Strelley to Redhill Pipeline Project

Lowering of Avove tunnel boring machine before laying the pipes at the Strelley to Redhill Project site - Courtesy of Avove

Severn Trent’s new 16km pipeline that will link the Derwent Valley Aqueduct to the Strelley and Redhill Reservoirs will boost the resilience of the network by providing up to an additional 25 million litres of water per day to 180,000 customers across North Nottinghamshire. Avove was appointed to deliver the pipeline project and due to the size and nature of the project, there were many considerations and challenges to traverse in order to maximise the value offered to Severn Trent and their customers. Through the power of innovation and synergy created between multiple Avove teams working together on the project, these challenges were successfully managed resulting in cost savings, carbon reduction and the delivery of the project running ahead of schedule.

The Challenge

In order to deliver the pipeline, there were many key factors to consider including completing the project to strict deadlines and within budgets, despite unavoidable delays with procurement of supplies from overseas. As well as these key project management factors, there were also environmental considerations involved within the construction of this pipeline, such as:

• Avoiding the disturbance of local wildlife.
• The presence of Waxcap mushrooms in the area, which are a protected species.
• Minimising disruption to the general public.
• The ecological risk of Japanese Knotweed in the area.
• Ensuring the project was carried out sustainably.

Avove’s tunnel boring machine ‘Maisie’ – Courtesy of Avove

The approach

The goal was to incorporate innovation and value engineering to propose an alternative approach that reduced the costs of the project, whilst delivering large carbon savings and maintaining the performance and integrity of the main. To deliver the project in a timely and cost-efficient manner, Avove introduced an Early Contractor Engagement Phase to review the initial outline design of the project. From this, it was possible to identify areas where processes could be optimised to reduce the time it would take to deliver the project and reduce costs. These included:

• Early procurement strategy: An early procurement strategy was implemented, securing 6km of pipe and fittings before the project began with arrangements made for the phased delivery of the additional 10km throughout the project.
• Competitive tenders: By leveraging a series of competitive tenders, significant buying gains were unlocked, ensuring cost-effectiveness for Severn Trent.
• Enabling works: The ECE phase was expanded to include preparatory work, with mobilisation and site enabling completed before Christmas 2023 – this early start set the stage for a streamlined project timeline.
• Integrated teamwork: The Avove team assigned to the project collaborated effectively with the Avove vegetation management team to effectively and sustainably manage all clearance activities.
• Strategic partnership: Avove entered into a strategic partnership with Waitings Ltd, who had demonstrated the ability to deliver complex projects with tight deadlines.
• Innovative crossing solutions: At critical crossing points, such as highways and railways, Avove proposed reducing pipe sizes, leading to smaller tunnel requirements and further reducing carbon emissions and construction costs.

The Strelley to Redhill site compound showing the TBM being lowered into the shaft and the pipes ready to be laid – Courtesy of Avove

The solution

The comprehensive review and collaborative efforts during the ECE (Early Contractor Engagement) phase allowed Avove to devise a solution that not only met the project’s objectives, but exceeded them.

• Optimised design: Avove proposed a redesign that reduced the pipeline size, which lowered material costs and environmental impact without compromising the pipeline’s performance.
• Value-driven procurement: By initiating early procurement, Avove secured materials at competitive rates, optimising the project’s budget and ensuring timely availability of resources.
• Pipe innovation: By reducing pipe sizes at critical crossings, the need for large tunnels was minimised, leading to significant cost savings and reduced carbon emissions.
• Powerful collaboration: The synergy between the Avove design, ecology, customer and vegetation management teams ensured efficient management of the project timeline.
• Land access achievement: The project team successfully overturned an Environmental Impact Assessment (EIA) decision through the Secretary of State; demonstrating how Avove can successfully complete projects, whilst still fulfilling our commitment to sustainability and preventing disruption to the environment.
• Accelerated project process: The team successfully installed the pipeline ahead of schedule, a significant achievement in the face of challenging weather and environmental factors.

Tunnel boring machine at the base of the shaft – Courtesy of Avove

The results

This project demonstrates how early management, expert planning, innovative processes and a sustainable focus can lead to substantial benefits for both the client and the environment. Thanks to the integrated partnership of our teams and suppliers, our sustainable approach and our innovative design proposal, we delivered over £8 million in cost savings.

Additionally, the project achieved significant reductions in carbon emissions, all while maintaining the performance and integrity of the pipeline. As we continue to work with Severn Trent to complete the remaining pipeline in this project, we will continue to demonstrate the power of innovative thinking, collaborative teamwork, a commitment to sustainability and expert planning.

Benefits

• Cost-savings: Avove’s approach resulted in £8 million in cost savings, making the project more cost-effective for Severn Trent.
• Carbon reduction: The optimisations in pipe size, fittings and tunnel dimensions led to a substantial reduction in carbon emissions.
• Improved efficiency: The early procurement and integrated management strategies streamlined the project timeline, allowing for quicker delivery without compromising quality.
• Sustainable infrastructure: The project’s design maintained the performance and integrity of the pipeline, while reducing its environmental impact.

The site compound - Courtesy of Avove