River: River Darwen
Length connected: 14 km
Area connected: 11.2 Ha
Completed: July 2018
Contractor: Wade Group Ltd
Of the many barriers to fish migration in the River Darwen, Hoghton Bottoms was the largest, and of all the weirs being tackles through the Ribble Life Together project the alterations to this weir will re-connect the greatest amount of habitat.
Hoghton Bottoms weir once provided water to Higher Mill, as well as Livesey’s Cotton Factory. The mill leat (channel that carried water collected behind the weir to the mill or factory) is now largely dilapidated but is still visible along its entire length from the weir to the viaduct over the river.
The weir itself at the top of a picturesque sandstone gorge which is the only feature of its type in the Ribble catchment. Additionally, there is a well-used footpath running alongside the left hand bank of the river which has meant that the weir itself has become a well known and often photographed local landmark.
It is due to this historic importance and it’s attraction to residents and visitors large changes to the structure of the weir were not possible. The most feasible option for this was a rock-ramp fish easement (by reducing the steepness of the weir’s gradient, fish will have a better chance of getting up shorter stretches and pools to rest in on the way up). The bedrock outcrop forms part of the channel, over which fish are able to swim.
Subsequent fish radio tagging study has found that brown trout can successfully use the fish pass to traverse the weir.