Penhale (Cornish: ‘Pennhal’, meaning ‘end of a marsh/moor’) is part of Perran Beach, a north-west facing bay in north Cornwall. Perran Beach is fringed by steep high cliffs. During high water the beach is isolated from Perranporth, but as the waters drop beyond Cotty’s Point, the bay opens up over 3km of fine-grained sand from Droskyn Point in the south to Ligger Point in the north.
The uppershore of the beach is dominated by its high climbing extensive dunes, which are designated for a diversity of ecological reasons. The dune system in this area is divided into three named areas of ‘Reen Sands’ to the south, ‘Gear Sands’ in the middle and ‘Penhale Sands’ to the north.
Though large parts of Penhale Sands remain undeveloped, largely as a result of their management and use for military training, some parts of the systems to the south have been developed as a golf course and a holiday park.
The archaeology of Penhale tells a rich story about the locations past. The sand of Penhale Sands have buried St Piran’s Oratory and a medieval settlement. More recently, the military use of the site means there are a number of Second World War structures, many of which would have been used for training purposes.
Coastal Change
The coastline of Cornwall is an ever-changing environment. It is energetic, dynamic, never still and changes with each wave and each tidal cycle. Some of the changes we see are gradual and barely noticeable, whilst others, such as rockfalls, happen suddenly and often shockingly.
From one visit to the next it can sometimes be difficult to see how a beach and dune system has changed, but information has been collected, and is being collected through the Making Space for Sand project, to help us better understand how the coastline is changing. The purpose of this section of the website is to understand each location has changed over time, how it could change in the future and understand the policies that influence how we can respond to these changes.
Shoreline Management Plans (SMP)
The Shoreline Management Plan (SMP) is a strategic planning and management assessment tool that helps identify and measure the risk associated coastal erosion and coastal flooding. The document makes a number of policy recommendations over short, medium and long term timeframes setting out a strategic approach to managing the built, natural and historic environments associated with the coastline. Within SMP there are four policy approaches which have been assigned to stretches of coastlines. The four policies are: No Active Intervention (NAI), Hold the Line (HTL), Managed realignment (MR), and Advance the line (ATL).
Penhale sits within Policy Development Zone 11 (PDZ11), in Management Area 30 (MA30), within Policy Units (PU) 30.1 and 30.5. The policy recommendations for these policy units are detailed in the table below and the SMP can be accessed through the Cornwall Council website.
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to scroll the below table
| Policy Unit | SMP2 Policy Plan | ||||
| 2025 | 2055 | 2105 | Comment | ||
| 30.1 | Undefended cliffs
Mail Policy Sub Policy |
NAI DnD |
NAI DnD |
NAI DnD
|
Will meet high level objectives and satisfy AONB and heritage coast criteria. Allow natural coastal evolution to occur to support conservation and designated features. |
| 30.5 | Penhale and Holywell Bay
Mail Policy Sub Policy
|
MR NF |
MR NF |
MR NF |
Policy intent here is to use MR to manage the dune system backing the entire frontage to accommodate for the natural variability of the system. This would allow priority to be given to enhancement of the natural dune system as a UK priority BAP Habitat.
There is a large amount of sediment locked up in the dune system which will be able to nourish the nearshore environment as the dune system rolls back. This will minimise the loss of intertidal area. There are a number of key access points to campsites on the beach that would be cut off if access points are not maintained. Beach safety/lifeguards also require access points, so it is important that these are taken into consideration with any MR.
Number of archaeological sites within the dunes in this area. They should be at risk but should nonetheless still be considered in any MR plans.
|
| Key Main Policy: HTL - Hold the Line, A - Advance the Line, NAI – No Active Intervention, MR – Managed Realignment
Sub Policy: DnD – Do not Defend, NF – Natural Features
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National Coastal Erosion Risk Mapping (NCERM)
National Coastal Erosion Risk Mapping (NCERM) provides a baseline of coastal erosion, for the coastline of England, over short, medium and long-term timeframes. The data is based on the natural and defence characteristics of the coastline and provides rates of erosion at differing levels of confidence to help better plan for worse case scenarios. The data provided is for guidance and does not estimate the absolute location of the future coastline.
The basic NCERM lines show erosion estimates for the Short Term (ST-20 years), Medium Term (MT-50 years) and Long Term (LT- 100 years). The data is further categorised by probability: 05 is 5% probability (a 1 in 20 chance of being exceeded) Red Shading, 50 is 50% probability of being exceeded (a 1 in 2 chance of being either exceeded or not exceeded) Orange Shading and 95 is 95% probability (a 19 in 20 chance of being exceeded) Yellow Shading. Click the link below to access the Cornwall Council NCERM Mapping site read the about section then click on layers.
Modelling Coastal Change
Using data that has already been collected, combined with data collected through the Making Space for Sand project, a series of models will be carried out at each location. This will help us better understand how each location may respond to sea level rise and gain a deeper understanding of how coastal sediments move and behave.
The complexity of the modelling, and the data collection that helps inform it, means that modelling outputs will not be the same on all sites. Some locations will be more thoroughly investigated to understand more complex issues and provide data that can be more widely applied to other sites with similar characteristics.
As the project develops this section of the website will expand, sharing new reports and coastal change projections when they are produced.
LiDAR surveys, which are explained on the Data Modelling page, have been carried out by the South West Coastal Monitoring program at this location. The image shared here visualises where sand has eroded (areas shaded in red) and where it has built up (areas shaded in blue), between the LiDAR surveys carried out in 2003 and 2020. The darker the shade of red or blue the greater the amount of sand erosion or accumulation has been observed. The image helps visualise that beaches are areas that change shape over time and will continue to do so as sea levels rise.
Beach and Dune Ecology
Beaches and dunes represent an important transition between the marine environment and the terrestrial environment. This transition creates a range of special habitats and exposes a range of interesting features, which that can result in these spaces being highly designated and protected. The Making Space for Sand project will survey a number of dune systems. These surveys will help highlight how they may be changing, will identify rare species, will map invasive species, help us understand overall dune condition and identify potential constraints to improving their condition.
There are a range of designations that recognise a variety of different features. There are also a number of dunes systems where data has been collected to understand their habitat value. These are explored, on a site-by-site basis, in the section below.
Designations
Special Area of Conservation (SAC)
A Special Area of Conservation (SAC) is an internationally recognised designation with the aim of protecting habitats or species that are of European importance. Land with SACs is considered to be part of a network of high-quality conservation sites, and those considered to be most in need of conservation at a European level.
The Penhale Dune SAC covers and area of approximately 622 hectares of exposed calcareous sand dunes, where active geomorphological and successional processes occur. However, of particular interest are the communities developing on sand overlying the adjacent hillsides, which has been blown inland by strong winds. Dune slacks that have developed support a large number of uncommon plant species.
Site of Special Scientific Interest (SSSI)
A Site of Special Scientific Interest or SSSI is a statutory conservation designation notified by Natural England denoting protection for biological and/or geological characteristics. The natural wildlife and geological features of SSSI’s are considered to be irreplaceable parts of the national heritage. These are protected in order to preserve their importance, and to prevent damage and development.
The Penhale Dunes SSSI covers an area of 1070.4 hectares. Penhale Dunes form part of the most extensive dune system in Cornwall and provide an outstanding example of a sand dune system with an exceptionally rich diversity of habitats and associated flora. Penhale Dunes is one of the richest moss sites in Cornwallis and is also of exceptional importance for both butterflies and moths.
Sign up to Making Space for Sand
If you would like to get involved in helping to make dunes more resilient and biodiverse, want to help develop coastal adaptation and emergency plans or just want to know more about what the project is learning about coastal change, please click here:
