The upgraded tidal gates strengthen long-term flood resilience for the city of Truro, protecting 185 commercial and residential properties as a critical part of the Environment Agency’s wider flood defence system. The new gates are designed to be closed during high spring tides and storm surges, providing reliable and increased protection for the next 30 years.
7m wide, 7m high
steel mitre gates replaced
Over
£3.1m
in social value raised
Over
£600k
contributed directly into local economy
Andrew Houghton, Operations Manager, Environment AgencyThis project represents a significant investment in Truro’s flood resilience. The barrier and its controls are more reliable, meaning we can ensure effective flood risk management for the community into the future.
The existing gates were coming to the end of their serviceable life, leading to increased maintenance requirements and reduced confidence during extreme tidal conditions. We applied a value-led engineering approach focused on whole-life performance, with durability, resilience and ease of maintenance built into the design. By drawing on asset management expertise from our water sector experience, we supported design decisions that simplify future inspections and maintenance, reducing long-term risk and improving reliability.
Historically the tide gate suffered from silt deposition, affecting the gates’ operational ability to open and close. An innovative system using a jet ring mixer was devised to disperse silt within the channel, significantly cheaper and more effective than the previous prop wash method.
To maintain the standard of flood protection during construction, temporary stoplogs were trialled in September 2023 ahead of gate removal to verify performance and inform the flood contingency plan. The stoplogs were deployed during high spring tides and remained operational until the replacement gates were installed and fully commissioned.
Creating wider value for the local community
As part of the scheme, we worked with Perranporth Cricket Club to repurpose the former barrier control room as a women’s changing room to support the growth of female participation in cricket, creating a lasting community benefit.
The Truro Tidal Gates project demonstrates how we apply value-led engineering and cross-sector expertise to deliver resilient infrastructure that protects people, property and the environment while creating wider social value for the communities we serve.
The Institution of Civil Engineers South West awarded this project the Judges’ Special Award in 2025.
Proactive and early stakeholder engagement contributed to an outstanding Considerate Constructors Scheme performance, achieving a perfect 45/45 audit score and securing a CCS Bronze Award in April 2025.
The project was also shortlisted as a finalist at the New Civil Engineer Awards in the Impact in Water and Environment – Contractor category, recognising its technical excellence in engineering and positive environmental outcomes.
The scheme was recognised with a Green Apple Environment Award, reflecting its strong environmental performance and sustainability credentials.