In October 2023, Storm Ciaran exposed a 90-metre-long section length of the Exmouth seawall foundation, resulting in the failure of the wall and pavement behind the wall and requiring an emergency closure of the promenade.
In response, the East Devon District Council, the area’s coast protection authority, brought Moffatt & Nichol in to investigate the cause of the failure and work with a local contractor to design the works to replace the failed section of wall to reopen the promenade before the Summer 2024. Moffatt & Nichol responded rapidly to request for assistance at a day’s notice.
The Exmouth seafront is a picturesque stretch of the Devon coastline at the start of the Jurassic Coast World Heritage Site. It also forms the boundary of the Exe Estuary, which is designated nationally and internationally as a haven for migratory birds. The beach and promenade are a focal point of activity, offering a pedestrian-friendly area for strolling, cycling, enjoying the views, and accessing the beach. The town’s sea defences were originally constructed by the Victorians at a time when beach levels were elevated, featuring a mobile dune system along parts of the beach. Since then, beach levels have continued to fluctuate, resulting in the gradual erosion of the dune systems in front of certain sections of the seawall.
Initial works involved specifying and supervising site investigations to confirm existing wall construction, defining the failure mechanism, and determining design parameters. Topographic, utility, UAV, and laser scan surveys were commissioned. Moffatt & Nichol’s duties included outline and detail design of the sea defence replacement, as well as site supervision, principal designer duties, and public consultation.
Moffatt & Nichol also liaised with regulators, including Natural England, supported the council with funding applications for studies and investigations, and prepared an economic assessment of erosion damages to outline a business case for funding.
The first phase of works was completed in May of 2024, with further works, aesthetic works, and an eastward extension to be completed after the main tourist season.
