A trust founded to preserve and promote one of Norfolk's most treasured waterways will be forced to stop working in March due to a lack of public funding.

The Wensum Valley Trust was established in 2007 to conserve the wildlife, landscape and heritage of the protected river, while improving public access.

The organisation relies on a volunteer work-force and grant funding from councils in the districts through which the river meanders. But as government cutbacks have filtered through to local authorities, the cash-flow has dried up.

Trust chairman Gordon Bambridge said the organisation was now preparing for 'hibernation' – keeping its structure and bank accounts open in the hope that money could become available in future which will allow it to be revived.

In the meantime, the trust's full-time manager has been notified that he cannot be employed after the end of March – at which point the group's work will cease and its office on Ruthen Place in Dereham will close.

Mr Bambridge said: 'It is a great pity the trust has got to finish, and even more of a pity that it has to happen on my watch. But we have simply been unsuccessful in finding commitments to finance the coming year.

'We are going to put it into hibernation and leave a small amount of money in the bank to keep it all alive. Hopefully, if money becomes available in the next few years, it could be revived.'

The Wensum Valley Trust took over the work of the Wensum Valley Project, which had been created 20 years earlier in recognition of the river's conservation importance.

It is a Site of Special Scientific Interest (SSSI) and a Special Area of Conservation (SAC) which hosts species of European importance including the white-clawed crayfish and the Desmoulin's whorl snail.

Using teams of volunteers from areas including Fakenham, Hoe, Sparham, Bawdeswell, Norwich and Dereham, the trust's projects have included building fishing platforms, clearing ponds and establishing walks and access schemes.

But the shortfall in core funding now means that �18,000 of Heritage Lottery money towards the �70,000 Wensum Community Owls Project (WenCOP) will have to be returned, as the required match-funding has not been secured.

Mr Bambridge, who is also a Breckland district councillor, said the trust needed about �50,000 a year to run effectively.

'All councils are short of money at the moment, so they have to look carefully at what they are spending,' he said. 'Breckland, like other councils, has had to withdraw their guarantees for our basic funding. I am sure that over the course of a year we could find funding for specific jobs, but it won't be enough to employ a project officer to make those jobs happen.'