Porthtowan Appendices

Appendix C Baseline Report

Stage 1 Report: Porthtowan

Cornwall Beach & Dune Management Plans

Prepared for Cornwall Council

9 July 2015

Ash House Falcon Road Sowton Exeter Devon EX2 7LB

Contents

Section Page 1 Introduction ...... 1 1.1 Background ...... 1 1.2 Project aim, objectives and approach ...... 1 1.3 About this document ...... 4 2 Site Visit Report ...... 5 2.1 Attendees ...... 5 2.2 Site Visit Record ...... 6 2.3 Thoughts on Potential Management Solutions for Consideration ...... 8 2.4 Data Sources ...... 8 2.5 Photos ...... 9 3 Environmental Characteristics ...... 10 3.1 Introduction ...... 10 3.2 Methodology ...... 10 3.2.1 Designated Nature Conservation sites and Protected Habitats Considered ...... 10 3.3 Environmental Setting ...... 11 3.3.1 Ecology ...... 13 3.3.2 Designated Geological Conservation Sites ...... 16 3.3.3 Landscape Setting ...... 16 3.3.4 Archaeology and Cultural Heritage ...... 16 3.4 Main human impact pressures affecting the natural dynamics of the site...... 16 4 Coastal Processes Understanding ...... 18 4.1 Introduction ...... 18 4.2 Shoreline Processes Overview ...... 18 4.2.1 Key Characteristics of the Coastline Today ...... 18 4.2.2 Forcing Factors ...... 24 4.2.3 Sediment Dynamics ...... 28 4.2.4 Historical Shoreline Change ...... 28 4.3 New Shoreline and Beach Profile Analysis ...... 28 4.4 Summary and Recommendations ...... 30 4.4.1 Summary ...... 30 4.4.2 Recommendations to Consider for Future Beach and Dune Management ...... 31 5 Site Summary ...... 32 5.1 Dune Inventory Summary ...... 32 6 References ...... 34

III

SECTION 1 INTRODUCTION 1 Introduction

Figure 1.1 The interaction of beach systems that compose the ‘beach environment’ and which must be considered together to provide a holistic approach to beach management (after James, 2000 in Frampton, A.P.R. (2010). “A review of amenity beach management”. Journal of Coastal research, 26(6), 1112‐1122, November 2010). The approach to managing the beaches and sand dunes was investigated in between 2006 and 2009 by Halcrow on behalf of the Cornwall and Isles of Scilly Coastal Group, and led to the production of the Cornwall Sand Dune and Beach Management Strategy (Halcrow, 2009a). The main focus of the strategy is the management of flood and coastal erosion, although the habitat and tourism value of the dunes will also be considered. This 2009 project delivered an Inventory of Beaches and Dunes; a Best Practice Management Guide and two pilot Beach and Dune Management Plans (BDMPs) for Harvey’s Towans and Fistral Beach. It is this 2009 work that this current project is building upon to develop six new BDMPs and review the two pilot BDMPs (see Section 1.2). 1.2 Project aim, objectives and approach The purpose of the project is to develop six new long‐term strategic BDMPs for Constantine Bay, Porthtowan, Summerleaze, Par Sands, Widemouth Bay and Praa Sands; and review the need (or

1 SECTION 1 INTRODUCTION

otherwise) to update the two pilot BDMPs produced in 2009 for Fistral Beach and Harvey’s Towans. This will be achieved by: 1. Identifying the best management approach; in terms of monitoring and intervention (when trigger levels are reached) requirements for beach and dune systems at each individual site, based upon the best practice framework developed as part of the Cornwall Sand Dune and Beach Management Strategy produced by Halcrow in 2009. 2. Providing a long‐term (50 year) approach to each site that is based upon an up‐to‐date understanding of the beach‐dune system and coastal processes at each site, as well as predictions of future coastal evolution. The locations of these eight sites is shown in Figure 1.2.

Figure 1.2 Map showing location of the eight BDMP locations.

Development of the BDMPs will involve four stages. Local community stakeholders and statutory stakeholders will be engaged to seek local knowledge and guide selection of preferred management options. These stages, and the times when engagement with local community representatives and other statutory consultees is planned, are shown in the flow diagram below (Figure 1.3). This report represents outputs from “Stage 1 – Baseline Understanding.”

2 SECTION 1 INTRODUCTION

Stage 1 – Baseline Understanding

Inception Meeting and Develop Engagement Plan

Data collation and review Site visits (with stakeholders)

Environmental baseline Coastal processes understanding

Confirm findings with Cornwall Council

Stage 2 – Define Issues and Objectives Identify issues for each site

Define objectives for future management of each site

Confirm issues and objectives for future management of each site with Cornwall Council and Stakeholders

Stage 3 – Develop Future Management Options

Identify appropriate management options to address issues identified

Appraise options (including environmental assessment and determination of trigger levels)

Discuss and agree preferred management approaches for each site with Cornwall Council and Stakeholders

Stage 4 – Reporting

Produce Draft Beach and Dune Management Plans

Cornwall Council comment and review

Produce Final Beach and Dune Management Plans and Leaflets for informing general public

Figure 1.3 Overview of the staged approach to developing BDMPs for the eight locations around Cornwall.

3 SECTION 1 INTRODUCTION 1.3 About this document This report provides the results of the Stage 1 work to develop the baseline understanding of the Porthtowan BDMP location (see Figure 1.4). Specifically, it:  Reports the findings of a site visit made on 11th March 2015 by members of CH2M’s project team and invited stakeholders (Section 2);  Provides details of the environmental characteristics of the BDMP area (Section 3);  Describes the coastal processes and recent shoreline evolution of the beach and dune system in the area (Section 4);  Summarises the information from Sections 2, 3 and 4 into a revised dune inventory record for the site, updating the dune inventory record produced as part of the 2009 Cornwall Dune and Beach Management Strategy (Halcrow, 2009b) (Section 5).

Figure 1.4 Map showing the Porthtowan BDMP location and extent (red outline).

4 SECTION 2 SITE VISIT REPORT 2 Site Visit Report

Over a period of four days, three members of CH2M’s project team visited the eight BDMP sites to capture information about each site and take ground‐level photos. At each site, client representatives, stakeholders and local community groups were given the opportunity to attend, meet with the project team, discuss their aims and objectives for the site, and raise any issues and concerns. Information collected during the site visits will be considered when developing later stages of the project, including:  Stage 1 – Baseline Understanding (refer to Sections 3 and 4 of this report)  Stage 2 – Define Issues and Objectives; and  Stage 3 – Develop Future Management Options. The site visit report for the Porthtowan BDMP area, which was undertaken on 11th March 2015, is presented within this section and provides:  a list of attendees at each site (Section 2.1);  a record of the site visit including both factual information, comment and opinion provided stakeholders (Section 2.2);  a summary of potential management solutions identified on the day of the site visit for consideration in later stage of the project (Section 2.3);  a section on ‘Data Sources’ where CH2M’s project team were informed of, or provided with, relevant information at the site or following the site visit (Section 2.4); and  a selection of photographs taken during the site visit to highlight salient points (Section 2.5). The information presented is a record of both information recorded during the site visit, and additional information provided by stakeholders as comments on the draft site visit report between 8th and 15th April 2015. 2.1 Attendees Name Role Organisation

Emma Allan Senior Coastal Scientist CH2M Hill

Emily Hewitt Environmental Scientist CH2M Hill

Mark O’Brien Officer Cornwall Council

Alison Mills

Cllr Mrs Joyce Duffin Cornwall Council Member

Lynne Davies Porthtowan Parish Councillor St Agnes Parish Council Member Porthtowan Beach Association (PBA)

Judi Strega Resident n/a Chairman Porthtowan Beach Association (PBA)

Nicky Pearce Resident n/a Secretary Porthtowan Beach Association (PBA)

Jack O’Shea Resident n/a Member Porthtowan Beach Association (PBA)

Nora Stapleton Resident n/a Member Porthtowan Beach Association (PBA)

Name Role Organisation

Phil Rees Technical advisor to Porthtowan Beach Association (PBA)

Comments on the draft site visit report for this location were received from: Cllr Lynne Davies (St Agnes Parish Council); Nicky Pearce (Porthtowan Beach Association); Phil Rees (Resident and technical advisor to PBA); Martin Clemo (Cornwall Council); and Jolyon Sharpe (Cornwall Council). 2.2 Site Visit Record Stakeholders expressed the view that there is no evidence that the dune was ever historically high. Historical pictures (such as photographs available from Francis Firth website that show how the dunes have changed over time) show low uneven mounds, with the marram grass being concentrated at the rear of the valley which is now a car park and access road. The car park was formed by removing much of the grass and started the process of hard landscaping etc. There has also been a noticeable increase in visitor activity not only during the summer but even during the off peak seasons. This activity has no doubt had an impact on the integrity of the dune system. There is no evidence that mining of the beach in 1898 changed this. A reported change of dune management approach in 1967 is considered by some stakeholders to be the key point in changing the nature (height) of the dunes. In the storms of winter 2013/14, this was observed that it was only when the waves were reflected by the funnel shape valley into a bigger wave did they impact the dune and surrounding area. This was observed in February 2014 where wave heights were their highest due to the culmination of several storms in quick succession. The car park, surf club and pump station is at greatest risk of damage from large waves. At or around the low water mark a sand bar is reported to be normally present. The beach profile changes seasonally whereby in winter the sand is taken offshore to expose rock and shingle at the top of the beach. During the spring period, the sand including the sand forming the bar migrates shorewards to cover all areas of the beach in a thicker layer of sand. In recent years there have been a significant number of storms particularly in 2014 which have had a significant impact on distribution of sand on all beaches along the North coast of Cornwall. These storms have exceeded the 1 in 10 year return periods with the result that the beach sand may have been taken much further offshore than normal. As a result it may take more than one season for the sand lying in deeper water to migrate shorewards back onto the beach during the summer period. The beach composition changes seasonally, and during the winter is rocky/shingle and in the summer is sandy. The sand is said to always come back in the summer. During the summer the sand at the top of the berm close to the high water mark is subject to desiccation over the neap tide periods and depending on the wind direction may be blown further onshore to form the dunes. The main issue at Porthtowan is the loss and flattening of the dunes for flood defence and that they are no longer vegetated. This is associated with the dunes diminishing in size and extent in recent years, to a point where they are now quite low lying with little or no vegetation cover. Sand does continue to accumulate and is blown across the dune surface as there is currently nothing in place to stabilise the sand. This is evident by the fact that the WWII pill box has been buried by sand for many years. As a consequence there is little to stop the sand from being picked up by the wind and blown further in land. It is reported by stakeholders that, over a relatively short time, this has resulted in a general lowering of the sand dune levels to a point where features that have been buried for many years have been re‐ exposed for the first time in living memory. Once the sand has been blown onto the road, stakeholders advised that it then acts as a channel to funnel the sand further inland. This leads to a build‐up of wind‐blown sand, causing a number of issues which the community would like to be resolved, as follows:

6 SECTION 2 SITE VISIT REPORT

 Removal of sand from Beach Road is required on a regular basis. Last year, the amount of sand on the road was the highest observed to date and Cory Environmental had to move sand from the road 3‐4 times per day. When sand is cleared from the car park it cannot be returned to the beach as it is considered to be hazardous material because it could contain oil, diesel etc. Therefore only the top layer of sand is put back on the beach, whilst the sand that comes into contact with the road surface is taken away which upsets the local community as it reduced the volume of sand resource in the system. Sand that is put back on the beach is placed below high tide, to give it a chance to blow onto the dune face and not back onto the road.  The road in front of Blue Bar (West Beach Road, starting from Sandy Road Car Park) is privately owned and the owners pay to clear the road. There is currently a dispute between the private land owners and Cornwall Council about this.  The footpath that runs across the dunes is covered by sand, showing how the sand has built up in this area.  The access path to the beach via Beach Road (opposite Blue Bar) is covered by sand and is uneven. Porthtowan Beach Association (PBA), with support from Cornwall Council, are in the process of evaluating the possibility of providing 'Access for All' to Porthtowan beach, improving beach access for people with disabilities. This is one of five projects being undertaken by the PBA who are applying for 'Blue Flag' status and the 'Seaside Award' for Porthtowan beach (see Photograph 2.1). A number of dune stabilisation methods have been implemented by Cornwall Council and the local community and are being tested for their success, they include the following:  Straw bales located within the dune face, placed 3‐4 weeks prior to the site visit in February 2015 (see Photograph 2.2), along with topping of the existing dunes and reshaping of the sand. The community are divided by the method of removal and reshaping of established dune and there is concern for the remaining patch of dune adjacent to the stream. Sand is accumulating around the bales, although children do play on them and horses eat them. There is dispute within the community regarding the eventual required height of the dunes and protection of the seascape view point from behind the dunes.  Brush Wood fencing.  Hoping to plant Marram Grass and other grasses. It was advised that a community survey by PBA in 2014 indicated that the majority of those questioned are in favour of keeping the lower dune level as it was historically and what nature is trying to return it to, rather than having a higher dune system (which it has been in more recent times). In the past, various methods of management have been trialled:  Christmas trees were placed within the dunes, but not favoured by the local community (largely due to visual impact) so were removed before their effectiveness could be established.  Fencing was placed in the dunes some time ago and were ok, but the local community has raised concern that difficulty arises when the sand buries the chestnut and wire fencing which is then re‐exposed later on causing a health and safety issue.  Chestnut paling was used to stabilise the dunes but sand built up too quickly so were not favourable to the local community.  Gabions were placed along the dune toe in the late 1980’s/early 1990’s, they worked initially, but then the dunes eroded. The gabions were moved to the opposite side of the beach, across the river mouth.  Fencing has been placed between the dunes and the river (on the north side), to restrict access and discourage people from walking through the grassy area of dunes here. Some planting has

taken place, including marram and smaller dune plants. Sometimes, the wind rips the marram grass out. There has also been invasion by other species including bramble and Rosa Regosa. In addition, there has also been issues with retaining dune fencing on site as it gets stolen or used as firewood. Children play in the dunes and jump of the fence into the dunes. A suggestion was made to add something outside of Blue Bar for children to jump from to prevent damage to the dunes. During Winter 2013/2014, the beach was steep, rock was exposed along with oil from the SS Torrey Canyon spill that occurred in 1967. Around the area of the lifeguard hut, the land can get flooded by seawater, although the flood water stops at the entrance to the car park. A South West Water drain does back‐up on the north side of the river. The River is dredged/cleaned of sand and was last completed in January 2015. The dunes on the west side of the river, seaward of the gabions, are stable. St Agnes Parish Council are undertaking an Open Development Plan and have started consultation. 2.3 Thoughts on Potential Management Solutions for Consideration  Plant marram and other grasses for the purpose of stabilising the dunes. Fencing will be required to protect the dunes whilst they recover. The local community would be happy to fence sections of the dune off whilst they recover, but not the entire dunes.  An information notice board about the dunes and management activity would be welcomed and help to educate the general public about the site and the efforts being made to restore the dunes.  Funding can be sought from Section 106 developer contributions (approximately 10‐20k is currently available). The local community have offered to fund some development if views are taken into account.  Work with the PBA, local community, businesses, landowners and beach users to manage the site in an integrated and sustainable way in the future. 2.4 Data Sources  An information pack was provided by Nicky Pearce.  Phil Rees has wave climate data from his work on the Wave Hub project 8 miles away at Hayle. Following the site visit Mr Rees also provided additional information about the historical evolution of the Porthtowan shoreline, information that is reflected in Section 6.3 above.  Reference Cornwall Council (produced by Royal Haskoning) Sand Loss Report, January 2015.  Plymouth University have undertaken studies of the beach and dunes at Porthtowan.  In 2008/2009, Plymouth University undertook wave readings just off the beach.

8 SECTION 2 SITE VISIT REPORT 2.5 Photos

Photograph 2.1 Access path to beach opposite Blue Bar.

Photograph 2.2 Straw bales in dune face placed in February 2015.

9 SECTION 3 ENVIRONMENTAL CHARACTERISTICS 3 Environmental Characteristics

3.1 Introduction The purpose of this section is to identify key environmental features within and near the Study Area. This is to ensure that appropriate consideration of these features is made when developing a future Beach and Dune Management Plan for Porthtowan (including ongoing monitoring and maintenance works and any new works that may be required). It should be noted that the level of detail presented in this document allows for an initial appraisal of environmental features to provide for an environmentally sustainable future management regime. This does not negate the requirement for future detailed environmental assessment which may be required to support consent applications or prejudge the scope of the assessment. Background information on possible consenting requirements and legislative drivers are described in the methodology section below.

3.2 Methodology Conservation designations and their qualifying interest features (with exception of Special Protected Areas (SPAs) see below), and UK priority Biodiversity Action Plan (BAP) habitats that lie within the study area or within 2km have been described and will require consideration during the development of the BDMPs. Only those features that are currently considered relevant to the Study Area, i.e. those that are likely to be impacted upon or are likely to have an influence on the proposed scheme, have been described. In the case of SPA sites, they have been considered within around 150km of the BDMP Study area and on the basis of bird‐habitat connectivity in line with standard practice for habitat regulations assessments (i.e. how the birds use the habitat in a region and so depend on different resources in a regional context, for example estuarine mudflats and fully marine areas at different stages of the tidal cycle). The designation information has been sourced using the online interactive mapping tool Magic http://www.magic.gov.uk/. 3.2.1 Designated Nature Conservation sites and Protected Habitats Considered The following nature conservation designations and their qualifying interests have been considered:  International Nature Conservation Sites:

o The Natura 2000 European network of protected sites represents areas of the highest value for natural habitats and species of plants and animals that are rare, endangered or vulnerable in the European Community.

o Special Areas of Conservation (SACs) are strictly protected sites designated under the EC Habitats Directive, and contribute to conserving habitat and species identified in Annexes I and II of the Directive.

o Special Protection Areas (SPAs) are strictly protected sites classified in accordance with Article 4 of the EC Birds Directive, which came into force in April 1979. They are classified for rare and vulnerable birds (as listed on Annex I of the Directive), and for regularly occurring migratory species.  National and Local Conservation sites:

o Site of Special Scientific Interest (SSSI) sites are nationally designated sites, selected for being the best examples of our natural heritage in terms of wildlife habitats, geological features or landforms. A SSSI area is notified as being of special interest under the Wildlife and Countryside Act 1981. Geological SSSI sites may also afford further

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designation as Geological Conservation Review sites (GCR) that make a special contribution to our understanding and appreciation of Earth science and the geological history of Britain, which stretches back hundreds of millions of years

o Marine Conservation Zones (MCZs). The Marine and Coastal Access Act 2009 allows for the creation of MCZs. MCZs protect a range of nationally important marine wildlife, habitats, geology and geomorphology, and can be designated anywhere in English and Welsh territorial and UK offshore waters. 27 MCZs were designated in 2013 with a further round of six recommended MCZs (rMCZ) are being considered for 2015.

o Local Nature Reserves (LNRs) are declared and managed for nature conservation by local authorities under the National Parks and Access to the Countryside Act 1949, and provide opportunities for research and education, or simply enjoying and having contact with nature.  Habitats and Species The government has a commitment “to conserve and enhance the biological diversity within the UK and to contribute to the conservation of global biodiversity through all appropriate mechanisms”. Former Biodiversity Action Plans (BAPs) were developed at a national and local level to protect and enhance the diversity of flora and fauna. The UK BAP (Biodiversity: The UK Action Plan, 2004) set out action plans for priority species and habitats. As a result of devolution, and new country‐level and international drivers and requirements, much of the work previously carried out by the UK BAP is now focussed at a country‐level rather than a UK‐level, and the UK BAP was succeeded by the 'UK Post‐2010 Biodiversity Framework' in July 2012. The UK list of priority habitats, however, remains an important reference source and has been used to help draw up statutory lists of priority habitats in England, as required under Section 41 (England) of the Natural Environment and Rural Communities (NERC) Act 2006. Habitats and species of principal importance, which could potentially be affected by the management options, are considered.  Heritage Designations:

o World Heritage Sites are designated to meet the UK's commitments under the World Heritage Convention. Sites are designated for their globally important cultural or natural interest and require appropriate management and protection measures.

o Historic and archaeological sites of significance are designated as historical assets by English Heritage and include listed historic buildings, scheduled monuments, registered parks and gardens, battlefields and protected wreck sites. They designation are afforded to protect against any future loss of their significance.

o Heritage Coast is a section of coast exceeding one mile in length that is of exceptionally fine scenic quality, substantially undeveloped and containing features of special significance and interest.  Landscape Designations:

o Area of Outstanding Natural Beauty (AONB) are designated under the National Parks and Access to the Countryside Act 1949, amended in the Environment Act 1995, with responsibility of care assumed by local authorities and the rural community. 3.3 Environmental Setting The Study Area contains the following nature conservation designations. These are central in the consideration of options for the beach and dune management plan:  Godrevy to St Agnes SAC  Godrevy to St Agnes SSSI

 Cornwall and West Devon Mining Landscape (UNESCO) World Heritage Site  The Cornwall Area of Outstanding Natural Beauty (AONB)  St Agnes Heritage Coast  National Trust managed coastline  Archaeological and Cultural Heritage designated features. These features are shown on Figure 3.1 and Figure 3.2, and discussed in further detail below.

Figure 3.1 Environmental designation features in the vicinity of the Porthtowan BDMP area.

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Figure 3.2 Historic environment, cultural and landscape designation features in the vicinity of the Porthtowan BDMP area.

3.3.1 Ecology 3.3.1.1 Designated Nature Conservation Sites The following nature conservation designations and their qualifying interest features are all within or lie in close proximity to the Study Area and will require consideration during the development of the BDMP (see Figure 3.1 above):  Godrevy to St Agnes SAC runs from the north‐western cliff edge of Porthtowan beach. This site is designated under article 4 (4) of the Habitats Directive (92/43/EEC) for the following Annex 1 habitats: Temperate Atlantic wet heaths with Erica ciliaris and Erica tetralix; and European dry heaths and for the following Annex II plant species Early gentian Gentianella anglica.  Godrevy to St Agnes SSSI encompasses a large portion of Porthtowan beach and is nationally designated for extensive maritime heathland and grassland, sand dune and scattered scrub communities together with rare plants. The site is also designated for its large breeding seabird colonies (on cliffs and offshore rocks).  Carrick Heaths SSSI comprises of ten sites, with the nearest site to Porthtowan approximately 2km southeast from its nearest point. The underlying soils at each site are largely derived from slatey mudstones, siltstones and shales which have given rise to clay soils with variable drainage regimes. These conditions have led to the development of mosaics of wet and dry heathland vegetation types, characterised by populations of nationally rare Dorset heath Erica ciliaris, and internationally important Southern Atlantic Wet Heath. The Carrick Heaths also support a range of characteristic fauna with nationally rare invertebrates, a range of bird species. Designated sites identified and considered, or discounted for bird‐habitat connectivity between the protected area and the site, are described below (see also Figure 3.3). Sites identified as having possible connectivity will require consideration during the development of the BDMP

 Falmouth Bay to St Austell Bay pSPA is approximately 16km from Porthtowan at its nearest point. The proposed SPA (pSPA) supports rare wintering birds and diving birds that are proposed for designation under the Birds Directive (2009/147/EC). The pSPA is a large area, and encompasses the Fal and Helford SAC within the pSPAs north western section. This site is designated under article 4 (4) of the Habitats Directive (92/43/EEC) for the following Annex 1 habitats: Sandbanks which are slightly covered by sea water all the time; Mudflats and sandflats not covered by seawater at low tide; Large shallow inlets and bays that include low tidal sandbanks and Atlantic salt meadows (Glauco‐Puccinellietalia maritimae). Other Annex I habitats that are present as a qualifying feature of the SAC but not the primary reason for selection include Estuaries and Reefs and includes the Annex II plant species Shore dock Rumex rupestris. Some connectivity with Porthtowan may be possible, but likely low due to the absence of similar rich estuarine habitat (no baseline information exists to confirm habitat type at Porthtowan that supports diving birds).  Marizion Marsh, southwest SPA is approximately 22km south from Porthtowan at its nearest point. The marsh is at the mouth of a wide coastal valley, separated from the sea by a shingle bar with fringing sand dunes. The marsh is important for passage and wintering birds associated in particular with the extensive reedbed. The site qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting populations of Annex I species Aquatic Warbler Acrocephalus paludicola (in passage) and Bittern Botaurus stellaris (over winter). Connectivity with Porthtowan is unlikely due the absence of freshwater habitat.  Tamar Estuaries complex SPA (approximately 68km northeast from Porthtowan at its closest point) The estuary system is a large marine inlet on the English Channel coast comprising the estuaries of the rivers Tamar, Lynher and Tavy. Habitats include extensive tidal mud‐flats bordered by saltmarsh communities. The mud‐flats contain extensive and varied infaunal communities rich in bivalves and other invertebrates, and feeding grounds for waterbirds in numbers of European importance. Saltmarshes provide important feeding and roosting areas for large numbers of wintering and passage waterbirds. This site qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting populations of Little Egret Egretta garzetta (on passage, and a population over winter) and Avocet Recurvirostra avosetta (over winter). Connectivity with Porthtowan is likely to be low due to the lack estuarine conditions present to support species.  Isles of Scilly SPA is approximately 80km southwest from Porthtowan from its closest point. The SPA qualifies for its seabird assemblage of international importance and breeding seabird assemblage of European importance. The isolated nature of the islands and rocks, together with their low levels of disturbance and predation, makes them particularly suitable for nesting seabirds. This site qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting populations of European importance of the following Annex I species Storm Petrel Hydrobates pelagicus and Lesser Black‐backed Gull Larus fuscus. The site also qualifies under Article 4.2 of the Directive (79/409/EEC) for regularly supporting a seabird assemblage of international importance of at least 20,000 seabirds. The SPA boundary only encompasses those areas used for nesting. The vast majority of the feeding areas used by the seabirds are marine waters outside the SPA. Connectivity with feeding areas seaward around Porthtowan is a possibility.  The Exe Estuary SPA (approximately 134km from Porthtowan) is a complex of coastal habitats waters, foreshore, low‐lying land, three saltmarshes and an unusual double spit across the mouth of the estuary, and the sand dunes of Dawlish Warren. The mud and sandflats support Eelgrass Zostera spp. and Enteromorpha beds, and contain an abundance of invertebrates including extensive Mussel Mytilus edulis beds, which together provide rich feeding habitats for wintering waders and wildfowl. The site qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting populations of Annex I species Avocet Recurvirostra avosetta and Slavonian Grebe Podiceps auritus (over winter) and qualifies under Article 4.2 of the Directive (79/409/EEC) as a wetland of international importance for regularly supporting at least 20,000 waterfowl. Unlikely to be any connectivity with Porthtowan due to the lack of estuarine influence.

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Figure 3.3 Potential bird‐habitat connectivity between the protected area and the BDMP site.

3.3.1.2 Biodiversity Action Plan (BAP) Habitats The following are listed as UK priority BAP habitats and are either represented in the Study Area or are within 1km as identified in the Cornwall County Council report: Ecological Assessment of Coastal Zone Management Issues at Porthtowan (Spalding Associates Ltd, 2005). Only habitats that are considered relevant to the Study Area, i.e. they are likely to be impacted upon or are likely to have an influence on the proposed scheme, have been described.  Coastal Sand Dunes

o Strandline embryo and mobile dunes (open dune) (Quality assessment: Unfavourable. Damage and presence of non‐native species) . Re‐instate pioneer, foredune and mobile dune wherever possible . Reduce trampling erosion significantly . Control ruderal and non‐native species

o Fixed dune grassland (Quality assessment: Unfavourable. Damage and presence of non‐ native species) . Reduce trampling erosion significantly . Reduce non‐native cover  Maritime cliff and slope (Quality assessment: Unfavourable. Some decline probable and presence of non‐native species)

o Reduce trampling erosion of cliff edges significantly o Reduce non‐native cover  Maritime heath (Quality assessment: Unfavourable. Lack of diversity in structure of heath)

o Create localised diversity in age structure of heath 3.3.2 Designated Geological Conservation Sites Porthtowan and surrounding area is designated a County Geology Site previously known as RIGS. County Geology Sites represents the most important places for geology and geomorphology outside statutory protected land but are not protected by law. The site Fishing Cove features exposures of a 60m thick olistostrome within the Porthtowan Formation and the site Black Cliff features sandstone dominated turbidites in the Porthtowan Formation (ERCCIS and Cornwall Wildlife Trust (2010)). 3.3.3 Landscape Setting The importance of landscape to the Praa Sands area is recognised by the following nationally and regionally important designations (see Figure 3.2 above):  The south easterly corner of the site and continuing around the headland is part of the internationally designated Cornwall and West Devon Mining Landscape (UNESCO) World Heritage Site.  Cornwall Area of Outstanding Natural Beauty (St Agnes) is encompassed by the characteristics of Cornwall and West Devon Mining Landscape (UNESCO) World Heritage Site, the rocky coastline from Porthtowan to Cligga Head, and includes Penhale Sands SAC (designated for its extensive dune system and associated plants, northeast of Porthtowan).  The St Agnes Heritage Coast stretches landward and seaward starting along the northern side of Porthtowan reaching Perranporth.  National Trust managed coastline runs from the northern end of Porthtowan and northerly to St Agnes. 3.3.4 Archaeology and Cultural Heritage As well as being rich in historical mining importance, there are also number of other sites and monuments located within the area and include a Scheduled Monument and a number of listed buildings (see Figure 3.2 above). In recent years, storms have uncovered a WW2 Pill Box at the rear, and roadside of Porthtowan beach, which has subsequently at present been covered with a mound of sand (observed during a site visit March 2015 – see Section 2). 3.4 Main human impact pressures affecting the natural dynamics of the site The following observations were made by Spalding Associates Ltd (2005) and are still relevant following the site visit in March 2015 (refer to Section 2):  Cliff and coastal footpath erosion  Trampling, erosion and loss of sand cover on dune and dune grassland  Fragmentation of the dune ridge/loss of dune vegetation  Increasing development pressure  Recreational use of the beach  Non‐native species. Additional observations and information noted since the 2005 Coastal Zone management Issues Report, based on observations obtained during site visit in March 2015 (refer to Section 2):  The dunes are no longer vegetated, apart from a stable area of dune that runs alongside the Stream.

16 SECTION 3 ENVIRONMENTAL CHARACTERISTICS

 The dune grassland behind the dune ridge is also very sparsely vegetated, with main area of concentration stream side.  Dune stabilisation trials: Christmas trees previously placed in view of stabilizing the sand to enhance sand dune formation as part of their management have been removed. Diggers have topped and re‐shaped the front of the dunes and placed straw bales and stacks of tree branches strategically along a created ridge.

17 SECTION 4 COASTAL PROCESSES UNDERSTANDING 4 Coastal Processes Understanding

4.1 Introduction This section of the report provides the coastal processes understanding for the Porthtowan BDMP area, which will be used in Stage 2 of the development of the BDMP for this area to help define the issues for each of the BDMP site and the objectives for their future management. Specifically, this section of the report presents a review of existing literature and the findings of new data analysis to assess the coastal processes and shoreline change at the BDMP location. The work draws primarily from key data sources, including the 2009 sediment budget report (Halcrow, 2009c), the SMP2 (Royal Haskoning, 2011a), latest beach profile monitoring data (Plymouth Coastal Observatory (PCO), 2014a and b) and new data received from stakeholders. It provides:  A review of past shoreline evolution, characteristics of the coastline today, hydrodynamics and sediment transport patterns, to provide a conceptual understanding of the coastline;  Review of the latest beach profile data by Plymouth Coastal Observatory (PCO);  Recommendations for consideration when developing the future management options. 4.2 Shoreline Processes Overview 4.2.1 Key Characteristics of the Coastline Today Porthtowan is located on the north coast of Cornwall, directly north of Redruth and with St Agnes Head to the north and Portreath to the south (refer to Figure 4.1). Porth Towan beach is bounded to the north and south by high cliffs which are comprised of resistant Devonian slate (Royal Haskoning, 2011b). The intertidal sandy beach is fairly dynamic; the depth of sand varies seasonally, although summer beach levels tend to be higher than winter ones (refer to Section 2). A sand bar is normally present at the position of the low water mark (refer to Section 2). A small river discharges out to the sea across the centre of the beach, with its source located in the nearby area of Menagissey. The beach is backed by fringing and climbing dunes, which extend inland within the steep‐sided river valley, within which the bay has formed. In 2009, the dunes were estimated to cover an area of approximately 1ha Halcrow (2009a). The dunes on the southern side of the small river, seaward of the gabions, are stable (refer to Section 2). However, there have been more significant changes to the dunes on the northern side of the river. Historically, the dunes on the north side of the stream were higher and were well‐vegetated, extending further inland where they met with the steep‐valley sides to form climbing dunes (observations made from Francis Firth photograph of Porthtowan in 1925, Francis Firth, online). As the town of Porthtowan developed, largely in response to tin mining in the valley, increased tourism and increased number of residential properties, the dunes were built‐on and became more heavily used, changing in form and state, as shown in Figure 4.2 and described below.  Around the time of the 1960’s, historical pictures (PDCG, 2015) show the dunes to be quite flat, with a reduction in vegetation on the surface to leave a large flat sandy area.  There was significant modification to the beach and frontal dunes following the Torrey Canyon Oil spill in 1967, which contaminated the sand on the beach and dunes at Porthtowan. During the remediation works, several thousand tonnes of oily sand had to be removed from the beach (PDCG, 2015). The top layer of sand was temporarily moved whilst the underlying contaminated sand was taken away from the site. During placement of the top layer back on the beach, some of the sand was also placed to the rear of the dunes (an area referred locally to as ‘the green’).  Through the 1960’s and 1970’s, the backshore and dunes continued to erode and apparently there were issues of wind‐blown sand into the village. This sand was subsequently removed and replaced on the beach (PDCG, 2015).

18 SECTION 4 COASTAL PROCESSES UNDERSTANDING

 In 1978, the District Council erected a row of gabions across the beach to help trap sand, however, 12 months later they were moved to the southern side of the stream to help stabilise the beach in front of the surf club (PDCG, 2015).  Between the late 1970’s and early 2000’s, a programme of dune fencing and Marram planting was implemented and proved to be successful as the dunes accreted and became more vegetated and stable. In 2006, a boardwalk was built across the dunes, but this was later buried by wind‐blown sand.  Between 2006 and 2012, in response to a period of strong‐onshore winds, blow‐outs formed within the dunes and the sand blown out from the dunes was deposited as various ridges and hummocks across the flat sandy area and ‘the green’. The previously planted Marram grass became buried during this time. Today, the dunes have diminished in size and extent to a point where they are now low lying with little or no vegetation cover (refer to Section 2). They are under pressure as sand is continually blown from the bare sand surface onto the road and they are subject to year round pedestrian trampling Halcrow, 2009a), which means that pioneer vegetation does not readily develop nor survive. On the day of the site visit (11th March 2015), the area of dune was raised up from the beach, with a gently sloping seaward dune face (see Figure 4.3 and Figure 4.4). Ridges and hummocks existed across the dune surface, but otherwise it was largely bare and devoid of vegetation. Areas of vegetation were concentrated on a dune ridge located at the seaward face of the dunes and adjacent to the stream (refer to Figure 4.5) and ‘the green’, an area that runs along the centre of the dunes adjacent to the stream (refer to Figure 4.6). A WWII pill box is present on the beach, but is currently buried by a mound of sand. Headland cliff recession at Porthtowan is limited low due to the resistant nature of the geology (Royal Haskoning, 2011b). Around the area of the lifeguard hut, the land can get flooded by seawater, although the flood water stops at the entrance to the car park (refer to Section 2). A South West Water drain does back‐up on the north side of the river. The river is dredged/cleaned of sand, with works last completed in January 2015. Management intervention at Porthtowan is ongoing and has in part been described above, more recent intervention measures include:  Removal of wind‐blown sand from:

o Beach Road is required on a regular basis. Last year, the amount of sand on the road was the highest observed to date and Cory Environmental had to move sand from the road 3‐4 times per day. When sand is cleared from the car park it cannot be returned to the beach as it is considered to be hazardous material because it could contain oil, diesel etc. Therefore only the top layer of sand is put back on the beach, whilst the sand that comes into contact with the road surface is taken away. Sand that is put back on the beach is placed below high tide, to reduce the risk of it being blown straight back onto the road.

o The road in front of Blue Bar (West Beach Road, starting from Sandy Road Car Park) is privately owned and the owners pay to clear the road.

o The access path to the beach via Beach Road (opposite Blue Bar) is covered by sand and is uneven. Cornwall Council and St Agnes Parish Council are working together and will soon implement a project to improve the beach access path and provide disabled access to the beach in order to maintain and fulfil the criteria requirements for Blue Flag status and the Cornwall Council Seaside Award.  A number of dune stabilisation methods have been implemented by Cornwall Council and the local community and are being tested for their success, they include the following (refer to Section 2):

o Straw bales located within the dune face, placed in February 2015 (refer to Figure 4.4), along with topping of the existing dunes and reshaping of the sand. Sand is accumulating around the bales, although children do play on them and horses eat them.

o Brush Wood fencing. o The local community are hoping to plant Marram Grass.  In the past, various methods of management have been trialled (refer to Section 2):

o Christmas trees were placed within the dunes, but were not favoured by the local community (due to visual impact) so were removed.

o Fencing was placed in the dunes some time ago and were not favourable to the local community and was removed as it become buried and then partly re‐exposed, posing a health and safety issue.

o Chestnut paling was used to stabilise the dunes but sand built up too quickly so this measure was not favourable to the local community.

o Fencing has been placed between the dunes and the river (on the north side), to restrict access and discourage people from walking through the grassy area of dunes here. Some planting has taken place, including Marram and smaller dune plants. Sometimes, the wind rips the Marram grass out. Following the 2013/2014 storms, Cornwall Council commissioned Royal HaskoningDHV to undertake a study to determine if the changes to the coastline at 13 selected sites, including Porthtowan, resulted in an increase in flood risk. The findings of the study would then be used to justify and secure government funding to undertake soft engineering works at the relevant sites. At Porthtowan, the study (Royal HaskoningDHV, 2015) found that the dune ridge at the location of beach profile 7a01215, located on the northern half of the beach and shown in Figure 4.10, had been lowered by 2m, not as a result of the storms but due to the manual movement of sand. They recommended that to prevent future overtopping under storm conditions, the dune ridge is restored to a level 0.5‐1.0m higher than the level in 2013/20144. Elsewhere, the report suggests that there has been no increase in risk of overtopping, compared to the pre‐storm condition. In a community meeting held after the release of the 2015 report (Cornwall Council, 2015), the residents agreed that the following should take place and it was intended that the works are completed before Easter 2015:  Wind‐blown sand on the green area behind the dune should be moved back to the dune.  There is a need to stabilise the sand on the dune and reduce the risk of it blowing back onto the green or the road. In the short‐term that bundles of brush wood or straw bales could be used to address this problem (as they will naturally decompose).  Marram grass will be planted and small areas of dune fenced off to allow the grass to become established.  Signs will be put in place to explain to local residents and the public about the work being carried out and why it is necessary.  Before the works take place, the public will have an opportunity to learn about the intended works and see examples of the materials that will be used to stabilise the dunes. Porthtowan is located within SMP2 PDZ11 / Management Area 29 and the future management policy for the frontage is Managed Realignment for the next 100 years (Royal Haskoning, 2011a). The SMP2 notes ‘the preferred approach at Porthtowan would be to manage the frontage under a managed realignment policy. This would accommodate the natural variability of this area and allow priority to be given to enhancement of the natural dune system as a UK priority BAP Habitat, whilst continuing to encourage natural and sustainable response to climate change impacts. The dune system is constrained on three sides by local development but appropriate management techniques have been employed historically to stabilise sand accumulations and encourage dune growth’.

20 SECTION 4 COASTAL PROCESSES UNDERSTANDING

Figure 4.1 Map showing location of Porthtowan and extent of BDMP (red outline).

2008

2010

2013 Figure 4.2 Historical aerial photographs of Porthtowan (source: Plymouth Coastal Observatory).

22 SECTION 4 COASTAL PROCESSES UNDERSTANDING

Figure 4.3 Winter beach at Porthtowan (taken during site visit 11th March 2015, looking west).

Figure 4.4 Gently sloping seaward face of the dunes at Porthtowan (taken during site visit 11th March 2015, looking north).

Figure 4.5 Vegetated dunes at Porthtowan (taken during site visit 11th March 2015, looking north).

Figure 4.6 Vegetated dunes on ‘the green’ at Porthtowan (taken during site visit 11th March 2015, looking south).

4.2.2 Forcing Factors 4.2.2.1 Typical Waves The coastline at Porthtowan is orientated north‐east‐south‐west, with the beach and dunes facing approximately 310 degrees (north‐west). The predominant wave direction along the north coast of Cornwall is reported to be from the west to north‐west (approaching from 270o – 315o), however, large swell waves from the south to southwest will refract around the Lands End Peninsula and reach the most westerly facing beaches, (with reduced energy) (Royal Haskoning, 2011b), such as Porthtowan.

24 SECTION 4 COASTAL PROCESSES UNDERSTANDING

The Perranporth Directional Waverider Buoy, operated as part of the South West Regional Coastal Monitoring Programme (SWRCMP), is the nearest wave buoy to Porthtowan, and has been reviewed for this study (refer to Figure 4.7 for the wave data point). The wave buoy is located approximately 10 miles north‐east from Porthtowan, and provides a record of wave height for a seven year period between 18th December 2006 and 30th June 2014. A plot of wave height in Figure 4.8 shows that the predominant wave direction in this area is from the west. The data set also indicates significant wave heights frequently exceed 5m during the winter months and that wave periods of 15 seconds and higher (i.e. powerful well waves generated by storms offshore) are not uncommon (Royal Haskoning, 2011b).

Figure 4.7 Map showing the location of the wave data collection point.

Figure 4.8 Offshore wave height recorded by the Perranporth Directional Waverider Buoy between 18th December 2006 and 30th June 2014 (PCO, 2014a).

4.2.2.2 Storm Waves Storm analysis undertaken by PCO (2014d) provides an overview of the storm conditions recorded by the Perranporth Directional Waverider Buoy since 2007. For each wave buoy in the SWRCMP, an individual storm threshold is set. A storm event is defined when significant wave heights equivalent to the 0.25 year return period (i.e. the threshold wave height (Hs) for 2 to 4 storms in an average year) occurs for set period of time (i.e. 16 hours). The significant wave height is calculated when a 5 year time series of data becomes available for the wave buoy and is then reset each year. Prior to that, the height is based on an educated conservative guess from looking at the wave data available. The reason that the 0.25 year return period is used is because the SWRCMP have found that in general there are 3 to 4 storms in any one year that result in the movement significant amounts of sediment. For their reporting, PCO produce a storm calendar. The calendar includes a graph, where each dot represents a storm (i.e. where the Hs exceeds the storm threshold) and shows the Hs for that particular storm. PCO plot the significant wave height for the 1 year return period for that particular buoy on the graph (calculated in the same way as significant wave height for the 0.25 year return period) as a red line. Where storms plot above the red line they are considered to be more severe/extreme and are listed in a separate table. The storm calendar and table for the Perranporth Directional Waverider Buoy are presented in Figure 4.9 and Table 4.1 respectively. The storm calendar shows that eight severe/extreme storms have exceeded the 1 year Return Period since 2007; three of those storms (38 %) occurred between October 2013 and February 2014. The impact of these storms on beach change is described in Section 4.3

Figure 4.9 Storm calendar for Perranporth (source: PCO, 2014b).

26 SECTION 4 COASTAL PROCESSES UNDERSTANDING

Table 4.1 Storms exceeding 1 year Return Period at Perranporth since deployment in 2007. Those occurring during the storm season October 2013 to February 2014 are shaded pink (source: PC0, 2014b).

Date Wave Height (m) Return Period

01/02/2014 7.28 Greater than 1 in 20 years

02/11/2013 7.06 1 in 10 years

27/12/2013 6.81 1 in 5 years

15/12/2011 6.75 1 in 5 years

12/03/2008 6.53 1 in 3 years

10/03/2008 6.37 1 in 2 years

11/11/2010 6.3 1 in 1 year

31/03/2010 6.25 1 in 1 year

4.2.2.3 Tides Tidal levels have been extracted from the current Admiralty Tide Tables (UKHO, 2013) for the closest location with the best available data, in this case Perranporth and St Ives, and converted to Ordnance Datum (mOD). The tide levels for Perranporth are presented in Table 4.2 and St Ives in Table 4.3. Table 4.2 Tide levels (in mOD) for Perranporth, adjusted from standard port Milford Haven.

Tidal Condition Tide Level (mOD)

Highest Astronomical Tide (HAT) Data not available

Mean High Water Spring (MHWS) 3.30

Mean High Water Neap (MHWN) 1.90

Mean Sea Level (MSL) Data not available

Mean Low Water Neap (MLWN) ‐1.10

Mean Low Water Spring (MLWS) ‐2.80

Lowest Astronomical Tide (HAT) Data not available

Table 4.3 Tide levels (in mOD) for St Ives, adjusted from standard port Milford Haven.

Tidal Condition Tide Level (mOD)

Highest Astronomical Tide (HAT) Data not available

Mean High Water Spring (MHWS) 3.20

Mean High Water Neap (MHWN) 1.80

Mean Sea Level (MSL) 0.14

Mean Low Water Neap (MLWN) ‐1.00

Mean Low Water Spring (MLWS) ‐2.60

Lowest Astronomical Tide (HAT) Data not available

4.2.3 Sediment Dynamics Sediment transport at Porthtowan is dominated by cross‐shore transport as the coastline waves approach the shoreline from generally the west or north‐west, virtually shore‐parallel, which creates a swash aligned coast (Royal Haskoning, 2011b). As described in Section 4.2, the beach at Porthtowan changes seasonally when during the winter sandy material is drawn‐down from the beach and stored on the nearshore bar and offshore to leave a more rocky and shingle beach (refer to Section 2). Sandy material is returned back onto the beach during the spring and summer months. Halcrow (2002) reports some potential for northward drift of material but as Royal Haskoning (2011b) note, if this does occur, net volumes are likely to be insignificant in relation to volumes contained on the beaches. Wind‐blown sand is a common occurrence at Porthtowan and is thought to be enhanced by the funnelling effect of the wind as it blows across the beach and into the steep valley (PDCG, 2015). It is assumed that sources of sediment are limited to the nearshore and offshore, since cliff erosion is low and therefore provides little input of sediment. 4.2.4 Historical Shoreline Change Porthtowan was not included as one of the nine locations in the Cornwall Sand Dune and Beach Management Strategy (Halcrow, 2009b) for which a detailed study was completed. Therefore analysis and interpretation of historical change from historical maps, historical aerial photographs and beach profiles is not available. 4.3 New Shoreline and Beach Profile Analysis Beach profile monitoring undertaken by PCO for the SWRCMP and provides recent data and analysis for the beach at Porthtowan. A summary of the findings from the latest annual survey report (PCO, 2014a) are presented in this section and provide an overview of beach profile change in the past year, between Spring 2013 and Spring 2014, and over the longer‐term from the baseline survey in 2007 to the most recent survey in Spring 2014. Note that the calculations of CSA for profile 7a01213 include the area of bare sand on ‘the green’, whilst 7a01215 includes the dune area.  Between Spring 2013 and Spring 2014 (refer to Figure 4.10), the two measured profiles lost significant amounts of material; both losing over 70m2 of material.  Over the longer term, between 2007 and Spring 2014 (refer to Figure 4.11), the beach profiles show the beach on the northern side of the stream (Profile 7a01215) has remained stable, and the beach on the southern side of the stream (7a01213) to have accreted, with an increase of 7% in cross‐ sectional area.  Mapping of the Mean High Water (MHW) contour (refer to Figure 4.12) shows variation of the position of the MHW contour, with no clear trend.  As part of the SWRCMP, PCO have also prepared two reports (PCO, 2014d and 2014e), which examine the change to a selection of the beaches along the south‐west coast, with a view to identify how beach change occurring as a result of the 2013/2014 winter storms compares to the longer‐ term behaviour of the beach. However, Analysis of beach volume change and a topographic difference model has not been completed for Porthtowan.

28 SECTION 4 COASTAL PROCESSES UNDERSTANDING

Figure 4.10 Beach profile change at Porthtowan Spring 2013 to Spring 2014 (source: PCO, 2014a).

Figure 4.11 Beach profile change at Porthtowan baseline 2007 to Spring 2014 (source: PCO, 2014a).

Figure 4.12 MHW contour change at Porthtowan (source: PCO, 2014a).

4.4 Summary and Recommendations 4.4.1 Summary The beach at Porthtowan is north‐west facing and exposed to the predominant westerly. Beach level and composition changes throughout the seasons in response to wave conditions with the draw‐down of beach material in the winter and return of beach material in the summer. Beach profile analysis shows the beach to have eroded during the past year, a response that is likely to have been driven by the severe 2014 storms. However, longer term data (2007 to 2014) shows the beach to have remained stable on the north side of the stream and accreted on the south side of the stream. Stability to the north is likely to have occurred via a balance of cross‐shore movement between the beach and dunes and potentially influenced by the recycling of wind‐blown sand from the roads/areas of build‐up onto the beach. The dunes have a natural tendency to roll back, which because of the steep valley sides would potentially result in their loss. The dunes have a long history of dune erosion and management intervention, with fundamental modification occurring in the 1960’s. Since this time, the dunes are generally observed to have been flatter with more bare sand and less vegetation. Sand is blown from the dunes landwards, which creates a problem when the car park and access routes become covered with sand. Despite efforts to manage the dunes, they have not yet been successfully stabilised and re‐established; the portion to which this can be attributed to recreational pressure or some other underlying physical processes needs to be investigated further. A desire by local residents to stop the process of sand being blown onto access routes, the car park and roads has called for ongoing management intervention, which dates back to the late 1970’s.

30 SECTION 4 COASTAL PROCESSES UNDERSTANDING

4.4.2 Recommendations to Consider for Future Beach and Dune Management They key issues at Porthtowan are dune erosion and sand being blown from the due surface onto beach access routes, the car‐park and roads. The key recommendations for Porthtowan are as follows:  The various attempts and results of management intervention at Porthtowan are well documented and observed by the PDCG and the lessons learned should be considered when implementing any future management techniques.  There is a clear need to manage the problem of wind‐blown sand and stabilise the dunes. Consideration needs to be given to the success of previous schemes, but allowing for the effect of strong winds and storms on this exposed coast.  Recycling of wind‐blown sand should continue and permanent removal of sand from Porthtowan should be limited wherever possible.  In their document, the PDCG (2015) have clearly laid out their long‐term aims for the beach and dunes and these should be, wherever possible, adhered to when developing solutions for the management of the beach and dunes at Porthtowan. Further, it is important that when developing solutions for Porthtowan to build upon the works agreed and possibly completed following the community meeting and the 2015 Royal HaskoningDHV report.  Investigate further and if not already completed, undertake detailed analysis of the beach and dune sand could be undertaken in order to determine its grain size distribution, composition, density, rounding etc., from which it may be possible to determined its overall tendency to becoming wind‐ blown. It has been suggested (refer to Section 2) that is quite likely that the sand from the beach is becoming progressively sorted as it moves from the beach onto the dunes and then along the road further up the valley. At each stage the sand is probably becoming finer with less dense constituents, and more rounded in character.  Investigate further the possibilities as to why tried and tested management solutions have not necessarily stabilised the dunes at Porthtowan. A number of management interventions have been implemented and trialled at Porthtowan and what may seem to be a common solution, such as fencing and planting, may not necessarily work at this location.

31 SECTION 5 SITE SUMMARY 5 Site Summary

5.1 Dune Inventory Summary DUNE SYSTEM PORTHTOWAN

CHARACTERISTICS

LOCATION MAP  See Figure 1.2.

AERIAL PHOTOGRAPH  See Figure 4.2.

DUNE EXTENT  See Figure 1.4.

AREA OF SITE  Active 1 ha  Total 1 ha DUNE TYPE  Hummocky.  Climbing. MORPHOLOGICAL  Blowouts. FEATURES OF DUNES  Stream through beach at side of dunes.

PAST (150 YRS)  Analysis of historical maps indicates an accreting dune system. EVOLUTION OF DUNES  Dune system developed through sand trapping and planting in 1970’s as part of a scheme to solve blown sand problems on the road behind the beach. VEGETATION TYPE  Yellow Dune, Dune Grassland.

BACKSHORE  Low lying valley bottom behind beach with valley sides rising either CHARACTERISTICS side. Some development in valley base but most on valley slopes.  Dunes restrained by infrastructure and buildings. COASTAL SETTING  Sandy cove at mouth of Porthtowan stream with shallow profile and a flat mid and lower intertidal zone.  Stream runs through beach and dunes.  Cobble and boulder storm beach and shingle ridge at top of foreshore.  Hard rock cliff headlands either side of cove.  Forms part of larger shallow plan shape bay which extends to the north and south.  North West facing dunes.

DRIVERS

LINKS TO ADJACENT  No significant longshore sediment movement outside of larger bay. COAST

WIND ENERGY  No contemporary data identified. Refer to SMP1 (Halcrow, 1999) for historical data. WAVE ENERGY  See Sections 4.2.2.1 and 4.2.2.2.

WATER LEVELS  See Section 4.2.2.3.

32 SECTION 5 SITE SUMMARY

SEDIMENT BUDGET  Offshore carbonate material is main contemporary beach sediment source.  Limited fluvial sediment inputs.

PRESSURES

ENVIRONMENTAL  Godrevy to St Agnes SAC. DESIGNATIONS  Godrevy to St Agnes SSSI.  UK BAP Priority Habitats with management objectives (Coastal Sand Dunes; Maritime Cliff and Slope; Maritime Heath).  See Section 3.3 also. ARCHAEOLOGY/  Cornwall and West Devon Mining Landscape (UNESCO) World HERITAGE Heritage Site  The Cornwall Area of Outstanding Natural Beauty (AONB)  St Agnes Heritage Coast  National Trust managed coastline  Archaeological and Cultural Heritage designated features (see Section 3.3.4). LAND USE  Areas of developed and undeveloped land behind dunes.

RECREATIONAL  Trampling all year round as popular with residents and tourists. PRESSURES  Significant erosion of central area of dune ridge.  Increasing development pressures. SAND EXTRACTION/  None known. DREDGING

COASTAL DEFENCES  Gabions at back of beach.  Short length of masonry wall in front of holiday flats. CURRENT MANAGEMENT  Fencing for sand trapping and exclusion. PRACTICES  Access road cleared of sand and sand then removed from site (and so coastal system) due to pollutant risk.  Dunes used as management tool to curtail aeolian transport and prevent inundation of property. SHORELINE  Policy Unit 29.4 (Porthtowan):

MANAGEMENT PLAN o Short term = Managed Realignment; medium term = Managed POLICY Realignment; long term = Managed Realignment.

(from Royal Haskoning, o Policy intent = “The preferred approach at Porthtowan would be 2011a) to manage the frontage under a managed realignment policy. This would accommodate the natural variability of this area and allow priority to be given to enhancement of the natural dune system as a UK priority BAP Habitat.” MANAGED BY  Cornwall Council.

33 SECTION 6 REFERENCES 6 References

 Cornwall Council (2015). Website: https://www.cornwall.gov.uk/council‐and‐democracy/council‐ news‐room/media‐releases/news‐from‐2015/news‐from‐january‐2015/community‐meeting‐looks‐ to‐the‐future‐of‐porthtowan‐beach‐and‐dunes/. Site accessed 10th March 2015.  ERCCIS and Cornwall Wildlife Trust (2010). County Geology Site Criteria for Cornwall and the Isles of Scilly  Frampton, A.P.R. (2010). A review of amenity beach management. Journal of Coastal research, 26(6), 1112‐1122, November 2010  Halcrow (2009a). Cornwall Sand Dune and Beach Management Strategy. Report produced by Halcrow Group Limited for the Cornwall and Isles of Scilly Coastal Advisory Group, September 2009.  Halcrow (2009b). Sand Dune Inventory. Cornwall Sand Dune and Beach Management Strategy. Report produced by Halcrow Group Limited for the Cornwall and Isles of Scilly Coastal Advisory Group, September 2009.  Halcrow (2009c). Sediment Budget Report. Cornwall Sand Dune and Beach Management Strategy. Report produced by Halcrow Group Limited for the Cornwall and Isles of Scilly Coastal Advisory Group, September 2009.  Halcrow (2002). Futurecoast CD. Produced by Halcrow Group Ltd for Defra.  Halcrow (1999). Land’s End to Hartland Point Shoreline Management Plan. Volumes 1 to 4. Report produced by Halcrow Group Limited for Cornwall and Isles of Scilly Coastal Group.  Plymouth Coastal Observatory (PCO) (2014a). Annual Survey Report. Land’s End to Hartland Point. Report Number AR43. Report produced for the South West Regional Monitoring Programme, September 2014.  Plymouth Coastal Observatory (PCO) (2014b). Review of South West Coast Beach Response to Wave Conditions During the Winter of 2013‐2014. Report Number SW SR01. Report produced for the South West Regional Monitoring Programme, June 2014.  Porthtowan Dunes Community Group (PDCG) (2015). Porthtowan – Focus on the Historic and Recent History of Porthtowan Dune and Green. Document prepared by the Porthtowan Dunes Community Group.  Royal HaskoningDHV (2015). Cornwall Beaches Sand Loss Advice. Report produced by Royal HaskoningDHV for Cornwall Council, January 2015. Report reference PB2784/R/303395/Exet.  Royal Haskoning (2011a). Cornwall and Isles of Scilly Shoreline Management Plan Review (SMP2). Report for the Cornwall and Isles of Scilly Coastal Group. February 2011.  Royal Haskoning (2011b). Cornwall and Isles of Scilly SMP2. Main Report, Final. Report produced by Royal Haskoning for the Cornwall and Isles of Scilly Coastal Advisory Group, February 2011.  Royal Haskoning (2011c). Cornwall and Isles of Scilly SMP2. Appendix C, Review of Coastal Processes and Geomorphology, Final Report. Report produced by Royal Haskoning for the Cornwall and Isles of Scilly Coastal Advisory Group, February 2011. Report reference 9T8801.  Spalding Associates Ltd (2005). Ecological Assessment of Coastal Zone Management Issues at Porthtowan, Cornwall. Report for Cornwall County Council  United Kingdom Hydrographic Office, UKHO (2013). Admiralty Tide Tables. Volume 1. United Kingdom and Ireland. Reference NP201‐13.

Appendix D Options Appraisal

Stage 3 Report: Future Management Options for Porthtowan

Cornwall Beach & Dune Management Plans

Prepared for Cornwall Council

22 January 2016

Ash House Falcon Road Sowton Exeter Devon EX2 7LB

Contents

Section Page 1 Introduction ...... 1 1.1 Background ...... 1 1.2 Project aim, objectives and approach ...... 2 1.3 About this document ...... 4 2 Porthtowan ...... 5 2.1 Options Appraisal ...... 5 2.2 Options Summary ...... 11 3 References ...... 14

III

SECTION 1 INTRODUCTION 1 Introduction

1.1 Background Many of the sand dunes and beaches around Cornwall’s coast are currently experiencing erosion and sediment loss. This is a pressing concern as these sand dunes and their associated sandy beaches are one of the most important resources in Cornwall due to: 1. Their role in providing protection against the risk of coastal flooding due to the dynamic nature of beach‐dune interactions and their sheer size preventing the sea from impacting upon the hinterland behind the dune systems. 2. Their role in providing important biologically diverse habitats that cannot be easily recreated elsewhere if it were to be lost to coastal erosion or inappropriate development. 3. Their role in providing access to the sea for residents and visitors alike, which is vital to the holiday industry upon which a significant proportion of Cornwall’s economy depends. It is vital therefore that the sand dunes and beaches around Cornwall’s coast, that represent some 15% of the total sand dune habitat in Britain, are managed in a holistic, sustainable way over the long‐term that balances the needs of each of the three distinct functions of sand dunes and beaches that combined make up the beach‐dune system. The approach to managing the beaches and sand dunes in Cornwall (refer to Figure 1.1) was investigated in between 2006 and 2009 by Halcrow (now CH2M) on behalf of the Cornwall and Isles of Scilly Coastal Group, and led to the production of the Cornwall Sand Dune and Beach Management Strategy (Halcrow, 2009). The main focus of the strategy is the management of flood and coastal erosion, although the habitat and tourism value of the dunes are also considered. This 2009 project delivered an Inventory of Beaches and Dunes; a Best Practice Management Guide and two pilot Beach and Dune Management Plans (BDMPs) for Harvey’s Towans and Fistral Beach. It is this 2009 work that this current project is building upon to develop six new BDMPs and review the two pilot BDMPs (see Section 1.2).

Figure 1.1 Map showing location of all dune locations in Cornwall assessed as part of the Cornwall Sand Dune and Beach Management Strategy (Halcrow, 2009).

1 SECTION 1 INTRODUCTION 1.2 Project aim, objectives and approach The purpose of the project is to develop six new long‐term strategic BDMPs for Constantine Bay, Porthtowan, Summerleaze, Par Sands, Widemouth Bay and Praa Sands; and review the need (or otherwise) to update the two pilot BDMPs produced in 2009 for Fistral Beach and Harvey’s Towans [NB: following Stage 1 of this project – see below – it was confirmed that the two 2009 pilot BDMPs will be updated though this project]. This will be achieved by: 1. Identifying the best management approach; in terms of monitoring and intervention (when trigger levels are reached) requirements for beach and dune systems at each individual site, based upon the best practice framework developed as part of the Cornwall Sand Dune and Beach Management Strategy produced by Halcrow in 2009. 2. Providing a long‐term (50 year) approach to each site that is based upon an up‐to‐date understanding of the beach‐dune system and coastal processes at each site, as well as predictions of future coastal evolution. The locations of these eight sites is shown in Figure 1.2.

Figure 1.2 Map showing location of the eight BDMP locations.

2 SECTION 1 INTRODUCTION

Stage 1 – Baseline Understanding

Inception Meeting and Develop Engagement Plan

Data collation and review Site visits (with stakeholders)

Environmental baseline Coastal processes understanding

Confirm findings with Cornwall Council

Stage 2 – Define Issues and Objectives Identify issues for each site

Define objectives for future management of each site

Confirm issues and objectives for future management of each site with Cornwall Council and Stakeholders

Stage 3 – Develop Future Management Options

Identify appropriate management options to address issues identified

Appraise options (including environmental assessment and determination of trigger levels)

Discuss and agree preferred management approaches for each site with Cornwall Council and Stakeholders

Stage 4 – Reporting

Produce Draft Beach and Dune Management Plans

Cornwall Council comment and review

Produce Final Beach and Dune Management Plans and Leaflets for informing general public

Figure 1.3 Overview of the staged approach to developing BDMPs for the eight locations around Cornwall; current stage highlighted by red box.

3 SECTION 1 INTRODUCTION 1.3 About this document This report identifies and appraises potential management options to address the issues and objectives identified in Stage 2 (CH2M, 2015b) as being ‘in scope’ for the Porthtowan BDMP area. These issues were identified from the baseline understanding developed for this location as part of Stage 1 (CH2M, 2015a). The potential management options to appraise have been identified using the Sand Dune Management Techniques Decision Support Tool (Halcrow, 2009), updated with additional techniques identified as part of Stage 3 of this current project. The updated tool and associated user guide will form part of the final project deliverables at the end of Stage 4 (refer to Table 1.3 above). Each potential option is appraised technically, environmentally and economically in the following way:  Technical Appraisal considers the likely performance of different options giving consideration to the understanding of coastal processes determined in Stage 1 of the project for the BDMP location. This aspect also considers likely trigger points when either management intervention should occur or when a change in management approach will likely to be implemented.  Environmental Appraisal considers potential impacts of options upon features of environmental designation and amenity, drawing upon baseline information defined Stage 1 of the project for the BDMP location.  Economic Appraisal is based (where appropriate) upon a broad assessment of costs of each option (low: £0‐£5k per 100m run; medium: £5k‐£50k per 100m run; high: £50k + per 100m run) as informed by ‘costs’ contained in the updated Sand Dune Management Techniques Tool referred to above. The level of maintenance required for each option (None: No maintenance required; low: Maintenance required within a 10 year period; medium: maintenance required every 1 to 10 years; high: maintenance required at least yearly) is also provided, as informed by ‘maintenance’ contained in the updated Sand Dune Management Techniques Tool. Where information is available, the Present Value1 (PV) ‘SMP2 stated costs’ for implementation of the stated policy and ‘SMP2 stated benefits’ (value of properties protected) for the policy (Royal Haskoning, 2011), and associated benefit cost ratio’s2 (BCR) are also given. The appraisal of options for Porthtowan is presented in the remainder of the document. The appraisal of all options is presented in tabular form, followed by a short summary discussion of what is considered the preferred approach to future management for the location, referring back to the project aims (refer to Section 1.2) and site specific objectives identified for Porthtowan in Stage 2 of this project (CH2M, 2015b).

1 Present value is the estimated current value of a future amount of money to be received or paid out, discounted at an appropriate rate.

2 Benefit cost ratio is a technique to value a project, directly comparing benefits and costs. The higher the BCR, the greater the benefits relative to the costs.

4 SECTION 2 PORTHTOWAN 2 Porthtowan

Porthtowan is located on the north coast of Cornwall, directly north of Redruth and with St Agnes Head to the north and Portreath to the south (refer to Figure 2.1).

Figure 2.1 Map showing the Porthtowan BDMP location and extent (red outline).

2.1 Options Appraisal The following Table 2.1 contains appraisal of a range of possible options for future beach and dune management for Porthtowan to address the issues and objectives identified for this location as part of Stage 2 of this project (refer to Section 1.3).

5 SECTION 2 PORTHTOWAN

Table 2.1 Options Appraisal Table for Porthtowan ID Issue Description BDMP Objective for Issue Current Sand Dune Management Category and Short (0‐20 Comments / Additional Technical Appraisal of Options Environmental Appraisal of Economic Appraisal Management Technique (identified from the Sand years), Medium Categories / Options of Options Practice related Dune Management Preliminary (20‐50 year) or Techniques To Be to issue Decision Assistance Tool (Halcrow, Long Term (50‐ Investigated 2009); UPDATED 2015) 100 years) Action

1 The beaches and dunes of Porthtowan are Work with natural processes Various dune STABILISATION Short term Dune stabilisation / restoration STABILISATION Planting eroding, lowering and flattening as a result to minimise risk in the future stabilisation methods to encourage sediment  Planting (and to prevent Long term positive benefits to Cost: low/medium, of a combination of natural processes (large through promotion of measures access to planted/ thatched entrapment would help address improvement of designated site (medium storm events) and human impacts. ongoing dune restoration implemented in areas erosion issues. Stabilisation methods features and BAP habitat. Assuming maintenance) Management of the coastal flood and using methods that the past. would not be appropriate native plants are used and  Thatching (and to prevent Thatching / Mulching erosion risks associated with this need to encourage sediment everywhere, but could be applied in represent species on site. access to planted/ thatched etc balance dune stabilisation measures with entrapment and dune key areas. growth with minimal visual areas Possible impacts from stabilisation Cost: low, (high visual impact. It also needs to recognise the Stabilisation methods would need to works on impact and low potential for  Mulching/ Matting/ Sand maintenance) potential for dune stabilisation measures to allow the continued interaction designated/rare/protected species, damage by vandalism. Binders be impacted by storms and/or human impact between the dunes and beach, although can be mitigated by best Control fencing (e.g. stolen/vandalism etc.). allowing natural processes to  Control Fencing (see also practice methods being applied. Cost: low, continue. Natural forms of ACCESS MANAGEMENT) (medium/high stabilisation, such as planting, ACCESS MANAGEMENT ACCESS MANAGEMENT maintenance) Short term thatching, mulching, matting and Positive impact to designated site  Zoning sand binders would allow this. features and BAP habitat from Zoning

Thatching also limits public access, access management.  Boardwalks Cost: medium, (high and makes use of natural materials. Advantages: natural processes can maintenance)  Control Fencing Access restrictions and information continue; eroded areas are able to Boardwalks MORPHOLOGICAL MODIFICATION signage in these areas would help recover; zoning limits trampling Short term Cost: medium, limit pressures on these areas and and erosion to zoned pathways  Dune Fencing (medium allow natural processes. encourage use of designated paths.  Planting (see STABILISATION). maintenance) Stabilisation methods need an Disadvantages: Existing access

ongoing commitment for monitoring, routes may need to be redirected management and maintenance. or closed; relocation of access routes needs to be considered carefully as not to impact on other designated features present; may impact upon natural dune processes; MORPHOLOGICAL MODIFICATION Long term positive benefits to improvement of designated features and BAP habitat. Possible impacts from fencing/planting works on designated features/protected species, although can be mitigated by best practice methods being applied. Fencing can be destroyed by storm‐ wave action. Fencing, when damaged, can be visually unattractive with possible impacts to setting of designated landscape, archaeological/cultural heritage features. Best practise maintenance management can mitigate this.

2 Landwards dune migration potential limited Reduce the risk of future ADAPT BACKSHORE Short term The SMP2 policy for MR may require ADAPT BACKSHORE SMP2 due to rising valley sides, means increased coastal erosion to the MANAGEMENT/USES adaptation of some backshore uses, MANAGEMENT/USES Relocation of car pressure and erosion potential in future as developed area behind the namely relocation of informal parking  Adapt Backshore Positive impact to designated site park and temporary

sea levels rise. dunes through coastal Management/ Uses areas and temporary assets features and BAP habitat by assets adaptation measures (e.g. (implementation will be dependent

6 SECTION 2 PORTHTOWAN

ID Issue Description BDMP Objective for Issue Current Sand Dune Management Category and Short (0‐20 Comments / Additional Technical Appraisal of Options Environmental Appraisal of Economic Appraisal Management Technique (identified from the Sand years), Medium Categories / Options of Options Practice related Dune Management Preliminary (20‐50 year) or Techniques To Be to issue Decision Assistance Tool (Halcrow, Long Term (50‐ Investigated 2009); UPDATED 2015) 100 years) Action Dune erosion is already impacting the coastal rollback of existing on local planning policy and allowing natural processes and Costs not specifically path. The backshore area is occupied by development) and directing landownership) to allow dune development/improvement of included in the SMP2, development that could be at risk from future development away rollback where ever possible, native species. but likely to be coastal erosion in the future. from areas at risk of coastal however ultimately the topography Impact informal parking areas and Medium to High. change. of the valley and road will limit long development from term rollback. rollback/removal Implementation will likely require Long term positive benefits to planning authority to define Coastal designated features/BAP habitat Change Management Areas in line through encouraging natural with the National Planning Policy processes. Framework. Relocation of informal parking areas and development would require careful consideration of impact to designated features in new location and impact on setting of designated landscape, archaeological and cultural heritage sites.

3 Access by visitors through the dunes using Minimise dune erosion ACCESS MANAGEMENT Short term Note that a boardwalk Restricted routes, designated ACCESS MANAGEMENT Zoning non‐defined access routes causes trampling caused by human access. has been implemented pathways, formalised routes such as  Zoning Positive impact to designated site Cost: medium, (high of dune vegetation, erosion of the dunes and in the past and was using post and rope, fenced off areas features and BAP habitat from maintenance) seasonal increase in amount of litter related  Boardwalks covered with wind‐ and clear information signage in the access management. Boardwalks to increased visitor numbers.  Control Fencing blown sand. Many dunes are all technically feasible. different types of dune Signage to educate and increased Advantages: natural processes can Cost: medium, PUBLIC AWARENESS Short term management have waste provision (bins) / carefully continue; eroded areas are able to (medium  Signs and Display Boards, been tried and tested at located to address littering issues. recover; zoning limits trampling maintenance) Guided Walks, Public Talks, Porthtowan therefore and erosion to zoned pathways Would restrict access to areas encourage use of designated paths. Control fencing Interpretative Leaflets, the suitability of currently experiencing trampling and Cost: low, Wardens and Visitor Centres difference techniques help re‐stabilisation and allow Disadvantages: Existing access (medium/high needs to be considered natural process to continue, routes may need to be redirected maintenance) alongside previous maintaining the dunes as a flood or closed; relocation of access attempts at dune defence. routes and SW coastal path needs Signage/boards management and their to be considered carefully as not to Cost: low, (high relative success. Would require ongoing commitment impact on other designated to maintain safe access routes, maintenance) features present; may impact upon signage etc natural dune processes; PUBLIC AWARENESS Environmental education provided by the public awareness campaign may help to promote conservation of the dunes which would promote recovery resulting in positive impact on BAP habitat and setting of landscape, archaeological and cultural. If ignored however, dune erosion will continue.

4 Beach levels vary regularly over short periods Ensure existing coastal Monitoring by MONITORING Short term Specify locations, Requires ongoing commitment from MONITORING The regional coastal of time. Monitoring as part of the South monitoring is continued, the South West landward extents pf coastal monitoring programme monitoring  Monitoring Schemes Will inform management decision West Regional Coastal Monitoring modified as necessary to Coastal profiles and frequency (funded nationally) and council. that can assist in the promotion of programme is funded Programme does not occur frequently provide greater coverage Monitoring of beach profiles Increased extent (beach and dunes) these features to ensure a positive nationally by enough to detect these rapid variations. and frequency of survey to Programme required. Landward and frequency of surveys (including long term impact on designated Government. Funding Monitoring has also only been occurring provide greater levels of since 2007. limited particularly post storm) will help understand sites and BAP habitat for the next 5 years consistently since 2007 so longer‐term data to inform future important to define dune and beach behaviour, monitor (to 2021/22) has trends are not necessarily apparent in the management decisions. the performance of management

7 SECTION 2 PORTHTOWAN

5 Wind‐blown sand onto roads and car parks Seek to minimise loss of Sand removal SEDIMENT MODIFICATION Short term Measures to reduce sand blown onto SEDIMENT MODIFICATION Beach recycling / behind the dunes requires regular clearance sediment from the from car park, roads and car parks, such as fencing reprofiling  Beach Recycling and Beach recycling/profiling has the by Cornwall Council/private landowners. beach/dune system via roads and Reprofiling (see could be used, combined with potential to smother designated Cost: medium,

Sand removed from site due to pollution clearing of river channel and private road. STABILISATION). redistribution of accumulated features/protected/rare species. (medium risks thus reducing overall volume of clearance of sand blown material along these fences (i.e. maintenance) sediment in the coastal system. onto road and parking areas.  Beach Nourishment recycling), to ensure sediment is kept The presence of plant on the beach Short term may cause disturbance to breeding Beach nourishment STABILISATION within the system as much as possible. Defined access pathways seabirds and other birds species Cost: high, (medium  Planting (and to prevent (using post and rope, designed for (designated features) maintenance) access to planted/ thatched disabled access also) should be STABILISATION areas Planting incorporated to restrict access to Long term positive benefits to  Thatching (and to prevent these areas, combined with Cost: low/medium, improvement of designated site access to planted/ thatched information signage. (medium features and BAP habitat. Assuming areas maintenance) Would require ongoing commitment native plants are used and  Mulching/ Matting/ Sand to maintain safe access routes, represent species on site. Thatching / Mulching Binders signage etc. etc Possible impacts from stabilisation

 Control Fencing (see also If sediment in the system become works on designated/protected Cost: low, (high ACCESS MANAGEMENT) overly diminished then beach species, although can be mitigated maintenance) nourishment may need to be ACCESS MANAGEMENT Short term by best practice methods being Control fencing considered at a point in the future. applied. Cost: low,  Zoning However this is unlikely to be ACCESS MANAGEMENT (medium/high economically viable and lead to  Boardwalks maintenance) further encroachment of sand on Positive impact to designated site  Control Fencing roads and car parks. As such, it is not features and BAP habitat from Zoning access management. considered appropriate at this time. Cost: medium, (high Advantages: natural processes can maintenance) continue; eroded areas are able to Boardwalks recover; zoning limits trampling and erosion to zoned pathways Cost: medium, encourage use of designated paths. (medium maintenance) Disadvantages: Existing access routes may need to be redirected or closed; relocation of access routes and SW coastal path needs to be considered carefully as not to impact on other designated features present; may impact upon natural dune processes.

6 Access paths covered by sand Ensure safe access to site for Periodic ACCESS MANAGEMENT Short term Measures to reduce sand blown onto ACCESS MANAGEMENT Zoning inhibits/hinders access for all visitors. all visitors along defined removal/redistri access paths, such as fencing could  Zoning Positive impact to designated site Cost: medium, (high Regular clearing required. paths and that sediment bution of sand be used, combined with features and BAP habitat from maintenance) cleared is retained within to seawards  Boardwalks redistribution of accumulated access management. Boardwalks beach‐dune system. occurs when it  Control Fencing material against the fencing, to builds up on ensure sediment is kept within the Advantages: natural processes can Cost: medium, SEDIMENT MODIFICATION Short term paths/against system as much as possible. Defined continue; eroded areas are able to (medium road. access pathways (post and rope, recover; zoning limits trampling maintenance) designed for disabled access also)

8 SECTION 2 PORTHTOWAN

ID Issue Description BDMP Objective for Issue Current Sand Dune Management Category and Short (0‐20 Comments / Additional Technical Appraisal of Options Environmental Appraisal of Economic Appraisal Management Technique (identified from the Sand years), Medium Categories / Options of Options Practice related Dune Management Preliminary (20‐50 year) or Techniques To Be to issue Decision Assistance Tool (Halcrow, Long Term (50‐ Investigated 2009); UPDATED 2015) 100 years) Action  Beach Recycling and should be incorporated, combined and erosion to zoned pathways Control fencing Reprofiling (see Short term with information signage. encourage use of designated paths. Cost: low, STABILISATION). Would require ongoing commitment Disadvantages: Existing access (medium/high STABILISATION to maintain safe access routes, routes may need to be redirected maintenance) signage etc. or closed; relocation of access  Planting (and to prevent Beach recycling / routes and SW coastal path needs access to planted/ thatched reprofiling to be considered carefully as not to areas impact on other designated Cost: medium,  Thatching (and to prevent features present; may impact upon (medium access to planted/ thatched natural dune processes maintenance) areas SEDIMENT MODIFICATION Planting  Mulching/ Matting/ Sand Beach recycling/profiling has the Cost: low/medium, Binders potential to smother designated (medium  Control Fencing (see also features/protected/rare species. maintenance) ACCESS MANAGEMENT) The presence of plant on the beach Thatching / Mulching may cause disturbance to breeding etc seabirds and other birds Cost: low, (high (designated features) maintenance)

7 The river channel requires periodic clearing Ensure sediment removed Periodic clearing SEDIMENT MODIFICATION Short term Return sand cleared from the river SEDIMENT MODIFICATION Beach recycling / of sand to manage flood risk upstream. from the river channel is of sediment channel back to the beach, to ensure reprofiling  Beach Recycling and Beach recycling/profiling has the

retained with in the beach‐ from river Reprofiling (see the sediment remains in the system potential to smother designated Cost: medium,

dune system. channel. STABILISATION). and to reduce flood risk upstream. features/protected/rare species. (medium This supports stabilisation measures maintenance) for this site. The presence of plant on the beach may cause disturbance to breeding seabirds and other birds (designated features)

8 The Shoreline Management Plan policy is for Ensure future management Porthtowan ADAPT BACKSHORE Short term Make sure Relocation of the parking area on the ADAPT BACKSHORE SMP2 Managed Realignment to occur to allow of the area is in line with Beach MANAGEMENT/USES management options west of the beach and any temporary MANAGEMENT/USES Relocation of car natural dune evolution of the UK BAP priority SMP policy and identify Association and assessed comply with assets (implementation will be  Adapt Backshore Impact to parking area park and temporary

habitat. This means that there will be potential funding streams to Porthtowan Management/ Uses SMP policy. dependent on local planning policy assets potential for some funding to be forthcoming enable economically Dunes Short term and landownership) would reinstate Positive impact to designated site for coastal flood and erosion risk sustainable beach and dune Community FUNDING natural rollback of the beach and features and BAP habitat by Costs not specifically allowing natural processes and included in the SMP2, management (e.g. dune management) from management to occur. Group both exist  Seek funding from dunes in this area. Elsewhere, dune development/improvement of but likely to be central Government. However, it is likely that and may be a Environment Agency roll‐back will be constrained by the partnership funding will be needed to fulfil suitable forums nature of the topography and by native species. Medium to High.  Seek funding from Local all of the required funding for such activities. to take forward Beach road. Relocation of informal parking Authority future MR will need to incorporate areas and development would integrated,  Seek funding from sole stabilisation methods to help require careful consideration of sustainable private source enhance the integrity of the dunes impact to designated features in management of  Seek match funding and address erosion issues. new location and impact on setting

the beach and (government+ private). of designated landscape, dunes. SMP Policy is MR medium to long archaeological and cultural term, so some funding for beach or heritage sites. dune management activities related to managing coastal flood/erosion FUNDING risk is likely to be available. An increase in funding could be Funding for activities beyond FCERM beneficial if allocated towards the will need to be derived from other positive long term impact on non‐FDGiA sources (i.e. private/non‐ protection of designated features, FDGiA sources). A funding BAP habitat and setting of partnership could be established for archaeological/cultural heritage this purpose. features

9 SECTION 2 PORTHTOWAN

9 UK Biodiversity Action Plan Priority Habitats Improve condition of UK BAP ECOLOGICAL MODIFICATION Short term Improves existing ecological health of ECOLOGICAL MODIFICATION Vegetation cut‐back / (coastal sand dunes, maritime cliff and slope, priority habitats. Maintain existing condition through for the dunes which is important in Positive long term impact to removal maritime heath) generally in unfavourable example: working with natural processes to improvement of designated site Cost: Low, (high condition. provide coastal flood and erosion risk features and BAP habitat maintenance)  Regular cutback of This includes need for removal of non‐native management with the aid of sand vegetation. dunes. Possible impact from cut‐ Planting invasive species within the dune vegetation. back/removal of non‐native species  Maintaining defences that Cost: low/medium, Removal of some vegetation may and planting on designated site control water levels. make ‘uncontrolled’ access more (medium features/protected/rare species maintenance)  Allowing coastal processes to problematic (i.e. non‐native although can be mitigated by best continue on maritime vegetation hinders access in places) practice methods being applied. and so needs to be undertaken in cliff/slope. combination with access

Improve existing condition through for management measures. example:  Removal of non‐native invasive species within the dune vegetation.  Planting with additional vegetation, such as marram grass

10 Future beach and dune management needs Ensure the identified No techniques contained in dune Consider the impact of N/A Environmental appraisal of options N/A to consider the environmental impacts on a environmental features are management preliminary decision potential future is provided above. variety of designated features, including: considered in management assistance tool for this aspect. management measures Consideration is required for: decisions for future coastal Appraisal of environmental impacts on on designated features  Godrevy to St Agnes SAC. flood and erosion risk difference features have different in this options ‐ Godrevy to St Agnes SAC (features  Godrevy to St Agnes SSSI. management. requirements depending upon the assessment. temperate wet heaths, European dry heaths and plant species early  Cornwall and West Devon Mining nature of the designation, and gentian) Landscape UNESCO World Heritage environmental appraisal should always Site. be undertaken when considering May require an HRA to confirm no management options. likely significant effect on the SAC  Cornwall AONB. from any management decisions.  Historic environment features, This will need to be confirmed with including scheduled and non‐ Natural England. scheduled monuments. ‐ Godrevy to St Agnes SSSI (maritime heath and grassland, sand dune, scattered scrub communities, rare plants and large colonies of breeding seabirds. ‐ BAP Habitat (coastal sand dunes, fixed dune grassland, maritime cliff and slope, maritime heath, ‐ County Geology Site ‐ landscape setting: Cornwall and West Devon Mining Landscape UNESCO World heritage site; Cornwall AONB, St Agnes Heritage Coast; national trust Coast line ‐ Archaeology and cultural heritage: scheduled monument, listed buildings alongside mining heritage and a WW2 Pill Box ‐ SW Coastal Path

10 SECTION 2 PORTHTOWAN 2.2 Options Summary Porthtowan beach is bounded to the north and south by high cliffs and backed by fringing and climbing dunes, which extend inland within the steep‐sided river valley. The dune system is constrained on three sides by local development and therefore is relatively small in size and extent. Erosion, from both natural processes and human impacts, has lowered and flattened the dunes to a point where they are now low lying with little or no vegetation cover. Consequently windblown sand is a problem and the dunes are subject to erosion from trampling. A number of dune stabilisation methods have been tried here, including using straw bales, Christmas trees, planting of marram grass and fencing to help retain sand, with limited success. However, current fencing and vegetation planting is proving successful. The wooden fence between the dune and the private road has also limited the amount of sand that has ‘escaped’ from the dune. Other recent management methods have included removal of wind‐blown sand from roads, the car park and access paths. A section of West Beach Road is privately owned, while the beach is managed by Cornwall Council. Dune restoration is managed by a partnership between the Porthtowan Dune Community Group and Cornwall Council. The SMP policy for Porthtowan is Managed Realignment (MR) in the short, medium and long‐term, so some funding for beach or dune management activities related to managing coastal flood/erosion risk is likely to be available. However, funding for activities beyond FCERM will need to be derived from other non‐FDGiA sources (i.e. private/non‐FDGiA sources). Planning for relocation of backshore uses, temporary assets and informal parking should be considered during the short term (implementation will be dependent on local planning policy and landownership). Relocation will allow reinstatement of natural processes in this location, provide some space for future dune roll‐back and lead to potential positive benefits to designated features and BAP habitat, while avoiding any impact on features elsewhere. The trigger for rollback will be when assets are assessed as being at imminent risk of loss to erosion (Halcrow, 2015) or when windblown sand issues become unmanageable, guided by ongoing monitoring. Coastal adaptation of more permanent buildings will require longer term land use planning with relevant land owners and authorities. Implementation will likely require development of Coastal Change Management Areas by the planning authority in line with National Planning Policy Framework. To address dune erosion issues, natural forms of stabilisation, such as planting, thatching, mulching, matting or sand binders (combined with the extension of fencing and signage) would allow natural processes to continue, help retain sand on the dune system, and assuming native plants are used, could have long term positive effects on BAP habitats. Although these are relatively low cost measures, they would require ongoing commitment to management and maintenance. Many different types of dune management have however, already been tried and tested at Porthtowan therefore the suitability of difference techniques needs to be considered alongside previous attempts at dune management and their relative success. Zoning for activities and restricting access to certain areas, with the use of boardwalks and signage / information boards, could help allow natural processes to continue, help minimise dune erosion and aid recovery of trampled areas. Redirection of existing routes would need to be considered carefully so as to not impact designated features. Environmental education provided by public awareness campaigns may help to promote conservation of the dunes, help address littering and promote dune recovery. Beach / dune rangers would reinforce the messages during the summer months. Fencing would help reduce windblown sand issues on the road, paths and car parks, and address associated disposal issues (removing sediment from the system) and disposal costs. Recycling of windblown sand accumulated along fencing could be implemented to minimise loss of sediment from the system, but there is potential to smother designated features using this method. Some form of fencing may be more beneficial, combined with planting, to retain sand on the dune system itself, enhance stabilisation of the dunes and promote a more natural dune system. Intervention would be to maintain a natural dune profile but it is unlikely to be possible to achieve raised dune heights to levels they once were using these proposed techniques. The frequency of ongoing monitoring by the regional coastal monitoring programme could be increased or supplemented by local inspection to include post‐storm events/post‐winter surveys, provide greater

11 SECTION 2 PORTHTOWAN

coverage and include monitoring of the performance of different management methods employed. This will provide information for later management decisions to inform of any patterns in dune erosion, dune height or lowering of beach levels. In this location BAP habitat is generally unfavourable, so removal of non‐native species should also have a positive long term impact on the improvement of designated features and BAP habitat. To feed into Stage 4, the management options discussed here have been divided into short, medium and long term interventions in Table 2.2 below. The short, medium and long terms indicated below, reflect the three SMP epochs (0‐20 years; 20‐50 years and 50‐100 years) to help focus management actions in line with the SMP. Table 2.2 Short, medium and long term management options for Porthtowan Short term Adapt backshore (relocation of assets) Dune stabilisation (planting, thatching, mulching, control fencing) Access management (zoning, boardwalks, control fencing) Morphological modification (dune fencing, planting) Public awareness (signage, wardens) Sediment Modification (sand recycling, reprofiling) Monitoring Funding Ecological modification (vegetation cut‐back) Medium term Adapt backshore (relocation of assets) Dune stabilisation (planting, thatching, mulching, control fencing) Access management (zoning, boardwalks, control fencing) Morphological modification (dune fencing, planting) Public awareness (signage, wardens) Sediment Modification (sand recycling, reprofiling) Monitoring Funding Ecological modification (vegetation cut‐back) Long term Adapt backshore (relocation of assets) Dune stabilisation (planting, thatching, mulching, control fencing) Access management (zoning, boardwalks, control fencing) Morphological modification (dune fencing, planting) Public awareness (signage, wardens) Sediment Modification (sand recycling, reprofiling) Monitoring Funding

12 SECTION 2 PORTHTOWAN

Ecological modification (vegetation cut‐back)

13 SECTION 3 REFERENCES 3 References

 CH2M (2015a). Stage 1 Report: Porthtowan. Report produced as part of the Cornwall Beach & Dune Management Plans project for Cornwall Council, June 2015.  CH2M (2015b). Stage 2 Report: Issues and Objectives. Report produced as part of the Cornwall Beach & Dune Management Plans project for Cornwall Council, September 2015.  Halcrow (2015). Coastal Change Adaptation Planning Guidance. East Riding of Yorkshire Council, August 2015.  Halcrow (2009). Cornwall Sand Dune and Beach Management Strategy. Report produced by Halcrow Group Limited for the Cornwall and Isles of Scilly Coastal Advisory Group, September 2009.  Royal Haskoning (2011). Cornwall and Isles of Scilly Shoreline Management Plan Review (SMP2): Final Report. Report produced by Royal Haskoning for the Cornwall and Isles of Scilly Coastal Advisory Group, February 2011.

Appendix E Site Actions Summary Map

Reproduced b y per m issionofOrdnance Survey onb eha lfofHMSO. Legend © Crowncopyrighta ndda tab a seright2015.Alrightsreserved. l Ordnance Survey Licence nu m b er10004904 7 J{ Keyloca tionstoensurea dequa tesignage a ndliterbinsa t reinplac e Aerialphotography courtesyofthe South W estRegionalCoastal MonitoringProgra m m e. Are a forpotentialsandtraptob e m[ im ple m ented toreduce wind-blownsan d rea chingca rpar k Pri m a rya ccessroutestofocusa cc ess m a nage m ent m ea sure s ¯ Zoneinwhich dunestab ilisationa n d ecologica l m odifica tion m ea sures m ost likelytob e required i n V isua lconditioninspectionshould a sses: s •Generalconditionofb ea ch,dunea ndother a ssets. •Deb risa ndliter. t •Da m a ge toinfor m a tionsigns. •N um b erofa ndsizeofb a resanda rea swithindun e stab ilizationzone. •Erosiona longa cce sroutes. s •Anystructureswhich need repairsuch a sb oardwa lksor fencing. •Growtha ndsprea d ofvegetationinplanted a rea sif im ple m ented. •V egetationcoverage a ndconditionwithindun e stab ilizationzone. •Distributiona nda b unda nce (i.e.increa se/decrea se)of inva sive species. •Em b ryodunefor m a tiona tthe dunetoe. •V olu m e ofb lownsandcolectingonroads/ca l rparksa n d Area ofsanda ccum ulation. Em ergency condition: sub sequentlyre m oved,andhowoftenre m ovaloccurs. Pathwa y erosiona long •Considerationofwhetherornottriggerlevelsha ve b ee n thesekey a ccessroutes. rea ched (see a lsooverlea fa nd/orSection4.4.2ofBDMP) .

0 50 100 Metre s Area storecyclesandto,supported b y dunestab ilisationm ea sures. Actioncondition: Accesspointerosionposes Re v By Chk d Apprv d Date Descriptio n hea ltha ndsafetyrisk. m[m[J{ Area storecyclesandto,supported m[ b y dunestab ilisationm ea sures. m[ J{ m[ J{ J{ CH2MHILL Geospatial Actioncondition: BurderopPark,Swindon,SN 40QD Tel:+44(0)1793812479Fax:+44 Accesspointerosionposes (0)1793812089 hea ltha ndsafetyrisk. www.ch2m .co m Em ergency condition: J{ Project: Pathwa y erosiona long Cornw a llSandDunea ndBea ch Ma nage m entStrateg y thiskey a ccessroute. J{ Drawing: Porthtowa n

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Docu m entPath:(\\Swin-fs-05\Geospatial)T:\Geospatial\Projects\Cornw a ll_BDMPs\MXDs\Designations\Porthtowa n. m xd ACTION CONDITIONS AND RESPONSES FOR PORTHTOWAN EMERGENCY CONDITIONS AND RESPONSES FOR PORTHTOWAN Criteria Response Criteria Response Unacceptable area of bare sand Pathways eroded leading to erosion of dune system and unsafe pathways

 Area is of significant size and/ or depth to cause concern and  Fence off bare sand areas to prevent access and enable  Pathways eroded to form a very steep path or significantly  Re‐route access pathways to avoid eroded areas using is unlikely to recover without management. recovery. cliffed path which causes significant health and safety risk to fencing and signage. Fence off eroded areas to enable beach users such as the elderly or children. recovery with planting and dune stabilisation methods  Area of bare sand has been present for more than one year  If vegetation does not establish following fencing, and area without recovering. of bare sand is of concern, implement dune stabilisation  Access point/ pathway has eroded to the magnitude stated applied as necessary. when beach visitor numbers are significant.  If erosion is close to beach, and sand is available, carry out  Area of bare sand is increasing in size. planting following discussion with Natural England. re‐profiling of pathway by adding sand to eroded areas to  Implement rotation of access routes to aid recovery. remove unsafe cliffing and large steps. Access Points eroded to a level at which they cause a health and safety risk.

 Access points eroded to form a high step which is not safe for  Construct boardwalks or steps along eroded access paths. pedestrians and is at high risk of causing injury.  Consider re‐routing pathways away from the eroded area  Access point has been eroded to form a steep cliffed step for where possible. Fence off and stabilise the eroded access more than one season. route to enable it to recover.  Erosion is continuing and access is becoming more difficult  Introduce “dog legs” wherever possible in access routes to and/or a greater health and safety risk. prevent uninhibited wind‐blow.

Wind‐blown sand

 Sand built up to within 1m of the top of walls/fencing at any  If sand is still on the beach/dune system (i.e. not reached point. the roads / car park), then recycle sand to other areas in the  Access pathways buried by sand to a point where poses a system (focus on areas of erosion). health & safety issue.  If sand is on road or car park, subject to pilot project,  Sand built up in car park and along roads. preference is to remove sand from road/car park and place at the back of the dunes so as to not remove sediment volume from system.