A historic weir damaged during floods two years ago is in danger of collapse unless campaigners can raise more than £600,000 for its restoration.

The weir at Hirst Mill on the River Aire at Shipley is 750-years-old but is at risk of collapsing, which would have serious implications for the upstream section of the river.

Now Hirst Weir Ltd, a company set up by members of Bradford Amateur Rowing Club (BARC), is working with the Environment Agency to raise money for repairs and to install a fish pass that would help species including barbel and trout access new habitats.

BARC has used Hirst Weir for almost 150 years and other rowing groups from Bradford Grammar School, Bradford University and Bradford & Bingley Canoe Club also use the waterway.

It sits within the Leeds Liverpool Canal Extended Zone Conservation Area and is also within the buffer zone of the Saltaire World Heritage Site.

Project co-ordinator at Hirst Weir Ltd Chris Morley said: “The Hirst Weir is an important historical structure in Shipley and is first mentioned in 1249.

“Its loss would be a major blow to the area, significantly altering the local natural environment.

“In the floods of July 2012 the weir suffered significant damage and was in danger of collapsing before emergency repairs were carried out by Hirst Weir Ltd funded by Bradford Amateur Rowing Club. However, the weir now requires a major renovation if its future is to remain secure.

“Hirst Weir Ltd is now looking for support from a range of possible funders as well as individual donations from the public.”

It is feared that if the weir failed, in addition to the river becoming unsuitable for rowing, there would be bank collapses upstream which could destroy footpaths.

BARC President Richard Phillips, who lives at Hirst Mill, said: “BARC was founded in 1867 and is one of the oldest sporting institutions in the city.

“The loss of the weir would be devastating not just for rowing and other water sports but because of the detrimental effect it would have on this area of outstanding natural beauty.

“We fully support and endorse Hirst Weir Ltd in its efforts to ensure the weir remains intact for another 750 years.”

Fisheries technical officer at the Environment Agency Jerome Masters said: “We are working with Hirst Mill Ltd to ensure that, once repaired, their weir will no longer prevent the free movement of fish.

“All fish species migrate up and down rivers in order to find the best places to feed, breed and shelter.

“Weirs can block these migrations so rivers do not hold the amount or variety of fish that should be there.

“A fish pass at Hirst Mill will form part of an increasing network of fish passage improvements on the River Aire which will one day lead to the return of species such as salmon and sea trout.”