Client
Affinity Water Limited
Value
£500,000
Sectors & Services
Water Industry Concrete Repair Coatings Membranes Cleaning & Preparation Projects
Downsgate 1 and 2 Service Reservoirs are key potable water storage assets located in Dover, forming an integral part of Affinity Water’s regional supply network. The reservoirs provide essential treated water storage and resilience for the surrounding catchment, supporting both daily demand and operational continuity.
Constructed as covered service reservoirs, they rely on the integrity of their concrete structures and roof waterproofing systems to protect water quality and maintain compliance with strict regulatory standards. Over time, deterioration to the roof slab and localised defects within the walls led to water ingress, creating an unacceptable risk to water quality and asset performance. This condition triggered the need for timely, planned refurbishment to secure the long-term serviceability of both reservoirs.
Services undertaken
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Detailed condition survey and inspection
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Roof waterproofing using the Triflex system
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Placement of new gravel overburden using conveyor system
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Internal and external overbanding of joints and cracks
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Resin injection to cracks
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Enlargement of existing hatches
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Closure of redundant openings
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Installation of new hatches, security covers, new roof drainage system, ducting and inspection chambers
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Formation of new perimeter drainage
CRL undertook a wide-ranging scope of works covering both structural repairs and waterproofing, applying a practical and innovative approach aligned with asset management and water industry requirements. Initial surveys confirmed widespread defects, including leaking joints, cracks and failures in the existing roof waterproofing. These findings informed a coordinated repair and refurbishment strategy addressing both immediate water ingress and long-term durability.
Internally and externally, joints and cracks were prepared and sealed using Masterseal 930/933 overbanding systems, providing flexible and durable waterproof detailing capable of accommodating movement. Cracks were further treated with resin injection to restore continuity and structural performance. Localised concrete repairs were carried out where deterioration had occurred, followed by the application of protective coatings to enhance durability in the aggressive reservoir environment.
Roof works formed a key element of the scheme. Given the weather conditions and the operational impact of keeping the reservoirs out of service, CRL worked closely with Affinity Water to adopt the Triflex waterproofing system. This solution allowed rapid installation and curing, enabling the roofs to be waterproofed efficiently and the reservoirs returned to service sooner than would have been possible with more conventional systems. New roof drainage was installed to manage surface water effectively, reducing the risk of future ingress.
The project also required significant alterations to access arrangements, including enlargement of existing hatches, closure of redundant openings and installation of new hatches and security covers. New ducting and inspection chambers were formed to support ongoing inspection and maintenance.
Due to restricted access, with no crane or telehandler availability, CRL deployed a conveyor belt system to place approximately 300 tonnes of new gravel overburden across the two reservoirs. This innovative method improved productivity, reduced manual handling risks and demonstrated CRL’s ability to transfer solutions from other sectors to overcome site constraints. The project highlights CRL’s strength in delivering complex concrete repairs and structural repairs UK within live water infrastructure environments.
"Affinity water has been most complimentary towards CRL with respect to what they consider to be our forward thinking and innovative mind set."
Olu Ogunwale | Framework Manager (Water) | CRL
The completed refurbishment provides Downsgate 1 and 2 reservoirs with a robust, maintainable waterproofing and repair solution that safeguards water quality and extends asset life. The Triflex roof waterproofing system, combined with new overburden and drainage, delivers long-term resistance to water ingress and environmental exposure. Flexible overbanding and resin injection treatments protect joints and cracks against future movement and leakage.
Concrete repairs and coatings enhance durability and reduce the likelihood of further deterioration, supporting reduced maintenance requirements. Improved access arrangements and inspection infrastructure aid ongoing asset management and monitoring. Collectively, these measures increase resilience, minimise operational risk and ensure the reservoirs remain fit for purpose within Affinity Water’s strategic network.
