Canvey Island Tidal Defence Works
location
Canvey Island
The Challenge
Canvey Island’s position—2 metres below the high tide level—means that any weakness in its defences carries a high risk of tidal flooding. The works cover a 3km stretch of the island’s sea wall, safeguarding around 15,000 residential properties, including 6,000 directly affected by this project.
The main challenge was delivering large-scale structural upgrades to an ageing revetment system within a live coastal environment, while maintaining flood protection and minimising disruption to the community.
The Solution
The project focused on strengthening the existing sea defences using durable, low-maintenance materials. The existing revetment was cleaned and exposed, with voids beneath filled using Lean Sand Asphalt (LSA) to restore stability and integrity.
A new toe was excavated into the foreshore and reshaped to form a stable slope, with asphalt delivered directly to the landward crest. Using long-reach excavators — including a 110-tonne machine with a 30m reach — allowed precise placement of materials without disturbing the existing structure.
How We Delivered
Delivery required careful sequencing to manage tidal windows and ensure safety throughout construction. Asphalt materials were delivered directly to the crest for efficiency, while long-reach excavators reduced the need for plant movement on the foreshore.
Each phase was supported by close coordination between HEP, the Environment Agency, Jacobs, and Balfour Beatty, ensuring that quality, safety, and environmental standards were consistently met. The foreshore was regraded and reinstated on completion to blend the works into the natural coastal profile.
Community & Environment
Given Canvey Island’s dense residential setting, community safety and engagement were key priorities. Regular communication with local stakeholders helped maintain awareness of progress and minimise disruption.
Environmentally, the works were planned around tidal conditions to reduce impact on marine habitats, with materials and methods selected for longevity and sustainability. The project also contributes to climate adaptation goals by enhancing the island’s resilience to sea-level rise.
The Outcome
The upgraded defences provide enhanced protection to thousands of homes, businesses, and community assets across Canvey Island. The project has extended the service life of the tidal revetment system and strengthened local flood resilience for years to come.
Through collaboration, precision, and sustainable delivery, the Canvey Island scheme demonstrates how modern coastal engineering can safeguard vulnerable communities while respecting the surrounding environment.
