Project Drivers
The Problem

The first promenade at Penzance was built in 1844 and was subsequently significantly repaired and rebuilt after sustaining substantial damage in the storms of March 7th 1962. The rebuilding took place between 1965 and 1967.

During these storms large sections of the coast wall were breached and parts of the promenade behind were washed away. It is considered that there are four key problems associated with the promenade:

Durability of the existing wall structure
Loss of beach material leading to deepening of water at the wall.
Potential for undermining the wall.
Overtopping of the wall leading to flooding, road closures and property damage.

Proposed Solutions

A range of methods of improving the promenade sea wall were considered. From these options the following feasible options remain:

• Improvements to the wall durability. It is recommended that a full condition survey be carried out along the face of the wall to determine the scale of joint mortar loss. It is also recommended that
• Ground penetrating radar be used to determine any location of anticipated voiding behind the wall. It will be necessary to validate these findings with land-based boreholes.
• It is recommended that a regular monitoring inspection regime be set up as follows:
• March each year to determine damage caused by winter storms
• November each year to identify any repairs that are required prior to the winter storms.
• Offshore Breakwater. The feasibility of utilising offshore breakwaters to retain beach recharge material can only be determined by detailed numerical (and physical) modelling. However, given the correct grading of beach recharge material being available in sufficient volume, offshore breakers could provide a coastal defence option.
• Sill or Perched beach. It is considered feasible to construct a perched beach behind a new revetment. However there are aesthetic considerations as the existing beach would be partly covered by a rock revetment and would be fully exposed at low tide.
• Toe Protection. A concrete toe protection structure is considered a feasible and cost effective option to the problem of wall undermining. However, it does nothing to protect adjoining areas of beach from wave attack.
• Raising the level of flood defences. This is considered feasible, providing that the loss of views by local residents can be balanced by the increase in flood protection.

ALTHOUGH THE PROMENADE AND PENZANCE HARBOUR ARE NOT CONTAINED WITHIN THE NEWLYN REGENERATION STRATEGY, THEY ARE PART OF THE HYDER TECHNICAL STUDY AND ARE INCLUDED WITHIN THIS NEWSLETTER REPORT JUST FOR YOUR INFORMATION.

IF YOU REQUIRE FURTHER INFORMATION WITH REGARD TO THIS ASPECT OF THE STUDY, PLEASE CONTACT MR NIGEL HORWELL AT PENWITH DISTRICT COUNCIL OFFICES, TEL. 01736 336618.
E MAIL: nigel.horwell@penwith.gov.uk