Council to drill holes along Southsea seafront over next few weeks - here's why

It is set to begin on Monday as part of the next stage of designs for new coastal defences and will involved a series of holes being drilled.

These investigations will take place over a period of four weeks at two locations, on the promenade and beach adjacent to Long Curtain Moat and Clarence Pier car park as well as to the east and west of Southsea Castle.

Portsmouth City Council will be using borehole rigs, excavators and dynamic probes as part of the work which will allow for the design to be further refined as part of the detailed engineering design phase of the project.

Various types of machinery will be used as part of the work however this is purely for ground investigation and isn’t part of construction of the defences themselves.

What types of investigations are being carried out?

- Cable Percussive Borehole – This is the most common type of investigation method used. The rig uses a weight to drive a 15cm diameter casing into the ground. This casing is then pulled back up to retrieve a core which is sent to the laboratory for analysis.

- Trial pit - Slightly larger holes are dug in the ground to allow the various layers of ground to be examined and further testing of materials if needed. These holes are then re-surfaced once the investigation is complete.

- Ground Penetrating Radar - This method uses radar signals to identify buried objects and voids beneath the ground.

Work sites will be safely contained using temporary fencing and will be supervised by on-site contractors.

Temporary footpath diversions will be in place at Long Curtain Moat whilst work is completed and will be clearly signposted.

Working hours will be between 7am and 7pm and the engineers will aim to minimise disruption wherever possible. If you are walking past, please do engage with our friendly team who will be more than happy to discuss the work taking place.

Thank you in advance for your patience and co-operation whilst this work is completed.

If you'd like more information on the Southsea Coastal Scheme, which will protect more than 8000 properties and 700 businesses from the risk of coastal flooding in Southsea, please visit www.southseacoastalscheme.org.uk