Erosion along the frontage at Clacton has necessitated the progressive protection of the cliff and foreshore during the last 100 years. The cliffs consist of Pleistocene gravels overlying London Clay and reach a level of 20 m above Ordnance Datum (Newlyn). The top of the clay is irregular and incised by buried channels which allow water to drain to the front of the cliff and weaken the clay forming the cliff base. On the foreshore the stability of the existing sea walls protecting the cliff base was endangered by erosion on the downdrift side of the two large groynes constructed a few years previously.
Remedial measures included the relief of perched water tables and drainage of the cliff by vertical and inclined bored drains; the protection of the toe by constructing stepped aprons and sea walls of pre-cast concrete components; the installation of a new groyne system and replenishment of foreshore material.
- © The Geological Society, London 1980