of water voles and we look forward to working with them in the future.

“I have spent the last three years working with landowners along this catchment to make it safe for voles to return and their support has been fundamental to realising this project.”

Geoff Sinclair, site manager at Fordham Hall Estate, said: “Thirty years ago voles would have been common on this stretch of the river and it will be marvellous to see them back,” he said.

Marcus Pearson, DP World, environmental manager, said: “This is what ecological conservation is all about, we have worked in partnership with Essex Wildlife Trust to identify and prepare a fantastic site for the translocation of over 300 water voles to one of the most picturesque and diverse river systems in Essex.”