Working on behalf of Denbighshire County Council, we’ve installed coastal flood defences in the seaside town of Rhyl on the coast of Denbighshire, North Wales. East Rhyl was protected by a number of historical coastal flood defences that were estimated to provide a 1:50- year standard of protection. These have overtopped in recent years causing extensive and prolonged flooding in the area.
Awarded via the SCAPE Civil Engineering framework we delivered the design and construction of a rock revetment structure immediately in front of the existing sea wall, improved approximately 600 metres of the current sea wall and promenade at Splash Point as well as replenishing the beach to provide a 1 in 200-year standard of protection.
The primary source of flooding in the area is wave overtopping. Flood modelling showed that wave overtopping at East Rhyl was set to increase due to:
Working in close partnership with Denbighshire County Council and our designers we identified several suitable options that would provide the required protection for the area as well as meeting the Welsh Government’s Flood and Coastal Risk Management Strategy requirements.
Drawing on our extensive experience of delivering coastal defence projects, we identified that rock armour would provide the most cost-effective method of coastal protection at East Rhyl.
With a 1 in 200-year standard of protection against storms and the impacts of climate change, rock armour is suitable for highly exposed areas. It is relatively inexpensive and highly effective at absorbing and deflecting the energy of the waves. The gaps between the rocks slow down the flow of the water meaning it has less erosive energy and the risk of wave overtopping is substantially reduced.
62% of the 128,000 tonnes of rock armour that was needed to complete the project was all taken from local quarries ensuring we supported the local economy.
Rich in marine archaeology, the East Rhyl coastline contains ancient fish traps, a submerged ancient forest and shipwreck that all provide a glimpse into the distant past. It is also near Liverpool Bay which is a Special Protection Area which is classified for the protection of:
Early engagement with local universities and environmental institutions enabled us to understand the ecological sensitivities in the area and incorporate mitigation measures into the environmental impact assessment to protect and preserve the historic underwater heritage.