ENGLISH HERITAGE COASTAL ESTATE RISK ASSESSMENT

RESEARCH DEPARTMENT REPORT SERIES no. 68-2011 ISSN 1749-8775 

ENGLISH HERITAGE COASTAL ESTATE 

RISK ASSESSMENT 

Abby Hunt

Research Department Report Series 

68- 2011 

ENGLISH HERITAGE COASTAL ESTATE 

RISK ASSESSMENT 

Abby Hunt 

© English Heritage 

ISSN 1749-8775 

The Research Department Report Series incorporates reports from all the specialist teams within the English 

Heritage Research Department: Archaeological Science; Archaeological Archives; Historic Interiors Research and 

Conservation; Archaeological Projects; Aerial Survey and Investigation; Archaeological Survey and Investigation; 

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Investigation Report Series. 

Many of these are interim reports which make available the results of specialist investigations in advance of full 

publication. They are not usually subject to external refereeing, and their conclusions may sometimes have to be 

modified in the light of information not available at the time of the investigation. Where no final project report 

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© ENGLISH HERITAGE 68 - 2011

EXECUTIVE SUMMARY 

Climate change has direct and immediate impacts on the coast and on historic assets 

located close to our shores. The necessity of defence in coastal locations and the abundance 

of natural resources in these areas have resulted in many millennia of human activity and 

occupation around the coast of England and many sites and monuments have survived in 

this now increasingly threatened environment. English Heritage (EH) has over 400 historic 

properties in its care nationwide; of these, eighty are classified as being in the coastal zone. 

This risk assessment has been undertaken to assess the likely impacts of accelerated coastal 

erosion and increasingly frequent and severe flood events on the EH portfolio of historic 

properties. In order to make an assessment of the level of risk, projections of future coastal 

erosion and information about areas potentially at risk of flooding, supplied principally 

by the Environment Agency, have been compared with data on the EH coastal estate. 

Collation of these datasets in a Geographical Information System (GIS) has facilitated the 

cross-referencing, analysis and efficient management of the data collected during the course 

of the study. From the analysis of these data, the properties have been assigned a risk level, 

based upon the likelihood of flooding or coastal erosion and the severity of the potential 

risk, according to the proportion of the property likely to be affected. 

Overall, eighty sites (approximately 19.5% of EH’s entire historic property portfolio) are 

located within or intersect the coastal zone; this figure was reduced to fifty-four sites (or 

13% of the total) when further selection criteria were applied, providing the core sample 

for this study. Coastal properties not considered in this study are principally in urban areas 

where continued maintenance of flood or erosion defences may be assumed. Of the fiftyfour 

EH coastal estate historic properties included in this assessment, forty-eight (89% of 

the total) were recognised to be at risk of flooding, while thirty-eight (70% of the total) 

were deemed to be potentially at risk of coastal erosion. All properties had some level 

of potential threat, but this level varies significantly between sites, as would be expected, 

given differing geological and topographical conditions. Two sites (Berney Arms Windmill 

and Landguard Fort) were assessed to have a high risk of flooding and four (Reculver 

Roman Fort, Daw's Castle, Garrison Walls and Innisidgen Burial Chambers) to have a high 

risk of coastal erosion. 

The two sites at high risk of flooding, while not necessarily at risk of complete destruction 

by flood waters, will potentially be at risk of damage and partial loss from more regular 

inundation and possibly threatened by long-term rises in sea levels. Of the four sites at 

high risk from coastal erosion, three (Daw's Castle, Garrison Walls and Innisidgen Burial 

Chambers) are situated on stretches of coast which are not presently provided with sea 

defences, and are unlikely to be in the future, since current government policy is based 

around adaptation to coastal change, rather than defence. In these cases, it will be essential 

to ensure adequate recording, monitoring and understanding of the sites prior to their 

partial, or even complete, loss in the longer term. At Reculver, there are hard coastal 

defences protecting the site, which will need to be well maintained. Nevertheless, the 

preferred Shoreline Management Plan policy for adjacent stretches of coastline at Reculver 

(including an area of ‘Managed Realignment’) has the potential to impact upon the landscape 

setting of the property. 


The information gathered for this study will inform future management of the coastal 

estate properties, helping to ensure that any predicted damage and/or loss from flooding 

and coastal erosion can be mitigated, and action taken, where feasible, to minimise 

potential risks. The risk assessment will also allow a prioritisation of relevant maintenance 

and protection measures, where possible and affordable. 

CONTRIBUTORS 

This report was written by Abby Hunt with contributions by Peter Murphy, who also 

edited the text. Linda Kilroy (EH Estates Team), Steve Trow (EH National Rural and 

Environmental Advice Team), Paul Pattison (EH Properties Presentation Team) and Dave 

Went (EH Archaeological Survey & Investigation Team) commented on the text. The 

Illustrations were prepared by Abby Hunt. 

ACKNOWLEDGEMENTS 

Thanks are due to the Environment Agency, in particular Nick Hardiman and Ed Wilson. 

The assistance of the SMP2 consultants and authorities who supplied the coastal erosion 

digital data was gratefully received, in particular, Jenny Jakeways (Isle of Wight), Andrew 

Colenutt (New Forest), Robin Siddle (North Yorkshire), Aaron McNeill (Northumberland), 

Stuart Dawks (Royal Haskoning), Delyth John (EA) and Sam Box (Halcrow). Many thanks 

also to the EH staff, past & present, who took the time to discuss the sites included in the 

study and to share their knowledge and information about the properties; Eleanor Breen, 

Richard Baker, Rob Harding, Mark Douglas, Jon Tate, Roy Porter, Mark Simmons, Gabriella 

Smith, Sara Rushton, Heather Sebire, Morgan Cowles and the Visitor Operations staff at 

all the sites visited in the course of this study. 

DATE OF STUDY 

May 2010 - July 2011 

CONTACT DETAILS 

English Heritage, 37 Tanner Row, York. YO1 6WP 

Abby Hunt, tel: (01904) 601910, email: abby.hunt@english-heritage.org.uk 

English Heritage, Fort Cumberland, Fort Cumberland Road, Eastney, Portsmouth PO4 

9LD 

Peter Murphy, tel: (023) 9285 6724, email: peter.murphy@english-heritage.org.uk 


CONTENTS 

1. INTRODUCTION 1 

1.1 Climate change 1 

1.2 The coastal environment and its management 2 

1.3 A risk assessment 4 

2. METHODOLOGY 6 

2.1 Selecting the properties 6 

2.2 Compiling the project GIS 7 

2.3 Additional information 8 

2.4 Assessing risk 9 

2.5 Limitations 10 

2.6 Outputs 10 

Environment Agency ‘flood zones’ explained 11 

3. SUMMARY OF ASSETS AT RISK 12 

4. OVERVIEW OF RISK BY REGION 14 

4.1 North East 16 

4.2 Yorkshire & The Humber 17 

4.3 East Midlands 18 

4.4 East of England 18 

4.5 South East 19 

4.6 South West 20 

4.7 North West 22 

5. CASE STUDIES 23 

5.1 Case study 1: Reculver Roman Fort and Reculver Towers 23 

5.2 Case study 2: Landguard Fort 28 

5.3 Case studies 3a & b: St Mary’s, Isles of Scilly (Garrison Walls & Innisidgen Burial Chambers) 

32 

3a. Garrison Walls 32 

3b. Innisidgen Burial Chambers 36 

5.4 Case study 4: Hurst Castle 41 

5.5 Case study 5: Scarborough Castle 45 


5.6 Case study 6: Daw's Castle 49 

6. CONCLUSION AND RECOMMENDATIONS 53 

7. BIBLIOGRAPHY 56 

APPENDIX 1: GAZETTEER OF EH COASTAL PROPERTIES INCLUDED IN THE STUDY 60 

North-East Region 60 

Yorkshire and the Humber Region 64 

East Midlands Region 65 

East of England Region 66 

South-East Region 68 

South-West Region 78 

North-West Region 91 

APPENDIX 2: NOTES ON SITE VISIT TO PIEL CASTLE 93 

APPENDIX 3 96 

APPENDIX 4: DATA SOURCES 97 

APPENDIX 5 99 


LIST OF ILLUSTRATIONS 

Figure 1. Distribution map 6 

Figure 2. North East region location map 16 

Figure 3. Yorkshire & The Humber region location map 17 

Figure 4. East Midlands region location map 18 

Figure 5. East of England region location map 18 

Figure 6. South East region (eastern part) location map 19 

Figure 7. South East region (western part) location map 20 

Figure 8. South West region location map 21 

Figure 9. Isles of Scilly (South West region) location map 21 

Figure 10. North West region location map 22 

Figure 11. Photograph of Reculver Towers from the east 24 

Figure 12. Map showing the extent of EH's area of responsibility at Reculver 25 

Figure 13. Photograph from the north-east corner of St Mary's Church at Reculver 27 

Figure 14. Photograph of Landguard Fort 28 

Figure 15. Aerial photograph of Landguard Fort with superimposed Lidar data 30 

Figure 16. Photograph of active erosion below the breastwork to the south-west of King Charles' 

Battery 32 

Figure 17. Garrison Walls location map 33 

Figure 18. Photograph of active erosion of the low cliff to the north-west of Woolpack Point 34 

Figure 19. Photograph of the lower entrance grave at Innisidgen 37 

Figure 20. Photograph of the coastline below Innisidgen Burial Chambers 38 

Figure 21. Orthorectified aerial view of the coastline around Innisidgen Burial Chambers 39 

Figure 22. Photograph of groynes and sea defences to the south-east of Hurst Castle 42 

Figure 23. Photograph of the western end of the west wing of Hurst Castle 43 

Figure 24. Photograph of Scarborough Castle 46 

Figure 25. Orthorectified aerial photograph of Daw's Castle 50 

Figure 26. Photograph of cliffs immediately to the east of Daw's Castle 51 

Figure 27. Map showing the area of Berwick Castle in the care of EH 60 

Figure 28. Photograph of Dunstanburgh Castle from the south 61 

Figure 29. Map showing the EH guardianship area around Gainsborough Old Hall 66 


Figure 30. Photograph of Calshot Castle 69 

Figure 31. Photograph from Deal Castle curtain wall 69 

Figure 32. Photograph of Dover Castle 70 

Figure 33. Photograph of Dymchurch Martello Tower. 71 

Figure 34. Map showing the north-eastern part of the Osborne House EH guardianship site 73 

Figure 35. Photograph of Portchester Castle 74 

Figure 36. Lidar surface data for Portchester Castle with superimposed flood zone data 74 

Figure 37. Photograph from the east side of Richborough Roman fort 75 

Figure 38. Photograph from the curtain wall of Walmer Castle 77 

Figure 39. Photograph of Bant's Carn Burial Chamber 79 

Figure 40. Photograph of Bayard's Cove Fort, Dartmouth 80 

Figure 41. Photograph of Cromwell's Castle, Tresco 81 

Figure 42. Photograph of erosion along the access path leading to Cromwell's Castle. 81 

Figure 43. Photograph of King Charles' Castle, Tresco 84 

Figure 44. Photograph of Old Blockhouse 84 

Figure 45. Photograph of Little Dennis Blockhouse 86 

Figure 46. Photograph of Porth Hellick Down entrance grave 87 

Figure 47. Photograph of Portland Castle 88 

Figure 48. Photograph of the cliff at Castle Cove, near St Mawes Castle 89 

Figure 49. Photograph of Merlin's Cave, Tintagel Island 90 

Figure 50. Photograph of the eastern elevation of Piel Castle 92 

Figure 51. Photograph of circular earthwork close to Piel Castle keep 93 

Figure 52. Photograph of erosion to the east of Piel Castle keep 94 


TABLES 

Table 1. Risk matrix used for assessing risk level to EH coastal estate sites and properties for the 

purposes of the current study 9 

Table 2. Table summarising the number of EH properties at risk from flooding or coastal erosion and 

the level of the risk 12 

Table 3. Table showing the number of EH historic sites and properties by principal functional period at 

potential risk from flooding and/or coastal erosion, including the number at high risk 13 

Table 4. Table showing the number of EH historic sites and properties in each region at potential risk 

from flooding and/or coastal erosion, including the number at high risk 14 

Table 5. Table of properties included in the study, by EH region, showing the level of risk from flooding 

and coastal erosion. 15 


1. INTRODUCTION 

English Heritage (EH) is guardian of over 400 historic properties 1 across England, ranging 

in date from the Neolithic to the 20 th century; these sites and properties range from 

small, individual buildings or ruins to large estates. The management and curation of this 

portfolio presents a myriad of challenges, including dealing with a range of threats to the 

fabric of structures, surviving archaeological remains and their landscape settings. One 

particular geographical area which will inevitably experience an increase in the severity 

and frequency of threat in the coming decades is the coast. With a changing global 

climate and rising sea levels, properties in coastal areas will face a new and increasingly 

serious set of conservation and management issues. Of all the EH historic sites and 

properties, eighty lie within 200m of the ‘Coastal Zone’, which is defined as ‘areas of 

marsh or mudflat, or elsewhere a 200m band inland of mean high water’ (Natural 

England 2007). This equates to approximately 10.4km of coastal frontage within the EH 

portfolio, and a further 2km of estuary frontage. In order to assess the potential risk 

to the EH properties in the coastal zone, it was decided to take the presently available 

data on flood risk and coastal erosion projections and examine where, and with what 

potential level of severity, this would impact on the properties in our care. 

1.1 Climate change 

Global climate change, for which there is growing, strong evidence, is the underpinning 

factor necessitating a risk assessment for EH coastal properties. While continuing 

research into climate change is showing that its effects, such as sea level rise and 

increasing occurrences of severe weather events, are clearly an issue, of greater concern 

is the rate at which these factors are changing; original estimates of the time-scale and 

scope of these impacts are continually being revised upwards to reflect the increasing 

pace and scale of change. Figures for the UK, published in 2006, indicated that sea level 

rise could equate to 0.99-1.21m, depending on location, by 2115 (Defra 2006, 3). Data 

from the UKCP09 (United Kingdom Climate Projections, http://ukclimateprojections. 

defra.gov.uk/), which is based on three different scenarios of greenhouse gas emissions 

(high, medium and low), indicates that by 2095 sea level rise in the southern part of 

the UK could be in the range of 0.21-0.68m (UKCP09, chapter 3). This figure takes into 

account vertical land movement and is based on the ‘medium’ scenario. The report also 

indicates that under a ‘high++’ scenario, although this has a very low (

As well as continuous processes, such as sea level rise (albeit not necessarily proceeding 

at a constant rate), climate change is having an impact on episodic, occasional events, 

such as storms, which are much more difficult to predict and mitigate. The frequency 

and severity of such events, whilst broadly unpredictable with any reasonable degree 

of probability, seems unlikely to decrease in the coming decades, given general climatic 

trends and environmental factors. It may be that using information from the impacts of 

past storm events will be the best means of preparing a future mitigation strategy. 

The broad implication of this rapidly developing evidence is that those responsible for 

managing coastal landscapes, whether they are valued for environmental, historic or 

current residential reasons, are going to be faced with increasingly testing problems in the 

coming century. In terms of the properties in the care of EH, the approaches to managing 

some of the most vulnerable will potentially need to be adjusted to take account of the 

increasing threats posed by climate change. 

1.2 The coastal environment and its management 

The coastal environment is dynamic and the process of coastal change is often episodic, 

rather than linear, which makes prediction and mitigation difficult. Isolated occurrences, 

such as storm surges, which may only last a matter of hours, can have immediate 

significant effects. In other cases, the changes are not immediate and the effect may occur 

some decades after the cause. 

England has a diverse and varied coastline, from hard-rock cliffs to low-lying soft coasts, 

which react differently, and at different rates, to changes in sea level, storminess and 

prevailing wave climate. The response of the coastline to erosion or accretion can also 

be affected by pre-existing man-made, management measures. In the last 100 years, 

approximately 865km of coastal protection has been constructed around England’s 

shores (MacInnes 2008, 32). The use of ‘hard’ defences (such as concrete sea walls) is 

now less common, as the ongoing costs are often untenable and the potential negative 

knock-on effects further along a coastline are better understood. Instead, there is now 

more emphasis on ‘soft’ defences and managed realignment; but this practice, whilst 

often beneficial to natural ecosystems, has the potential for negative impacts on the 

historic environment (English Heritage 2008, 7). 

The emphasis in coastal management now is on adaptation to coastal change rather 

than defence, wherever this is thought most appropriate. Some locations, such as those 

of major settlements or infrastructure, are of such national economic significance that 

defence is the obvious response. Elsewhere, in sparsely populated areas especially, the 

costs of defence are not justified in relation to the value of the assets protected, and 

so adaptation will be required. These principles underpin the document ‘Adapting to 

Coastal Change: Developing a Policy Framework’ (Defra 2010a). In the future many of 

the decisions about the best form of adaptation for individual rural communities will be 

made at a local or regional level. To facilitate this, Defra has funded a series of ‘Coastal 

Change Pathfinders’ around the country. Their aim is to generate new innovative ideas 

in terms of improving understanding of how coastal communities can adapt to coastal 

change and what the costs and benefits of different approaches are; these also provide 

© ENGLISH HERITAGE 

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practical lessons and examples which can be shared with other practitioners (www.defra. 

gov.uk/environment/flooding/coastal-change-pathfinders). This is entirely consistent with 

the Coalition Government’s emphasis on Localism, to be embodied in new legislation. 

Given the changing nature of the coastal environment, managing the coastline is a 

challenge. From the mid-1990s, a first generation of Shoreline Management Plans 

(SMPs) were produced for each section of the English coast. The aim was to provide a 

large-scale assessment of the risks associated with coastal processes, to ensure that the 

risks to people and the developed, historic and natural environments were reduced, 

and to promote coordinated management of the coastline. These original SMPs have 

been revisited in the past few years, incorporating revisions and changes in policy and 

responses from public consultation. Most of the SMP2s have now been finalised and 

published. The SMP model works on a time frame of short term (0-20 years), medium 

term (20-50 years) and long term (50-100 years), a definition which will be adopted 

throughout this report. For each stretch of coast, or ‘Policy Unit’, a preferred policy 

option is selected for the successive time frames: ‘Hold The Line’, ‘Advance The Line’, 

‘Managed Realignment’ or ‘No Active Intervention’. The historic environment is only 

one of a wide range of factors which influence policy selection. SMP documents play 

an important role in understanding potential coastal changes and developing policies 

to address any threats, which may impact upon EH properties and the landscapes 

surrounding them. They are not statutory documents, but they are now being used to 

help define Coastal Change Management Areas (CCMAs) as defined in the Department 

for Communities and Local Government’s Planning Policy Statement (PPS) 25 Supplement: 

Development and Coastal Change. This presents a range of planning options including 

provision for ‘roll-back’ of threatened coastal settlements within these areas. Although 

planning guidance is now being reviewed, it seems probable that some elements of the 

PPS25 supplement, including CCMAs, are likely to be retained. 

The review led by Sir Michael Pitt in 2008, undertaken in response to the floods which 

struck across the United Kingdom in the summer of 2007, resulted in a number of 

recommendations to improve resilience to increasing risks of flooding. It also identified 

problems inherent in previous legislation which had given local authorities the authority 

to drain land, build defences and provide flood warning, but did not define a local 

leadership role for this nor specify a national overview role for the Environment Agency 

(EA). The results of the Pitt Review were subsequently addressed by the Flood and 

Water Management Act 2010 and are being implemented through the National Flood 

and Coastal Erosion Risk Management Strategy for England (Defra/Environment Agency 

2011). In the preparation of the Strategic Environmental Assessment (SEA) report to 

support the development of the National Flood and Coastal Erosion Risk Management 

(FCERM) Strategy, the EA identified that the implementation of FCERM measures had 

the potential to impact upon cultural heritage and landscape. However, it was considered 

that the impacts tended to be location specific and the identification of significant 

issues in these areas on a national scale was difficult and fell outwith the scope of the 

assessment, thus the identification of heritage issues was to be ‘passed down’ to be 

assessed at a more appropriate, location-specific level (Environment Agency 2010b, 

3). To some degree the current study provides this level of assessment for sites and 


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monuments in the care of EH, but does not extend to the wider historic environment. 2 

One of the key points to be taken forward from the Pitt Review was the need to 

reconsider the assumption that long-term flood and coastal erosion risk management 

plans in England would be funded by central Government. The funding system for flood 

and coastal erosion risk management authorities has, until recently, been 95% funded 

by central Government. The proposal for projects from 1 st April 2012 is that there will 

be a ‘payment for outcomes’ funding approach. This would encourage local investment 

in flood and coastal erosion risk management, giving those areas at risk more of a say in 

action taken (Defra 2010b, 7). It is envisaged that the burden of funding flood and coastal 

risk management projects will be shifted away from the general taxpayer and central 

government and be devolved to local groups and communities (those who would be 

direct beneficiaries of the schemes), who would be required to raise funds, but could 

then apply for an allocation of capital Flood Defence Grant-in-Aid, providing the project 

met stated criteria and delivered one of four outcome measures. This change has the 

potential to impact on the management of sites in the care of EH, for example, where a 

change in overall coastline management policy is to cease maintaining existing defences. 

It also remains to be defined whether EH, in a case where an EH historic property was 

seen potentially to benefit from the construction of a flood protection scheme, might be 

invited to contribute towards the cost. 

In the light of changes in funding for maintenance of sea defences, the EA has produced 

an information pack for landowners and asset owners. Included in this is the Asset 

maintenance policy protocol for sea defences (for England only) (Environment Agency 2010a), 

a document which provides guidance and sets out the decisions and options involved in 

a situation where the EA has historically maintained sea defences, but such activities are 

planned to be discontinued. 

1.3 A risk assessment 

Clearly, it is a difficult matter to quantify with certainty the effects of coastal erosion or 

flooding that will affect EH’s coastal properties over the coming decades. However, it is 

possible to indicate those properties most at risk and to identify the parts of the sites and 

monuments with the highest vulnerability. Using the available data, this study will examine 

the probability of flood events or coastal erosion, consider the level of severity that their 

impacts could have on heritage assets, and rank the risk accordingly. 

In taking a risk-based approach, the aim is to address a number of questions, namely 

what could happen, why, and what is the probability of it happening? Once this has been 

established, it is then a case of identifying what losses or damage may be caused, so 

that the effects can be reduced or managed (MacInnes 2008, 32). Although risks can be 

assessed, and management measures suggested and implemented to reduce the threat, 

the risk can rarely be totally eliminated. In managing historic properties and landscapes, 

being prepared for the risk of flooding or coastal erosion and aware of the potential 

2. English Heritage intends to undertake a wider national study of the impacts of flooding and erosion on the coastal 

historic environment; this will be initiated with a regional study of the county of Yorkshire (see National Heritage 

Protection Plan. Activity 2C1: Major Environmental Threats, Protection Result 2C1.3). 


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consequences is key. This includes the acknowledgement that protection of historic 

environment sites from natural processes may not always be possible. In such cases, 

other measures to ensure that historic assets are fully understood and recorded to the 

highest available standards may be the only means to ensure a measure of preservation 

for future generations. 

The results of this study are set out in this report initially through an explanation of the 

methodology and sources used, followed by a broad summary of the assets at risk. A 

regional overview follows, considering the general character of the coastline in each EH 

region and the general trends of risk. A selection of properties have been selected for 

more detailed case studies; these have been selected because of particular risk factors 

or high levels of risk to the sites. The remaining properties in the study sample are 

summarised in a gazetteer. The conclusion includes some generic recommendations 

which may assist in future planning and management of some of the properties. As well 

as this report, the output of this study is the project Geographical Information System 

(GIS). This will be available for interrogation and consultation by internal stakeholders 

wishing to view the various datasets, and will be a useful tool for those preparing future 

management plans for sites and monuments in the care of EH. The structure of the GIS 

can also potentially be transferred to future projects looking at similar themes. 

This report and its recommendations do not commit EH to any course of action, but 

it envisaged that the results will be considered and discussed when formulating future 

management plans for the relevant properties. It is hoped that some measures can be 

implemented as appropriate, if funding permits, in the medium- to long-term. 


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2. METHODOLOGY 

2.1 Selecting the properties 

In the first instance, a query was run on the entire dataset of EH properties held in the 

corporate GIS to select those that lay within 200m of the coastal zone (see Section 1 for 

definition of the latter). This returned a sample of eighty properties, distributed around 

the country. This group was further reduced by discounting those monuments within 

large, urban areas, where major flood or erosion defence systems exist, coastal erosion 

is not an issue, and where a ‘Hold The Line’ policy option is in place. The result, a list of 

fifty-four properties, form the core of the study (see Figure 1). 

N 

Figure 1. Map showing the distribution of the fifty-four EH historic properties included in 

the study. Background mapping SRTM data courtesy of the CGIAR Consortium for Spatial 

Information. 


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2.2 Compiling the project GIS 

In order to manage the datasets and interrogate the spatial data effectively, it was 

decided to bring the information together in a project GIS, compiled in ESRI’s ArcGIS 

software (version 9.3.1). Background mapping, to provide an overall context for the 

sites, was created by using digital tiles of the relevant areas of Ordnance Survey (OS) 

mapping at 1:10 000 scale and the national dataset from the OS depicting the High Water 

Mark around the coast of the UK, supplied by the EH Corporate GIS team. Historic 

OS mapping was also acquired for some individual sites (where relevant), imported into 

the project GIS, and georeferenced, if the positional information had not already been 

created. Statutory datasets were also added to the GIS to illustrate environmental and 

heritage designations relating directly to the properties or their surrounding areas; these 

include SSSIs, AONBs, Ramsar areas, Listed Buildings, Scheduled Monuments and World 

Heritage Sites. The EH Corporate GIS team also provided data layers (in ESRI shapefile 

format) depicting the EH regions and the extent of the area in the care of EH for each of 

the fifty-four properties included in the study. 

Where there was existing spatial data for individual sites, this was incorporated 

into the GIS. In some cases, archaeological survey plans of sites, produced by the 

EH Archaeological Survey & Investigation Team, were available and these were 

georeferenced to bring them in to the correct location on the British National Grid. 

Examples of orthophotography, produced by the former EH Metric Survey Team, were 

also imported. In the specific case of the Garrison Walls, on the Isles of Scilly, a trial GIS 

was compiled in 2007 to assess the viability of such a system as a site management tool; 

this site-specific GIS and its associated data were also incorporated into the current 

project GIS. 

Datasets from other organisations were also obtained to add further information to the 

GIS and to give a fuller picture of the local setting of the properties. Geological mapping 

at 1:625 000 scale (bedrock geology), covering the whole of the UK, was downloaded 

from the British Geological Survey website (www.bgs.ac.uk). Aerial photography and 

Lidar data were acquired from two sources. Firstly, the Channel Coastal Observatory 

(CCO; www.channelcoast.org/), which is the website for the Strategic Regional Coastal 

Monitoring Programmes of England. This website provides a free, online download 

facility for the data held by the organisation, which includes good quality, rectified aerial 

photography and Lidar data. The limitation of this resource is that the primary area of 

coverage is limited to the south of England, from the Bristol Channel around to the 

Thames Estuary. For areas outside the CCO data holding, aerial photography and Lidar 

data were acquired from GeoStore (www.geostore.com/PGA), which provides Infoterra 

data products (aerial photography and digital height data) through Next Perspectives 

under a Pan Governmental Agreement (PGA), to which EH is a signatory. 

The Environment Agency (EA) has produced flood risk mapping for the UK and the 

digital version of this dataset for inclusion in the project GIS was acquired direct from 

the EA. The data include mapping of the potential extent of flood zones 2 and 3 (see 

‘EA Flood zones explained’ information box below, after Section 2.6), historic flood 

data and flood storage areas. The EA also provided data on individual sites which was 

incorporated into the project GIS. 


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At the outset of the project, it was hoped that a digital dataset of the coastal erosion 

risk mapping for England, produced by the EA, would be available. Unfortunately the 

release of the complete nationwide dataset was postponed, and at the time of writing 

(May 2011) was still awaiting approval. Consequently, it was decided that the coastal 

erosion data for each individual coastal management area, used in the preparation of 

the SMP2, would, where possible, be obtained separately and incorporated into the 

project GIS. The relevant SMP2 authorities or consultants were contacted and, in most 

cases, the data was successfully obtained. This resulted in variants between some of the 

datasets, but generally the information included potential erosion rates over 20, 50 and 

100 year periods, in some cases presented as a ‘with present management’ scenario with 

additional data illustrating a ‘no active intervention’ scenario. 

2.3 Additional information 

As well as digital datasets, other documents were consulted during the study to provide 

contextual information for the sites and site-specific detail. The data sources used are 

tabulated in Appendix 4. 

A study called ‘Futurecoast’ was commissioned by Defra in 2002, the work for which 

was undertaken by the Halcrow Group (Halcrow 2002). The aim of the study was to 

gain a better understanding of the coastal change in the coming century for the open 

coastline of England and Wales, focusing on larger-scale coastal behaviour and taking 

a geomorphological-based approach. It was intended to be used as an underpinning 

element of the SMP2s to allow longer-term trends to be incorporated into forward 

plans for coastal defences. The results of this study, the analysis of 6,000km of shoreline, 

have been made available on an interactive CD-ROM along with thematic reports, data, 

interpretative reports and predictive mapping. This information was consulted in the 

course of the present study to augment other data sources and to provide a fuller image 

of predicted coastal change at various sites. 

As mentioned above, SMPs are a crucial element in the management of coastal 

environments. The latest generation of SMPs (SMP2s), were consulted, where available, 

to provide information about the proposed management policies for various sections 

of coastline. Many of the SMP2s also include maps of possible extents of future coastal 

erosion; where it was not possible to obtain this mapped data digitally, the hard copy 

reports were consulted. 

The maintenance of EH properties is the responsibility of the Estates Team, which sits 

within the Conservation Department of the National Collections group. The team 

delivers cyclical and response maintenance to the sites and produces maintenance project 

plans for the entire estate on an annual basis. These projects are prioritised based 

on information contained within the AMP (Asset Management Plan) system. Periodic 

Condition Surveys and Reports, conducted to EH’s Standard for Periodic Condition 

Surveys and Reports (ref. EHS0004/2:2006) specification, are commissioned for each 

of the properties by the EH Estates Programme Development Team every five years. 

These documents contain a schedule of the individual assets comprising the area in 

guardianship (where applicable), record condition and defects, provide a prioritisation of 


8 

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action and recommend further assessment; these generally focus on repairs and remedial 

works. Where relevant, these have been consulted in the course of this study to provide 

information about defects relating to flooding and/or coastal erosion which have already 

been noted and are part of the maintenance plans, but also to highlight potentially 

vulnerable areas of sites which are perhaps not currently being monitored or addressed 

by the maintenance schedule. 

The EH Scheduled Monuments at Risk (SM@R) database, which contains assessments of 

all scheduled EH sites and a categorization of principal threats, was also consulted. The 

risk levels assigned to the sites in this study in the SM@R database are tabulated in Table 

5 (see below, Section 4). 

2.4 Assessing risk 

The method for assessing the risk to the sites and monuments in the care of EH in this 

study was to visually examine the digital data in the project GIS in order to establish the 

potential threat from coastal erosion or flooding. This was achieved by viewing datasets 

together in the GIS and noting where the predicted flood zones and potential extents 

of coastal erosion intersected the polygons defining the extent of the area in the care 

of EH. If there was no correspondence between the EH estate area and the potential 

risk zones, then the site was deemed to be at low risk. Where there was an overlap, the 

size of the overlap was ascertained and the percentage of the property potentially under 

threat from flooding and/or coastal erosion was calculated. Other factors, such as the 

nature of underlying geology, site staff observations, condition reports and SMP policies 

for Policy Units (as outlined above), were also taken into consideration at this stage, to 

further refine the risk level. In some published risk assessments, the level of significance of 

a property or site is taken into consideration; however, in this case, as all the properties 

are in the care of EH and are either scheduled or listed, indicating that they are all of 

national importance, this criteria was not considered to be a useful quantifier. A basic 

risk matrix (Table 1, below) was developed to allow a definition of the risk level. Where 

possible, site visits were made to confirm the data and analysis derived from the project 

GIS, and to obtain up-to-date photography of known problem areas. 

% area of site 

affected 

Probability of flooding/coastal 

erosion 

Low Moderate Significant 

Negligible Low Low Low 

up to 25% Low Low Medium 

25-50% Low Medium Medium 

50-75% Medium Medium High 

75-100% Medium High High 

Risk level 

Table 1: Risk matrix used for assessing risk level to EH coastal estate sites and properties for 

the purposes of the current study 


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2.5 Limitations 

The prediction of future trends in coastal erosion, and indeed flooding, is not a precise 

science. There are various digital modelling routines which enable potential flood 

patterns to be predicted, but these do not provide a definitive statement of future 

flood events, they merely indicate the most likely extents of flooding given a certain set 

of circumstances and factors. As research into climatic patterns and changes advances, 

models of potential impacts will doubtless be revised. The EA flood zone mapping used 

for this project, must be viewed as a projection of future events rather than a certainty. 

Variables which cannot be predicted mean that future flooding could be less severe than 

the maps suggest, but by the same token, it may be more severe. This latter situation is 

perhaps more likely in view of the recent upward revisions of the rate of climate change 

and sea level rise. In addition, individual severe storms may precipitate damaging flood 

events, which are almost impossible to predict. Modelling for worst case scenarios is not 

a pessimistic exercise, it is simply a matter of being forearmed against the full range of 

possibilities. 

The caveats attached to flood risk mapping also apply to coastal erosion risk mapping. 

Although a number of SMP2s provide maps with lines indicating the extent of coastal 

retreat over 20, 50 and 100 years, these lines are based on projections of current rates 

of change and models and are not guaranteed statements of future events. Often, the 

scale of the coastal erosion maps does not allow for discrete areas of geology, which 

may impact on rates of erosion or susceptibility to wave action, to be factored in to the 

generic erosion lines. Clearly these may have an impact at an individual site scale. The 

projections often assume the good maintenance of existing coastal defences into the 

future. However, with increasingly restricted funding, this cannot be taken for granted. In 

addition, even well-maintained defences can be over-topped in severe storm episodes 

and the extent of erosion behind the defences that this may cause is difficult to predict. 

Despite the inherent difficulties in predicting future climate patterns and storm 

frequencies, the available data give a reasonable indication of possible future impacts 

based on the current understanding of general trends. By using these data, a baseline 

understanding of threats and risk level to the EH coastal estate can be ascertained. Then, 

as future studies allow the refinement of predictions, updated data can be fed in to the 

project GIS, compared against the EH property portfolio and any changed priorities can 

be addressed. 

2.6 Outputs 

As noted in the introduction, this report is one element of the project’s outputs. The 

main product is the GIS tool created to assist the future management of the coastal 

sites. It is possible to derive maps from the system illustrating site-specific data with 

relative ease. Queries can also be run on the data to answer particular management 

issues and assist with forward planning. The project data will be available digitally to any 

EH staff with access to ArcMap GIS software (stand-alone or via DeskGIS); options for 

disseminating the data via read-only methods which do not require the full software, 

such as free-to-download GIS readers, will also be investigated. The GIS model has been 

designed to be transferable, so that the GIS structure and datasets can, where relevant, 

be adopted by comparable projects. 


10 

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Environment Agency ‘flood zones’ explained 

Data provided by the EA on areas potentially at risk from flood are illustrated in zones 

on maps, relating to fluvial (river) and tidal flooding. The areas of risk are categorized 

as ‘flood zone 2’ or ‘flood zone 3’ and it is assumed that these are the extents of the 

areas that would be affected by flooding if there were no flood defences. 

• Flood zone 2 shows areas of land which have an annual probability of flooding of 

between 0.1-1% (from rivers) or 0.1-0.5% (from the sea); this equates to a 1 in 

1,000 to 1 in 100 chance of flooding from rivers or 1 in 1,000 to 1 in 200 chance 

of flooding from the sea. Flooding to the full extent of this outlying zone has a low 

probability, but would potentially be an extreme event. 

• Flood zone 3 shows areas of land which have an annual probability of flooding 1% 

or greater (from rivers) and 0.5% or greater (from the sea); this equates to a 1 in 

100 or greater chance of flooding from rivers or a 1 in 200 or greater chance of 

flooding from the sea. 

The EA categorizes the level of risk of flood as: 

• Significant (chance of flooding in any year greater than 1.3% or 1 in 75) 

• Moderate (chance of flooding in any year is 1.3-0.5% (between 1 in 75 and 1 in 

200) 

• Low (chance of flooding in any year is 0.5% (1 in 200) or less 

These definitions are used throughout this report. 

Information from: 

http://www.environment-agency.gov.uk/homeandleisure/floods/default.aspx 


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3. SUMMARY OF ASSETS AT RISK 

Having assessed the historic properties in the EH coastal estate against the available 

risk datasets, the results demonstrate that all the sites in the study face some level of 

threat from either flooding, coastal erosion or both. Thirty-two are considered to be 

at risk from both coastal erosion and flooding, with fifteen of these at low risk in both 

categories. Considering the risk types individually, the majority of the properties fall 

into the low risk or no risk categories (68% for flood risk and 79% for coastal erosion 

risk). While the level of risk to most of these properties is low, it should by no means 

be ignored. The threat is still present and could be exacerbated by one-off climatic 

events, but in terms of general trends, they are unlikely to be at immediate, serious risk. 

In terms of prioritizing mitigation works, defensive measures and maintenance work, 

the properties in the lower risk categories would be given lower weighting. Those sites 

at medium or high risk from flooding (28% of the study sample) or coastal erosion 

(19%) are potentially going to be at greater risk and possibly within a shorter time 

scale. Accordingly, these sites should be given a greater weighting when considering 

prioritisation of works and particular attention paid to the parts of the area in the care of 

EH identified as being most at risk from flooding and/or erosion. 

Risk level 

Flooding 

Risk type 

Coastal 

Erosion 

Low 31 27 

Low/Medium 2 1 

Medium 13 6 

High 2 4 

n/a 6 16 

Total 54 54 

Table 2: Table summarising the number of EH properties at risk from flooding or coastal 

erosion and the level of the risk 

The fifty-four EH sites and properties included in this study range in date from the 

Bronze Age period (approximately 2700-700BC) to the 19 th century, although a number 

are multi-period landscapes or structures. As with the chronology of the sites, many are 

also multi-functional, having fulfilled a number of roles over the centuries; Portchester 

Castle, for example, incorporates a Roman fort, a medieval castle and priory, and a 

17 th century prisoner of war camp. The sites are tabulated below (Table 3) by principal 

construction or functional period against the risk type; where there are significant phases 

of use across a number of time periods, the site has been classed as ‘multi-period’. The 

high number of medieval and Tudor sites reflects the importance of the coast in military 

terms, particularly the latter period when Henry VIII’s programme of strengthening 

England’s coastal defence resulted in the construction of a number of forts at strategic 

locations. As the figures indicate, risk is spread relatively evenly across all periods of site. 


12 

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The most common broad category of sites in the study sample comprises defensive 

fortifications, indicating the crucial, strategic role that coastal locations have played in 

England’s military past, as mentioned above; of the fifty-four sites in the study, thirtyseven 

(of varying dates) fall into this category. The next most numerous category is 

religious, ritual and funerary monuments, which account for thirteen of the sites. The 

remainder fall into the categories of domestic, transport, commercial, and gardens, parks 

and open spaces. 

Period 

Number of sites by risk type 

Flooding 

Coastal 

Erosion 

Flood & 

Coastal 

Erosion 

Total 

High risk 

Prehistoric 0 1 3 4 1 

Roman 2 0 2 4 1 

Saxon 0 1 0 1 1 

Medieval 8 2 7 17 0 

Tudor 2 2 11 15 0 

Post medieval 2 0 3 5 1 

19th Century 2 0 2 4 1 

Multi-period 0 0 4 4 1 

Table 3: Table showing the number of EH historic sites and properties by principal functional 

period at potential risk from flooding and/or coastal erosion, including the number at high risk 

54 


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4. OVERVIEW OF RISK BY REGION 

The properties comprising EH’s coastal estate are each described in summary, with an 

assessment of risk level, in Appendix 1, with seven covered in more detailed case studies 

(Section 5). This section provides a regional overview of the character of the coastal 

zone, summarizes the property data in each region and gives an outline of the principal 

risks. Information on the general coastal character of each region has, in the main, been 

taken from the Process Reports in the Thematic Report section of the Futurecoast study 

(Halcrow 2002). More detailed information about the geology and coastal character in 

the vicinity of each individual site in the study is presented in the relevant cases studies 

(Section 5) or gazetteer section (Appendix 1). 

Of EH’s nine regions, two contained no properties fulfilling the criteria for inclusion in this 

study; the West Midlands region, which has no coastline, and the London region, where 

monuments in the care of EH are considered to be adequately protected by the flood 

defences for the city. The figures for the sites in each EH region are summarized in the 

table below (Table 4). 

EH Region 

Coastal 

Erosion 

Number of sites by risk type 

Flooding 

Coastal 

Erosion & 

Flooding 

Total 

High Risk 

North East 0 4 4 8 0 

Yorkshire & Humber 2 0 0 2 0 

East Midlands 0 1 0 1 0 

East of England 0 5 1 6 2 

South East 0 4 13 17 1 

London - - - 0 - 

South West 4 2 12 18 3 

West Midlands - - - 0 - 

North West 0 0 2 2 0 

6 16 32 54 6 

Table 4: Table showing the number of EH historic sites and properties in each region at 

potential risk from flooding and/or coastal erosion, including the number at high risk 

Table 5 (opposite): Properties included in the study, by EH region, showing the level of risk from 

flooding and coastal erosion. The final column also shows the level of risk assigned to the sites 

in EH’s Scheduled Monuments at Risk (SM@R) database; those highlighted in blue are sites 

whose primary vulnerability is ‘erosion’ (although ‘erosion’ can include coast, natural, wind or 

visitor). 'CERA' is an abbreviation of Coastal Estate Risk Assessment. 


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Property name 

EH Region 

CERA risk 

level (flood) 

CERA risk 

level (coastal 

erosion) 

SM@R 

risk level 

Berwick Castle North East Low n/a Low 

Berwick Ramparts North East Low Low Medium 

Dunstanburgh Castle North East Low Medium Low 

Lindisfarne Priory North East Low Low Low 

St Paul’s Monastery North East Low n/a Low 

Tynemouth Castle and Priory North East Low Low Low 

Warkworth Castle North East Low n/a Low 

Warkworth Hermitage North East Low/Medium n/a Low 

Scarborough Castle Yorkshire & The Humber n/a Medium Low 

Whitby Abbey Yorkshire & The Humber n/a Low Medium 

Gainsborough Old Hall East Midlands Medium n/a n/a 

Berney Arms Windmill East of England High n/a Low 

Burgh Castle East of England Low n/a Low 

Landguard Fort East of England High Low Medium 

Mistley Towers East of England Low n/a Low 

St Olave's Priory East of England Low n/a Medium 

Tilbury Fort East of England Medium n/a Low 

Calshot Castle South East Medium Low Low 

Deal Castle South East Medium Low Low 

Dover Castle South East Low Low Low 

Dover, Archcliffe Fort South East Low Low Medium 

Dymchurch Martello Tower South East Low Low Low 

Fort Cumberland South East Medium Low Medium 

Hurst Castle South East Medium Medium Low 

Netley Abbey South East Low Low Medium 

Osborne House South East Low/Medium Low/Medium n/a 

Portchester Castle South East Medium Low Low 

Reculver Roman Fort and Reculver 

Towers 

Richborough Roman Fort and 

Amphitheatre 

South East Low High Medium 

South East Low n/a Medium 

Rochester Castle South East Low n/a Medium 

Temple Manor, Strood South East Low n/a Medium 

Upnor Castle South East Medium n/a Low 

Walmer Castle South East Low Low Low 

Yarmouth Castle South East Medium Low Low 

Ballowall Barrow South West n/a Low Low 

Dartmouth Bayards Cove South West Medium Low Low 

Dartmouth Castle South West Low Low Medium 


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Daw's Castle South West n/a High Medium 

IOS - Bant's Carn Burial Chamber South West Low Low Medium 

IOS - Cromwell’s Castle South West Low Medium Medium 

IOS - Garrison Walls South West Low High High 

IOS - Harry’s Walls South West Low n/a Medium 

IOS - Innisidgen Burial Chambers South West Low High Medium 

IOS - King Charles’ Castle South West n/a Low Medium 

IOS - Old Block House South West n/a Low Medium 

IOS - Porth Hellick Down South West Low Low Medium 

Over Bridge South West Medium n/a Medium 

Pendennis Castle South West Low Low Low 

Portland Castle South West Medium Low Low 

St Catherine’s Castle, Fowey South West Low Low Low 

St Mawes Castle South West Low Low Low 

Tintagel Castle South West Low Medium Medium 

Piel Castle North West Medium Medium Medium 

Ravenglass Roman Bath House North West Low Low Low 

4.1 North East 

N 

Alnwick 

NORTH EAST 

Berwick Castle 

Berwick Ramparts 

Lindisfarne Priory 

Newcastle-upon-Tyne 

0 30 60 km 

Dunstanburgh Castle 

Warkworth Castle 

Warkworth Hermitage 

Durham 

Middlesbrough 

Tynemouth Castle 

& Priory 

St Paul’s Monastery 

Figure 2. Location map showing EH historic sites and properties 

in the coastal zone in the North East region. Background 

mapping SRTM data courtesy of the CGIAR Consortium for 

Spatial Information. 

The coastal area of the EH 

North East region stretches 

from Berwick-upon-Tweed to 

Staithes. The general character of 

this stretch of coastline consists 

of long sandy beaches on the 

Northumberland coast, limestone 

cliffs and foreshore along the 

County Durham coast, and rock 

platforms and cliffs cut into the 

Magnesian limestone around South 

Shields and Sunderland. The coast 

of the southern part of the region 

tends to be composed of relatively 

softer rocks. 

Along this coastline, EH has 

responsibility for eight properties 

in the coastal zone. The threat 

level is generally low, with no 

properties at immediate serious 

risk from coastal erosion or 

flooding. However, there is a 

moderate risk of coastal erosion 


16 

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occurring in the next 100 years around Dunstanburgh Castle and the potential for 

flooding to occur in the vicinity of Warkworth Hermitage, which could potentially affect 

access to the site. 

4.2 Yorkshire & The Humber 

The EH Yorkshire and The Humber region covers the coastline from Staithes to 

Cleethorpes, including the Humber Estuary. The region is broadly characterised by 

eroding cliff and beach units north of Flamborough Head, with softer, less resilient 

geology to the south giving rise to salt marshes and sand dunes. Erosion along this 

stretch of coast is a well-documented and wide-spread phenomenon; in places along the 

Yorkshire coast, particularly within the East Riding of Yorkshire, the average rate of loss 

is 1.8m per year, although this does fluctuate greatly over time and between locations 

(Defra 2010a, 34). This is most clearly demonstrated by the cliffs of Holderness where 

there is significant erosion, averaging a loss of 1-3m each year (Halcrow 2002). The 

shoreline to the south of the River Humber is typically more low-lying than elsewhere in 

this region. 

EH has responsibility for two sites within the coastal zone in this region, neither of which 

is at significant risk from coastal erosion or flooding. However, both properties (Whitby 

Abbey and Scarborough Castle) are in areas which have witnessed significant landslips 

and loss of land from local cliffs; some of these events are related to coastal erosion, but 

some are a result of the local geological conditions and groundwater drainage. 

Whitby Abbey 

N 

Northallerton 

Scarborough Castle 

YORKSHIRE & THE HUMBER 

Flamborough 

Head 

York 

Leeds 

Kingston-upon-Hull 

Humber Estuary 

Sheffield 

0 30 60 km 

Figure 3. Location map showing EH historic sites and properties in the coastal zone in 

the Yorkshire & The Humber region. Background mapping SRTM data courtesy of the 

CGIAR Consortium for Spatial Information. 


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4.3 East Midlands 

N 

EAST MIDLANDS 

Leicester 

River Trent 

Nottingham 

Gainsborough Old Hall 

Northampton 

Lincoln 

The 

Wash 

0 30 60 km 

Figure 4. Location map showing the EH portfolio 

in the coastal zone in the East Midlands region. 

Background mapping SRTM data courtesy of the 

CGIAR Consortium for Spatial Information. 

The EH East Midlands region includes 

a length of coastline from Cleethorpes 

to the middle of The Wash, c15km 

north-west of King’s Lynn. Parts of the 

coastline, particularly the Lincolnshire 

coast, consist of relatively soft geology 

and are low-lying. The coast in this region 

also consists of areas of salt marsh and 

estuarine systems, while The Wash 

itself is a marine basin carved out of the 

Jurassic clays of eastern England (Halcrow 

2002). 

The sole EH historic property within the 

study area in this region is Gainsborough 

Old Hall, situated in the vicinity of the 

River Trent. The site is at moderate risk 

of flooding. 

4.4 East of England 

N 

Peterborough 

Cambridge 

LONDON 

The 

Wash 

Tilbury Fort 

Norwich 

EAST OF ENGLAND 

Ipswich 

Mistley Towers 

Thames Estuary 

Berney Arms 

Windmill 

Burgh 

Castle 

Landguard Fort 

St Olave’s 

Priory 

0 30 60 km 

Figure 5. Location map showing EH historic sites and 

properties in the coastal zone in the East of England region. 

Background mapping SRTM data courtesy of the CGIAR 

Consortium for Spatial Information. 

The EH East of England 

region includes the coastline 

from the middle of The Wash 

around the coast of Norfolk 

and Suffolk to the northern 

side of the Thames Estuary. 

This part of the coast is long 

and diverse, consisting of 

sandy/gravelly beaches, cliffs, 

low-lying marshland and sand 

dune units in the north of the 

region (the north Norfolk 

coast), with sand/shingle 

beaches and unconsolidated 

cliff and dune units along 

the eastern coast of Norfolk 

and the Suffolk coast. To 

the south of the region, the 

coast consists primarily of 

eroding cliffs with mud and 

sand flats and a number of 

substantial estuaries. There 

has been extensive land-claim 


18 

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across the region. The eastern coast of Norfolk and the Suffolk coasts are particularly 

susceptible to erosion and to storm surges; the effects of the latter are magnified by the 

soft geology and low-lying coastline. Storm surges along this part of the coast can reach 

heights of 2m in extreme circumstances and surges of c1m in height occur several times 

each year (Halcrow 2002). 

Within the coastal zone of the East of England region there are six properties in the care 

of EH. Four of the properties have a low or medium flood risk and no coastal erosion 

risk (due to their location on estuaries). Berney Arms Windmill and Landguard Fort (see 

Section 5, Case Study 2) are both at high risk of tidal flooding, as the entirety of each 

area of EH responsibility lies within the projected flood zone 3. Despite Landguard’s 

coastal location, the risk from coastal erosion is low, assuming that the present flood 

defences are maintained and continue to function efficiently. 

4.5 South East 

The EH South East region covers the coastline from the south side of the Thames 

Estuary all the way to the Hampshire/Dorset border, just east of Christchurch. The 

coastline has a varied character, with eroding cliffs, mud and sand flats, and estuary units 

along the north Kent coast, and cliffs and shingle beaches, which are generally subject to 

erosion, around the coast in the east of the region; this region includes the highest chalk 

cliffs in Britain at Beachy Head. The southern coast of the region consists of cliffs, beaches 

(some shingle), estuary units and ebb tidal deltas. There are also three natural harbours 

(Chichester, Langstone and Portsmouth). The Isle of Wight is also within the South East 

Upnor Castle 

Temple 

Manor 

Rochester 

Castle 

Thames Estuary 

Maidstone 

SOUTH EAST 

Hastings 

Reculver Roman Fort 

& Towers 

Richborough 

Roman Fort 

Margate 

Dymchurch Martello Tower 

Deal Castle 

Walmer 

Castle 

Dover Castle 

Archcliffe Fort 

0 20 40 km 

Figure 6. Location map showing EH historic sites and 

properties in the coastal zone in the South East region (eastern 

part). Background mapping SRTM data courtesy of the CGIAR 


N 

region and almost all the 

cliff stretches on the island 

are eroding; there have 

been major landslides on 

the southern coast of the 

island (Halcrow 2002). 

There are seventeen 

properties in the care 

of EH within the coastal 

zone of the South East 

region. Just over half of 

these are at low risk from 

flooding, while eight have 

been identified as being 

at moderate risk from 

flooding. A number of 

the sites at risk from tidal 

flooding are located in 

exposed, coastal positions, 

often in a low-lying 

situation, which makes 

them more susceptible to 


19 

68 - 2011

potential flood events. There are also two sites in the region at medium risk of coastal 

erosion and one at high risk. The latter is Reculver Roman Fort and Reculver Towers, 

which has suffered from erosion over many centuries (see Section 5, Case Study 1). 

SOUTH EAST 

N 

Bournemouth 

Hurst Castle 

Calshot Castle 

Southampton 

Netley Abbey 

T h e 

S o l e n t 

Yarmouth Castle 

Portchester Castle 

Fort Cumberland 

Osborne House 

0 20 40 km 

Figure 7. Location map showing EH historic sites and properties 

in the coastal zone in the South East region (western part). 

Background mapping SRTM data courtesy of the CGIAR 


4.6 South West 

With the longest coastline of all the EH regions, the character of the coast around 

the South West region is diverse. The south-eastern part of the region includes Poole 

Harbour, one of the world’s largest natural harbours. The south-western section of 

the coast is predominantly rocky with beaches, cliffs (many of which are eroding) and 

estuaries; the beaches on the south Devon and Cornwall coast tend to be sandy and 

backed with eroding cliffs and headlands. Land’s End and the north Cornwall coast are 

characterised by high cliffs with rocky fringes, detached rocky outcrops and numerous 

indentations, with some sandy beaches. Along the north Devon and Somerset coast, 

there are cliffs, beaches, dunes and mudflats, with some erosion resistant limestone 

headlands. The beaches and dunes are subject to erosion in localised areas (Halcrow 

2002). The significant estuary systems in the region include Plymouth Sound, the Dart 

Estuary, the Fal Estuary and the Camel Estuary. 

With such a long coastline, it is not surprising that the South West region also has the 

largest number of EH historic sites and properties in the coastal zone, a total of eighteen. 

Of these, eight are located on the Isles of Scilly. Across the EH properties in this region, 


20 

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N 

Over Bridge 

Bristol Channel 

Bristol 

SOUTH WEST 

Daw’s Castle 

Tintagel Castle 

Exeter 

Bayard’s 

Newquay 

Cove Fort Portland Castle 

Plymouth 

Ballowall Barrow 

St Catherine’s Dartmouth Castle 

Castle 

Pendennis 

St Mawes Castle 

Castle 

0 30 60 km 

Figure 8. Location map showing EH historic sites and properties in the coastal zone in the 

South West region. Background mapping SRTM data courtesy of the CGIAR Consortium for 

Spatial Information. 

King Charles’ 

Castle 

BRYHER 

Cromwell’s 

Castle 

New Grimsby 

TRESCO 

Old Blockhouse 

Bants Carn Burial Chamber 

& Halangy Down 

Ancient Village 

Harry’s Walls 

ST MARY’S 

ST MARTIN’S 

N 

Innisidgen Burial 

Chambers 

the flood risk level is relatively low; 

eleven sites are assessed as being at low 

flood risk and three at medium flood 

risk. Coastal erosion may affect sixteen 

of the sites in this region within the next 

100 years. Of these sixteen sites, two 

are at medium risk and three at high risk. 

Of the sites at high risk, two are on the 

Isles of Scilly (Innisidgen Burial Chambers 

and Garrison Walls; see Section 5, 

Case Study 3) and one is on the north 

Somerset coast (Daw's Castle; see 

Section 5, Case Study 6). 

Garrison Walls 

0 1 2 km 

Hugh Town 

Porth Hellick Down 

Burial Chamber 

Figure 9. Location map showing EH historic sites and properties in the coastal zone on the 

Isles of Scilly (South West region). © Crown Copyright and database right 2011. All rights 

reserved. Ordnance Survey Licence number 100024900. 


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4.7 North West 

The EH North West region incorporates the coast from the Dee Estuary in the 

south to the Solway Firth in the north, including Morecambe Bay. In general, the coast 

between the Dee Estuary and the Fylde Peninsula consists of a backshore of limestone 

promontories, clay cliffs and a low-lying alluvial plain with former marshland, with a 

foreshore of sand and shingle beaches, and clay cliffs along the Blackpool frontage 

(Halcrow 2002). To the north of this, Morecambe Bay is characterised by extensive 

intertidal flats with salt marsh areas. The northern part of the coast in this region consists 

mainly of shingle and sand beaches backed by soft clay cliff and dunes; this part of the 

coast is susceptible to erosion. 

There are two sites in the care of EH within the coastal zone of the North West region, 

Piel Castle and Ravenglass Roman Bath House. The latter is not at immediate risk from 

either flooding or coastal erosion. Piel Castle is located on an island in the western part 

of Morecambe Bay. This situation puts it at moderate risk from future coastal erosion 

and flooding. There is also evidence of historical erosion of the castle and the southern 

part of the island. Piel Castle was visited as part of the current study; field notes from this 

visit are included in this report as Appendix 2. 

N 

Solway Firth 

Carlisle 

Ravenglass 

Roman Bath 

House 

NORTH WEST 

Piel Castle 

Morecambe 

Bay 

Blackpool 

0 30 60 km 

Liverpool 

Figure 10. Location map showing 

EH historic sites and properties 

in the coastal zone in the North 

West region. Background mapping 

SRTM data courtesy of the CGIAR 



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5. CASE STUDIES 

The following sites were selected as case studies from the fifty-four properties in the 

study sample because of present or projected specific, significant risks. The case studies 

represent desktop studies, augmented in some cases by field visits, which summarise 

the history of the site, the geological nature of its location, previous research, potential 

impacts of flooding and/or erosion, and put forward recommendations, where relevant. 

5.1 Case study 1: Reculver Roman Fort and Reculver Towers 

Flood risk Low Erosion risk High 

NGR TR 228 693 Scheduled Monument 1018784 

NMR no. 

TR 26 NW 1 

TR 26 NW 2 SSSI 

Thanet Coast 

TR 26 NW 72 

EH Estates no. 517 RAMSAR 

Thanet Coast & 

Sandwich Bay 

EH region South East SPA 

Thanet Coast & 

Sandwich Bay 

The site 

Reculver Roman Fort and Reculver Towers are located on a low, sandy cliff on the 

North Kent coast. The archaeological remains on the site include traces of an Iron 

Age farmstead, a temporary Roman military camp, a Saxon Shore Fort, a monastery 

and a medieval church. Much of the site is a Scheduled Ancient Monument (scheduled 

monument no. 1018784, formerly RSM no. 31399). The area in the care of EH is smaller 

than the scheduled area and consists of four contiguous land parcels. The parcel including 

St Mary’s Church was indentured to the state in 1925, the parcel to the south of the 

church was gifted to the state in 1934, the parcel to the east also came into the care 

of the state in 1934 via conveyance and the parcel to the south-east came into state 

guardianship in 1966. The EH area of responsibility around Reculver includes c165m of 

coastline. The EA owns some land parcels nearby, including land which adjoins the area in 

the care of EH at its north-east corner (see Figure 12). The site is adjacent to the Thanet 

Coast SSSI and the Thanet Coast and Sandwich Bay RAMSAR area. 

Coastal erosion has long been an issue at Reculver and attempts have been made for at 

least 200 years to try and stabilise the coastline. Documentary evidence suggests that 

the loss of the north wall of the Roman fort occurred around 1800: ‘The walls on three 

sides are very visible, but the fourth, towards the north, has been very lately, nearly all 

of it, destroyed by the falling of the cliff down on the sea shore, where vast fragments 

of it lie’ (Hasted 1800). Having purchased the towers at Reculver in 1809, in order to 

preserve them as navigation marks, Trinity House initially built groynes around the coast 

to prevent further erosion, supplementing this with a facing of ragstone blocks around 

the cliff in 1866. The coastal defences, which abut the northern side of the area in EH 


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Figure 11. View of Reculver from the east, showing the present defences at the foot of the 

Towers and illustrating the amount of coastline already lost here. Photograph by Abby Hunt. 

care and consist of sea walls, groynes and beach recharge schemes, are owned and 

maintained by the EA. The ragstone apron immediately to the north of St Mary’s Church 

is regularly maintained by EH; observations of this area in the recent Periodic Condition 

Survey Report (Bailey Partnership 2010b) indicate that minor cracking and vegetation 

growth was occurring on the area of sloping masonry, which was addressed by raking out 

and applying mastic pointing. 

Archaeological knowledge and previous research 

A number of documented campaigns of excavation have been undertaken at the site 

from the 1870s, along with two watching briefs (1994 & 2004). Over the past 200 

years, numerous articles on Reculver and finds recovered at the site have appeared in 

The Archaeological Journal, The Journal of Roman Studies, Archaeologia and Archaeologia 

Cantiana, among other journals. The archaeological rescue and research work on the 

Roman shore-fort have been brought together in a monograph published through the 

Kent Archaeological Trust focusing, which also place the site in its broader context (Philp 

2005). 

Field observations of the site were recorded by the Ordnance Survey in 1963 enabling 

the revision of the 25-inch scale map. 

Geology/predicted trends 

The geology around Reculver is predominantly Thanet Sand Formation (consisting of 

sand, silt and clay), with a London Clay Formation (clay and silt) shore platform. With 

limited availability of drifting foreshore sediments affecting the natural coastal process of 

beach replenishment, the potential for erosion is relatively high. Coastal retreat has been 

occurring at this location for centuries, if not millennia; the coastline was possibly as much 

as 3km further north during the Roman period, giving an indication of the scale of retreat 


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Area in the care of EH 

Environment Agency owned area 

Potential area of ‘Managed Realignment’ 

0 250 500 m 

Figure 12. Map showing the extent of EH's area of responsibility at Reculver. The coloured lines 

to the west of the site represent the potential mean erosion rate over the next 20, 50 and 100 

years (from north to south). © Crown Copyright and database right. 2011. All rights reserved. 

Ordnance Survey Licence number 100024900. 

here. The line of ‘sand and mud’ as shown on the Ordnance Survey mapping of the area 

can be seen to have receded landwards by approximately 130m between the present 

map edition and the first edition (Ordnance Survey 1894). Current predictions place 

the future rate of change for the stretch of coast to the north of Reculver Country Park 

(west of the EH property) at something in the region of 15m over the next 50 years and 

a further 15m in the following 50 years, equating to roughly 30m in 100 years. This is an 

approximated figure, assuming a progressive and uniform rate of recession. The cliffs in 

this area are ‘simple cliffs’ (i.e. cliffs which are generally characterised by a steep cliff face, 

narrow foreshore zone and rapid removal of toe debris, with erosion occurring as rock 

falls, topples or slides depositing material directly on to the foreshore), with a maximum 

height of 5m AOD, which are marginally stable where toe protection exists. Futurecoast 

software indicates that future erosion rates, for the Reculver to Minnis Bay area, are in 

the ‘high’ band and that the area will suffer foreshore narrowing. 

Future management of this stretch of coastline, as proposed in the SMP2 document 

for the Isle of Grain to South Foreland, is to ‘Hold The Line’ in the immediate vicinity 

of the site. In practice, this means that a section of sea defence, some 700m in length 

and primarily consisting of boulders, is programmed to be retained and maintained over 

the next 100 years. However, the policies for the adjacent stretches of coast (Reculver 

Country Park to the west and the shellfish hatchery to Plumpudding Island to the east) 


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are ‘No Active Intervention’ and ‘Managed Realignment’ respectively. The potential 

erosion to the west of the EH historic property over the next century could amount to 

17m in the first 50 years, with an additional 16m in 100 years, resulting in a loss of 33m 

of coastal land. Whilst not impacting directly on the area in EH care, this level of erosion 

could affect the Roman road to the west of the fort, alleged to run between Sturry and 

Reculver. To the east of the site, the policy of ‘Managed Realignment’ will potentially 

result in the loss of a section of land up to c250 ha. At present the exact extent of 

the realignment is unknown and the intention is to monitor change as it happens, with 

the construction or upgrading of secondary defences to mitigate the risk of large scale 

flooding. It is envisaged that realignment would be stopped on the seaward side of the 

railway line to the south of Reculver, which joins Whitstable and Margate. Although not 

directly impacting on the area of the monument in the care of EH itself, the loss of land 

will affect the context and landscape setting of the property. Loss of coastline on either 

side of the site would result in it the Roman fort and towers gradually coming to occupy 

a promontory-type location on the coast. 

Whilst the height of the land that the fort and church are built on (generally 10-13m 

AOD) make overtopping of the defences unlikely, the danger is that a breach of the 

defensive wall could lead to rapid erosion of the soft material upon which the site stands. 

With coastal erosion occurring on either side of the site, there is also the possibility that 

the erosion could be focused on the edges of the maintained, hard defences, eventually 

cutting back around behind (to the south) of the monument. 

The EA Flood zone data indicates that the elevated area, upon which the historic 

property stands, would potentially not be at risk of tidal flooding, however, the 

surrounding land would be (flood zone 3 – i.e. a greater than 0.5% annual probability of 

flooding). 

Recommendations 

• The extent and impact of the policy of ‘Managed Realignment’ to the east of Reculver 

Roman Fort and Reculver Towers is not fully known and the shoreline’s response is 

similarly uncertain. The coastline in this area is clearly vulnerable to change and clear 

communication with the agencies monitoring the effect of the realignment will be 

crucial to assess future impacts on the EH historic property at this location. 

• The maintenance of the ragstone apron revetting the cliff upon which the property 

stands, in conjunction with the EA maintaining the broader sea defences along this 

part of the coast, will ensure some degree of protection, but good maintenance is 

essential to safeguard the future of the northern side of the historic property. 

• Monitoring of the coastal side of the site after severe stormy weather could 

potentially highlight any issues at an early stage and allow remedial works to be 

undertaken in order to stem any erosion before significant damage is done. This may 

be of further importance if land to the east of the site is allowed to retreat, thus 

potentially exposing the eastern side of the historic property to increased risk of 

erosion or flooding. 


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• In the event of significant erosion, a programme of inspection of exposed deposits or 

sections to assess the archaeological significance of any finds. Recording of these finds 

(whether drawn, surveyed or excavated) would allow preservation by record and 

incorporation into the archaeological record for the site. 

• A comprehensive desktop study to assess and synthesise existing research and 

accurately locate previous excavations on a map would allow areas which have 

been under-researched or are little understood to identified, allowing a prioritised 

programme of recording and research to be undertaken. A firm understanding of 

the landscape context of the site would also need to be achieved, particularly if 

surrounding areas are to be sacrificed to coastal erosion. 

Figure 13. View from the north-east corner of St Mary's Church at Reculver, looking east; the 

area in the distance is subject to a proposed 'Managed Realignment' policy. Photograph by 

Abby Hunt. 


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5.2 Case study 2: Landguard Fort 

Flood risk High Erosion risk Low 

NGR TM 284 319 Scheduled Monument 1018969 

NMR no. 

TM 23 SE 2 

TM 23 SE 230-3 Listed Building 1030415 

TM 23 SE 268 

EH Estates no. 375 SSSI Landguard Common 

EH region East of England Local Nature Reserves Landguard Common 

Natural Areas 

Suffolk Coast and 

Heaths 

The site 

Landguard Fort is situated at the end of a peninsula to the south-east of Felixstowe, 

Suffolk; there have been defensive fortifications in this location since the mid-16 th century. 

The defensive value of this peninsula lies in its command of the approaches and eastern 

side of Harwich Haven, a natural harbour at the confluence of the rivers Stour and 

Orwell; the channel of the latter would have forced most vessels to pass very close to 

Landguard Point (and thus, the defensive fortification), at the south end of the peninsula. 

A series of forts has been built on the site, starting during the reign of Henry VIII with 

the construction of an earthen fortification reinforced with timber and brushwood in 

1543, which was rebuilt in 1588; the site of this fortification is thought to have been lost 

Figure 14. Landguard Fort with Felixstowe Container Port and the River Orwell in the distance. 

Photograph by Peter Murphy. 


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to coastal erosion (Scheduling Document 2001, ref. AA 41490/1). A second fort was 

built on the site in the 1620s, with an augmentation of the defences begun in 1665. This 

structure was demolished in the early 18 th century, to make way for a replacement. A 

new battery was started in 1717, with rebuilding work undertaken in 1745-50 along with 

some other lesser alterations in the latter half of the 18 th century. Partial remains of the 

17 th -century fort and its moat survive as buried features, to the east of the extant fort, 

under the glacis of the mid-18 th -century fort. A further rebuilding of the fort, to bring it 

up to date and improve its defensibility, was undertaken between 1870-8. The present 

structure principally consists of elements dating to 1745-50 and 1870-8, with parts 

from 1717-20 (Brown et al 2004, 4). The demolition and redevelopment of the forts 

has reflected the changing nature of military engineering and changes in coastal defence 

requirements over a number of centuries. It is this continuity of defences and the survival 

of buried and above-ground remains of a relict military landscape which contribute to the 

outstanding importance of Landguard Fort. 

The site is under pressure from the development of the port of Felixstowe to the north. 

Expansion and development of the docks has already compromised the landscape setting 

of the monument and there are further plans for construction on the peninsula. 


Excavations focusing on the 17 th -century defences at Landguard were commissioned by 

EH and carried out by Suffolk County Council in 2001. The results of the excavations 

have been published in Post-Medieval Archaeology (Meredith et al 2008). 

Landguard Fort was subject to an analytical investigation by the EH Archaeological 

Survey & Investigation Team in 2003. This resulted in two reports, focusing on Right 

Battery and Darell’s Battery (Brown et al 2004; Pattison et al 2005); both elements of the 

fort were extensively photographed and surveyed for the purposes of this work. 

There are in excess of 250 maps, plans and surveys of Landguard Fort held in the EH 

Plans Room (collection ref. PF/LAF); these include annotated maps, excavation drawings, 

maritime charts, measured drawings, measured surveys, rectified photography and sketch 

plans, dating from 1779 to 1999. There is also an album containing 44 photographs of 

Landguard Fort, taken in 1975, in the EH archive (ref. AL0667). 


Landguard Fort is situated on a sand and shingle spit which has, historically, been 

extending in length through natural processes (Halcrow 2002, Local-Scale Shoreline 

Response, Felixstowe Pier to Landguard Point). There is a concrete seawall along this 

stretch of coast as far as the south end of Landguard Common (to the north-east of the 

fort), beyond which there are timber groynes and at the end of the spit is a jetty. The 

jetty, added in 1867 to restrain the movement of the spit, has acted as a terminal groyne 

and has assisted the build-up of the wide shingle beach. From the late 19 th century, there 

has been a slight accretion at Landguard Point, but the changes have been limited due to 

the presence of sea defences. 


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Assuming present management practices are retained and continued (which is the 

preferred policy set out in the SMP2 for this policy unit, sub-cell 3C, MA 20), then the 

presence of the jetty will ensure that the wide beach is maintained at Landguard Point. 

The section of the coast with the seawall, to the north-east of the fort, may see some 

steepening of the foreshore in response to sea level rise. Data from the Futurecoast 

report suggests that in a situation of unconstrained coastal processes, over a period 

of 100 years, there is still likely to be sufficient shingle to maintain a barrier along this 

frontage, with some slight movement, but in general, the area would remain stable 

(Halcrow 2002). 

According to the EA flood risk maps the area in the care of EH is situated within 

flood zones 2 and 3 and is at risk from tidal flooding, with a greater than 0.5% annual 

probability of flooding. Some estimates put the potential sea level rise in this area (the 

East of England) at 1.2m by 2115 (Defra 2006), which could have an impact on the 

monument and increase the possibility of flooding. The moat surrounding the fort, for 

example, is, in places, only 1-2m above current mean low water level. 

Figure 15. Aerial photograph of Landguard Fort with a tile of Lidar data superimposed. The 

Lidar data illustrates the relative height of the land surface - in this case, graduating from blue 

(low-lying land at c0m AOD) to red (land up to c16m AOD). The area in the care of EH is 

shown by the red line; the blue line represents the Mean High Water level. Height data and 

aerial photography licensed to English Heritage for PGA, through Next Perspectives. 


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• Collate the archaeological interpretation and survey plans (including unpublished 

survey data) and ensure that they are included in future management plans for the 

site. At present, the Periodic Condition Survey and Report for the site states that 

‘there does not appear to be any record of any earlier archaeological survey’ of the 

site (Donald Insall Associates 2009, section A7.0), despite several publications, freely 

available, from 2003-5. 

• The Periodic Condition Survey Report for the site notes that the property is 

generally in ‘fair’ condition, but that some of the batteries are in ‘poor’ condition. 

With the increased risk of flooding, any areas of defect which are low-level and could 

potentially be exacerbated by rising water levels should be given increased priority. 


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5.3 Case studies 3a & b: St Mary’s, Isles of Scilly (Garrison Walls & Innisidgen 

Burial Chambers) 

3a. Garrison Walls 


NGR SV 898 103 Scheduled Monument 1018370 

NMR no. SV 81 SE 30 Listed Building 1291751 

EH Estates no. 329 AONB Isles of Scilly AONB 

EH region South West Heritage Coast 

Isles of Scilly Heritage 

Coast 

SAC Isles of Scilly Complex Natural Areas Isles of Scilly 

The site 

The Garrison Walls are the surviving defences around the headland, known as The 

Garrison, at the west of Hugh Town on St Mary’s, the largest of the Scilly Isles. The 

extent of the defences and their scale reflect the strategic importance of the Isles of 

Scilly. The extant remains, which range from earthwork banks and ditches to substantially 

built sections of curtain wall with stone-built batteries, represent phases of fortification 

starting at the end of the 16 th century and stretching through to the Second World War. 

It is the excellent preservation of these coastal fortifications, and their multi-phase, multiperiod 

development, that makes them nationally important. A full history and analysis 

of the development of the Garrison Walls has been presented in a recent publication 

(Bowden and Brodie 2011). 

The entirety of the Garrison Walls is a Scheduled Ancient Monument (scheduled 

monument no. 1018370, formerly RSM 15434), but not all of the scheduled monument is 

in guardianship. The part of the Walls in the care of EH is approximately 2km in length, 

consisting primarily of the stone-built walls and a number of batteries and bastions, and 

incorporates two listed buildings; the monument was placed in guardianship in 1972. 

The part of the defences excluded from the guardianship area is a 400m section of 

breastwork, consisting of earthwork bank and ditch, at the north-west of the headland, 

between Steval Point Battery and King Charles’ Battery. There are a further five 

Figure 16. An example of active 

erosion of the low cliffs just 

below the breastwork to the 

south-west of King Charles' 

Battery. Photograph by Abby 

Hunt. 


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N 

Newman’s 

Platform 

King Charles’ Battery 

Steval Point 

^ 

^ 

^ 

^ 

Lower Benham 

Battery 

The Garrison 

^ 

Upper Broom 

Platform 

^ 

Colonel George 

Boscawen's Battery 

^^ 

^ 

^ 

Lower Broom 

Platform 

^ 

Woolpack 

Point 

0 250 m 

^ 

Morning Point 

Battery 

EH guardianship area 

Active erosion (Sept 2010) 

Figure 17. Map of Garrison Walls showing features and 

places mentioned in the text; active erosion observed in 

September 2010 is also shown. 

scheduled monuments in the centre of the headland which are enclosed by the Garrison 

Walls. The site lies within an area covered by a number of environmental designations 

(see table above). 

All around the headland, the effects of coastal erosion are visible (Figure 16). Storms 

battering the headland have caused undercutting of the cliffs and, in some cases, 

collapse. There are several places where this erosion will potentially have, or is already 

having, an impact on the part of the monument in the care of EH. During the course 

of the 2005 archaeological survey of the site, vulnerable areas of the monument were 

identified. Undercutting of the cliff was observed in the vicinity of King Charles’ Battery, 

along the eastern side of the headland (between Upper Broom Platform and Morning 

Point Battery), between Morning Point Battery and Woolpack Point, around Colonel 

George Boscawen’s Battery and south of Steval Battery (see Figure 17). A site visit for 

the purposes of this current study, in September 2010, confirmed that a number of the 

affected locations identified in 2005 are still actively eroding. Parts of the scheduled 

monument not in EH guardianship (the breastwork to the south-west of King Charles’ 


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Figure 18. Active erosion of the low cliff to the north-west of Woolpack Point. Photograph by 

Abby Hunt. 

Battery) were also observed to be under threat from cliff collapse during the 2010 field 

visit; erosion was recorded in additional locations to those observed during the 2005 

survey, suggesting that it is a recent occurrence. 


There is a rich resource of historic mapping available for the site, which provides 

information about the development of the Garrison Walls and indicates the nature of 

changes in the coastline of the headland. 

An album of 117 photographs of various locations around the Garrison Walls, taken 

between 1948 & 1976, is held in the EH archive (ref. AL0899). These could potentially be 

a useful resource for ascertaining levels of erosion at various locations around the walls. 

There are virtually no records of archaeological excavation on the headland prior to 

2006, with the exception of two watching briefs in 1990 and 1993 (Fletcher 2007, section 

3). Archaeological surveys of the site have been undertaken in 1978, 1991 and 2005. 

A broad range of research work has been done on the Garrison Walls by English 

Heritage, mainly in 2005-6, including archaeological excavation, a photographic survey, 

elements of photogrammetry and archaeological and architectural surveys. Much of this 

work has been brought together in the recent publication Defending Scilly (Bowden and 

Brodie 2011) and various specific site research reports are currently in preparation. A 

preliminary conservation plan for the site was prepared in 2007, outlining the site and the 

threats, issues and summarising previous research (Fletcher 2007). 


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The geology of the western part of St Mary’s is granite bedrock topped with a layer 

of stone and clay, often 1-3m in thick, which is known locally as ‘ram’. The ram is 

unconsolidated and thus susceptible to wave action; erosion of the low cliffs often occurs 

in the form of undercutting, which creates substantial ‘caves’ at their toes, which will 

eventually cause the cliffs to collapse. On top of the ram is often a layer of black earth 

and peat, which can be 0.5-1m deep (visible in Figures 16 and 18). 

The data drawn together for the SMP2 for this part of the Isles of Scilly suggests that the 

predicted coastal erosion around the Garrison headland with the present management 

policy (which is ‘No Active Intervention’) is minimal, in the order of up to 2m in the next 

century. Whilst gradual, regular erosion may be minimal, the main threat to this part 

of the island is the occasional, substantial erosion caused by severe storm events. This 

erosion is clearly less easy to predict and model, but is potentially a greater threat. 

Certain erosion ‘hotspots’ have already been identified through the survey work 

and ongoing maintenance programme. The Periodic Condition Survey and Report 

commissioned in 2009 by the EH Estates Programme Development Team identifies 

the stretch of the wall between King Charles’ Battery and Newman's Platform as being 

vulnerable to erosion, particularly during stormy weather (Van der Steen Hall Architects 

2009). The current recommendation is to negotiate repair and protection of the cliff 

face here. The other areas which are at risk of erosion, as itemised in the 2009 defects 

survey, are mainly on the eastern side of the headland, between Lower Broom Platform 

and Lower Benham Battery. The latter feature has already been repaired, following 

storm damage in 2004 and also in the 1970s. The current management regime clearly 

makes allowance for the identified areas of erosion and monitoring programmes are in 

place for some of these areas (for example, Upper Broom Platform). In other places, 

around Upper and Lower Broom Platforms, the insertion of a boulder barrage has been 

recommended. 


• The existing research and survey work should be collated and made easily accessible, 

as this will provide an excellent baseline for future monitoring work. A programme 

of monitoring, particularly in the aftermath of storm events, would enable rates of 

change and loss of parts of the monument to be accurately ascertained. This would 

allow timely mitigation where possible, or further recording where new information 

was exposed. 

• A GIS, or similar system, should continue to be developed to allow data, research 

and monitoring information to be collated and analysed to inform future management 

of the monument. 

• Areas of protection works should be monitored to ensure that erosion is not shifted 

further along the coast, particularly in the case of ‘hard’ protection. 

• The Estates Team maintenance plan should be compared with archaeological survey 


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information and erosion data to ensure that all the areas at risk from erosion are 

regularly inspected and maintained, where appropriate. 

• The occurrence of cliff undercutting in the vicinity of the EH guardianship monument 

should be mapped and monitored, to allow a pattern of change to be built up and to 

predict areas at risk from future cliff collapse. 

3b. Innisidgen Burial Chambers 


NGR SV 922 127 Scheduled Monument 1013271 

NMR no. SV 91 SW 30 AONB Isles of Scilly AONB 

EH Estates no. 329 Heritage Coast 

Isles of Scilly Heritage 

Coast 

EH region South West Natural Areas Isles of Scilly 

SAC 

Isles of Scilly Complex 

The site 

The Innisidgen Burial Chambers are located on the north-east coast of St Mary’s. 

The monument consists of a pair of entrance graves/chambered tombs, known as 

the upper (or Innisidgen Carn) and lower burial chambers. These are good examples 

of Bronze Age funerary monuments, with capstones and kerbing surviving on both 

monuments; the upper tomb is the better preserved and more complete. Both tombs 

are scheduled ancient monuments (scheduled monument no. 1013271, formerly RSM 

15400), designated along with a prehistoric field system on Innisidgen Hill, and are in the 

guardianship of EH. The area in guardianship only covers the area of the burial chambers 

themselves, not the intervening land. Consequently, two discrete areas, one of 12m by 

10m (lower) and one of 9m by 7m (upper), along with the access to the site, represent 

the extent of EH’s responsibility. The monuments have been in the care of the State 

since 1950 and are located in an area covered by a number of environmental designations 

(see table above). Visitors access the site via a coastal footpath from Halangy Down. 

There are no coastal defences around this part of the island, and so it is susceptible 

to erosion, particularly from the action of the sea during extreme storm events; 

undercutting wave action is one of the main threats to the relatively low, soft cliffs. 

The northern edge of the lower burial cairn is currently situated just 14m from the cliff 

edge. During prehistory the monuments would have been further inland from their 

contemporary coastline, but rising sea levels over the past centuries have altered their 

topographic setting. 


The Innisidgen Burial Chambers have not been formally excavated; infill from the lower 

chamber was removed in 1950, but this was an unrecorded and unauthorised excavation. 


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Figure 19. The lower entrance grave at Innisidgen. Photograph by Abby Hunt. 

A plan of the upper chamber (Innisidgen Carn), with two sections, reproduced from the 

notes and observations of George Bonsor (who visited the Scillonian megalithic sites in 

1899-1901), has been published (Hencken 1933, 18). A further article on the chambered 

tombs on St Mary’s was published in 1963 which includes a basic plan of the lower 

chamber at Innisidgen (referred to as ‘Innisidgen North’ in the article; Ashbee 1963, 12). 

There are plans of the burial chambers held in the EH Plans Room. There are three 

plans of the upper chamber, dating to 1949, 1968 and 1982. These are all very similar, and 

appear to be derivations of the same drawing. 

Other general works on the prehistory and prehistoric burial monuments on the islands 

are available, but there are no other detailed studies of the Innisidgen burial chambers. 


This part of St Mary’s is characterised by its low cliffs (approximately 4m high) with 

rocky foreshore. The cliffs around the Isles of Scilly in general are simple cliffs, standing 

to a height of no more than 10m AOD, consisting of weak superficial deposits on hard 

rock (granite) and susceptible to erosion. There is potential for foreshore narrowing in 

this location, which will increasingly expose the backshore and lead to a greater risk of 

erosion during storm events. Active erosion, in the form of undercutting of the low cliffs, 

can be seen at this location, as well at other points on the coastline of St Mary’s (see 

Figure 20), and is clearly a current issue of concern. 

The data drawn together for the SMP2 for the Isles of Scilly indicate that this part of the 

island will potentially be susceptible to substantial coastal erosion. The indicative rates of 

coastal erosion suggest that in the next 50 years, approximately 12m will be lost from 

the coastline in this area, with a further 23m over the following 50 years, amounting to 

35m lost in total over the next century (see Figure 21). This has serious implications for 

the Innisidgen Burial Chambers, in particular the lower tomb, which would be entirely 

lost in this scenario. Given the location of the monument and the local topography and 


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Figure 20. The coastline below Innisidgen Burial Chambers. The low cliffs are being eroded, 

with wave action undercutting them and creating 'caves', visible along the foot of the cliff. 

Photograph by Abby Hunt. 

geology, there is little that can be done to prevent this loss. The upper tomb, located at 

a higher elevation (c19.5m AOD) and further inland, would not be so severely affected 

by such erosion, although in 100 years it will potentially be less than 20m from the cliff 

edge. These rates give an indication of gradual coastal change over time, but they do not 

allow for individual, severe storm events, which may have dramatic and more immediate 

impacts on the erosion of the coast. Coastal erosion is clearly an active issue in the 

vicinity of this site and while the lower burial chamber itself may not be immediately at 

risk for another 50 years or so, the gradual erosion of the coastline has the potential to 

reveal archaeological deposits associated with the monuments. In addition to the threat 

to the archaeological remains themselves, the predicted coastal erosion will also affect 

access to the site. The coastal path which approaches the lower burial chamber from 

the north-west is also likely to be partially lost to coastal erosion within 50 years, with 

further loss over the subsequent 50 years. There are potential implications for access to 

the site if this path is lost and the rerouting of the access path is perhaps an option which 

needs to be assessed. 

The predicted level of erosion in this area will not only affect the guardianship monument 

and access paths, but will also have a direct impact on two scheduled monuments. The 

first of these is scheduled monument no. 1013271, which includes the burial chambers 

and the associated field system. The potential erosion over the coming 100 years 

could see a loss of 70% of the area of this scheduled monument (c1.3 ha), representing 

important contextual information for the prehistoric monuments. In addition, an adjacent 

scheduled monument (scheduled monument no. 1013272, formerly RSM 15401), 

consisting of a civil war breastwork and two prehistoric hut circles, could be lost in its 

entirety within 50 years, if the erosion predictions are correct. As mentioned previously, 

the rate of predicted loss may not be gradual and could occur much more quickly in the 

event of a number of severe storm events. 


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N 

Mean High Water level 

Area of EH responsibility 

Monument 

Access 

Potenital extent of erosion by: 

2025 

2055 

2105 

0 25 50 100 m 

Figure 21. Orthorectified aerial view of the coastline around Innisidgen Burial Chambers, with 

the potential extent of erosion over the coming century superimposed. The lower tomb is the 

left-hand monument. Image courtesy of Channel Coastal Observatory www.channelcoast.org. 


• The burial chambers and their landscape context should be fully recorded and 

interpreted. Non-intrusive archaeological investigation of the monument and its 

setting would offer a cost-efficient assessment of the area and would allow previous 

research to be validated and augmented. As there is a strong possibility that the 

site may be lost in the coming century, consideration may be given to archaeological 

excavation of parts of the site if it was felt this would further add to the evidence 

base for the monument. If this cannot be accommodated prior to erosion of the 

monument, then plans should be put in place for rescue excavation as and when 

erosion does occur. 


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• Laser scanning of the chambers, in particular the lower tomb which is at greater risk 

of erosion, should be considered. This would provide a highly accurate, 3D record of 

the structure(s) and would also offer a number of future presentation options. 

• Re-routing access paths to the monument should be considered. Whilst the current 

path may be ‘safe’ for 50 years, a particularly severe storm event could accelerate the 

rate of erosion and impact upon the coastal path much sooner. 

• The cliff face should be monitored regularly (and following any severe storm events 

and subsequent collapses or erosion) to ascertain if any archaeological deposits 

are being exposed. This may include artefacts, environmental deposits or sections 

through earthworks. 

Plans (held in EH Plans Room) 

649/8 Annotated plans and sections of Porth Hellick Down, Innisidgen and Bant's Carn 

burial chambers (March 1949) 

649/46 Plans and sections of Porth Hellick Down and Innisidgen burial chambers 

(September 1968) 

469/P7 Location plan and sections of Porth Hellick Down, Innisidgen and Bant’s Carn 

burial chambers (4 March 1982) 

1958 Survey. Sketch floor plan of the lower burial chamber. 1” to 2’ (4 June 1958) 


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5.4 Case study 4: Hurst Castle 

Flood risk Medium Erosion risk Medium (assuming continuation of 

present shoreline management processes) 

NGR SZ 318 897 Scheduled Monument 1015699 

NMR no. 

SZ 38 NW 1 

SZ 38 NW 195 

National Park New Forest 

EH Estates no. 309 SSSI 

Hurst Castle & 

Lymington River Estuary 

EH region South East RAMSAR 

Solent & Southampton 

Water 

SPA 

Solent & 

Southampton Water 

SAC 

Solent Maritime 

The site 

Hurst Castle is a coastal artillery fortress located at the end of a 1¼ mile (2km) long 

shingle spit (Hurst Beach) at the western entrance to the Solent. The core of the 

monument is a Tudor artillery fortress built in the early 1540s, which was subsequently 

altered in the early to mid-19 th century, with two casemated wings added in the 1860s. 

The castle remained in active use until after the Second World War. The area in the care 

of EH covers 21.25 ha (52 acres), incorporating the castle, earthwork elements of the 

castle’s defences, two lighthouses (one of which, Hurst Lighthouse, is a Listed Building, 

no. 1275169), a pier, the quay (currently used by the passenger ferry) and an area of 

mud flats to the north-west of the castle. The site was transferred into the care of the 

State in 1930. The castle itself, including the lighthouse, is a scheduled ancient monument 

(scheduled monument no. 1015699, formerly RSM 26716). The scheduling document 

mentions that the earthworks of a battery, built in 1852, with the footings of barracks at 

the rear, still survive to the west of the West Wing, but are ‘considerably eroded by the 

sea’ (file ref. AA66279/1). 

The castle is accessed by a spur of the Solent Way public footpath and it is managed 

by Hurst Castle Services. The site is situated in an area with a number of ecological/ 

environmental designations. The Hurst castle and Lymington River Estuary SSSI is 

designated as such due to the nationally important breeding populations of terns and 

black-headed gulls, as well as rich invertebrate fauna, an important assemblage of 

brackish water organisms and an especially rich salt marsh fauna community on the spit 

itself. The spit is also noted for coastal geomorphology; it represents a classic shingle spit 

formation (SSSI citation, 2). 

As it is located on a spit, a dynamic and mobile landform, Hurst Castle is at the mercy of 

potentially extreme environmental conditions. It has been noted by the Property Curator 

(National Collections, Curatorial Team) that the castle’s caponier is regularly flooded. It 

was also noted that the shingle on the south and south-west side of the castle can be 

removed by the sea in rough weather, revealing the castle’s foundations (R Porter, pers 

comm). 


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Figure 22. Groynes and sea defences to the south-east of Hurst Castle. Photograph by Abby 

Hunt. 


Hurst Castle has been subject to some research in the past, and features in thematic 

publications, such as The History of the King’s Works. There have also been three editions 

of the guide book to the castle published (Ministry of Works 1949; Coad 1985a, 1990). 

There have been no analytical investigations of the site carried out by the EH Research 

Department teams, with the exception of a wall painting condition audit (ref. 48/1997). 

There are 355 sheets of various types of plan relating to Hurst Castle and the 

surrounding area held in the EH Plans Room; these plans include measured drawings, 

measured surveys, photogrammetric surveys, maritime charts, excavation plans, lists and 

sketches, ranging in date from 1742 to 1998 (collection ref. PF/HUR). In addition, EH also 

holds a Ministry of Works ‘Blue Album’ containing 140 photographic prints of the site, 

dating from the early 1930s (ref. AL0756). 


Hurst Castle is located at the end of a long, shingle spit. Spits are naturally mobile, 

dynamic coastal features and are potentially susceptible to climate change and associated 

sea level changes. Historic mapping demonstrates that the form of the spit at Hurst has 

changed considerably over the last 150 years or so; the first edition 25-inch to the mile 

OS map, dating to 1868 (Ordnance Survey 1868), shows that, at that date, the spit was 


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some 100m further to the south-west than it is on modern mapping. In addition, over 

the past 150 years, there has been accretion, in the order of 60-70m, at the eastern end 

of the spit, to the north-east of the castle, and the formation of a shingle bar across the 

entrance to Keyhaven and Mount Lakes, behind the spit. 

The foreshore along this stretch of coast consists of mud/clay and shingle, with a beach 

ridge forming the backshore. There is likely to be foreshore narrowing in the future; 

historically there has been a relatively high level of foreshore change (in a landward 

direction). Although, with a continuation of the current management regime, there is 

unlikely to be significant change in the shoreline, in an unconstrained scenario, this would 

become change of very high magnitude. 

Presently, the spit is maintained by the New Forest District Council, on behalf 

of Hampshire County Council and EH, through a process of beach recycling and 

replenishment. The policy option for Hurst Spit for the next 100 years, as proposed in 

the SMP2 for this stretch of coastline, is to ‘Hold The Line’. The maintenance of the spit 

is recognised as being essential, as a breach of the feature could result in tidal flooding of 

residential properties in Keyhaven, Lymington and the broader West Solent area (North 

Solent SMP, 264). In addition, the internationally important inter-tidal habitats in the lee 

of the spit, and the castle itself, benefit from the maintenance of the spit. These factors 

make it very likely that central government funding for the maintenance of the spit will be 

ongoing. 

Figure 23. The western end of the west wing of Hurst Castle with fragments of brick ruins in 

the foreground. Photograph by Abby Hunt. 


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• The castle has been subject to numerous recording projects, primarily focussing on 

the structural elements, however the broader landscape context of the castle and 

any outlying features, such as earthwork defences, should also be subject to detailed 

recording. A search of the plans archive, to assess the extent of the pre-existing 

plans/surveys, would be necessary to ensure there was no duplication of work. The 

current Periodic Condition Survey and Report, commissioned by the EH Estates 

Programme Development Team, notes that there are brick ruins to the north-east 

and west of the castle on the beach which are susceptible to sea spray and erosion 

(see Figure 23); the survey’s recommendation is to record and monitor these items 

(item no. 84 asset no. 255, Bailey Partnership 2010). A survey and analysis of the 

setting of the castle and features outside the structure itself would provide a baseline 

for future monitoring and would enhance the understanding of the site’s setting and 

context. 

• The Periodic Condition Survey and Report also identifies a number of issues 

relating to erosion of fabric due to sea/wave action and recommends that these are 

addressed as a matter of importance. In addition, monitoring of exposures of the 

foundations of the castle undertaken in the aftermath of extreme storm events, 

particularly when significant movement of shingle has occurred, would be a sensible 

measure to take. 

References 

SSSI Information (Hurst Castle and Lymington River Estuary) http://www.english-nature. 

org.uk/special/sssi/sssi_details.cfm?sssi_id=1001019, accessed April 2011 


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5.5 Case study 5: Scarborough Castle 

Flood risk n/a Erosion risk Medium 

NGR TA 050 892 Scheduled Monument 1011374 

TA 08 NW 35 

North Bay to South 

NMR no. 

SSSI 

TA 08 NE 4 

Toll House Cliff 

Yorkshire & The 

EH Estates no. 557 EH region 

Humber 

The site 

Scarborough Castle is situated at the east of the town of Scarborough, on a headland 

protruding into the North Sea with steep cliffs to the seaward side. The south-west, 

inland side of the headland is defined by Castle Dikes, a steep natural escarpment. 

Archaeological remains on the headland include the still partially extant medieval castle, 

a Roman signal station, buried evidence of Late Bronze Age/Early Iron Age occupation, 

various structures relating to 18 th and 19 th century military occupation and a Second 

World War direction finding station (Pearson 1999). The area in EH’s care includes the 

castle’s outer bailey area as well as the flanking cliffs, including Castle Cliff and The Holms, 

up to the inland side of Marine Drive. However, only the flat-topped area of the headland 

containing the outer bailey is a Scheduled Ancient Monument (scheduled monument no. 

1011374, formerly RSM 13300). This area was transferred into the care of the State in 

1920. The area incorporating the flanking cliffs is also in the care of EH, but it is leased 

out to Scarborough Borough Council. The EH area of responsibility does not directly 

include coastal land, as Marine Drive skirts the foot of the cliffs. The area in the care of 

EH incorporates parts of the North Bay to South Toll House Cliff SSSI, designated for its 

geological interest. 

Erosion has affected the castle headland in the past, as evidenced by boulder debris at 

the foot of the cliffs and visible scars from cliff slips. Marine Drive, which links the North 

and South Bays, was constructed between 1898 and 1908 (Pearson 2009, 103) and 

has provided an effective coastal defence for the castle headland. The defences were 

enhanced in 2002 with the addition of a rock barrier to further protect the road. Despite 

this protection, there has still been slippage and rock falls along the cliff face. 


In 1998, an analytical archaeological investigation of the site was undertaken by the 

former RCHME (now English Heritage) (Pearson 1999). The entire area of the site in 

the care of EH was surveyed at 1:1000 scale, using a total station theodolite to establish 

a network of control points from which archaeological features were measured and 

drawn, producing a metrically accurate plan. The analytical report also draws together 

and summarises the history of the site and previous archaeological research on the castle 

headland; this includes the discovery of buried drains as far back as 1746, with subsequent 

excavations in 1888, 1907 and 1921-5, the latter being the most extensive and important 

(Pearson 1999, 6-8). Further small-scale watching briefs have occurred since this date, but 


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Figure 24. Scarborough Castle viewed from the north-west across North Bay. The scars of 

former landslips can be seen along the cliff face below the castle. Photograph by Abby Hunt. 

have added little to the record. Since the mid-1980s, geophysical and earthwork surveys 

have been undertaken to augment and enhance the information about the site revealed 

by excavation. 

York University compiled a conservation plan in 1999 which also drew together previous 

research and described the headland’s history (York University 1999). 

Most recently, in 2010, the EH Properties Curatorial Team commissioned a geophysical 

survey of the site to try to further elucidate the unexcavated archaeology on the site, in 

particular, the early occupation of the headland. The survey did identify some anomalies 

which have little or no surface expression and may have some archaeological potential, 

but it was not able to substantially further enhance the understanding of these features 

(Archaeological Services Durham University 2010). 

Despite the series of archaeological investigations on the site, there are still a number 

of questions remaining, especially in relation to the early occupation. Much of the 

uncertainty centres on the edge of the cliff-top area, which is, by its very nature, the 

most difficult area to investigate for health and safety reasons. 

As part of the current management regime, Scarborough Borough Council commissions 

abseil inspections of the headland cliffs at regular intervals, approximately every 4 years. 

It is possible that the photographic evidence gathered during these surveys could be 

assessed for archaeological potential and any exposures of buried features. The most 


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ecent EH Periodic Condition Survey and Report for the site, undertaken in 2008/9, 

identifies a need to regularly monitor the cliff-edge and parts of the curtain wall (Purcell 

Miller Tritton 2009b). It also suggests the use of the photography from the abseil survey 

to allow assessment of parts of the curtain wall for maintenance purposes. The eastern 

end of the curtain wall at the southern end of the site is perhaps most vulnerable to 

damage in the event of cliff slippage and further erosion. 


Scarborough Castle is situated on a headland consisting of bedded sandstone and 

limestone, capped with boulder clay. Futurecoast classifies the cliffs at Castle Hill, 

Scarborough as composite cliffs of jointed weak rock up to a maximum height of 80m 

AOD, which are inactive and have a low sensitivity to climate change and very low 

recession potential – assuming that toe protection is in place. If the protection, i.e. Marine 

Drive, was removed or became ineffective, then the cliff movement would become 

reactivated and there would be substantial debris/falls. However, it is to be assumed that 

Marine Drive, as an element of the local infrastructure will be maintained and kept in 

good repair. In terms of future shoreline movement along this part of the coast, there 

is predicted to be negligible change. However, there is the likelihood of the foreshore 

narrowing, due to low sediment supply as a result of the toe protection works, which 

could result in more frequent overtopping of the defences, particularly during severe 

storm events. This could lead to the possibility of inactive landslips being reactivated. 

Whilst direct, wave-action coastal erosion is largely kept in check by the existence of 

Marine Drive, the headland at Scarborough is susceptible to weather erosion; as the 

effects of climate change become more pronounced and extreme weather events 

become commonplace, the potential for rotational slips will increase. Increasingly stormy 

weather patterns and extremes of temperature will have a potentially disruptive effect 

on the geological bedding here, with the reactivation of landslips. While the degree of 

threat is difficult to predict, regular monitoring (as included in the current EH cyclical 

maintenance programme) will allow appropriate engineering solutions to be developed as 

problems become apparent. 

The EA flood zone data suggests that there is no risk to the castle site from tidal 

flooding, assuming the maintenance and efficacy of the Marine Drive defences. 


• The cliff abseil survey photography should be assessed for archaeological potential 

or exposure of buried archaeological remains/deposits, as well as for maintenance 

purposes. 

• Building fabric should be recorded, where possible, in case elements are lost due to 

cliff falls. The possibility of using remote methods, for example, reflectorless EDM, 

photogrammetry or kite aerial photography, should be investigated. 

• Planned replacement of the cliff-top fence in the next 10-20 years (as recommended 

in the Periodic Condition Survey and Report) may necessitate archaeological 


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investigation of this area. Potential excavation or a watching brief should be written 

into the planned works. 

• The value of acquiring a remote dataset, such as Lidar, for monitoring the cliff-edge 

area should be assessed. It would need to be at suitable resolution (25 or 50cm) to 

show changes to the cliff-top and would be a repeatable monitoring method. Lidar 

may also show subtle features in these areas which are difficult to access. 


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5.6 Case study 6: Daw's Castle 

Flood risk n/a Erosion risk High 

NGR ST 062 432 Scheduled Monument 1020882 

NMR no. 

ST 04 SE 1 

Blue Anchor to 

SSSI 

ST 04 SE 112 

Lilstock Coast 

EH Estates no. 179 Natural Areas 

Vale of Taunton and 

Quantock Fringes 

EH region South West 

The site 

Daw’s Castle is located approximately 1km to the west of Watchet on the North 

Somerset coast. It is located at approximately 75m AOD and occupies a cliff-top location, 

overlooking Warren Bay. The site comprises of the earthwork remains of a fortified 

Saxon stronghold (or ‘burh’) known from documentary and excavated evidence to date 

from the late 9 th century. Research suggests that the earthwork bank originally formed a 

complete circuit, enclosing just over 2 ha (c5 acres) and measuring around 700m in length 

(McAvoy 1986, 57); the northern/north-western section of this defensive work has been 

lost to coastal erosion in the form of earlier cliff collapse. Partial loss of the monument 

has occurred in the past century, as traces of the seaward earthwork defences to the 

western end of the site were depicted on the OS First Edition 25-inch to 1 mile scale 

map dating to 1888. It is difficult to ascertain the full extent of the part of the monument 

which has already been lost. In 2004, it was noted that there was evidence of recent 

coastal erosion at the foot of the cliffs below the monument, possibly caused by coastal 

protection works elsewhere along the coast (Fletcher 2004, 4). 

The site was purchased by EH and taken into the care of the state in 1983, as a response 

to ongoing damage from agricultural activity. The area of EH’s responsibility incorporates 

the cliff-top field, containing the earthwork remains of the monument, down to the High 

Water Mark at the foot of the cliffs; this is an area of approximately 6.8 ha (17 acres). 

The area of EH responsibility excludes the disused limekilns at the east of the site (listed 

building no. 1180302), although the pots and some structural material relating to these 

kilns do fall within this area. 

Due to potential difficulties and danger accessing the site through the main gate to 

the south (off the busy B3191 road), the site does not appear in EH literature and is 

not generally advertised. However, the site lies on the West Somerset coastal path, a 

permissive right of way which is located close to the cliff edge. 


Excavations were undertaken at the site in 1982; these consisted of two trenches across 

the main earthwork bank, one across the south-western half of it and one across the 

south-eastern half of it. In addition three square sondages were cut into the area of 

high ground in the interior, which returned very little evidence. The trenches allowed 


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N 

0 75 150 m 

Figure 25. Orthorectified aerial photograph of Daw's Castle with the 2004 EH archaeological 

survey (showing the surviving earthworks and excavation trench locations) superimposed. The 

red line indicates the extent of the area in the care of EH. Image courtesy of Channel Coastal 

Observatory www.channelcoast.org 

the identification of two distinct phases of the defences, one possibly dating to the later 

9 th century (871-899AD), consisting of a relatively small mortared wall with a c7m-wide 

bank behind it, and another dating to the late 10 th century, consisting of a larger, wider 

mortared wall with a bank to the rear and a berm and ditch in front of it. 

An archaeological survey of the site was undertaken in 2004 by the EH Archaeological 

Survey and Investigation Team and a report on the work is available (Fletcher 2004). 

As part of this survey, a plan of the earthwork remains was made (see Figure 25), 

which provides a metrically accurate plan against which future monitoring work can 

be measured. One of the reasons for undertaking the survey was to record the 

archaeological remains in advance of the moving of the West Somerset coastal path; the 

path now follows the cliff edge, cutting across the earthworks at the western end of the 

site. 


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Figure 26. The cliffs immediately to the east of Daw's Castle; recent slippage visible in the 

photograph illustrate the friable nature of the rock. Photograph by Abby Hunt. 


This stretch of coastline, from Blue Anchor to St Audrie’s Bay, is characterised by 

complex cliffs, standing up to 80m AOD, with a mud/clay foreshore. The cliffs are 

composed of jointed weak rock and are active, with potential for erosion, falls and 

rotational slides (Figure 26). The predominant geology is blue lias and marl with 

limestone and gravel. The geological layers are bedded with bands of various soft rocks, 

including clay, which leave this area particularly prone to slumping. 

Information from Futurecoast (Halcrow 2002) indicates that future erosion rates along 

this stretch of coastline are in the ‘moderate’ band and that the area will suffer foreshore 

narrowing at a rate similar to the observed historic rate. The data also suggest that the 

cliffs have a low rate of recession potential (i.e. annual erosion), in the range of 0.1-0.5m 

per year, while there is a medium rate of recession potential in a single landslide event in 

the range of 10-50m (or a potential area of 0.2-1ha). The latter scenario has a possible 

frequency of 10-100 years. 

The draft SMP2 for this stretch of coast (Hartland Point to Anchor Head SMP2: 

Blue Anchor to Watchet, Policy Unit 7d24) opts for a preferred policy of ‘No Active 

Intervention’ through all three epochs under consideration, i.e. up to 2105. The intention 

is to allow the continuation of natural coastal evolution in this area, enabling geological 

processes which are central to the importance of the Blue Anchor to Lilstock Coast 

SSSI to continue. The SMP2 acknowledges that one of the implications of the policy is 

that there will potentially be loss of parts of the Daw's Castle scheduled monument, and 

thus the area of EH responsibility, although it does highlight that this is dependent on the 

location of future erosion. 


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The Periodic Condition Survey and Report for the site, completed in 2009 for EH, 

recommended an annual inspection of the coastal slope and cliffs to the north of the 

monument (Hughes 2009b). This should enable any cliff slips which may have an impact 

on the monument to be noted and assessed. It should be noted that two of the ‘drainage 

channels’ which are recorded in the Periodic Condition Survey and Report as cutting 

across the crest of the scarp (DC1 and DC6) are in fact not drainage channels, but the 

excavation trenches from 1982, within which the backfill has sunk leaving ‘channels’ across 

the earthwork bank. 


• The results of annual coastal slope and cliff inspections should be clearly 

communicated and any advanced warning of imminent cliff collapse should be 

highlighted. 

• The archaeological survey plan should be used to identify the most ‘at risk’ elements 

of the site and in the event of deterioration of the condition of the site, in particular 

around the area of the cliff edge, the opportunity to further investigate the 

earthwork remains should be taken. 

• In the event of cliff slippage, the acquisition of Lidar imagery would potentially be 

useful to assess the scale of loss at the site and to provide an accurate record of the 

new profile of the cliff. This would need to be at a suitable resolution to serve this 

purpose, i.e. 25cm or 50cm resolution. 


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6. CONCLUSION AND RECOMMENDATIONS 

Given the diversity of properties within the EH portfolio and their various topographical 

and geological settings, there is no single, uniform solution to the risks posed to the 

structures, archaeological remains and historic landscapes by flooding and coastal erosion. 

In some cases, there will not be a solution to the predicted changes and thorough 

recording allied to an acceptance of loss may be the only viable course of action. In other 

cases, the future management of the sites and properties may be shaped to minimise the 

risk to the historic fabric of the sites and the landscape setting of the monuments. 

This study has brought together a number of datasets relating to EH’s coastal estate 

and it is vital to ensure that this information is available to those formulating the future 

management plans for the sites. The information can be fed into the AMP Project, so that 

the Estates Team can identify areas of properties most likely to be affected by flooding 

and/or coastal erosion and maintenance plans can be adjusted to take this into account, 

possibly in terms of prioritizing repairs and ensuring that parts of sites exposed to 

wave action, for example, are kept in a good state of repair. EH’s Integrated Emergency 

Planning (IEP) Department, which sits within the National Safety Team in the National 

Collections Group, maintains a register recording risks to EH properties. The results 

of this assessment will also be supplied to the IEP Team so that information about risk 

from flooding and coastal erosion can usefully be fed into EH’s Emergency Strategy and 

Emergency Response Plan for relevant properties, so that in the event of a severe flood 

or erosion event, there are contingency plans in place. Maintaining good communication 

between the internal stakeholders from the various parts of the organisation and sharing 

information relating to coastal erosion and flooding between groups and departments 

is crucial. Ensuring that there is a high level of awareness of the potential level of risk 

from coastal erosion and flooding at specific sites is an important part of positioning the 

organisation to deal with future eventualities and enabling planning to minimise potential 

negative impact to the coastal estate. 

With the shift in the funding of flood and coastal erosion defence schemes away from 

central government, as outlined by Defra (2010b), it is possible that EH will be invited to 

contribute to future schemes. However, the funding basis for managing nationally-owned 

coastal assets has yet to be determined. This will be an additional consideration in future 

management of sites and properties in EH care and it will be necessary to monitor how 

the funding systems for coastal defences develop. 

Although many properties in the present study are assessed as being at low risk of 

coastal erosion and/or flooding, this does not mean that these threats can be ignored. 

There is still a substantial risk of flooding or erosion, just a relatively lower risk than at 

some other sites. As highlighted in the introduction, the available data allows an analysis 

of risk to sites from predicted flood events, but does not permit a comprehensive 

assessment of potential damage from one-off extreme events, such as storm surges. 

In managing the sites, the potential for these extreme events to occur must be borne 

in mind when planning for the future and contingencies should be put in place, where 

possible. 


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The following general recommendations are suggested in the light of the findings of the 

study, in addition to those outlined for specific sites in the case studies (Section 5) and 

gazetteer (Appendix 1). These are not an indication of commitment to these options, but 

they are areas which should be included in discussions about the future management of 

the EH coastal estate. 

• The EA offer a free service providing flood warnings direct by telephone, mobile 

telephone, email, SMS text message, fax or pager are available to try and provide 

as much warning of one-off flood events as possible (currently accessible via 

https://fwd.environment-agency.gov.uk/app/olr/home). Where EH properties are 

at risk from flooding, whether low or high risk, registering for this service must 

be seen as essential to allow as much warning as possible in the event of an 

unpredicted, one-off flood episode. 

• Where a property in the care of EH has been highlighted as being at risk from 

coastal erosion, the development a future programme of monitoring to maintain 

an understanding of the progression of the process is a key element of managing 

the site going forward. This risk assessment has been completed using currently 

available projections for coastal erosion, but this is liable to revision as further 

research and studies are completed in the future. It is vital that the most up-todate 

coastal erosion risk mapping, and any changes in the impacts this would entail 

for EH properties, is made available to those involved in managing the sites or 

monuments, so that decisions can be made as to the best future course of action. 

• As with flood risk, coastal erosion can also happen in one-off, unpredictable 

events, such as landslips following severe storms. In cases such as this, it would be 

useful to have baseline data against which to quantify land lost through isolated 

events. Potential sources of such information are orthophotography or Lidar; both 

types of imagery are georeferenced and can be used digitally to analyse changes 

between two periods of time. Whilst these are costly to commission specifically, 

data can be obtained from sources such as GeoStore for PGA (utilising data freely 

available through the Pan Governmental Agreement) and the Channel Coastal 

Observatory. However, there is no guarantee that imagery for the required dates, 

or indeed sufficiently up-to-date imagery, would be available, nor that the imagery 

would be of high enough resolution to show the level of detail along coastal 

edges. 

• Where properties have been identified as being at high risk of erosion, but there 

is no financially viable or sustainable way of arresting this problem, it is crucial 

to ensure that the sites have been fully understood, analysed and recorded, so 

that any future losses can be recreated from records. This may take the form of 

excavation, archaeological survey, remote sensing or a combination of methods, 

but the programmes need to be agreed and put in place, so that recording is 

undertaken before any losses occur. This need is particularly acute at sites where 

losses may happen in sudden, one-off events, such as landslips or storm surges, 

which cannot be predicted with any certainty. 


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• Information about high-level coastal management policy for sections of coastline 

incorporating sites and properties in the care of EH, as well as the policy for 

adjacent areas, should be taken into consideration when looking at future 

management. Whilst historic monuments may be protected by a ‘Hold The 

Line’ policy, neighbouring policy units may not fall under the same preferred 

management option. In the case of Reculver Roman Fort and Reculver Towers, 

as explained in Case Study 1 (section 5.1), the adjacent land to the east is 

subject to a policy of ‘Managed Realignment’, the eventual full extent of which is 

acknowledged as being unknown, but will be monitored as it occurs. In this case, 

liaison with the relevant agencies to ensure information about predicted changes 

adjacent to the site will be crucial to ensure any potential impacts are flagged up 

in good time to allow mitigation measures to be put in place, if appropriate. 

• EH site staff and other EH staff visiting unstaffed sites on a regular basis will be 

well-placed to report on one-off events, such as landslides, rock falls and erosion 

episodes in the aftermath of storm surges. These observations, which are not part 

of a regular inspection or maintenance regime, need to be collated, added to the 

information about the site and made centrally available, enabling the highlighting of 

any issues as they occur and the escalation of problems as soon as possible. 

It is clear that future projections of sea level rise and flooding events are going to pose 

increasing threats to many historic assets in the coastal zone. The current study has 

shown that using presently available datasets for projected flood and erosion risks and 

comparing them with a sample historic asset group, in this case the EH coastal estate, it 

is possible to assess levels of risk. Ongoing management of the threats posed by climatic 

change to the EH coastal estate will require regular consultation of the most up-todate 

projections available, to ensure that alterations in potential impacts of flooding or 

erosion are fully understood and the organisational response is aligned to the revised 

information. By utilising a GIS to collate, manage and analyse the data, it is straightforward 

to run queries on the dataset and will allow future, revised datasets to be loaded into the 

GIS and queries to be repeated to ascertain levels of change. The methodology is easily 

adaptable and it is proposed that it could be rolled out to larger groups of historic assets, 

possibly on a regional or thematic basis. 

The Coastal Estate Risk Assessment has brought together a diverse range of sites and 

properties in the care of EH and has highlighted and quantified, using the best currently 

available data, potential flood and erosion issues facing the sites in the future. It is hoped 

that by raising awareness of the threats to the properties from flooding and coastal 

erosion, measures can be put in place to minimise future negative impacts on the national 

collection of monuments in the care of EH. 


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7. BIBLIOGRAPHY 

Ainsworth, S, Bowden, M, McOmish, D and Pearson, T 2007 Understanding the 

Archaeology of Landscapes: A guide to good recording practice. Swindon: English Heritage 

Archaeological Services Durham University 2010 Scarborough Castle, Scarborough, North 

Yorkshire. Geophysical surveys, report 2378. Durham University 

Ashbee, P 1963 ‘The Chambered Tombs on St Mary’s, Isles of Scilly’ in Cornish 

Archaeology, 2, 9-18 

Bailey Partnership 2010a Hurst Castle: Periodic Condition Survey Report. Report number: 

309/2008 

Bailey Partnership 2010b Reculver Towers and Roman Fort: Periodic Condition Survey Report. 

Report number: 517/2008 

Bowden, M and Brodie, A 2011 Defending Scilly. Swindon: English Heritage 

Brown, M, Barrett, N and Pattison, P 2004 Landguard Fort report no.3: Right Battery, 

Felixstowe, Suffolk. Archaeological Investigation Report Series AI/22/2004. Swindon: 

English Heritage 

Campbell, A (ed) 2004 Heritage Unlocked: Guide to free sites in Cornwall and the Isles of 

Scilly. London: English Heritage 

Coad, J 1985a Hurst Castle, Hampshire Guidebook. London: English Heritage 

Coad, J 1985b ‘Hurst Castle: the evolution of a Tudor fortress 1790-1945’ in Post Med 

Arch. 63-104 

Coad, J 1990 Hurst Castle: Hampshire. London: English Heritage 

Colvin, H M et al 1982 The History of the King’s Works, Volume 4: 1485-1660 (Part 2). 

London: HMSO. 539-44 

Curwen, J F 1910 ‘Piel Castle, Lancashire’ Trans Cumberland Westmorland Antiq Archaeol 

Soc 10, 271-87 

DEFRA 2006 Flood and Coastal Defence Appraisal Guidance FCDPAG3 Economic Appraisal. 

Supplementary Note to Operating Authorities – Climate Change Impacts http://archive.Defra. 

gov.uk/environment/flooding/documents/policy/guidance/fcdpag/fcd3climate.pdf, accessed 

22nd June 2011 

DEFRA 2010a Adapting to Coastal Change: Developing a Policy Framework. http://archive. 

Defra.gov.uk/environment/flooding/documents/manage/coastalchange-policyframework. 

pdf, accessed 14th June 2011 


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DEFRA 2010b Future funding for flood and coastal erosion risk management. http://archive. 

Defra.gov.uk/environment/flooding/funding/documents/flood-coastal-resilience-policystatement.pdf, 

accessed 7th June 2011 

DEFRA/Environment Agency 2011 Understanding the risks, empowering communities, 

building resilience: the national flood and coastal erosion risk management strategy for 

England. London: TSO 

Donald Insall Associates 2009 Landguard Fort: Periodic Condition Survey Report. Report 

number: 375/2008 

English Heritage 2008 Climate Change and the Historic Environment. Swindon: English 

Heritage 

English Heritage 2010 English Heritage Information Pack 2010. London: English Heritage 

English Heritage 2011 The National Heritage Protection Plan. Version 1. http://www.englishheritage.org.uk/professional/protection/national-heritage-protection-plan/plan/, 

accessed 

7th June 2011 

Environment Agency 2006 Understanding flood risk: Using our Flood Map. Bristol: 

Environment Agency 

Environment Agency 2010a Asset maintenance policy protocol for sea defences (for England 

only). Bristol: Environment Agency 

Environment Agency 2010b National flood and coastal erosion risk management strategy: 

Strategic environmental assessment report. Consultation Document. Bristol: Environment 

Agency 

Fletcher, M 2004 Daw’s Castle, Somerset. An archaeological survey. Swindon: English 

Heritage 

Fletcher, M 2007 Conservation Plan for St Mary’s Garrison, St Mary’s, Isles of Scilly. English 

Heritage: Unpublished report 

Halcrow 2002 Futurecoast. CD-ROM, project code FD2002, produced for Defra 

Halcrow 2004 National Trust. Coastal Risk Assessment. Phase One Report. October 2004. 

Report prepared for the National Trust 

Hasted, E 1800 ‘Parishes: Reculver’ in The History and Topographical Survey of the County 

of Kent: Volume 9, 109-25. [via British History Online] http://www.british-history.ac.uk/ 

report.aspx?compid=63544, accessed 4 May 2011 

Hencken, H O’N 1933 ‘Notes on the Megalithic Monuments in the Isles of Scilly’ in 

Antiquaries Journal, XIII, 13-29 


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Hughes, P 2009a Bayards Cove Fort: Periodic Condition Survey Report. Report number: 

180/2009 

Hughes, P 2009b Daws Castle: Periodic Condition Survey Report. Report number: 179/2009 

Linzey, R 2003 ‘Landguard Fort and Batteries: Conservation and Management’ in 

Conservation Bulletin 44, 15-17. 

MacInnes, R 2008 Coastal Risk Management - A Non-Technical Guide. SCOPAC 

McAvoy, F 1986 ‘Excavations at Daw’s Castle, Watchet, 1982’ in Proceedings of the 

Somerset Archaeological and Natural History Society 130, 47-61 

Meredith, J, Anderson, S, Egan, G, Higgins, D and Pattison, P 2008 ‘Excavation 

at Landguard Fort: an investigation of the 17th-century defences’ in Post-Medieval 

Archaeology 42 (2), 229-275 

Ministry of Works 1949 Hurst Castle Guide. London: HMSO 

Natural England 2007 Improving coastal access: Our advice to Government 

http://www.naturalengland.org.uk/ourwork/enjoying/places/coastalaccess/ 

improvingcoastalaccessreport.aspx, accessed 7th June 2011 

Newman, R 1987 ‘Excavations and survey at Piel Castle, near Barrow-in-Furness, 

Cumbria’ in Trans Cumberland Westmorland Antiq Archaeol Soc 87, 101-16 

Newman, R 1996 ‘Further structural analysis at Piel Castle,1987-94’ in Trans Cumberland 

Westmorland Antiq Archaeol Soc 96, 121-37 

North Solent Shoreline Management Plan (December 2010) www.northsolentsmp.co.uk , 

accessed April 2011 

Ordnance Survey 1868 County Series 25-Inch to the mile map. Hampshire, sheets 88.14 and 

93.2 

Ordnance Survey 1888 County Series 25-Inch to the mile map. Somerset, sheet 36.13 

Ordnance Survey 1894 County Series 25-Inch to the mile map. Kent, sheets 24.6 and 24.7 

Pattison, P, Williams, A and Barker, L 2005 Landguard Fort report no.4: Darell’s Battery, 

Felixstowe, Suffolk. Archaeological Investigation Report Series AI/8/2005. Swindon: English 

Heritage 

Pearson, T 1999 Scarborough Castle, North Yorkshire. Archaeological Investigation Report 

Series AI/11/1999 Swindon: English Heritage. 

Pearson, T 2009 Scarborough: A History. Chichester: Phillimore 


58 

68 - 2011

Philp, B 2005 The Excavation of the Roman Fort at Reculver, Kent. Dover: Kent 

Archaeological Rescue Unit 

Pitt, Sir M 2008 Learning lessons from the 2007 floods, independent review by Sir Michael 

Pitt. London: The Cabinet Office 

Purcell Miller Tritton 2009a Piel Castle: Periodic Condition Survey Report. Report number: 

489/2008 

Purcell Miller Tritton 2009b Scarborough Castle: Periodic Condition Survey Report. Report 

number: 557/2008 

Scheduling Document 2001 Landguard Fort and Associated Field Works, RSM 21407, File 

ref. AA 41490/1 

UKCP09 2009 Online Marine & coastal projections report. http://ukclimateprojections. 

Defra.gov.uk/content/view/825/500/, accessed 27th June 2011 

UKCIP 2011 UKCIP Climate Digest: April 2011. http://www.ukcip.org.uk/climate-digest/cdapril-2011/, 

accessed 12th May 2011 

Van der Steen Hall Architects 2009 Garrison Walls IOS: Periodic Condition Survey Report. 

Report number: 329-03/2009 

York University 1999 A management and conservation plan for Scarborough Castle. York 

University: Unpublished report 


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APPENDIX 1: GAZETTEER OF EH COASTAL PROPERTIES INCLUDED 

IN THE STUDY 

North-East Region 

Berwick Castle 

Flood risk Low Erosion risk n/a 

NGR NT 993 534 Listed Building 1290213 

Scheduled Monument 1015520 

N 

Figure 27. Map showing the area of Berwick 

Castle in the care of EH (shaded pink) with the 

possible extent of the EA flood zones 2 and 3 (in 

blue). © Crown Copyright and database right 2011. All 

rights reserved. Ordnance Survey licence no. 100024900. 

Berwick Castle formed part of the 

defences of the town of Berwick-upon- 

Tweed and, in part, dates back to the 

12th century. The surviving remains in 

EH guardianship relate mainly to the 

late 13th century remodelling of the 

earlier castle and the early/mid-16th 

century; they are an integral part of the 

internationally significant town defences. 

Water Tower and White Wall extend 

beyond the 5m contour and form part 

of the Mean High Water line. It is these 

sections of the castle remains which 

are potentially at risk from flooding; 

the south-western 20m of the wall and 

tower are within the EA’s predicted 

flood zone 2 (tidal flood risk with an 

annual probability of 0.1-0.5%; see 

Figure 27). 

Recommendation 

• Monitoring of areas of property at risk from flooding, particularly in the aftermath of 

storm surges/flood events. 

Berwick Ramparts 

Flood risk Low Erosion risk Low 

NGR NU 003 530 Listed Building - 


Forming part of the defences of the town of Berwick-upon-Tweed, the ramparts which 

survive today were constructed in the 16th century. The ramparts in guardianship cover 


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approximately 9ha, but only a small proportion of the monument is located close to the 

edge of the River Tweed estuary. As a result, the risk to the monument from flooding is 

minimal. The EA’s projected flood zone 2 overlaps with a small part of the monument to 

the north of the old Berwick Bridge and Fisher’s Fort and Four Gun Battery. 

Dunstanburgh Castle 

Flood risk Low Erosion risk Medium 

NGR NU 257 219 Listed Building 1153477 


Figure 28. Dunstanburgh Castle from the south. Photograph by Al Oswald. 

Dunstanburgh Castle, built in the 14th century, occupies a coastal headland 

approximately 2km to the north of the village of Craster. The rocky headland is at the 

northern point of the Great Whin Sill, a geological formation consisting of igneous 

quartz-dolerite black basalt. This hard rock formation is generally resistant to erosion, 

but there are defiles at points along the Sill, occasionally allowing water through the 

cliff-line; this is often witnessed to the west of the castle, beyond the boundary of the 

EH guardianship area. The area of the guardianship property includes c570m of coastal 

frontage and the SMP2 for Northumberland suggests a general figure of 2m of shoreline 

lost to coastal erosion over the next 100 years, with a potential sea level rise of 0.8m, 

although these are only indicative figures. However, digital data used to compile the 

SMP2 erosion risk mapping indicates that around the castle headland, erosion could be 

up to 12m in the next 100 years. In this scenario, much of the eastern curtain wall of the 

castle and the northern end of the western curtain wall would potentially be at risk of 

collapse. 


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A detailed archaeological survey of the castle and its surrounding landscape, using 

differential survey-grade GPS, was undertaken in 2003-4 by the EH Archaeological 

Survey & Investigation Team. The survey provides a metrically accurate plot (c2- 

4cm accuracy) of the castle and associated shoreline, suitable as a baseline for future 

monitoring. 

Lindisfarne Priory 




Although there was an early monastic foundation on Lindisfarne, no visible remains of 

this now survive; what is visible today dates to the re-foundation of the monastery, a 

Benedictine house, in the early 12th century. The EH guardianship area, which has been 

in the care of the State since 1913, incorporates the church and claustral buildings of the 

12th century foundation and is located at the south-west of the eastern part of Holy 

Island. The southern part of the guardianship area, which is adjacent to the coastline, 

stands at approximately 8m AOD (Above Ordnance Datum). The SMP2 indicates that 

it lies within a policy unit (4.8) which is assigned a policy of ‘Hold The Line’. As a result 

of this policy, there is potentially no significant risk from coastal erosion at this location. 

The issue for the site is the access road from the mainland, which currently becomes 

submerged at high tide, thus limiting access to the island. With a potential net sea level 

rise of 0.99m in the north-east of England (DEFRA 2006, 3), the causeway, which is at an 

average of 2m AOD, could be further restricted. The responsibility for the maintenance 

of this lies elsewhere and as an element of essential infrastructure, it must be assumed 

that it will be maintained into the long-term. 

St Paul’s Monastery 


NGR NZ 339 652 Listed Building 1025198 


St Paul’s Monastery, located close to the edge of the River Don, some 700m south of 

the River Tyne, originated as an Anglo-Saxon foundation of the late 7th century. The 

extant ruins, which are presently in the guardianship of EH, consist primarily of parts 

of the 12th century Benedictine priory adjacent to the south side of the parish church. 

The guardianship area covers approximately 0.34ha. The site stands above 5m AOD 

and is outwith the EA’s predicted Flood zones 2 and 3 (tidal flood risk), thus placing it at 

minimal risk of flooding. Its estuary location removes it from the threat of coastal erosion. 


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Tynemouth Castle and Priory 


NGR NZ 373 694 Listed Building - 


Tynemouth Castle and Priory, situated on a headland to the north of the mouth of the 

River Tyne, contains evidence of human activity from the Iron Age through to the 20th 

century. Extant remains include 13th-century elements of a Benedictine monastery 

founded on the site in the late 11th century, Napoleonic defences and 20th-century gun 

emplacements. The EH guardianship area covers 6.96ha and the site stands at 30m 

AOD, with the guardianship area extending to Mean High Water mark at the northern 

side. The SMP2 coastal erosion data suggests that the preferred policy (‘Hold The Line’) 

for this section of coastline (Policy Unit 26.7) provides some level of protection against 

significant erosion at the site. Estimates of loss to erosion are in the region of 1m over 

100 years at the north of the guardianship area and up to 5m in the same period at the 

east of the site. Slightly greater erosion (up to 15m) may occur at Prior’s Haven, the bay 

to the south of the site, however, the guardianship area should be protected from any 

significant effect, as the access road on to North Pier lies between the site and the area 

of possible erosion. The EA flood zone data suggests that the northern and southern 

edges of the guardianship area are potentially at risk from tidal flooding; this would not 

impact on the structural remains, as they are at the top of the cliff, but there is possibly 

a risk of the cliffs being undercut, thus causing landslips or cliff falls. The cliffs around the 

guardianship site are currently subject to regular stability assessments, which identify any 

risk of cliff collapse and advise remedial works. 


• Visual inspection for evidence of exposed archaeological deposits in cliff-face sections, 

particularly in the aftermath of storms or cliff collapse. 

Warkworth Castle 




Warkworth Castle is a fine example of an aristocratic fortified residence, set on the 

eastern bank of the River Coquet. The surviving remains date in part to the 12th century, 

with many subsequent alterations, rebuilds and restoration up to the mid-19th century. 

The EH guardianship area covers 2.8ha and within that area the castle keep stands 

at around 25m AOD, while the western edge of the guardianship area is adjacent to 

the river at less than 5m AOD. The majority of the site is outwith the EA’s indicative 

flood zones, but a band at the western side of the site could potentially be affected by 


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tidal flooding (encroaching some 15m onto the guardianship site) and fluvial flooding 

(encroaching some 10m onto the guardianship site); the latter is indicated by flood zone 

3, which represents an annual probability of flooding of greater than 1%, or a 1 in 100 

year event. The possible effects of such flooding may be to undercut the river bank, 

which is steep on the western side of the guardianship area, thus affecting elements of 

the castle bailey in this part of the site. A more detailed desktop exercise should indicate 

the scope of archaeological potential affected by this scenario in this area of the site. 


• Ascertain the likely presence and nature of archaeological remains in the area which 

might potentially be affected by flooding. In the case of a severe flooding event, 

monitor any impact on the western side of the bailey, in particular observing and 

recording any features exposed by erosion. 

Warkworth Hermitage 

Flood risk 

Low (historic fabric); 

Medium (access) 

Erosion risk 

n/a 



Warkworth Hermitage dates from around 1400 and was the chantry chapel associated 

with Warkworth Castle; it was abandoned after the mid-16th century. The monument 

consists of a chapel, sacristy and the hermit/priest’s lodgings, created by cutting chambers 

into the sandstone cliff. The Hermitage itself stands at around 5m AOD, while the 

landing stage and path, giving access to the monument, lie between 0-5m AOD. The site 

lies on the northern bank of the River Coquet, so it is not susceptible to coastal erosion. 

However, the EA’s indicative flood zone data suggests that tidal flooding (both flood 

zones 2 and 3) could potentially encroach upon the landing stage and access path. The 

site has recently been affected by flooding (although this was caused by heavy rainfall) 

and it is clear that this has the potential to be an issue in the future, particularly in relation 

to tidal flooding. 


• Ensure that access to the site is not compromised in the aftermath of a flooding 

event. 

Yorkshire and the Humber Region 

Scarborough Castle 

See Section 5.5, Case Study 5 


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Whitby Abbey 

Flood risk n/a Erosion risk Low 

NGR NZ 903 112 Listed Building 1316347 

Scheduled Monument 1017941 Park & Garden 1001467 

Whitby Abbey is a Benedictine monastery, with its origins in the 11th century, although 

the medieval structure stands directly on the site of a 7th century religious house. The 

abbey stands on a headland overlooking the town of Whitby. The guardianship area is 

smaller than the area of the scheduled ancient monument and does not extend north 

beyond Abbey Lane; it is thus set back some distance from the cliff edge. East Cliff, the 

area to the north of the abbey, is susceptible to erosion and cliff slips have occurred 

here in the recent past. With the present management regime, SMP2 data suggests that 

there may be as much as 70m of cliff lost over the next 100 years. This will not impact 

directly on the guardianship area but will potentially impact on the broader landscape 

setting of the abbey. A programme of excavation, geophysics and photogrammetry (part 

of the Whitby Abbey Headland Project) has been undertaken in the area to the north 

and north-east of the abbey precisely to address these losses, so a substantial quantity of 

preservation by record has already taken place. 

East Midlands Region 

Gainsborough Old Hall 

Flood risk Medium Erosion risk n/a 

NGR SK 813 900 Listed Building 1359773 

Scheduled Monument - 

Gainsborough Old Hall is a 15th-century timber-framed house which has served many 

functions in its history, including a linen factory, a theatre, a ballroom and an auction 

house. It is currently used as a museum and offices by Lincolnshire County Council, 

who administer the building on behalf of EH. The hall is situated just below 10m AOD 

in the east of the town of Gainsborough; it is located around 140m from the eastern 

bank of the River Trent. The EA flood risk mapping indicates that the hall is within an 

area potentially affected by tidal flooding in flood zones 2 and 3 (the latter indicating an 

annual probability of flooding greater than 1%, or 1 in 100; see Figure 29). Given that the 

property is situated within the conurbation of Gainsborough, the responsibility for wider 

flood defences in this area does not fall to EH; the EA maps show that there are flood 

defences in place along the banks of the Trent, in the vicinity of the hall, which would 

potentially reduce the likelihood of a significant flood event. 


• Ensure that a disaster management plan is in existence for the property to cover the 

eventuality of a flood. 


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N 

Figure 29. Map showing the EH 

guardianship area around Gainsborough 

Old Hall (shaded pink) with the extent of 

EA flood zones 2 and 3 (shaded blue). The 

blue line along the river indicates EA flood 

defences. 

© Crown Copyright and database right 2011. 

All rights reserved. Ordnance Survey licence no. 

100024900. 

East of England Region 

Berney Arms Windmill 

Flood risk High Erosion risk n/a 

NGR TG 465 050 Listed Building - 


Berney Arms Windmill was built in 1865, initially to grind material in the cement making 

process and subsequently, after conversion in 1883, it was used in the process of 

draining surrounding marshland. The mill remained in use until 1951. The mill is low-lying, 

occupying a position at approximately 0m AOD on the western bank of Berney Arms 

Reach, and as a result the whole of the guardianship area is susceptible to tidal flooding, 

in both flood zones 2 and 3. There are flood defences in the river bank, consisting of a 

steel sheet pile wall with earth backfill behind, installed by the EA in the late 1990s; these 

defences block the mill’s tidal sluice gate, but also seal the scoopwheel chamber against 

tidal intrusion. 

Burgh Castle 


NGR TG 475 047 Listed Building 1372902 


Burgh Castle is a Roman, late 3rd century ‘Saxon Shore’ fort (Gariannonum Roman Fort), 

situated on the eastern bank of the River Waveney, adjacent to Glebe Marshes. In the 

11th-12th century a Norman motte & bailey castle was built within the fort; by this date, 

the west wall of the fort had already partially, or completely, collapsed. The guardianship 

area only incorporates the remaining walls of the fort and not the fort interior. The 

EA flood zone data indicates that the EH guardianship area lies just outside flood zone 


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2 (tidal), and is therefore not at immediate risk of flooding. However, the site is also 

designated as a Scheduled Ancient Monument, which encompasses a much broader area 

than the guardianship site. Flood zone 2 overlaps with the fringes of the western side of 

the scheduled monument, which may need to be a consideration in future management 

of the site. 

Landguard Fort 


Mistley Towers 


NGR TM 116 320 Listed Building 1240390 

1261061 


Mistley Towers are all that remains of the parish church built by Robert Adam in 1735. 

The majority of the church was demolished c1870, leaving just the two towers standing. 

The EH area of responsibility includes the towers and a curtilage around them; the 

guardianship area totals just under 1900m 2 . The property stands at approximately 5m 

AOD and is just over 100m from the bank of the River Stour. The EA flood risk maps 

show that the property lies outwith the predicted flood risk zones. The situation of the 

property negates the risk of coastal erosion in the next 100 years. 

St Olave's Priory 


NGR TM 459 995 Listed Building 1172374 


St Olave's Priory, a 13th-century Augustinian priory incorporated into a post-Dissolution 

mansion, stands at approximately 3m AOD, some 140m to the east of the River 

Waveney. EA flood risk mapping shows that the property is not within the predicted 

flood zones, thus indicating that there is a very low probability of fluvial or tidal flooding 

reaching the guardianship area. The situation of the property negates the risk of coastal 

erosion in the next 100 years. 

Tilbury Fort 


NGR TQ 651 753 Listed Building 1375568 



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The existing Tilbury Fort, located on the northern bank of the River Thames, was built 

in 1670, replacing an earlier, Henrician artillery blockhouse. The fort served as a defence 

of the approach to London and the strategically important dockyards at Woolwich and 

Deptford and was reused in the First and Second World Wars. The fort is substantially 

unaltered and has been in the care of the State since 1948. The EA flood risk maps 

show that Tilbury Fort sits within flood zones 2 and 3, which places the whole of the 

EH guardianship area at risk from tidal flooding. However, the EA data also indicates that 

the site is located in an area identified as benefitting from flood defences during a major 

flood. The existence of the defences is expected to reduce the frequency of flooding 

in these areas (Environment Agency 2006, 4); for this reason, the risk level has been 

reduced to medium, rather than high. 

South-East Region 

Archcliffe Fort, Dover 


NGR TR 315 403 Listed Building - 


Archcliffe Fort has its origins in the 16th century as a Henrician fort, but the surviving 

remains are primarily of a 17th-century bastion trace fortification, with 19th-century 

modifications. The location of a railway to the seaward side of the fort, constructed in 

1928, offers the site a good degree of defence from the sea. The fort is located at just 

over 15m AOD and is not at risk of flood, based on the EA projected flood zones. 

Calshot Castle 

Flood risk Medium Erosion risk Low 

NGR SU 489 025 Listed Building 1302351 


Calshot Castle is a Henrician artillery castle, built in 1539-40. It consists of a central tower 

surrounded by a concentric curtain wall and a moat. It was used for various military, 

defensive functions up until the Second World War, and thereafter as a sea plane base, 

until 1961. The castle is positioned at the end of a spit at the entrance to Southampton 

Water. EA flood zone data indicates that there is a risk of flooding at the site, both from 

flood zone 2 and 3 events, the latter indicating an annual probability of flooding from the 

sea of 0.5% or greater. The impact of flooding on the monument would clearly depend 

on the flood level reached, and it may be access to the site which is more at risk. The 

Periodic Condition Survey Report notes that pointing in the stone apron on the seaward 

side is being eroded by wave action; in the event of flooding this may be exacerbated and 


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deteriorate more quickly. Data collated for the SMP2 for this area suggests that with the 

continuation of the present management regime, Calshot Castle is unlikely to be affected 

by coastal erosion. 

Figure 30. Calshot Castle. Photograph by Peter Murphy. 

Deal Castle 




Deal Castle is a relatively unaltered Henrician artillery castle, dating from 1539-40. It 

formed parted of a broader defence scheme along this stretch of coast, and indeed 

Figure 31. View from Deal Castle curtain wall to the south-east showing the proximity of the 

broad shingle beach. Photograph by Abby Hunt 


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nationwide, from this period, which also included Walmer Castle (see below). The 

castle itself consists of a central, circular keep with six semi-circular bastions at its base, 

surrounded by six larger, semi-circular bastions and a dry moat. The guardianship area 

also includes the Captain’s Garden, situated to the west of the castle on the opposite 

side of the road. All of the guardianship area falls within the EA flood zones 2 and 3, the 

latter indicating an annual probability of tidal flooding of 0.5% or greater. The flood zone 

maps show that there are flood defences to the north-east of the castle, but these do 

not continue across the entire coastal frontage of the castle. Data contained in the SMP2 

document for this area (Isle of Grain to South Foreland, Policy Unit 4b23, Sandown 

Castle to Oldstairs Bay) suggests that, with the present management regime, there 

will be a narrowing of the foreshore, but no significant coastal erosion that will have an 

impact on the area in the care of EH. 

Dover Castle 


NGR TR 325 419 Listed Building 1070326 


Dover Castle is a multi-period site, perhaps best known for its medieval royal castle, but 

also incorporating remains of an Iron Age hillfort, a Roman lighthouse, a Saxon church, 

a possible Saxon settlement site, a 16th-century gun battery, and tunnels dating to the 

medieval and post-medieval periods. The secret, Second World War tunnels under the 

castle have recently been re-interpreted with a new presentation scheme by EH. The 

EA flood zone data indicates that the castle, and the broader area in the care of EH 

guardianship, is not likely to be at risk from flooding. Information in the revised SMP for 

this area (South Foreland to Beachy Head, Policy Unit 4c2, revised 2006) indicates that 

the preferred policy is to ‘Hold The Line’, which would result in no significant coastal 

erosion over the next 100 years. 

Figure 32. Dover Castle. Photograph by Abby Hunt 


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Dymchurch Martello Tower 




Dymchurch Martello Tower was one (no. 24) of a chain of 74 martello towers built 

along the Kent and Sussex coasts at the start of the 19th century, as a defence against 

the threat of invasion from France. By the 1870s the tower was obsolete in military 

terms, but was subsequently re-used as a coastguard station and lookout. The tower 

is approximately 35m from the Mean High Water level and is situated at less than 

5m AOD. However, recent multi-million pound defensive works have included the 

construction of a 2.5km sea defence wall, which runs in front of Martello Tower no.24 

(Figure 33). Assuming the effectiveness of the defences and their continued good 

maintenance and upkeep, flooding and/or erosion are unlikely to affect this site greatly. 

Figure 33. Dymchurch Martello Tower (left of centre) with the construction of the new 

defensive works visible along the seafront; photograph taken from a kite-mounted camera. 

© English Heritage. Photograph by Bill Blake Heritage Documentation. 

Fort Cumberland 


NGR SZ 683 992 Listed Building 1104273 



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Fort Cumberland, a bastion fortress, was built in 1746, reconstructed in 1786 and had 

additions and alterations made to it in the 19th century. The present fortress is a wide 

pentagon on-plan and has a sharply-angled bastion at each of the five points. It was 

among the last fortresses of this type to be built in Britain and is a very good example of 

18th-century military architecture. Part of the monument is currently in use as EH offices. 

It is located at the south-east of Portsea Island at the entrance to Langstone Harbour, 

and is situated at less than 4m AOD. Digital data from the North Solent SMP2 indicates 

that there is no significant risk of coastal erosion to the site over the coming 100 years. 

However, the site does lie, almost entirely, within the EA’s flood zone 2 (tidal), which 

indicates that there is a 0.1-0.5% (or less than 1 in 200) annual probability of a flooding 

event. 

Hurst Castle 


Netley Abbey 




Netley Abbey was a Cistercian house founded in the mid-13th century, making it one 

of the last Cistercian foundations in England. The standing remains show evidence of 

modification in the 15th century and the buildings were re-used as a private residence in 

the 16th century, after the Suppression. There is evidence that gardens associated with 

this later use were created to the east of the claustral area. The house had gone out of 

use by the end of the 17th century, and from the 1730s onwards it was depicted as an 

overgrown ruin in various engravings and paintings. The EH guardianship area lies outside 

the EA flood zones, indicating that it is at minimal risk of tidal flooding. Coastal erosion 

data, from the North Solent SMP2, indicates that over the next 100 years, there may be 

up to 25m lost from the coast near Netley Abbey, but the site would still be 200m inland 

of the high water mark, placing it at very low risk from coastal erosion. 

Osborne House 

Flood risk 

Low (across most of 

estate); Medium (Queen's 

Alcove/Bathing Pavilion) 

Erosion risk 

Low (across most 

of estate); Medium 

(Barton Wood) 

NGR SZ 516 948 Listed Building 1223802; 1223967 

(Queen's Alcove) 

Scheduled Monument - Park & Garden 1000929 

Osborne House on the Isle of Wight was purchased by Queen Victoria in the mid-1840s 

and remained a favoured royal residence until her death. The appearance of the estate 


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N 

Queen’s Alcove 

Barton Wood 

Figure 34. Map showing the north-eastern part of the Osborne House EH guardianship site. 

The guardianship site is shaded pink, the extent of EA flood zone 2 is shaded blue and the 

green dots represent listed buildings. The lines illustrate the potential extent of coastal erosion 

in the next 20 (pink), 50 (green) and 100 (purple) years. 

© Crown copyright and database right 2011. All rights reserved. Ordnance Survey licence no. 100019088 

today broadly dates to the work done in the 1840s, although it had previously been in 

residential use since at least the 17th century. The area in the care of EH covers the 

house and estate, an area of approximately 154 ha; this also includes 1.25km of coastal 

frontage. The EA flood zone mapping indicates that there is a minimal threat of tidal 

flooding to the estate, focussed on the eastern fringes of the estate. However, this area 

does include the Bathing Pavilion and the Queen’s Alcove (the latter a Grade II Listed 

building), both of which could potentially be affected by tidal flooding. In addition, the 

eastern fringes of the estate are potentially at risk from coastal erosion. The data from 

the Isle of Wight SMP2 suggests that there could be a loss of 80-90m from the coast 

over the next 100 years in the Barton Wood area, approximately up to the line of 

Boundary Drive (see Figure 34). 

Portchester Castle 


NGR SU 625 046 Listed Building 1229190 


Portchester Castle originated as a Roman Saxon Shore fort in the late 3rd century. 

Subsequently, there was Anglo-Saxon settlement within the walls; evidence of buildings, 


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Figure 35. Portchester Castle. Photograph by Peter Murphy. 

ploughing and cultivation from this period has been discovered. In the north-west corner 

of the fort is a medieval castle, which is believed to have been started in the early 12th 

century, and to have seen a number of further phases of repair, extension and alteration 

throughout the medieval period. There was also an Augustinian priory founded within 

the walls of the fort in 1120; the priory church of St Mary’s survives in the south-eastern 

corner of the fort and is still in use, although it is excluded from the EH guardianship 

area. The site was used intermittently as a prisoner of war camp from the mid-1600s 

N 

Figure 36. 1m resolution Lidar 

surface data for Portchester Castle, 

overlain by the EH guardianship 

area (pink shading) and the 

possible extent of flood zones 2 

(blue hatched area) and 3 (pale 

blue cross-hatched area). 

Height data licensed to English 

Heritage for PGA, through Next 

Perspectives. 


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until the early 19th century. Portchester Castle is located on the northern edge of 

Portsmouth Harbour, at approximately 2-4m AOD. Data from the SMP2 indicates 

that, with no active intervention, there could be a loss of 6m within 20 years, 9m in 

20-50 years and 14m in 50-100 years time. However, assuming a continuation of the 

present management, there will be no substantial coastal erosion in this area. The SMP2 

proposes a ‘Hold The Line’ policy in this area, so significant erosion is unlikely to occur. 

EA flood zone data indicates that the site is at moderate risk from flooding. Tidal flooding 

in flood zone 3 (i.e. a greater than 0.5% likelihood of annual flooding) could potentially 

encroach onto the ditches surrounding the fort, right up to the base of the eastern and 

southern walls. A larger area of the fort could be affected by tidal flooding in flood zone 

2, with the potential extent of flooding covering the eastern part of the fort and the 

north-eastern corner of the castle (see Figure 36); this latter scenario has a 0.1-0.5% (or 1 

in 1000 to 1 in 200) probability of happening. 

Reculver Roman Fort and Reculver Towers 


Richborough Roman Fort and Amphitheatre 




Figure 37. View from the east side of 

Richborough Roman fort, showing the adjacent 

railway line and River Stour. Photograph by 

Abby Hunt. 

Richborough Roman Fort was originally 

located at the south-eastern end of the 

Wantsum Channel, a body of water 

which formerly separated the Isle of 

Thanet from the mainland. This channel 

was originally 3 miles wide in places and 

was a busy route for trade and travel. By 

the 16th century, however, the channel 

had all but dried up. The site played a key 

role in the history of Roman Britain, as 

it is thought to be one of the potential 

locations from which the invasion was 

launched in 43AD and certainly provided 

a bridgehead for the invading forces 

thereafter. The surviving remains include 

various phases of the port and town 

founded on the site and the subsequent 

Saxon Shore fort, constructed c275AD; there was a Roman presence on the site into the 

5th century. The east wall of the 3rd century fort no longer survives, having succumbed 

to erosion after the site had fallen out of use. The River Stour flows along the eastern 

side of the site and there is a railway line at the foot of the escarpment (Figure 37), which 

offers some degree of protection. The EA flood zone data indicates that there is minimal 


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isk of flooding to the guardianship area, potentially just at the eastern extremity of the 

site. The amphitheatre is located at a height and distance from the River Stour which 

removes it from any flood risk. 

Rochester Castle 




Rochester Castle is a Norman construction – the keep dates to the early 12th century 

– with 14th century alterations. It is located at a strategic point on the River Medway, 

controlling the important crossing point of the London-Canterbury road (Watling Street). 

The parts of the site under EH guardianship are the keep and sections of the curtain wall. 

The bailey is maintained by Medway Council as an open amenity space. The western 

side of the bailey is presently skirted by the Esplanade road. The site is situated at 7-14m 

AOD, elevating it above substantial flood risk. The EA flood zone data shows that a small 

part of the northern section of surviving curtain wall may be affected by tidal flooding 

(flood zone 3), while a small section of the western curtain wall is also potentially at risk 

from fluvial flooding (flood zone 2). The likelihood of floods of the extent predicted 

causing substantial damage, however, is limited. 

Temple Manor, Strood 




Temple Manor is situated to the west of the River Medway, in Strood. It is a 13th-century 

manorial building, constructed by the Templars, with 17th century brick additions and 

extensions. The building is situated between an industrial estate and a railway line. The 

railway line runs between the EH guardianship area and the River Medway, thus affording 

the site some degree of protection against river flooding. The EA flood zone mapping 

suggests that the site is at minimal risk of flooding from the river. Assuming that the 

railway, as an item of critical infrastructure, is well maintained, then this will ensure a level 

of flood protection for the site into the foreseeable future. 

Upnor Castle 





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Upnor Castle is situated on the western bank of the River Medway, just under 3km 

north-east of Rochester Castle. The first stage of the defensive fortification on the 

site was built during the Elizabethan period, around 1560, and was then expanded and 

added to in the 17th century. A barrack block was added to the south-west of the castle 

in 1719. The EA flood zone data indicates that there is a risk of fluvial flooding (flood 

zone 2, i.e. 1 in 100 annual probability), although this generally seems to be restrained 

by the breakwater forming the eastern extent of the castle. However, the risk from 

tidal flooding is more significant and both flood zones 2 and 3 (indicating a 1 in 100 in 1 

in 200 annual probability) could potentially extend over the breakwater and up to the 

main castle buildings. The SMP2 for this section of the estuary (Policy Unit E4 06, Lower 

Upnor to Medway Bridge) is to ‘Hold The Line’ for the next century, which will see the 

maintenance of existing defences. The protection of scheduled monuments within this 

policy unit is also an aim of the SMP2. Although there is a flood risk to this guardianship 

site, the retention of defences in this area, including the good maintenance and upkeep of 

the Upnor Castle breakwater, should minimise the potential impact of flooding. 

Walmer Castle 



Scheduled Monument 1013381 Park & Garden 1000291 

Figure 38. View from the curtain wall of Walmer Castle, looking east. The road adjacent to the 

castle can be seen in the middle of the photograph, with a footpath and broad shingle beach 

beyond it. Photograph by Abby Hunt. 


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Walmer Castle is a Henrician artillery fort, built in the late 1530s, consisting of a central 

circular keep within a curtain wall; the latter has four projecting bastions, giving the castle 

a quatrefoil plan. Since the early 18th century, the castle has been the home of the Lords 

Warden of the Cinque Ports, a ceremonial role which it still fulfils today. The area in the 

care of EH includes the castle and the surrounding gardens. The castle is situated to the 

east of a broad shingle beach (Figure 38), and stands approximately 200m away from the 

Mean High Water mark. There is also a road (Kingsdown Road) to the east of the castle, 

skirting the moat. The EA flood zone data indicates that the guardianship area is not at 

risk from flooding. Data contained in the SMP2 document for this area (Isle of Grain to 

South Foreland, Policy Unit 4b23, Sandown Castle to Oldstairs Bay) suggests that, with 

the present management regime, there will be a narrowing of the foreshore, but no 

significant coastal erosion that will have an impact on the area in EH care. 

Yarmouth Castle 




Yarmouth Castle, on the Isle of Wight, was one of the last coastal forts to be built by 

Henry VIII. Construction began in 1547, and was followed by continuous occupation until 

1901. The fort is quadrangular in form with an unusual arrow-head bastion incorporated 

into the south-east corner. The original entrance to the east was abandoned in the 

late 17th century and a new one inserted to the south; the south side of the castle also 

includes a range of 16th- and 17th-century buildings. At the same time as this phase of 

occupation, the courtyard was filled with earth to create a level gun platform; the extra 

weight of this alteration was supported by the construction of angular buttresses on the 

seaward side of the west and north walls. Together with Hurst Castle on the mainland, 

Yarmouth Castle forms a pair of defensive castles guarding the western approach to the 

Solent. The EA flood zone data indicates that the whole of the guardianship area is at 

risk from flooding (tidal flooding, flood zones 2 and 3). The Isle of Wight SMP2 for this 

section of coast (Policy Unit IW51, Yarmouth Town and Bouldnor) presents a scenario 

of continuing the present management regime by maintaining the defences, which would 

result in a prevention of coastal retreat and erosion. However, the policy does not 

remove the risk of tidal flooding, which will remain a significant risk. 

South-West Region 

Ballowall Barrow 


NGR SW 355 313 Listed Building - 



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Ballowall Barrow, a multi-phase, prehistoric funerary monument, is situated 

approximately 160m to the north-east of the coast, defined here by Ballowall Cliff. 

The barrow is situated just over 95m AOD. Its situation, the geology of this area and 

predicted erosion rates make it unlikely that the site will be subject to coastal erosion or 

flooding in the short, medium or long term. 

Bant's Carn Burial Chamber and Halangy Down Ancient Village, St Mary’s (Isles of Scilly) 


NGR SV 910 124 Listed Building - 


Bant's Carn Burial Chamber and Halangy Down Ancient Village consist of a number 

of well-preserved and interrelated remains from prehistoric to Roman times. Bant's 

Carn Burial Chamber is a very good example of a Bronze Age entrance grave, one of a 

number of such monuments to be found on the Isles of Scilly. It is located at the top of 

the coastal slope, around 35m AOD, placing it out of the way of immediate risk from 

flooding or erosion, and making it unlikely that it will be adversely affected in the next 

100 years. The ‘Ancient Village’, which dates predominantly to the later Iron Age and 

Roman periods, consists of agricultural terraces and banks, and a group of stone-built 

houses. The latter were excavated in the 1950s and late 1960s, revealing many internal 

details and a number of finds. The area of the field system and settlement in EH care 

is located on a coastal slope between 11.5 and 33m AOD; the western corner of the 

area is over 40m away from the current coastline. To the south-west of the guardianship 

monument, towards Carn Morval Down but part of the same designated scheduled 

monument group, are prehistoric settlement remains much closer to the coastline which 

Figure 39. Bant's Carn Burial Chamber at the southern end of Halangy Down Ancient Village. 

Photograph by Abby Hunt 


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are presently subject to erosion. Coastal erosion data from the SMP2 suggests that 

there will be coastal recession in the order of 15m in the next 100 years, which would 

not represent a significant threat to the guardianship area, but would present continuing 

erosion issues for the broader scheduled monument. 

Bayard’s Cove Fort, Dartmouth 


NGR SX 879 510 Listed Building 1208168 


Figure 40. Bayard's Cove Fort, Dartmouth showing the apron wall on 

the estuary frontage. Photograph by Abby Hunt 

Bayard’s Cove Fort, located on the southern edge of the town of Dartmouth and on 

the western side of the Dart estuary, was built in the first half of the 16th century. 

The artillery fort acted as second line of defence for Dartmouth Harbour and was 

held by both sides in the Civil War. It was also used as a machine-gun post for a short 

period during the Second World War. The fort is constructed of local limestone rubble 

mortared walls and has 11 equally-spaced gunports at ground level. The eastern elevation 

of the fort fronts onto the Dart Estuary and there is an apron wall at the foot which acts 

as a sea defence. The EA flood zone data suggests that there is a risk of tidal flooding 

to part of the monument; this monument is in flood zone 3, which indicates an annual 

probability of flooding of more than 0.5% (a 1 in 200 year event). 


• The Periodic Condition Survey for the monument records that, whilst generally 

sound, there are some open joints in the apron wall at the foot of the east elevation 

of the fort (Hughes 2009a, A3.0, item 32). In the aftermath of severe flooding, 

inspection of the apron wall would potentially allow any deterioration in the fabric of 

the wall to be monitored and the integrity of the sea defence to be maintained. 


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Figure 41. Cromwell's Castle, Tresco, viewed from the east. Various repairs and revetment along 

the neck of land joining the castle to the island are visible. Photograph by Abby Hunt. 

Figure 42. Erosion of the access path leading to Cromwell's Castle. Further erosion, caused 

by the undercutting of the low, friable cliffs, can be seen towards the top of the photograph. 



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Cromwell’s Castle, Tresco (Isles of Scilly) 

Flood risk Low Erosion risk 

Medium (access path and 

neck of land to east of castle) 

NGR SV 882 160 Listed Building 1141198 


Cromwell’s Castle, on the north-west coast of Tresco, was built in the early 1650s, 

replacing an earlier blockhouse, and had a seaward gun platform added in the 18th 

century. The castle was built once Tresco had been taken by the Parliamentarians to 

more effectively guard the deep-water anchorage and channel between Bryher and 

Tresco, a primary access route into the heart of the Isles of Scilly. The castle itself is built 

on a solid, projecting bedrock shelf, which appears to be relatively resistant to erosion. 

This would suggest that the main castle structure is unlikely to be significantly affected by 

coastal erosion in the coming century, in line with the SMP2 data which suggests erosion 

of 1m in the next 100 years. However, during a site visit in September 2010 it was noted 

that there had been recent erosion to the southern side of the neck of land leading 

to the castle, which is included in the EH guardianship area, and there was evidence 

of recent maintenance work to revet the sections in question (see Figure 41). The 

recommended access path to the south-east of the castle, which is also the signposted 

access route to King Charles’ Castle, also showed evidence of substantial active erosion, 

which in places had caused almost the entire width of the path to collapse (see Figure 

42). These issues have been noted in the Periodic Condition Survey and Report for the 

site and their ongoing maintenance, and, in the case of the path, possible re-routing is 

prioritised. As noted in this document, however, it is possible that one severe storm 

event could accelerate the issues significantly and cause substantial damage. It is also quite 

possible that in the long-term, the castle could become virtually cut off from the island. 

These are factors which will need to be addressed in the longer term management of the 

site. 

Dartmouth Castle 




Dartmouth Castle is an enclosure castle located on a rocky outcrop at the mouth of the 

River Dart estuary. There has been a castle on the site since the 14th century, but the 

present structure dates from the 1480s, when a chain tower was built to protect the 

harbour. Modifications were made to the structure in the first half of the 16th century as 

part of Henry VIII’s overhaul of the coastal defences of England. The guardianship area 

includes this castle, a mansion and a post-medieval coastal battery. The EA flood zone 

data indicates that there is a risk of flooding, but this is only predicted to affect a relatively 

small area at the northern part of the guardianship area (tidal flooding, flood zones 2 


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and 3) and a small part of the southern end of the area (the latter in flood zone 2, i.e. 

0.1-0.5% or less than 1 in 200). The part of the site most likely to be affected by tidal 

flooding is the Guntower (Old Castle) which is situated immediately to the north-east of 

St Petrox Church. The Dart Estuary is a deep water channel which is constrained by high, 

resistant rock cliffs. The draft SMP2 for this stretch of coast (Durlston Head to Rame 

Head SMP2, Berry Head to Strete) indicates that there will be some coastal erosion, but 

not a significant level. 

Daw’s Castle 


Garrison Walls, St Mary’s (Isles of Scilly) 

See Section 5.3, Case Study 3a 

Harry’s Walls, St Mary’s (Isles of Scilly) 




Harry’s Walls is an unfinished artillery fort, dating to 1552-3, which formed part of the 

broader, mid-16th-century for the islands’ defence. The importance of the fort lies in its 

design, the first of its kind in England, which was developed in Italy and represented the 

forefront of military engineering. The fort itself is situated on a knoll, some 18m above 

the High Water Mark (or 20-24m AOD), to the north-east of Porth Mellon Sand. To the 

south and west of the monument are private dwellings. Predicted erosion suggests that 

there is not likely to be any impact directly on the monument and even with a rise in the 

sea level, the elevated position of the monument will keep it out of direct danger. 

Innisidgen Burial Chambers, St Mary’s (Isles of Scilly) 

See Section 5.3, Case Study 3b 

King Charles’ Castle, Tresco (Isles of Scilly) 




King Charles’ Castle, situated on the north-west coast of Tresco and overlooking New 

Grimsby Harbour, was built around 1550 in response to a threat from the French. The 

castle is cruciform on plan and the walls containing the gun ports still survive to just 


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Figure 43. King Charles' Castle, Tresco. Photograph by 

Abby Hunt. 

over 3m high. By the 1590s, the 

principal stronghold on the Isles of 

Scilly was Star Castle on St Mary’s 

and King Charles’ Castle had lost 

its earlier importance. During 

the English Civil War, an earthen 

artillery defence was added to the 

north and east of the castle by 

the Royalists, designed to protect 

the castle from landward attack. 

Archaeological and documentary 

evidence indicate that the castle 

fell out of use after the 1650s. It 

is situated approximately 150m 

north-east of Cromwell’s Castle, a later structure which replaced it. The castle is 

situated on high ground at approximately 42m AOD and is over 100m inland of the 

present coastline. This elevation and position means that the guardianship area is at no 

significant risk of flooding or coastal erosion. The only potential indirect threat to the site, 

which could impact on its management, is the erosion of the access path to the south 

(see Cromwell’s Castle description above for further detail). 

Old Blockhouse, Tresco (Isles of Scilly) 




Old Blockhouse, situated on the east coast of Tresco, is a small gun blockhouse built in 

the mid-16th century, which was used by the Royalists in the Civil War and was still in 

use in the mid-18th century. As well as the structure surrounding the gun platform, Old 

Blockhouse also includes earthwork defensive elements. The monument stands at c20m 

AOD, which means that 

it is not at risk of flooding. 

However, the potential coastal 

erosion at this location (as 

indicated by the SMP2 data) 

suggests that within 100 years, 

the coast could recede by up 

to 25m, leaving the edge of 

the EH guardianship area just 

16m from the shoreline. This 

is not an immediate threat, 

but the general trend is one 

of coastal erosion, and this 

Figure 44. Old Blockhouse viewed from the north-west, 

across Old Grimsby Harbour. Photograph by Abby Hunt. 

should be a consideration in 

the management/conservation 


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of the monument in the much longer term. Evidence of further, seaward defences within 

the deep deposits of blown-sand has been revealed by erosion and this is likely to 

accelerate as the shoreline recedes; however, in terms of direct management, this area of 

the site, to the north-east of the blockhouse, is outwith the EH guardianship area. 

Over Bridge 


NGR SO 816 196 Listed Building - 


Over Bridge was designed by Thomas Telford in 1825 and opened in 1830. It is a singlespan, 

stone-built bridge, c100m in length and 9m wide, crossing the western channel 

of the River Severn on the outskirts of Gloucester. The bridge is no longer in use and 

the approaches are grassed over. EA flood zone data shows that there is a risk of 

tidal/fluvial flooding in flood zone 2, which could affect much of the bridge structure, 

c50% of the area in the care of EH. According to the 2009 Periodic Condition Survey 

Report for the site, there are a number of examples of cracking in the bridge masonry 

and an observation that there has been some distortion of the bridge structure and 

movement in the span. The report recommends that these issues are addressed, for 

example, through the use of precise locational targets around the bridge to allow future 

monitoring of movement, with an initial priority level of ‘1’, i.e. within a matter of months 

or a year, and to be repeated every 4 years. Given the flood risk, it is also important that 

the fabric of the structure is in a good state of repair to prevent any damage from water 

ingress during a flooding episode. Assuming the fabric is maintained in a good state of 

repair, the severity of damage from flooding could be limited, although in the case of a 

severe flooding episode, damage from waterborne debris may also prove to be an issue. 

Pendennis Castle 

Flood risk 

Low (Pendennis Castle); 

Medium (Little Dennis 

Blockhouse) 

Erosion risk 

Low (Pendennis 

Castle); Low (Little 

Dennis Blockhouse) 

NGR SW 824 318 Listed Building 1270096; 1270099 (Little 

Dennis Blockhouse) 


Pendennis Castle originated in the 1540s as an artillery fort and then saw continuous 

military occupation until the 1950s. Its longevity as a defensive fortification is due to 

its strategic location on a peninsula at the north of Falmouth Bay, protecting the large 

natural anchorage of Carrick Roads to the north. The structural remains of the castle 

buildings and batteries illustrate the development of coastal defence over a period of 

400 years. The main part of the guardianship area, including the castle and Civil War 

defences, is located at an elevation of 40-50m AOD and is at negligible risk from flooding 


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Figure 45. Little Dennis Blockhouse to the south-east of 

Pendennis Castle, viewed from the north. Photograph by 

Abby Hunt. 

and coastal erosion. However, 

a small blockhouse, known 

as Little Dennis Blockhouse, 

also in the care of EH (List 

number 1270099, Grade 1), is 

situated close to the shoreline 

(at 1.5-5m AOD) at the end 

of the peninsula to the southeast 

of the main castle. The 

blockhouse was built in the 

mid-16th century. Resistant 

geology means that there is 

little risk of coastal erosion 

to the majority of the area 

in the care of EH. However, 

EA flood zone data indicates 

that a small part of this area, 

around the base of Little 

Dennis Blockhouse, could 

be affected by tidal flooding 

(flood zone 2). A site visit in September 2010 revealed some evidence of active erosion 

in the foreshore adjacent to Little Dennis blockhouse and a rock-cut gully to the north of 

it. Increased wave action on these areas and severe flooding episodes could exacerbate 

this problem. 


• Monitor the condition of the erosion and gully to the north of Little Dennis 

blockhouse. If the problem becomes more pronounced, assess whether this will 

impact on the structural integrity of the blockhouse and take appropriate action. 

Porth Hellick Down Burial Chamber, St Mary’s (Isles of Scilly) 




Porth Hellick Down is one of the largest and best-preserved Bronze Age entrance 

graves on the Isles of Scilly. It is also a typical example of this monument type. The 

tomb was excavated in 1899, but very few contemporary artefacts were found, the 

majority having been removed by an even earlier, unrecorded excavation. The Ministry 

of Works restored the tomb for public presentation in the mid-20th century; this work 

resulted in the modification of some parts of the monument and the loss of the tomb’s 

outer kerb. The monument forms part of a wider prehistoric landscape, as it is one of 

a number of Neolithic and Bronze Age burial monuments in this area and is associated 

with a prehistoric field system to the north-west. The entrance grave is located at 27m 


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Figure 46. Porth Hellick Down entrance grave. Photograph by Abby Hunt. 

AOD, which places it at negligible risk of flooding. The threat of coastal erosion to the 

monument is also minimal, as it lies over 150m inland from the current coastline and 

predictions suggest that only 1-2m will be lost from the coastline in this vicinity in the 

next 100 years. 

Portland Castle 


NGR SY 685 744 Listed Building 1205262 


Portland Castle is located at the north of the Isle of Portland, a tied island joined to the 

mainland by Chesil Beach. The castle, one of Henry VIII’s defensive fortifications, was 

built in the 1540s overlooking Portland Harbour and in a strategically important position 

in relation to the English Channel. It saw various periods of military activity through 

until the 20th century, including use as a seaplane station during the First World War. 

The construction of the castle is primarily Portland ashlar with a rubble apron below 

the outer defensive wall on the coast side, which offers a degree of protection from 

the sea; the apron was observed to be in relatively good condition during a site visit in 

September 2010. EA flood zone data indicates that there is a risk of inundation to over 

50% guardianship area (the north-western part, including the keep and car park) from 

flood zone 2 tidal flooding. There is also a risk to a smaller area (the northern part of 

the car park and possibly the garden area to the south of the castle) from flood zone 

3 tidal flooding, although this would potentially be minimised by the castle’s defensive 

walls acting as flood defences. This section of the coast is presently well defended 

against erosion. However, the SMP2 (South Devon & Dorset Coastal Authorities Group, 

Durlston Head to Rame Head SMP2, Osprey Quay to Grove Point) indicates that to 

maintain current levels of protection into the long term, present defences may need to 

be upgraded. 


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Figure 47. The north-eastern side of Portland Castle. Photograph by Abby Hunt. 

St Catherine’s Castle, Fowey 




St Catherine’s Castle is one of a number of Henrician coastal forts dating to the late 

1530s, constructed as a response to heightened threats to attack from France and Spain, 

following the English Reformation. It was brought into service and re-armed during both 

the Napoleonic and Second World Wars. The blockhouse is built on a platform cut 

into the rock and is situated approximately 20m AOD, some 60m from the Mean High 

Water level. There is a slight risk of tidal flooding to the south of the castle, but this is not 

predicted to encroach on the area under English Heritage’s guardianship. 

St Mawes Castle 

Flood risk Low Erosion risk Low (castle); Medium (land above 

Castle Cove) 

NGR SW 841 328 Listed Building 1136705 


St Mawes Castle, an artillery castle situated at the southern tip of a broad headland 

on the eastern side of the mouth of the River Fal, opposite Pendennis Castle, was 


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Figure 48. The cliff at Castle Cove, below the overflow car park to the north-west of St Mawes 

Castle, showing signs of erosion. Photograph by Abby Hunt. 

completed by the mid-16th century. The castle and the surrounding landscape then 

continued in military use until the Second World War; features from this latter period 

include a searchlight battery beyond the coastal revetment wall. The castle itself, which 

is constructed of local rubble sandstone with granite for quoins, coping and other 

architectural detailing, displays a high quality of architectural finish. The EA flood zone 

data indicates that the fringes of the area in the care of EH may be affected by flood 

zone 2 tidal flooding, but around the castle, this will generally be contained by the outer 

defensive wall – assuming the wall is maintained in good condition. The SMP2 data 

for this stretch of coast suggests that there will be little in the way of coastal erosion. 

However, a site visit in September 2010 revealed that there is erosion taking place 

within part of the area in EH's care to the north-west of the castle, on low, soft cliffs at 

Castle Cove, just below the area currently used as an overflow car park (see Figure 48). 

Although vegetation is binding some of the cliff material, there is evidence of relatively 

recent slippage and there is potential for undercutting in the event of further sustained, 

heavy wave action and raised sea levels. 


• Ensure that the low cliff below the overflow car park is inspected for signs of active 

erosion, particularly in the aftermath of severe storm events. 


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Tintagel Castle 

Flood risk Low Erosion risk Medium 

NGR SX 049 891 Listed Building - 


Tintagel Castle, on the north Cornwall coast, is built on a rocky promontory, linked to 

the mainland by a narrow neck of land. The castle itself dates to the early part of the 

13th century, but there has been settlement at Tintagel for much longer, including a 

post-Roman occupation dating from the 5th-7th centuries. The site has been extensively 

excavated and surveyed. The guardianship area is at a slight risk from flooding, but this 

is limited to the area along Castle Road. Site staff have reported recent rock falls in 

Merlin’s Cave and at the beach to the east of the promontory (Sept 2010). These rock 

falls are undoubtedly a result of wave action/coastal erosion. The 2008 EH Periodic 

Condition Survey Report addresses the issue of rock falls and erosion and notes that 

the EH structural engineer is regularly monitoring the situation and emphasises the need 

to continue this monitoring, as cliff failure could have a potentially serious impact on the 

monument and site staff/visitors. 


• Further rock falls should be reported and monitored so that any patterns can be 

predicted and significant falls pre-empted. Information should be fed back into the 

Estates Team’s reporting process. 

Figure 49. Merlin's Cave (the left-hand cave) at the foot of the cliff on the eastern side of 

Tintagel Island, where recent rock falls have occurred; there are a number of structural and 

archaeological remains on the cliff above. Photograph by Abby Hunt. 


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North-West Region 

Ravenglass Roman Bath House 


NGR SD 088 959 Listed Building - 


Ravenglass Roman Bath House was associated with the nearby Roman fort. The surviving 

fabric of the bath house stands over 100m inland from the Mean High Water level and 

is situated at a little under 15m AOD; it is outside the EA’s projected flood zones. The 

scheduled Roman fort is located approximately 50m to the south of the bath house and 

is not under the guardianship of English Heritage. The Roman fort has been bisected 

by the insertion of a railway line in the mid-19th century. This offers some degree of 

protection to the remains of the fort and to the east of the railway and the bath house, 

but the remains to the west have suffered from significant coastal erosion. 

The Roman fort and bath house were surveyed in 1998 by the RCHME Archaeological 

Field Survey team; a survey report was produced, including a metrically accurate plan of 

the site at that date. 

Piel Castle 

Flood risk Medium Erosion risk Medium 

NGR SD 223 636 Listed Building 1283004 


Piel Castle was built in the early 14th century by the monks of Furness Abbey. It is 

situated at approximately 7m AOD on a small island at the mouth of the deep water 

harbour of Barrow-in-Furness; this location was chosen to allow the monks to control 

the shipping and trade with the Isle of Man and Ireland via Piel Harbour, which was also 

held by the abbey. The castle is built of coursed stone collected from the beach, with 

imported sandstone for architectural details and finishing. The main part of the structure 

is the large keep, which was originally divided into three parallel compartments; the 

easternmost of these no longer survives intact, as the eastern wall of the castle has 

collapsed, due to erosion. Parts of the inner and outer curtain walls also survive and 

the earthworks of an inner and outer moat are still well-defined. The SMP2 for North 

West England and North Wales sets out a planned policy of ‘No Active Intervention’ 

for Piel Island (Policy Unit 13.5), with the predicted implication that the castle would be 

at increasing risk from flooding and erosion in the short term, and at risk from further 

erosion in the long term (i.e. 50-100 years). However, the SMP2 does indicate that 

consent could be available for localised defence schemes to allow for the management 

of Piel Castle as a nationally important monument. A coastal assessment of the site was 

commissioned by EH in 2009 and the report notes that some of the defences are in a 


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poor or very poor condition (Purcell Miller Tritton 2009a, A 7.0); a recommendation of 

repair in the short term and the development of more robust coastal protection in the 

medium- to long-term is made. 

For notes on a site visit in September 2010 and details of previous excavation and survey 

work done on the site, see Appendix 2. 

Figure 50. The eastern elevation of Piel Castle. Large chunks of collapsed masonry can be seen 

on the beach in the foreground, a result of erosion in the 18th century. Photograph by Abby 

Hunt. 


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APPENDIX 2: NOTES ON SITE VISIT TO PIEL CASTLE 

Abby Hunt and Marcus Jecock of EH’s Archaeological Survey & Investigation Team 

visited Piel Castle on 2nd September 2010. A rapid walk-over inspection of the site was 

undertaken to compare the extant remains on the ground with those depicted on a 

survey plan completed in 1983-4 by the former Cumbria and Lancashire Archaeological 

Unit and to evaluate the site as part of the EH Coastal Estate Risk Assessment. 

The history of the monument is covered in the two recent articles on archaeological 

investigation at Piel Castle (Newman 1987 and 1996) and in an earlier work (Curwen 

1910). The majority of the architectural detail at the site, both in situ and found amongst 

the tumbled masonry on the beach, is also recorded in the two more recent accounts. 

However, the survey plan of the castle included in the report on the 1983-4 work 

(Newman 1987, 104) is somewhat lacking in detail, particularly in relation to earthwork 

remains within the inner and outer baileys. The major earthworks, such as the moat, are 

depicted, but more subtle features and variations within the larger earthworks are not. 

Some of these features are under threat from erosion and recording and interpretation 

is therefore advisable in advance of any future loss. A particular example noted during 

the site visit is a circular feature at the north-eastern corner of the keep, situated at the 

edge of the island (Figure 51). This earthwork appears to represent the remains of a 

buried structure, the full extent of which is not totally clear as part of it is overgrown, 

but the eastern side appears to have already been lost to erosion; further investigation 

could clarify the nature of the feature. Elsewhere, to the west of the outer bailey moat, 

Figure 51. Circular earthwork surviving to the north-east of the keep within the inner bailey. 



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approximately 30m north-west of the outer south-west tower, the remains of a low wall 

were observed on the external bank of the moat. In addition, traces of ridge and furrow 

were observed in the outer bailey along with other earthworks, which may be field 

boundaries. Further investigation of these features would elucidate the nature of activity 

in this area after the castle had fallen out of use. 

Some evidence of small-scale active erosion was noted (on the sloping edge of the island, 

just to the east of the keep), although recent consolidation work has been undertaken 

to arrest this (see Figure 52). Recent repairs to the foot of the grouted stone revetment 

protecting the south of the island were also noted. Early prints and engravings suggest 

that most of the substantial collapse, due to coastal erosion, of the eastern part of the 

keep occurred in the eighteenth and early nineteenth century, prior to the construction 

of sea defences in the mid-nineteenth century by the Duke of Buccleuch (Newman 

1987, 101). The state of the various coastal defences around the south and east of the 

island, which include stone-filled gabions, grouted stone revetment and rock armour, is 

summarised in the Coastal Inspection report which appears as an annexe of the Periodic 

Condition Survey Report for the site (Purcell Miller Tritton 2009a, A7.0). During the 

present site visit, a number of points around the south and east of the island were noted 

where parts of the castle structure are now situated very close to the edge of the island 

(for example, the central southern buttress of the keep is currently c3.5m from the edge 

of the island). Continuation of the current maintenance and repair programme is essential 

to minimise the risk from coastal erosion to the southern end of the island and the 

potential loss of more archaeological 

evidence. A programme of monitoring 

to track any changes to the island’s 

coastline would be beneficial, so that 

mitigation work can be targeted on 

those areas most immediately at risk 

of further erosion. 

Figure 52. Erosion to the east of the keep. 


Overall, while the history of the site 

and architectural remains have been 

well served by previous research, 

there is potential for further useful 

work to be done on the extant 

archaeological remains of the castle 

and features associated with it. A 

detailed earthwork survey (to Level 3 

standard, as defined in Ainsworth et 

al 2007, 23-4) and possibly geophysical 

exploration would enhance the 

current knowledge of the context 

of the castle and potentially provide 

more detail about its development. 

Some of the questions raised by the 

more recent work on the site, such 

as the location of a well, whether the 


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kitchen was a detached building (Newman 1996, 135), the purpose of the rectangular 

building adjacent to the north-east tower and if there was a barn and/or bakehouse 

within the outer bailey (Newman 1987, 110), could be addressed by a more detailed 

survey. In addition, it would enable the accurate mapping of the current position of the 

island’s coastline, providing a baseline against which to monitor future erosion. 


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APPENDIX 3 

Flow chart illustrating how properties were selected for this study 

All sites and monuments in EH portfolio 

Yes 

Is the 

property 

within 200m 

of the ‘coastal 

zone’? 

No 

Exclude property 

from study 

Is the property 

within an urban, 

built-up area 

with good flood 

defences? 

Yes 

Exclude property 

from study 

No 

Is the property 

at significant risk 

from flooding 

and/or coastal 

erosion? 

No 

Include in gazetteer 

& summarise property 

details 

Yes 

Assess level of risk from 

flood and/or erosion 

Yes 

Is the 

property 

suitable 

as a case 

study? 

Include in relevant 

table(s), gazetteer & 

summarise property 

details 

Research 

& prepare case 

study 

No 

FINISH 


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APPENDIX 4: DATA SOURCES 

Tables of types of data source used in the study and layers used in the project GIS, with 

suppliers of data. 

Data source 

Type 

1:10 000 Ordnance Survey mapping Digital 

High Water Mark data (OS) 

Digital 

Historic OS mapping 

Digital 

Statutory designation datasets 

Digital 

EH regions 

Digital 

EH estate boundaries 

Digital 

Archaeological surveys 

Digital 

Orthophotography 

Digital 

Geological mapping 

Digital 

Garrison Walls GIS 

Digital 

Aerial Photography (CCO) 

Digital 

Aerial Photography (PGA) 

Digital 

Lidar (CCO) 

Digital 

Lidar (PGA) 

Digital 

EA Flood Risk Mapping 

Digital 

SMP2 erosion data 

Digital & Hard copy 

Futurecoast 

Digital 

SMP2 reports 

Digital & Hard copy 

EH Periodic Condition Survey Reports Hard copy 

EH Scheduled Monuments At Risk database Digital 

GIS layer 

EH Datasets 

EH estate boundaries 

EH regions 

OS 1:10000 mapping for EH coastal 

properties 

Scheduled Ancient Monuments 

Listed Buildings 

Registered Parks & Gardens 

Environmental Designations 

AONB 

Supplier 

EH Corporate GIS Team 








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Heritage Coasts 

National Nature Reserves 

RAMSAR 

SSSI 

Marine Data 

High Water Mark 

National data 

England and Wales boundaries 

Risk Mapping 

Flood Risk Mapping 

SMP2 coastal erosion 

Geological mapping 

DiGMapGB-625 data 1: 625 000 ESRI® 

[Bedrock geology] 

Aerial Photography 

25cm resolution PGA aerial photography 

for EH coastal properties (where available) 

25cm resolution aerial photography for EH 

coastal properties (where available) 

Lidar 

2m resolution Lidar coverage for EH 

coastal properties (where available) 

Lidar terrain data 1m resolution 

Lidar surface data 1m resolution 







Environment Agency 

SMP2 authorities/consultants 

British Geological Survey 

PGA supplier Next Perspectives 

Channel Coast Observatory 

Channel Coast Observatory 




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APPENDIX 5 

Table showing properties from the original group of eighty properties which were 

excluded from the final study sample; the reasons for exclusion are shown. 

Property name 

Sir Walter Raleigh, statue of (Old Royal Naval 

College, Greenwich, London) 

General Gordon, statue of (Victoria 

Embankment, London) 

Lord Portal, statue of (Victoria Embankment, 

London) 

Carabiniers Memorial (Chelsea Embankment, 

London) 

Belgian War Memorial (Victoria Embankment, 

London) 

Samuel Plimsoll, statue of (Victoria Embankment, 

London) 

Lord Trenchard, statue of (Victoria 

Embankment, London) 

EH Region 

London 

London 

London 

London 

London 

London 

London 

Reason for 

exclusion 

Urban location 







Montgomery, statue of (Whitehall, London) London Urban location 

The Cenotaph (Whitehall, London) London Urban location 

Viscount Alanbrooke, statue of (Whitehall, 

London) 

London 


Viscount Slim, statue of (Whitehall, London) London Urban location 

Bessie Surtees House, Newcastle-upon-Tyne North East Urban location 

Blakeney Guildhall, Norfolk East of England Urban location 

Chapter House and Pyx Chamber, Westminster 

Abbey 

Chester Castle: Agricola Tower and Castle 

Walls, Cheshire 

London 

North West 




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Christchurch Castle, Dorset South West Urban location 

Greyfriars’ Cloisters, Great Yarmouth, Norfolk East of England Urban location 

Jewel Tower, London London Urban location 

Jordan Hill Roman Temple, Dorset South West Elevation 

Marble Hill House, Twickenham, Middlesex London Inland 

Milton Chantry, Gravesend, Kent South East Urban location 

Cow Tower, Norwich, Norfolk East of England Urban location 

The Old Merchant’s House, Great Yarmouth, 

Norfolk 

East of England 


Royal Garrison Church, Portsmouth South East Urban location 

Row III Houses, Great Yarmouth, Norfolk East of England Urban location 

Winchester Palace, Southwark London Urban location 


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ENGLISH HERITAGE RESEARCH DEPARTMENT 

English Heritage undertakes and commissions research into the historic 

environment, and the issues that affect its condition and survival, in order to 

provide the understanding necessary for informed policy and decision making, 

for sustainable management, and to promote the widest access, appreciation 

and enjoyment of our heritage. 

The Research Department provides English Heritage with this capacity 

in the fields of buildings history, archaeology, and landscape history. It brings 

together seven teams with complementary investigative and analytical skills 

to provide integrated research expertise across the range of the historic 

environment. These are: 

* Aerial Survey and Investigation 

* Archaeological Projects (excavation) 

* Archaeological Science 

* Archaeological Survey and Investigation (landscape analysis) 

* Architectural Investigation 

* Imaging, Graphics and Survey (including measured and 

metric survey, and photography) 

* Survey of London 

The Research Department undertakes a wide range of investigative and 

analytical projects, and provides quality assurance and management support 

for externally-commissioned research. We aim for innovative work of the 

highest quality which will set agendas and standards for the historic 

environment sector. In support of this, and to build capacity and promote best 

practice in the sector, we also publish guidance and provide advice and training. 

We support outreach and education activities and build these in to our projects 

and programmes wherever possible. 

We make the results of our work available through the Research Department 

Report Series, and through journal publications and monographs. Our 

publication Research News, which appears three times a year, aims to keep 

our partners within and outside English Heritage up-to-date with our projects 

and activities. A full list of Research Department Reports, with abstracts and 

information on how to obtain copies, may be found on www.english-heritage. 

org.uk/researchreports 

For further information visit www.english-heritage.org.uk

ENGLISH HERITAGE COASTAL ESTATE RISK ASSESSMENT

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