To safeguard the historic Western Breakwater at Porthcawl, Wales, innovative repairs were imperative.
Constructed in 1828, this 180-meter structure shields Sandy Bay from extreme waves. Its failure could expose around 530 homes and175 businesses to coastal flooding risks. Though resilient, the Grade II Listed breakwater needed substantial repairs due to its exposure during storms, heightened by climate change-induced sea level rise.
Starting from January 2019, Ove Arup and Partners collaborated with Bridgend County BoroughCouncil to conduct an exhaustive structural assessment and devise intricate remedial strategies. The project also introduced eco-engineering interventions, notably a unique artificial reef at the base of the breakwater. As the breakwater couldn’t be altered due to its listed status, an innovative approach emerged–an artificial reef made from modular panels installed on a smooth concrete bed.
This design includes various water-retaining features, such as artificial rockpools, alongside Reckli’s tested formliner patterns and oyster shell motifs. The baseline survey showed the potential for thriving of marine life, including honeycomb worm Sabellaria alveolata reefs, Ulva lactuca, Fucus serratus, and Actinia equina. It was therefore decided to trial a new eco-engineering unit with honeycomb worm reef texture as an intervention to potentially attract new worm settlement and a home for the associated species.
In collaboration with Swansea University and Resting Reef, new concrete mixtures incorporating local crushed cockle shells and ashes were experimented with. These innovations, along with the varied textures, will be assessed for their potential to enhance biodiversity within this remarkable coastal ecosystem. This project encapsulates the amalgamation of traditional structures with cutting-edge eco-engineering for holistic coastal protection.