Experts predicted the water vole would be extinct in Sussex by 2003

The boost in the water vole population comes as a result of work to improve its riverside habitat.

There are now 342 of the creatures, immortalised as Ratty in Wind in the Willows, as opposed to 100 when the project started.

Experts had predicted the water vole population in Sussex could be extinct by 2003 after a 97% drop in their numbers between 1990 and 1997.

Due to the plight of water voles facing extinction we had to take conservation action in the Sussex area Paul Smith, Environment Agency

Their numbers fell by an average 88% across the rest of the UK in the same period.

Landowners, Sussex Wildlife Trust and West Sussex County Council supported an innovative project by environmental bodies to reverse the decline.

The partnership created 61 kilometres of six-metre-wide grass margins along watercourses so the voles could make their habitats and thrive there.

Paul Smith of the Environment Agency's Fisheries, Recreation and Biodiversity team, said: "Due to the plight of water voles facing extinction we had to take conservation action in the Sussex area.

Intensive farming

"The main problems were as a result of intensive farming - watercourses where the voles make their habitats had suffered from heavy engineering work for flood defence and land drainage purposes.

"Predators such as mink were also a major factor in the decline of the water vole in the county."

He said the joint approach should safeguard water voles' future in Sussex.

The partnership included the Environment Agency, the Chichester Sustainable Farming Partnership, WildCru and the Farming and Wildlife Advisory Group.