Canwick WRC (2026)
The new 3,600m3 glass-coated steel tank from Hayes GFS Ltd - Courtesy of @one Alliance
Canwick Water Recycling Centre (WRC), located to the south-east of Lincoln, serves a significant proportion of the city and surrounding communities. It treats wastewater from both residential and commercial sources before safely returning it to the environment. As part of Anglian Water’s wider network, the site plays a key role in supporting a complex and interconnected system of assets that must operate reliably under varying hydraulic conditions. The Canwick catchment is subject to increasing regulatory scrutiny around storm overflows and environmental performance. Updated requirements introduced through PR24 place greater emphasis on storm storage capacity, settlement performance and the reduction of intermittent discharges to receiving watercourses.
Background
Canwick WRC operates within a well-established site that has evolved over time to meet the needs of the communities it serves. It includes a range of treatment assets such as storm tanks, grit chambers and return systems, all working together as part of a wider integrated network. The site is also closely linked with upstream assets, including Washingborough WRC, which supports a coordinated approach to managing flows and optimising performance across the catchment.
The surrounding area includes agricultural land and environmentally sensitive watercourses, meaning that protecting the local environment remains a key priority.
Inside the new storm tank – Courtesy of @one Alliance
Anglian Water’s @one Alliance was appointed to design and deliver a £3.3 million scheme to increase storm storage capacity at Canwick WRC, ensuring regulatory compliance while enhancing operational resilience and supporting future network integration. Throughout both the design and construction phases, careful planning and collaboration were required to maintain treatment performance, protect effluent quality, and minimise the risk of storm discharges.
The project demanded a compliant, robust and future-ready solution that could be safely delivered within a live operational wastewater treatment site. The resulting scheme not only addressed immediate regulatory requirements but also provided the flexibility and resilience needed to support future network demands, delivering long-term benefits for both customers and the environment.
The issue
The primary challenge at Canwick WRC was to increase storm storage capacity to comply with updated regulatory requirements. Hydraulic assessments determined that a total storm storage volume of 9,173m3 was required. With the existing infrastructure providing only 5,597m3 of capacity, a deficit of 3,576m3 needed to be addressed. Delivering this additional storage was essential to ensure the site could continue to effectively manage peak storm flows, maintain high standards of effluent quality, and satisfy Environment Agency requirements. The upgrade also supports the wider wastewater network strategy, including the planned integration of flows from Washingborough.
New pump station steel tank and sump pocket & pumps – Courtesy of @one Alliance
To align with broader network improvements, the scheme needed to be delivered early in AMP8. This was carefully managed within a live operational environment, where space is limited and existing infrastructure is already in place. The solution therefore needed to be practical and efficient to construct, while ensuring continuous treatment operations were maintained throughout, minimising disruption and continuing to provide a reliable service for customers and the environment.
The solution
The solution for Canwick WRC was developed through detailed planning and design, ensuring that the additional storm storage could be integrated effectively within the existing site while maintaining operational performance and minimising disruption.
The initial concept identified the need for a new storm tank to provide the required increase in capacity. This was further refined through detailed hydraulic modelling, using existing asset data such as invert levels, weir settings and system interactions, to ensure the new infrastructure would operate seamlessly alongside the current storm storage system.
Glass-coated steel tank
A key aspect of the design was the adoption of a glass-coated steel storm tank from Hayes GFS Ltd, providing a modular and space-efficient alternative to traditional in situ concrete construction. This approach enabled the required capacity to be delivered within the site’s constrained footprint while reducing construction complexity and programme duration.
The new 3,600m3 glass-coated steel tank from Hayes GFS Ltd – Courtesy of @one Alliance
The design allows the new and existing storm tanks to operate in parallel, using level control instrumentation and three feed pumps to enable coordinated, simultaneous filling. A gravity return system was incorporated to discharge flows back into the treatment process via an actuated valve and a newly constructed valve chamber, connecting into the existing return chamber (MH1). This arrangement improves operational reliability by reducing reliance on mechanical systems while maintaining controlled and efficient flow management.
The new 7m high storm storage tank has a diameter of approximately 28m, providing a working volume of 3,600m3. This has increased the total storage capacity on site to 9,173m3; meeting the regulatory requirements.
Mechanical & electrical systems
Supporting M&E systems include:
- Ultrasonic level monitoring from Pulsar Measurement.
- Local control panels integrated into the existing kiosk, and provision for telemetry and future MCC/SCADA integration from TES Group.
- An automated storm tank cleaning system from Eliquo Hydrok Ltd using a CWF flushing bell with manual siphon air release has been incorporated to reduce maintenance requirements and improve operational efficiency.
The Eliquo Hydrok Ltd CWF flushing bell within the new tank – Courtesy of @one Alliance
Constructability
Constructability was a key consideration throughout, with the design tailored to suit the constraints of a live operational site. A hybrid construction approach was adopted, combining efficient installation methods with practical solutions to avoid existing infrastructure. This included the installation of feed pipework supported on gravel with directional supports, the construction of a pipe bridge over the existing grit chamber to avoid complex underground services, and the development of new civil infrastructure such as a pump station chamber, valve chamber and associated slabs. Cable routing was carefully planned to integrate with existing systems, ensuring continuity of control and monitoring.
The use of a prefabricated, modular tank reduced on-site construction time and improved quality control, while construction activities were carefully phased and sequenced to maintain continuous treatment operations. Controlled tie-ins and planned installation works ensured that the WRC remained fully operational throughout delivery, providing a practical, resilient and future-ready solution that meets both regulatory and operational requirements.
Canwick WRC Storm Tank Project: Supply chain – key participants
The successful delivery of the Canwick scheme has relied on a collaborative, multi-disciplinary approach between many key suppliers:
- Client: Anglian Water
- Project delivery: @one Alliance
- Principal contractor: Barhale
- EICA & mechanical contractor: Kemada
- Coring subcontractor: Endeavour Drilling
- GFS tank: Hayes GFS Ltd
- Storm tank flushing bell: Eliquo Hydrok Ltd
- Pump skid fabricator: Waveney Pumps Ltd
- Flygt pumps: Xylem Water Solutions
- Gorman-Rupp pumps: Hydromarque Ltd
- Valves: AVK UK Ltd
- MCC: TES Group
- Pipework & fittings: Saint Gobain PAM UK
- Pipework & fittings: Wolseley UK
- Instrumentation: Pulsar Measurement
- Scaffolding: Tubes Scaffolding
The new 75kW pumps – Courtesy of @one Alliance
Environmental benefits
From an environmental perspective, the increased storm storage capacity significantly reduces both the frequency and impact of storm overflow events, helping to improve settlement performance and reduce pollutant loads entering receiving watercourses. This in turn supports improved effluent quality and contributes to the protection and long-term health of downstream ecosystems.
The adoption of an above-ground, modular storm tank solution has also helped to reduce construction-related carbon impacts by minimising excavation requirements and significantly reducing the volume of concrete used. Alongside this, shorter construction durations and more efficient use of materials have further contributed to lowering the scheme’s overall carbon footprint. In addition, the enhanced system reduces the risk of uncontrolled discharges during periods of extreme weather, strengthening environmental compliance and improving resilience for the future.
Operational benefits
From an operational standpoint, the scheme delivers a substantial uplift in hydraulic capacity, enabling the site to better manage peak flows and maintain stable performance under a wide range of operating conditions.
By integrating the new storage tank with the existing infrastructure, the system now benefits from improved redundancy and greater operational flexibility, with parallel tank operation allowing flows to be distributed more efficiently and reducing pressure on individual assets.
Access to the tank roof – Courtesy of @one Alliance
The introduction of automated cleaning systems and modern instrumentation reduces day-to-day maintenance requirements while improving overall operational efficiency. Real-time monitoring capabilities further support proactive asset management and more informed operational decision-making. Importantly, the scheme also enables the progression of the Washingborough transfer, helping to unlock wider network optimisation and supporting future growth and resilience across the wider catchment.
Conclusion
The Canwick Storm Tank Project demonstrates how targeted infrastructure investment can address regulatory requirements while delivering wider operational and environmental benefits. And at the time of writing, the project is nearing completion, with final commissioning and close-out activities currently underway.
By increasing storm storage capacity to meet PR24 requirements, the scheme ensures compliance with Environment Agency standards and significantly improves the site’s ability to manage peak hydraulic events.
The project has been delivered within a constrained operational environment, using a modular and efficient design approach that minimises disruption and reduces carbon impact. At the same time, it enhances resilience, redundancy, and long-term asset performance. The successful integration with upstream assets, particularly the Washingborough scheme, highlights the importance of coordinated, system-wide planning.
Overall, the scheme provides a robust, future-ready solution that supports environmental protection, operational continuity, and sustainable growth, offering a strong example of best practice in storm management across the water industry.
New feed pipe at Canwick WRC - Courtesy of @one Alliance
