Elsham Reservoir (2026)
Construction of Elsham Reservoir - Courtesy of @one Alliance
Anglian Water’s Strategic Pipeline Programme is one of the most ambitious infrastructure programmes ever undertaken within the UK water sector. Spanning more than 500 kilometres of interconnected pipelines, pumping stations and treatment assets, the programme will fundamentally change how water is moved across the Anglian Water region, providing long-term resilience for millions of customers. Located at the head of the 52km East-to-Lincolnshire (E2L) Strategic Pipeline, Elsham Reservoir will be a pivotal site within the network.
Introduction
Anglian Water’s @one Alliance is currently delivering the Elsham Reservoir Scheme in close collaboration with the Strategic Pipeline Alliance (SPA). The scheme comprises a new high-capacity pumping station, a conditioning plant, storage reservoir, lagoon infrastructure and extensive cross-site pipelines and valve controls.
Together, these assets are being delivered to enable treated water from East Lincolnshire to be safely conditioned, stored and transferred into the wider strategic grid.
Once fully operational, Elsham Reservoir will be a key asset within Anglian Water’s future water supply strategy, providing both hydraulic capability and operational flexibility. The scheme is being delivered using a collaborative alliance model, with early contractor involvement, integrated design and construction, and a strong focus on digital enablement and carbon reduction.
As construction progresses on site, Elsham is already demonstrating how large-scale strategic assets can be delivered in a way that balances resilience, environmental responsibility and long-term value for customers. The project is not only addressing immediate supply challenges, but is also being developed as a digitally enabled, future-ready asset that will support Anglian Water’s network for decades to come.
Reservoir precast wall panel installation – Courtesy of @one Alliance
The issue
Anglian Water’s supply demand balance is under increasing pressure as a result of several converging long-term challenges; population growth across the East of England continues at one of the fastest rates in the UK, with significant housing and commercial developments planned over the coming decades. This growth is driving a sustained increase in water demand and placing additional strain on existing sources and infrastructure.
Climate change is compounding these pressures. Hotter, drier summers, changing rainfall patterns and an increased frequency of drought events are reducing the reliability of traditional water sources. Local abstractions, which have historically underpinned supply in many areas, are becoming increasingly vulnerable during prolonged dry periods. This is reducing the overall resilience of the network and increasing the risk of supply interruptions.
At the same time, environmental protection and resilience requirements continue to tighten, and Anglian Water must meet its statutory obligations under the Water Resources Management Plan 2019 (WRMP19), while also protecting sensitive watercourses, wetlands and habitats. Environmental legislation increasingly limits abstraction from vulnerable sources, particularly during periods of environmental stress, requiring alternative approaches to balancing supply and demand.
WRMP19 identified the need for strategic transfers to move water from areas of relative surplus to areas of higher demand. Within this context, the East-to-Lincolnshire strategic pipeline was identified as a critical intervention. To enable water from East Lincolnshire to be transferred into this pipeline, a conditioning plant at Elsham was required to ensure water quality, compatibility and compliance with regulatory standards.
Without the intervention of this project, delivered by the @one Alliance, Anglian Water would face increased risks to security of supply, greater reliance on environmentally sensitive abstractions, and potential non-compliance with statutory obligations. The Elsham scheme is therefore being progressed as a element of Anglian Water’s Best Value Plan, addressing both immediate operational risks and long-term resilience challenges, while aligning with environmental and regulatory requirements.
Reservoir precast wall panel installation – Courtesy of @one Alliance
Elsham Reservoir Scheme: Supply chain – key participants
The Elsham Reservoir Scheme is being delivered through a collaborative supply chain, with early contractor involvement and strong integration across disciplines.
- Project delivery: @one Alliance
- Principal contractor: Skanska
- Site engineering services: East Anglian Site Engineering
- Reservoir: FLI Precast Solutions
- Civils contractor (ECI & main works): Bell Formwork & Civil Engineering Services Ltd
- SMR (for sub-base construction): Richardson Recycling
- Low-carbon pipeline system: Saint Gobain PAM UK
- MEICA subcontractor: FSD
- MEICA subcontractor: Glasswell & Last
- MCCs (high-lift PS & chlorine building): Cema Ltd
- Pumps: SPP Pumps Ltd
- Valves: AVK UK Ltd
- Gantry cranes: ABUS Crane Systems Ltd
- Ortho dosing kiosk: Lintott Control Systems
- HV Equipment: Power Testing Ltd
- Steel buildings: North Lincs Structures Ltd
- Sample kiosk & security access hatches: Technocover
- Generator: Stuart Power
- Generator fuel tank: AVK-SEG
- Site accommodation & storage: Algeco UK Ltd
- Fencing & barriers: Heras Mobile Fencing & Security Ltd
- Lagoon Liner: ARM
- Plant hire: Q Crane & Plant Hire Ltd
- Plant hire: Flannery Plant Hire (Oval) Ltd
This integrated approach is ensuring that expertise from across the supply chain is being harnessed to deliver a high-quality, resilient solution that provides long-term value.
Construction of the new reservoir – Courtesy of @one Alliance
The solution
The solution being delivered at Elsham is a fully integrated set of assets designed to work together as part of the wider strategic pipeline system.
Conditioning plant
The new water conditioning plant will dose chlorine and ortho phosphoric acid to ensure that water transferred from East Lincolnshire is safe, stable and compatible with the wider network.
This facility is being constructed with resilience, maintainability and future operational flexibility at the forefront of the design.
Pumping station
To support the conditioning plant, a new pumping station is currently being constructed to provide the hydraulic capacity required to transfer large volumes of treated water into the strategic pipeline. The pumping station is being designed to operate efficiently across a range of demand scenarios, providing the ability to respond dynamically to changing network conditions.
Storage reservoir
A new storage reservoir is being delivered alongside the pumping station, providing operational flexibility. The reservoir is designed to balance fluctuations in demand, smooth operational transitions and provide a buffer during maintenance activities or unplanned network events. This storage capacity significantly enhances the resilience of the system and reduces the risk of supply interruptions.
Lagoon & secondary pumping station
The solution also includes a lagoon and secondary pumping station, which are being constructed to support on-site water management and enhance overall system reliability. These assets are enabling controlled management of flows and supporting safe and efficient operation under a range of conditions.
Pipelines
Nearly 1.6 kilometres of additional cross-site pipelines, comprising 600mm and 700mm ductile iron mains, are being installed to integrate the Elsham assets into the wider E2L transfer system. Associated valve controls, including actuated and interlocked valves, are being provided to allow flexible and secure operation of the site within the strategic network.
Reservoir roof installation underway – Courtesy of @one Alliance
Innovations & carbon savings
A defining feature of the scheme is its integration into Anglian Water’s Digital Twin Programme. The site is being delivered as both a physical and virtual asset, with a detailed digital replica developed alongside construction.
This digital twin will enable real-time monitoring, predictive maintenance and scenario modelling, supporting improved operational decision-making and long-term efficiency.
Carbon reduction has been embedded into the solution from the outset and these measures are delivering substantial carbon savings while maintaining performance and resilience.
Design decisions the actively reducing embodied carbon, include tarmacing in place of concrete for internal roads where possible, the use of secondary materials such as SMR for sub-base construction, optimisation of generator sizing and fuel storage, and increased use of GGBS within concrete mixes.
The project also utilises innovative low-carbon pipework supplied by Saint Gobain PAM UK. This installation is one of only four globally and the first in the UK, to deploy this technology. Compared with conventional alternatives, it is projected to achieve carbon reductions of more than 80%.
As construction progresses, the benefits of this integrated solution are becoming clear. The scheme is enhancing security of supply, reducing reliance on environmentally sensitive abstractions, and providing a flexible, future-ready asset that supports Anglian Water’s long-term strategic objectives.
New reservoir site overview – Courtesy of @one Alliance
Conclusion
The project is a critical step forward in Anglian Water’s journey towards a more resilient, adaptive and sustainable water network. As works continue on site, the project is already demonstrating how strategic infrastructure can be delivered through collaboration, innovation and a clear focus on long-term outcomes.
By enabling the transfer of treated water into the strategic pipeline, Elsham Reservoir will strengthen regional resilience, support compliance with WRMP19 obligations and protect the environment by reducing reliance on stressed local sources. The integration of digital twin technology and embedded carbon reduction measures ensures that the asset is not only fit for today’s challenges, but also ready to adapt to those of the future.
In the wider context of the Strategic Pipeline Programme, Elsham is more than a single site. It is a foundational asset that underpins Anglian Water’s strategic vision, helping to secure reliable water supplies for customers and communities for generations to come.
