Sea-floor erosion, combined with the localised movement of stone blocks due to wave impact on the outer harbour wall and the deterioration of the structure on the inner harbour wall, have seen significant destabilisation of the structure.
It is predicted that the functionality of the Cobb as a breakwater would end in the 2040’s, potentially resulting in the loss of the harbour, and over 100 residential and non-residential properties will be at increased risk of flooding and coastal erosion.
The project aims to stabilise the Cobb to maintain its status as a breakwater, a coastal flood and erosion defence and a safe harbour for many different types of vessels and businesses.
It is being proposed to strengthen and stabilise the structure which may include construction of a low-level concrete toe foundation strengthening wall along with tension piles to anchor the inner harbour walls.
Design options have been extensively reviewed by the project team and the wider statutory authorities including Historic England, Marine Management Organisation, and the Environment Agency. The project team are currently reviewing the scheme design options with a view to come to a preferred option that can be presented to stakeholders and the public. The preferred design will have a material effect upon construction timeline and therefore the project team is not in position to comment upon the construction programme at this time.