The Environment Agency has removed part of a dilapidated weir in Sheffield to help preserve some of the structure while making the River Don more accessible to fish.
Work started in April to remove two-thirds of Ward End Weir at Hillsborough, allowing the watercourse to revert to a more natural habitat for wildlife.
The removal will leave the Don with one fewer barriers – creating a fish highway to allow salmon and sea trout to return to their historic spawning grounds within and upstream of the city. Fish including brown trout and grayling can now migrate freely up and down the river to find the best places to feed, breed and shelter.
Ward End weir was in a poor state of repair and was close to collapsing. It has no registered owner, and if it was left in its current state, it would likely have disintegrated along its entire length over time.
By removing a section of the weir in a controlled way, the Environment Agency has safely retained a short section of the weir on each riverbank as a way of preserving a part of the city’s historical heritage. Doing this was more cost-effective than rebuilding the weir and maintaining it into the future.
Dr Jerome Masters, Fisheries Technical Officer at the Environment Agency, said:
Water quality in the River Don has improved greatly in the past 20 years, supporting a recovering fish population. But many structures such as weirs prevent fish from reaching historical spawning grounds within and upstream of Sheffield.
Iconic species such as salmon are a symbol of a healthy thriving river environment that contributes to an attractive sense of place and enhances local development - it would be fantastic to see them in Sheffield once more.
Adult salmon are already able to migrate as far upstream as Kilnhurst, near Rotherham, and need only for weirs to be made passable for populations to re-establish in their historic spawning grounds within and upstream of Sheffield.
The industrial heritage of Sheffield is of course of great importance, so we have retained about a third of the weir’s length for posterity.
Many fish need clean gravel to spawn on. Mud often settles in the slow water behind weirs, smothering the river bed, making it unsuitable for spawning fish.
Since the weir removal, the River Don is now returning to a natural series of shallow, fast sections, separated by deeper pools, creating better conditions for the brown trout and grayling that live there and for the invertebrates they feed on.
The work has been funded entirely from environmental budgets, and therefore the work has had no impact on funding that is used for flood risk projects.
The weir removal will have no effect on flood risk to properties either upstream or downstream.