In-river works for the removal of the 3m high weir at Bowston in Cumbria have now been completed, South Cumbria Rivers Trust (SCRT) has announced.
Funded by the European Agricultural Fund for Rural Development, removal of Bowston weir which spanned the width of the River Kent SSS/SAC will allow the river to renaturalise, and is expected to see a 44% uplift in biodiversity, reduce flood risk and improve navigation and fish migration.
Removal was a staged process and included installing a rock rapid downstream of the weir to act as a hydraulic control, notching the weir in stages and forming a proto-channel upstream of the weir.
Contractors Ebsford Environmental structural engineer’s assessment identified that the right bank fish pass suffered some erosion and the base of some of the gabions evidenced undercutting. It was decided to act upon the recommendation to keep the fish pass in place and protect its upstream facing wall with large boulders. These have been infilled with river gravels. Voids were also detected in the base of some of the gabions, and these have been filled and large boulders placed immediately in front to armour them.
The weir at the start of the removal works. Image courtesy of SCRT
Removal works nearing completion. Courtesy SCRT