Following the success of our 2017 fish passages we are now moving on to the next six fish passages that have been planned for 2018.
Cow Hey Weir– Located on Cow Hey Brook, near it’s confluence with Bashall Brook, this structure was originally built to provide water for the mill which was located downstream. The mill has now almost totally disappeared, with the only evidence of the mill being the mill race.
After careful appraisal it has been determined that the weir can be totally removed and replaced with a rock ramp easement which is the most desirable option in terms of fish passage and geomorphology.
Dean Brook– Dean Brook Weir is a stone and concrete weir which lies at the foot of Dean Brook near its confluence with the River Calder. The weir is preventing the upstream migration of fish from the Calder into Dean Brook and, as it is in a state of disrepair, is also affecting the geomorphology of the brook, causing erosion on the downstream river banks.
Full removal of this weir would be possible, however there would be a risk of to the surrounding fields and nearby property and so a rock ramp fish passage will be installed instead. By making this weir passable over two kilometres of habitat Dean Brook will be opened to migratory fish.
Houghton Bottoms– Houghton Bottoms is the second weir that will be removed on the River Darwen. The weir lies at the top of a steep sided sandstone gorge, the only feature of this type in the catchment. Both of the river banks are steep and heavily wooded and the river here is narrow, deep, and fast flowing. The weir itself is constructed of large stone blocks and is well known local landmark.
Due to the importance of the weir to local residents it has been agreed that rock ramp fish easement will be constructed up the left-hand side of the weir. This will ensure that the weir retains the features which make it a unique and important local landmark whilst enabling migratory fish to move upstream.
Lower Darwen– This weir is one of many on the River Darwen which pose a barrier to fish migration due to the historic industrial nature of the area. The weir is on a secluded section of the river and close to residential, recreational, and industrial areas, as well as the River Darwen Parkway Local Nature Reserve.
After careful consideration of the structure and condition of the weir, as well as the area surrounding the weir, a full or partial removal of the site is thought to be too high risk. Instead a rock ramp bypass will be created around the left-hand side of the weir which will follow the approximate path of the overspill from the river. As well as allowing fish to migrate upstream, this fish passage channel will help to stabilise the banking and reduce the risk of damage to the weir.
Old Laund– Old Laund Clough, a tributary of Pendle Water is a potentially valuable nursery stream for salmonids, however a 1.5-meter-high stepped stone and concrete weir is currently posing a barrier to fish migration here.
The weir is part of the historic Old Laund Hall Farm and is thought to have been constructed between 1910 and 1929. It is assumed that it supplied water to a mill, although no direct link to any of the many mills in the area can be established.
Full or partial removal of the weir would not be feasible due to the weirs role in supporting the constructed channel which lies upstream of the river, and so a rock ramp fish passage will be created. This rock ramp will enable fish migration and help to preserve and support the existing weir structure and the surrounding channel walls.
West Bradford– West Bradford weir is a stepped weir located on West Bradford Brook as it runs through the village of West Bradford. Due to central village location of the weir several members of the public have highlighted their concern that fish are unable to migrate upstream.
The weir is made of concrete clad stone and lies in a wall lined channel with residential properties on the left bank of the river and a main road on the right. The weir is close to the confluence with the River Ribble and has good habitat upstream, making it a potentially valuable spawning area. Although the weir is relatively small at 0.7 metres high, the lower step makes it almost impossible for fish to jump the upper step in normal flow conditions. Therefore, a rock ramp is being created to enable the passage of fish whilst retaining the weir.
These projects have been made possible thanks to funding from European Maritime and Fisheries Fund and European Structural and Investment Funds.