East Devon District Council has completed the excavation of eight trial pits in Exmouth as part of its Beach Management Plan for the town.
Exmouth’s 2015 Beach Management Plan (BMP), which was produced by coastal flood and erosion risk management consultants CH2M, established the need for the trial pits.
The aim of the BMP is to manage the risk of coastal flooding and erosion, with consideration given to the current condition of existing beach and coastal defenses, as well their long term future.
The work, which involved digging a narrow trench in front of the seawall using an excavator, took place between Alexandra Terrace in the west and Orcombe Point in the East.
The pits were then inspected by a coastal engineer to establish the nature of the material on which the seawall is built and the depth of its toe (the depth of the wall hidden beneath the beach).
Information gained from the trial pits will be used to determine emergency trigger levels for intervention to protect the sea wall and what future action could be required to prevent the seawall being undermined, should the amount of beach material – which protects the wall – be reduced during a storm. For example, if the wall was found to be built on soft, vulnerable material, then it might be necessary to ensure sufficient rock armor is available locally to be used in an emergency.
The integrity of the seawall is a critical factor in ensuring the safety of Exmouth – should it fail, then the seafront could be at risk from coastal erosion and flooding.