Appendix C Baseline Report
Stage 1 Report: Praa Sands
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 ...... 7 2.4 Data Sources ...... 8 2.5 Photos ...... 8 3 Environmental Characteristics ...... 13 3.1 Introduction ...... 13 3.2 Methodology ...... 13 3.2.1 Designated Nature Conservation sites and Protected Habitats Considered ...... 13 3.3 Environmental Setting ...... 14 3.3.1 Ecology ...... 15 3.3.2 Designated Geological Conservation Sites ...... 18 3.3.3 Landscape Setting ...... 18 3.3.4 Archaeology and Cultural Heritage ...... 18 3.4 Main human impact pressures affecting the natural dynamics of the site...... 18 4 Coastal Processes Understanding ...... 19 4.1 Introduction ...... 19 4.2 Shoreline Processes Overview ...... 19 4.2.1 Key Characteristics of the Coastline Today ...... 19 4.2.2 Forcing Factors ...... 28 4.2.3 Sediment Dynamics ...... 33 4.2.4 Historical Shoreline Change ...... 34 4.3 New Shoreline and Beach Profile Analysis ...... 35 4.4 Summary and Recommendations ...... 39 4.4.1 Summary ...... 39 4.4.2 Recommendations to Consider for Future Beach and Dune Management ...... 39 5 Site Summary ...... 41 5.1 Dune Inventory Summary ...... 41 6 References ...... 44
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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, as illustrated in Figure 1.1.
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.”
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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 Praa Sands BDMP location (see Figure 1.4). Specifically, it: Reports the findings of a site visit made on 9th 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 Praa Sands 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 Praa Sands BDMP area, which was undertaken on 9th 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). 2.1 Attendees Name Role Organisation
Anne‐Marie Moon Senior Coastal Scientist CH2M Hill
Emily Hewitt Environmental Scientist CH2M Hill
Tim Wood Project Manager Cornwall County Council
Nick Ely Project Manager Environment Agency
Jake and Catherine Lai Residents Representing Alex from Little Cottage who was unable to attend
Christine Bell Resident House on cliff at western end
Cllr Tanis Board Councillor and Resident Breage Parish Council
Norman Coward Resident and car park owner
Carole Crow Resident House on cliff at eastern end
Lindsey and Brad Trethewey Residents House on cliff at eastern end
Ian and Jane Gibson Residents In process of purchasing house on cliff at eastern end
Comments on the draft site visit report for this location were received from: Cllr John Keeling (Cornwall Council); Jake Lai (Resident); Cllr Tanis Board (Breage Parish Council); Susanna Bell (Resident); and Jolyon Sharpe (Cornwall Council).
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2.2 Site Visit Record It was noted at the start of the site visit that beach levels are presently very low at the western end of the beach, having dropped significantly over the past three weeks [prior to the site visit]. This was suggested to have been the result of westerly winds and waves moving material along the beach, from the western end to the eastern end. The beach levels at the eastern end of the beach are noted to have shown a corresponding increase in level. It is possible that the sand would return to the western end of the beach should an easterly storm occur, as the material has not been lost from the system. This is a very dynamic beach and residents noted that beach levels regularly change At the western end of the beach, there is an area of rocks at the bottom of the slipway (see Photograph 2.1). Residents stated that these were deposited here recently (over the past 3 weeks; i.e. February 2015) and that they need clearing as in the past they have prevented RNLI and lifeguard access to the beach. Residents noted that the sand level at the western end of the beach had dropped drastically in the vicinity of the slipway and café in the last couple of weeks – estimated at 4m drop. Sand usually comes up to the bottom of the hand rail (see Photograph 2.1). Residents at the western end currently hire machinery to move rock from lower down the beach – which is in Cornwall Council’s ownership – to the toe of the cliff to help manage erosion risk. A resident noted that when looking down from the top of the cliff there is black geotextile visible just above the rock and that there is erosion and evidence of cliff slips above this, indicating that the erosion protection needs to be extended higher up the cliff face. It was noted that there is less or no vegetation cover on the cliff face where there have been cliff falls. The importance of the vegetation as UK BAP habitat (Maritime Cliff and Slopes) requires key consideration together with opportunity for enhancement. Residents have been informed that it would be too costly to construct rock revetment here (i.e. not economically viable). There was a significant drop in beach level and erosion of the cliff at the western end as a result of the 2013/ 2014 winter storms and a significant landslip took place immediately east of the cafe. Here works have been carried out to stabilise the eroded cliff line, re‐profiling the slope, placing geotextile (to be vegetated) and placing rock across a significant area. This was undertaken for the council and designed by Mott Macdonald to halt/stall erosion at western end. It has been reported that these rocks are being moved around by the sea and spreading out around that area of the beach; the local view is that the rocks that were placed here being much smaller compared to the significantly larger rocks which were placed in front of the surf look out and which have not moved in 25 years. There are also concerns that the rock now makes access difficult and risks people becoming cut off by the tide as it has been observed that the tide now fills this area first and visitors are forced to walk across the rock as they cannot get around it on the sand to reach the steps, causing health and safety issues. There are steps immediately to the east but we were informed that they are private RNLI steps. There are significant areas of peat exposed which residents stated are not usually visible (see Photographs 2.2, 2.3 and 2.4) indicating lower beach levels. Moving east across the beach the dune face had been eroded (during the 2013/ 2014 storms). On the bare sand dune faces there are health and safety issues as in the summer children climb, slide down and dig into the sand on the dune face. There are also steps which have become difficult to use due to drops forming from the bottom step to the beach (see Photograph 2.5). Residents noted that there were not enough easily usable access points along the beach. To the east of this section the marram grass observed was first planted by residents and the parish council in 1983 and replanted in 1990 when the dunes were realigned. The importance of the dunes as a UK BAP habitat requires a key consideration together with opportunity for enhancement At the eastern end of Praa Sands the cliff face is very steep and is eroding. In particular there was significant erosion resulting from the 2013/ 2014 storms. It was noted that this was the result of erosion from the sea but also flooding from the road behind (due to a blockage in the culvert that runs beneath
6 SECTION 2 SITE VISIT REPORT the road) resulting in saturation of the cliffs and erosion. Since then the gulleys have been cleared reducing this issue; although further investigation of this issue may be warranted. At one property trees were lost from the garden due to erosion during these storms, and one tree remains on the beach (Photograph 2.6). Beach levels have increased around the tree trunk. A buried electrical cable attached within the garden has also become exposed with one end hanging down the face of the eroded cliff to just above beach level. There are signs of erosion/slumping on the cliff face. At Little Cottage (at the eastern end of the beach) new garden fences have had to be constructed along the cliff edge as previous ones were lost as the cliff retreated by about 4m in the winter 2013/14 storms. Residents along this eastern section of the beach have employed a company to design sea defences including rock revetment. The report outlining the design, prepared by Philip Desmonde Partnership Ltd, has been provided since the site visit. This needs to be considered in the beach management plan. There are no government funds available however residents are prepared to pay for private defences to prevent, or at the very least slow down, erosion. This will also require planning consent and consideration of impacts on neighbouring properties. The Pill Box at the very eastern end of the beach indicates higher beach levels at this location (Photograph 2.7) as sand levels have increased around it. Residents noted that there has been erosion of the cliff behind the pill box. It was stated that in 1985 it was not possible to walk behind the pill box as it was too close to the cliff. Previous to this it was on the cliff top. Sand at present, has covered large rocks at this end of the beach, making walking and access from The Coast Path to the beach a little difficult to gauge safe footing; though residents advise that the sand comes and goes and so the rocks are regularly covered and uncovered as a result. The erosion of cliff over recent years has forced the coast path, which previously ran along the cliff edge, onto the beach at this point (see Photograph 2.8); this diversion is also understood to have been implemented to prevent people making their way over the dunes. The coast path requires key consideration of safe route and access. The route from the beach at the western end is via the sandbar café, again with residents noting that there were not enough access points along the beach. Cllr Board provided photographs to show the change in beach level over time and other information relating to past changes to the beach. Email addresses were provided by those who would like further information. 2.3 Thoughts on Potential Management Solutions for Consideration Construction of proposed private coastal defence to protect cliff toe from erosion at eastern end; this will need to consider implications for adjacent sections of coast, including the sand dunes at Par Sands. Protection to cliff toe at western end ‐ look into alternative low cost options as well as rock revetment, being mindful of implication of options for the sand dunes at Par Sands. Also consider safe access routes over/along the top of the defence. Beach recycling if material does not return from the eastern end to the western end – however impacts across the whole beach system would need to be considered in detail, along with the dynamism of the beach which may make such operations unsustainable/impractical. Beach nourishment and significant coastal defences are likely to be effective but uneconomic due to the number of assets at risk. Beach monitoring to continue to show where material is moving from and to. Beach re‐profiling to manage beach levels and rock at access points. This should be linked to trigger levels set based on monitoring data. Review location and number of access points to beach and signage for access points.
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Dunes management needs to continue as historically with planting and fencing to manage realignment due to sea level rise and to deal with the impacts of hard defences at the eastern and western ends of the dunes. Investigate potential use of RNLI steps as an emergency route off the beach and placed fixed notices accordingly. Consider establishing a ‘friends’ group to bring together local residents, businesses, landowners and beach users to help manage the site in and integrated and sustainable way in the future. 2.4 Data Sources Notes and photographs provided by Cllr Board. To be returned to her at the earliest opportunity. Tanis also informed us that she had a lot of other historic photographs and that we are welcome to contact her to see them. Her telephone number is on the scanned letter as she does not use email. Tim Wood has photos of Praa Sands showing higher sand levels than present and photos of the beach pre and post rock armour, which he provided following the site visit. 2.5 Photos
Photograph 2.1 Rocks at bottom of slipway at western end of beach.
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Photograph 2.2 Evidence of peat exposure indicating lower than normal beach levels.
Photograph 2.3 Evidence of peat exposure indicating lower than normal beach levels.
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Photograph 2.4 Evidence of peat exposure indicating lower than normal beach levels.
Photograph 2.5 Low beach levels leading to a sizeable drop at bottom of access steps.
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Photograph 2.6 Erosion of cliff during winter 2013/2014 storms resul