Porth Hellick Sea Defence Proposals


What’s the problem?

Porth Hellick is one of the more remote sites that we plan to protect, with few buildings nearby. At the eastern side of the beach sheds are used by local fisherman. Porth Hellick Pool just to the north is the largest freshwater source on St Mary’s. Porth Hellick Pool is an important source of water for Higher Moors SSSI. The pool is partly protected by the vegetated dune behind the beach. 

There are gaps along the dune (shown below in yellow). At the eastern side the dune is significantly lower and needs repairing (shown below in green). Erosion has been caused by people walking through the dunes along multiple routes, as well as by boats being launched on the eastern side. These low points allow sea water to flood across the dunes during storms. If sea water gets into Porth Hellick Pool it affects local wildlife and St Mary’s water supply.


What's the suggested solution?

The proposed work renourishes the dune to fill the gaps and rebuild the dune at the eastern side. The renourishment will use sand similar in colour and size to existing sand, which will be covered by a biodegradable coir matting. This will then be overlaid with topsoil and replanted using non-invasive local plant species as much as we can, whatever we use needs good dune-binding properties. Natural England are requesting that the restored sand dune sections are planted with native species, rather than the non-native Fascicularia bicolor.  A new ramp about 22 m long by 3.7 m wide will be constructed on the eastern side for vehicles to launch boats. A boardwalk will be installed at the western end of beach (highlighted in orange above) to provide easy access for the public and to protect the dune from erosion. The new dune will blend into the surroundings and will not significantly change how it looks. 

Close up of proposed ramp at Porth Hellick and dune renourishment


Proposed boardwalk at Porth Hellick


What’s the likely impact?

The work could disturb birds using the Higher Moors area, but this disturbance would be temporary and is likely to have a low impact. A significant archaeological feature at Porth Hellick is the memorial stone for Sir Cloudesley Shovell, which would need to be temporarily removed until the work is completed.

The construction compound will be located in the field immediately to the north-east of the beach. Vehicles will access the beach by the farm track off Carn Friars Lane and public access to the beach will be available using the footpath at the western end of the beach. 

Aerial image of proposed Porth Hellick sea defence works



We have had a great deal of feedback on the Porth Hellick proposals, so thank you to everyone who submitted their questions and concerns. Due to the amount of feedback we have created a seperate Porth Hellick FAQ page that can also be accessed from the left hand side menu as well as this link

If you have any further questions about the proposals please get in touch with us at adaptivescilly@scilly.gov.uk