Coronation Parade was built in the late 1930s as a series of concrete arches and a promenade with retaining wall to the rear. The structure stops the cliff from eroding and protects a significant number of homes and businesses as well as associated infrastructure. Upon visual inspection, evidence of deterioration of the arches was found which included cracks throughout the structure and corrosion of steel reinforcement.
To prevent further deterioration of the arches, repair works were undertaken and completed in 2017 at a cost of £3.3 million. This included repairing the existing damage to the structure and the installation of a protection system to stop any further corrosion of the reinforcing steel (cathodic protection). In order to further protect the promenade/access way and provide waterproofing to the structure, an impervious decking material was laid.
A rock revetment has also been proposed which will replace the existing concrete apron, adjacent to the eastern end of the promenade.
Furthermore, regular shallow land slips at the top of the cliffs mean the cliff face is highly susceptible to erosion. The most recent of these slips occurred during the winter of 2015/16 and was caused by freezing conditions followed by a prolonged period of wet weather.
In order to prevent further erosion of these cliffs, Cliff stabilisation works have been proposed and will be implemented in the future. This work will involve clearing vegetation on the upper slope on a width of 26m and 75m enabling the installation of vertical drains on a 5m grid, minimum 2m into sandstone. Soil nails, 32mm hollow bar, will be installed in boreholes. The soil will then be retained by mesh and erosion control matting.