River Wensum may be given Norwich freedom of city honour

The River Wensum could be joining a list including former speedway rider Ove Fundin and insurance company Aviva

A medieval city which owes its existence to a river is hoping to grant the waterway the Freedom of the City.

Norwich City Council wants to bestow the honour on the River Wensum, as part of an attempt to protect it.

Green group leader Lucy Galvin proposed the motion, saying it was threatened by invasive species and pollution.

If granted, the Wensum will join a list including art patrons Sir Robert and Lady Sainsbury, playwright Arthur Miller and Norwich City Football Club.

The river rises in north west Norfolk before passing through Norwich to join the Yare

The river was one of the main reasons the Anglo-Saxons created a settlement at Norwich and by 1066 it was one of the most important boroughs in England.

After the port declined, the Wensum suffered years of neglect.

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Ms Galvin said the river was taken for granted."The Wensum is particularly under threat from abstraction and urbanisation, pollution from agriculture and industry and invasive species," she said.

"Development of use of the river is welcomed, but the importance of its biodiversity must, especially in view of increased threats, be recognised, protected and enhanced."

The white-clawed crayfish is believed to be extinct locally due to a plague spread by non-native American crayfish

Other new measures put forward by Ms Galvin included developing planning policies to protect biodiversity and mitigate flooding and writing to Anglian Water asking for evidence on what is being done to prevent sewage spills.

In its upper reaches, the Wensum is a rare chalk stream, a Site of Special Scientific Interest and has been designated a special area of conservation.

The Freedom of the City is an honorary title, usually given to people and organisations to recognise their contributions to a city.

Ursula Juta, from the Norfolk Rivers Trust, welcomed the motion, describing it as "crucial", as reported by the BBC-funded Local Democracy Reporting Service.

It was unanimously approved and the council will investigate whether it is possible to give the river the status.