Address: 11 Hockley Court, 2401 Stratford Road, Hockley Heath, Solihull, B94 6NW
Email: info@cpccivils.net Phone: 0121 766 7019
2024 © CPC Civils Ltd. All rights reserved.
Design by eSterling
Project Value
£2,000,000
Client Name
Kier
Project Type
Waterway Engineering
The scheme was constructed through one of the wettest years in Huddersfield’s history with several major floods to the river. This did cause some challenges. The workforce persevered and overcame these challenges to complete the new weir and fish pass and received the appreciation and recognition from the Canal and River Trust.
The purpose of the project was to reinstate the failed weir across the river Calder at Cooper Bridge near Mirfield. To comply with Environment Agency, it was also necessary to include a fish pass as part of the works.
Cooper Bridge Weir is located at Cooper Bridge Junction where the Huddersfield Broad canal joins the Calder and Hebble Navigation from the south. The function of the weir is to maintain the upstream water levels of the Calder and Hebble and the Huddersfield Broad canals. Approximately two thirds of the original weir structure have failed in the past and had since been replaced with other materials over the years.
The principal structures to be constructed were a new 40m long reinforced concrete weir to replace the existing one and a Larinier fish pass and an elver pass. The weir included a concrete crest with steel sheet piles up and downstream tying into a sloping concrete apron to the upstream and a stepped concrete apron to the downstream.
The river Calder is a fast-flowing river which has a high flash flood risk. Maintaining the flow of the river whilst constructing the new Weir and Fish Pass in the river was going to require advanced programming and temporary works installation.
For more information see the Canal and River Trusts article and waterways blog below.
The Project was split into 3 construction phases;
- Install a sheet pile cofferdam a third of the way into the river to enable the Fish pass base to be constructed. Remove the section of the existing weir down to formation. Continuous de-watering of the ground water and de-silting before discharging the clean ground water back into the River. Once the reinforced base was constructed, remove sections of the upstream wall of the cofferdam to divert the river to flow through Phase 1.
- Construct a temporary bridge capable of taking a 70ton crane and walkway over Phase 1 to enable the remnants of the weir to be removed and a stone causeway built out into the river. Install a large cofferdam the full width of the weir to allow the 40m long, 6 step reinforced concrete weir to be constructed one step at a time. Construct new retaining wall and masonry wash wall. Place Rip Rap anti scour stone downstream of the new weir. Remove the sheet piled cofferdam to allow the river to flow over the new weir.
- Close of the upstream wall of the Phase 1 cofferdam. Construct the new reinforced concrete fish pass and the remains of the weir. The new Fish Pass incorporated an Elver pass as well as a Lariner pass with baffles and resting pool. Install new fish monitoring equipment. Remove the Phase 1 Cofferdam. Landscaping to surrounding land and new fencing to the edge of the fish pass.
