The Felixstowe Coastal Defence Project Protects UK Commerce and the Environment
Felixstowe, on the Suffolk coast, is at risk of flooding during times of high surge tides. Existing coastal defences were nearing the end of their useful life, with many of the groynes no longer effective at retaining the sand on the beach. This led to lowering of the beach and undermining of the seawall. Improved coastal defences were urgently needed.
The Environment Agency, in partnership with Suffolk Coastal District Council, awarded the Felixstowe Coastal Defences project to Black & Veatch for detailed design and site supervision work.
At risk was a high-density urban area consisting of 960 residential properties, 428 nonresidential properties and the tourist frontage to the town. The Port of Felixstowe is the largest and busiest container port in the UK.
Coastal Defence Scheme
A Black & Veatch study had identified the highest priority frontage most exposed to high-energy storm events and in the poorest condition. Failure of these defences could result in flooding of the entire risk area, which was expected within five years. Black & Veatch designed a coastal defence scheme consisting of 21 rock groynes and 250,000 cubic metres of beach recharge.
Black & Veatch experts faced many complex problems. With the contractor, a method was developed to improve access to the beach from the land, avoiding the use of marine plant. This consisted of undertaking the beach recharge works before rock groynes construction began. The beach was “over-recharged” – this was shown prior to construction to be more cost-effective than using marine floating plant.
Through coastal modeling, the Black & Veatch team demonstrated to the statutory authority that the proposed scheme would not have an impact on the coastal processes and, therefore, would maintain the integrity of the existing habitat within the Site of Special Scientific Interest (SSSI). This ensured compliance with environmental legislation.