Coastal Trends Report. North-East Norfolk and North Suffolk (Subcell 3b - Kelling to Lowestoft) RP006/N/2008 April 2008

Transcription

1 Coastal Trends Report North-East Norfolk and North Suffolk (Subcell 3b - Kelling to Lowestoft) RP006/N/2008 April 2008 Title here in 8pt Arial (change text colour to black) i

2 We are the Environment Agency. We protect and improve the environment and make it a better place for people and wildlife. We operate at the place where environmental change has its greatest impact on people s lives. We reduce the risks to people and properties from flooding; make sure there is enough water for people and wildlife; protect and improve air, land and water quality and apply the environmental standards within which industry can operate. Acting to reduce climate change and helping people and wildlife adapt to its consequences are at the heart of all that we do. We cannot do this alone. We work closely with a wide range of partners including government, business, local authorities, other agencies, civil society groups and the communities we serve. Published by: Shoreline Management Group Environment Agency Kingfisher House, Goldhay Way Orton goldhay, Peterborough PE2 5ZR enquiries@environment-agency.gov.uk Environment Agency 2008 All rights reserved. This document may be reproduced with prior permission of the Environment Agency. Further copies of this report are available from our publications catalogue: or our National Customer Contact Centre: T: enquiries@environment-agency.gov.uk. ii

3 Looking north towards Overstrand (Photo: Environment Agency)

4 Glossary Accretion Bathymetry Chart Datum Erosion Foreshore Foreshore rotation Longshore drift MHWS MHWN MLWN MLWS MSL Ordnance Datum SMP The accumulation of sediment on a beach by the action of natural forces or as a result of man-made artificial structures The topographic relief of the seabed The level to which all soundings on a marine navigational chart are based The loss of material from a beach by the action of natural forces or the result of man-made artificial structures interfering with coastal processes The area of beach lying between high water and low water Foreshore steepening or flattening resulting in the convergence or divergence of high and low water marks Movement of sediment parallel to the shoreline level of Mean High Water Spring tides level of Mean High Water Neap tides level of Mean Low Water Neap tides level of Mean Low Water Spring tides Mean Sea Level The mean sea level ( as derived from 6 years of observation at Newlyn, Cornwall) used as a datum for calculating the absolute height of land on official British maps. Shoreline Management Plan

5 Coastal Trends Analysis PURPOSE AND APPLICATION 1.2 BACKGROUND 1.3 BEACH TOPOGRAPHIC PROFILE DATA 1.4 ANALYSIS METHODOLOGY 1.5 FUTURE OUTPUTS 2.0 NORTHEAST NORFOLK AND NORTH SUFFOLK (SUB-CELL 3B) COASTAL TRENDS 2.1 INTRODUCTION 2.2 GENERAL DESCRIPTION KELLING TO LOWESTOFT 2.3 OUTLINE OBSERVATIONS Kelling (Weybourne) to Cromer Cromer to Cart Gap, Happisburgh Cart Gap, Happisburgh to Winterton Winterton Ness to Great Yarmouth Great Yarmouth to Lowestoft 3.0 GRAPHICAL VIEW OF RESULTS APPENDIX 1 DETAILED RESULTS APPENDIX 2 - REFERENCES

6 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Figure 1 The Anglian Coast

7 1.1 Purpose and application This report is intended as a tool to assist coastal managers in a variety of their functions including; strategic planning, capital engineering works and maintenance programmes. In addition to this the report will be of assistance with general education and awareness raising of coastal issues. The outputs also will also aid the determination of beach health parameters within NFCDD (National Flood and Coastal Defence Database). 1.2 Background The Anglian coastline stretches from Grimsby near the mouth of the River Humber to Southend-on-Sea on the northern side of the outer Thames estuary (figure 1). With a total length of approximately 470km the coast is a diverse mixture of dune fronted flood plains, shingle barrier beaches, saltmarsh and soft cliffs. There are no significant geological hard rock coastal areas and thus significant proportions of the coast are vulnerable to marine flooding and erosion. This is likely to be compounded by climatic change and sea level rise in the future. In order to reduce the impacts of this upon the built and natural coastal environment much investment has been made in both hard and soft engineering solutions over the last century. This has resulted in significant proportions of the coast being artificially held to prevent the loss of development and infrastructure located in vulnerable areas. The Environment Agency has undertaken regular strategic coastal monitoring of the Anglian coast since The rational behind the programme is to assist the implementation of appropriate and sustainable works on the coast whether this be works undertaken by the Agency for the purpose of flood risk management or works undertaken by various maritime district council partners for erosion reduction purposes. An additional output from the monitoring programme is the assessment of coastal dynamics to inform long term strategic plans for the coastline. The vehicle for this is the Shoreline Management Plan (SMP) process, which is currently being reviewed along the entire Anglian coast. The Anglian Coastal Monitoring programme collects a variety of data including; Annual aerial photographs Annual topographic beach surveys (winter and summer) at 1km intervals Bathymetric surveys (extension of beach survey lines out to approximately 10 metre depth offshore) Continuous wave and tide recording (nearshore and offshore) In addition to this, in-depth monitoring addresses specific sea defence scheme requirements at a variety of locations along the coast. At the time of writing, the Anglian monitoring programme has begun phase VII, which includes a suite of five offshore, and twenty nearshore continuous wave and tide recorders. Various reports based upon the data collected over the years have been produced. Until now the work undertaken has been unable to assess any significant trends in the data due to the insufficient length of time over which the data has been collected. However the Agency now possesses 15 years of beach topographic data and it is therefore possible to analyse these to determine initial indicators of longer-term

8 trends. Data collected in the future can be readily added to this analysis to further ascertain the validity of the trends. 1.3 Beach topographic profile data The Environment Agency has collected beach topographic profile data at 1km intervals along the coast since Profiles are taken twice yearly in summer and in winter. The most recent set of available data means that there is now a continuous record of beach levels spanning fifteen years. Generally the area of interest is the average rate of beach erosion or accretion along the coast. In addition to this, gradual change to the gradient or steepness of the beach is of particular interest to coastal managers. The analysis of trends in beach morphological behaviour may have significant impacts upon coastal management decisions in the future. Artificially defended beaches that are experiencing erosion and steepening trends may prove to be increasingly difficult and expensive to maintain. Even with maintenance, the structures may fail because of inadequate structural support or ground movements from diminishing quantities of beach material and subsequent beach platform loss. However it is not the intention of this report to ascertain such issues at a local scale. The ongoing revisions of the Shoreline Management Plans (SMP) and Coastal Strategic Studies, which are currently being compiled along the Anglian coast, are the appropriate vehicle for this assessment. The length of the Anglian coast means that there are over 400 topographic profiles that have been collected over the years. For the purposes of regional strategic coastal management, the entire UK coast has been divided up sediment cells and sub-cells (HR Wallingford, 1994 & Defra, 2006). These are individual discrete sections of the coast that are considered to be independent from each other in terms of coastal processes. The relevant sections on the coast are: - Flamborough Head to Donna Nook Sub-cell 2a+b 1 Donna Nook to Gibraltar Point Sub-cell 2c Gibraltar Point to Old Hunstanton Sub-cell 2d Old Hunstanton to Kelling Sub-cell 3a Kelling to Lowestoft Ness Sub-cell 3b Lowestoft Ness to Felixstowe Sub-cell 3c Harwich to Canvey Island Sub-cell 3d These boundaries are convenient divisions for the separation and publication of the results of the trends analysis reports. 1 The first SMP review for this section of coast will encapsulate the coast from Flamborough Head to Gibraltar Point. Only that part of the coast south of the Humber is within the Anglian region.

9 1.4 Analysis methodology The profile data presented in this report is in the form of beach level analysis. The data was analysed using a function of SANDS software (1). Tidal levels and conversions from Chart Datum to Ordnance Datum were kindly supplied by Proudman Oceanographic Laboratory from their POLTIPS software (2). Generally, the accepted definition of the foreshore is the intertidal region between the highest and lowest tide level. Here the area between the MHWS (Mean High Water Springs) and MLWS (Mean Low Water Springs) level is used 2. Figure 2 demonstrates the principle of beach profile change over time along with changes to beach gradient. Along certain stretches of coast where seawalls or other structures constrain the landward movement of the coast, beach volumetric change may be of interest. This is particularly relevant where artificial beach nourishment is undertaken. In other areas, where long frontages are unconstrained by linear defences the, quantification of beach volumetric change is of less importance. Figure 2. Conceptual diagram of a beach profile showing shoreline advance/retreat and foreshore change parameter. Figure 3 demonstrates how the analysis was performed and a trend is obtained. The example used in figure 3 is from an eroding beach, which is retreating with an average trend of 3.86 m yr -1. However in any single year the actual erosion observed varies considerably. For example between 1996 and 2000 very little erosion occurred whereas between 2000 and 2001 the beach retreated by almost 20 m. 2 For some profiles where there are limited data at MLWS the data from MLWN (Mean Low Water Neaps) is utilised.

10 Figure 3. Suite of coastal profiles after SANDS beach level analysis with linear regression of MSL giving annual trend (data gaps are due to certain profiles not extending down to MLW level) An important factor in coastal risk management policy decision making is foreshore steepening. A wide flat beach can dissipate incoming wave energy much more readily than a narrow steep beach. Using historical Ordnance Survey data, Taylor et al (2004) concluded that 61% of the coastline of England and Wales had steepened since the first OS County Series Survey published between 1843 and Of the remainder 33% had flattened and 6% experienced no rotational movement. Earlier work by Halcrow (1998) used the method to assess the Anglian coast to assist in the development of a management strategy for the Environment Agency s coastal flood defence predecessor, Anglian Water. This study concluded that 78% of coast had experienced steepening between the mid 1800 s to the 1970 s. The analysis in this report uses a similar methodology to that of Taylor et al and although the length of time covered in this report is an order of magnitude less than their data-set, the data utilised here is likely to be of much greater accuracy. The positional accuracy quoted in Taylor et al for OS maps are +/-5m for pre-1945 County Series Maps and +/-3.5m for post-1945 National Grid mapping. Whereas the accuracy of the Anglian Coastal Monitoring profiles is +/-0.05m vertical and +/-0.02m horizontal. Changes in the gradient of the beach between MHWS and MLWS are expressed in the form of the foreshore change classification system (Halcrow, 1988) shown in table 1. Positive Foreshore Change Parameter (FCP) values indicate a beach system advancing seaward and negative values show a system retreating landward. The individual FCP numbers indicate either flattening, steepening or no rotation. As no pair of MHWS and MLWS trendlines were likely to possess exactly the same gradient, every profile could be described as either flattening or steepening. In order to eliminate insignificant rotational changes any change of less than 1.5% of the mean width of the foreshore was considered to be no change. In addition to this, judgement

11 was used where some apparent rotational changes were deemed to be unreliable due to high degrees of foreshore variability. 1.5 Future outputs Future updates of this report will include updated information on beach trends using the latest available profile data. In addition to this, the report may include extended analysis utilising other data sets collected by the Shoreline Management Group. Bathymetric surveys have been undertaken at 5 year intervals and this will be enhanced as part of the phase VII ( ) monitoring programme. In addition to this, output from the wave and tide recording buoy deployments will be included. These reports will support and inform the move towards a risk-based monitoring programme for 2011 and beyond.

12 Table 1. Foreshore change classification system adapted from Halcrow (1988)

13 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Figure 4 the North Norfolk Coast

14 2.0 Northeast Norfolk and North Suffolk (sub-cell 3b) coastal trends 2.1 Introduction The information presented here is the result of data collected along the Northeast Norfolk and Suffolk coast from Kelling to Lowestoft. This coast is physically diverse with high soft cliffs, up to 70m above sea level, to the north and lower cliffs in the southern section. The section between Cart Gap, 2Km south of Happisburgh, and Winterton is a dune fronted low lying flood plain which contains a significant proportion of the Norfolk Broads. South of Winterton a stretch of low lying cliffs leads to the town of Great Yarmouth which is principally built upon a sandbank that formed at the mouth of the River Yare. Between the mouth of the Yare and Lowestoft the beaches are again backed by low lying sea cliffs. The area has suffered from a number of well documented storm events, the most notable being the great storm of January 1953 where flooding occurred on a large scale around the entire east coast of England, Belgium and the Netherlands. Along this coast both Great Yarmouth and Sea Palling were badly flooded. In 1938 the area around Horsey, south of Sea Palling, was extensively flooded after a storm breached the dune defences. Elsewhere on this coast the sea cliffs have a long history of gradual coastal erosion with a number of villages documented as being lost to the sea over the centuries. Much of this coastline is currently defended against marine flooding and coastal erosion with classic hard defences. The principle towns of Sheringham, Cromer, Great Yarmouth and Lowestoft have been defended against coastal erosion since the mid 19 th century. In addition to this some of the minor towns and villages have a long standing tradition of coastal defence. The older defences tend to be substantial seawalls and promenades covering a relatively short length of coastline. In the years after the 1953 storm there was a major campaign of defence construction which has resulted in the majority of this coastline now having defence structures in place. One of the consequences of widespread coastal defence structures is that the sediment that otherwise would have been eroded from the cliffs is retained and therefore is not available as beach material. As this coast is generally regarded as a single sediment cell dominated by southerly net longshore drift, this is likely to have contributed to diminishing beach levels. A consequence of this is the major sea defence works that are required along the Cart Gap, Happisburgh to Winterton frontage and the rapid erosion of the beach (and subsequently the cliffs) at Happisburgh village. The Shoreline Management Plan (SMP) for this section of coastline was completed in 2006 (Halcrow, 2006). This noted that the ongoing supply of beach material from cliff erosion was an essential feature of this coast and concluded that the long-term technical sustainability of many of the defences along the Kelling to Lowestoft coast was a major issue.

15 2.2 General description Kelling to Lowestoft Figure 5, overleaf, shows the general results of the analysis, which are summarised in table 2 below. Appendix 1 shows the names and general locations of the profiles. No. Percentage Accretion General No Change (+/- 0.25m yr) Trend Erosion No data Flattening Foreshore Steepening Gradient No rotation or movement No data Defences at Structures profile location No structures Table 2 - general results of analysis 2.3 Outline observations Of the 77 topographic beach profiles along the Kelling to Lowestoft coast, 44% have shown some erosional trend of the foreshore over the last 15 years. This figure does not include the coast from Cart Gap, Happisburgh to Winterton (which has a long history of retreat of the dune ridge) as this has been mitigated by various beach nourishment campaigns over the last ten years and therefore no natural trends of beach evolution. The majority (75% 3 ) of this coast is artificially held by structures thus the beaches have been unable to behave naturally (to a significant degree), and where applicable roll back, in response to the forces shaping the coast. However, only 25% of the profiles have shown any significant foreshore steepening trend with the majority of profiles showing no rotation or movement. The following section offers description of the results of the analysis as well as graphically showing the trends overlaid over a suite of aerial photographs that were taken during summer Unless stated otherwise all trends and rates expressed relate to changes on the foreshore i.e. on or between the MHWS and the MLWS levels. 3 This figure relates to actual long-shore structures at the location of the profile determined from 2006 aerial photography.

16

17 2.3.1 Kelling (Weybourne) to Cromer N2B7 and N2A1, Weybourne (east) cliffs. Both profiles show modest erosion with a greater rate at the low water mark producing a slightly steepening beach profile. N2A2 and N2A3, Sheringham lifeboat station. Profiles show no significant movement and no steepening. N2A4, Sheringham (east) Beeston cliffs. Significant retreat of MLWN position at a rate in excess of 1m year. No MHWS retreat due to coast protection works. Foreshore steepening apparent. N2A5, Beeston cliffs (east). Modest retreat of MLWN position at a rate of 0.5m year. No MHWS retreat due to coast protection works. Foreshore steepening apparent. N2A6, West Runton cliffs. Profile shows no significant movement and no steepening. N2A7, West Runton Gap. Steady retreat of MHWS and MLWN positions. Trend of beach flattening apparent due to greater trend of retreat at MHWS. N3E1, East Runton cliffs. Steady retreat trend of MHWS and MSL positions. Reduced retreat of MLWN/S position giving a flattening foreshore trend. N3E2, Cromer (west) cliffs. Steady retreat of MHWS and MSL positions. Highly variable lower foreshore with no significant trend. N3E3, Cromer west beach. No change of upper beach positions, lower beach variable with no overall trend. Summary The area is dominated by cliffs that are undergoing erosion fronted by wide sand and shingle beach. Significant stretches of chalk outcrops within the cliff material offer some limited resistance to cliff erosion when compared to the remainder of the Subcell 3b coast. This section of coast possesses a different orientation to the remainder of the 3b coast. To the west of Cromer the coast is broadly north facing and therefore its exposure to predominantly northerly wave (and storm) action differs from the coast east of Cromer. Several of the profiles along this section show little or no movement of the foreshore. The greatest beach erosion is occurring at the coast adjacent to the Runtons Cromer to Cart Gap, Happisburgh N3E4, Cromer east beach. Some variability but generally a stable beach with no retreat trend at any level.

18 N3E5, Royal Cromer Golf Club. Profile shows a significant accretion of the MHWS position at a rate in excess of 1m year. Both MSL and MLWN position show little change. N3E6, Overstrand. Variable beach showing modest retreat at all levels except MHWS which is constrained by the seawall, giving a steepening foreshore N3D1, Overstrand, Clifton Way. Site of a major landslip in the mid 1990 s. Lower beach shows modest erosion trend. Upper beach shows accretion trend which is likely to be attributable to the rock bund, constructed in 1990 s, constraining erosion. Foreshore steepening apparent. N3D2, Sidestrand. The Sidestrand and Trimingham frontage possesses the highest cliffs in the area, with heights up to approximately 65 metres above sea level. Site has a long history of significant cliff erosion. Data shows that beaches here show some variability although a strong erosion trend is apparent. N3D3, Trimingham (west beach). Significant foreshore erosion trend apparent at all levels. Reduced rate at MLWN gives a slightly flattening foreshore change parameter. N3D4, Trimingham village. Currently defended with timber revetment (with concrete apron) and groyne field. Limited beach erosion due to concrete apron remaining intact despite failure of the timber section of the defence. N3D5, Trimingham (east beach). Modest beach erosion trends at all levels. N3D6, Vale Road beach access. Upper beach shows erosion trend of 0.5m year, lower beach shows accretion of approx 1m year giving a foreshore flattening trend. N3C1, Mundesley cliffs (west). Beach shows some variability with general erosion trend. Data shows period of very low beach levels in late 1990 s with some recovery since. N3C2, Mundesley. Strong erosion trend of upper beach levels with no significant change on lower beach. N3C3, Mundesley cliffs (east). Highly variable beach levels with overall trend of erosion on upper beach. N3C4, north of Bacton Gas Site. Variable beach levels with erosion trend of upper beach levels and accretion of the lower beach giving a flattening foreshore. N3C5, Bacton Gas Site. Data shows strong beach accretion trend of all levels although some significant erosion of upper beach apparent since N3C6 to N3C8, Bacton and Walcott seawall. All profiles from this location show erosion of lower beach. Upper beach levels constrained by seawall. Data from these profiles show a brief period of higher upper beach levels between 1999 and 2004 which has subsequently disappeared.

19 Environment Agency copyright and/or database rights All rights reserved. Environment Agency copyright and/or database rights All rights reserved. Figure 6 - Beach Road, Happisburgh 1992 and 2006 N3B1, Ostend. Profile shows an accretion trend of upper beach. Timber revetment at this location was extensively refurbished in Lower beach shows consistant erosion trend causing beach steepening to occur. N3B2, north Happisburgh cliffs. Profile shows significant erosion trend at all levels and beach steepening throughout monitoring period.

20 N3B3, Beach Road Happisburgh. Survey located at an area of significant erosion throughout monitoring period (figure 6). Profile shows severe erosion at all levels and beach steepening. N3B4, Doggetts Lane. A highly variable beach although no significant overall trend apparent. N3B5, Cart Gap. Variable beach with modest overall trend of erosion. Summary The coast between Cromer and Happisburgh is characterised by high cliffs, up to ~65m near Trimingham, in the north, reducing to relatively low sand/mud cliffs, 8-10m high, in the southern section south of Bacton Gas Site. At Walcott the cliff height reduces to less than 5m and a small area of hinterland is subjected to periodic flooding through overtopping during storm and high tide events. The entire area has a long history of coastal erosion with significant loss of land and property over the centuries. Recession of the cliff top position was calculated from historic Ordnance Survey maps dating back to the 1880 s and an average rate of approximately 1m year was ascertained for much of this frontage. The maximum cliff top recession was found to have occurred between Overstrand and Trimingham where the cliff had retreated at ~ 2.25m year. The majority of profiles collected along this section of coast show an erosional trend throughout the monitoring period. North of Bacton Gas site there is little evidence of foreshore steepening having occurred, however, south of the site between Bacton and Cart Gap, Happisburgh virtually all the profiles show a steepening trend Cart Gap, Happisburgh to Winterton Cart Gap is the boundary between North Norfolk District Council s operational responsibility for coast protection and the Environment Agency s responsibility for sea defence. The 11Km of coastline between Cart Gap and Winterton has a long history of recession and flooding. There are documented records of flood events having occurred here since the 12 th century; however the two most recent events in 1938 at Horsey and the 1953 breach at Sea Palling are the best documented. Shortly after the Anglian Coastal Monitoring Programme began in 1991 a major sea defence strategy has been implemented along this frontage. This work was instigated as a result of very low beach levels and subsequent erosion of the clay platform underlying the beach. The work consisted of a series of nine offshore reef structures at the northern end of the coast and a major beach nourishment campaign. Figure 7 shows the change at Sea Palling between 1992 and Natural coastal evolution trends can not be ascertained from the profile data along this frontage due to the engineering works that have been undertaken along this frontage.

21 Environment Agency copyright and/or database rights All rights reserved. Environment Agency copyright and/or database rights All rights reserved. Figure 7 - the coast at Sea Palling 1992 and 2006

22 Environment Agency copyright and/or database rights All rights reserved. Figure 8 Movement of Winterton Ness from 1992 to Winterton Ness to Great Yarmouth N4D1, Winterton Ness north. Although beach levels are variable there is a clear erosion trend with minor foreshore flattening having occurred. N4D2, Winterton Ness. A strong accretion trend attributable to a northward migration of the ness throughout the monitoring period (as can be seen in figure 8). No rotational change of the foreshore. N4D3, Winterton Ness south. A strong erosion trend likely to be attributable to the northward migration of the Ness. Some limited engineering works implemented in recent years adjacent to car park appear to have temporarily arrested erosion trend. No rotational change of the foreshore.

23 N4D4, Winterton Ness south. An overall erosion trend with high beach variability. Some accretion has occurred since 2004 although this may be temporary. Some foreshore flattening apparent. N4C1, Winterton Ness south. Although beach levels are variable there is overall a strong erosion trend. Foreshore steepening apparent. N4C2, Hemsby north. A variable beach with an overall erosion trend. No foreshore rotational change apparent. N4C3, Hemsby south. Data shows an overall erosion trend prior to 2002 with significant accretion having occurred since. Foreshore location is now seaward of 1992 position. Some foreshore flattening apparent. N4C4, Scratby north. Beach shows some variability with an overall erosion trend. No foreshore rotational change apparent. N4C5, California. Significant steady erosion trend with foreshore steepening apparent. N4B1, between California and Caister. Significant accretion has occurred coincidental with the construction of a rock fishtail groyne 140m south of profile in circa This structure is partially buried in 2006 aerial photographs. Accretion peak occurred in 2000 with some beach erosion since. N4B2, Caister north. Massive accretion occurred after construction of rock reefs circa Trend rate of ~ 10m year not indicative of future trend. N4B3, Caister. Steady beach erosion with no rotational change of the foreshore. N4B4, Great Yarmouth and Caister Golf Course. Strong erosion between 1991 and 2002 with some accretion since. Minor beach flattening apparent. N4B5, Great Yarmouth North Denes. Located north of North Denes ness. After a period of minor accretion prior to 1996 coast reverts to steady erosion trend. Minor beach flattening apparent. N4A1, Great Yarmouth North Denes ness. Generally a steady accretion trend of the ness since 1991 with no rotational change of the foreshore. N4A2 to N4A5 Great Yarmouth beach. All 4 profiles show steady accretion trend over entire monitoring period. No rotational change on all profiles. N4A6 and N4A7, Great Yarmouth South Denes. Both profiles show erosion trend over monitoring period. In 2007 construction of the Great Yarmouth Outer Harbour began at this location. Summary Data shows this section of the coast to be dynamic with both rapid erosion and accretion occurring at various locations along the coast.

24 Although, from examination of historic Ordnance Survey maps, many areas i.e. Scratby and California, have shown very little cliff-top erosion over the last century. Current rates of beach erosion in these areas mean that it is unlikely that this will continue in the long-term. Most of the main Great Yarmouth beaches are showing strong accretion rates with the exception of the southern section at South Denes. This is the location of the Great Yarmouth Outer Harbour, which at the time of writing is under construction Great Yarmouth to Lowestoft SWG1, Gorleston beach. Data shows a brief period of erosion between 1993 and 1996 with a subsequent steady accretion trend since. No foreshore rotational trend apparent. SWG2, Gorelston beach south. Steady accretion trend throughout monitoring period. No foreshore rotational trend apparent. SWG3, Gorleston Golf Course. Generally beach accretion has occurred, however very low beach levels were observed in the 2001 surveys. Some degree of foreshore steepening trend apparent. SWG4, Hopton north. A variable beach with no overall trend or foreshore rotation evident. Periods of very low beach levels observed. SWF1, Hopton south. Generally a strong erosion trend with periods of very low beach levels observed during winter surveys of 1997, 2001, 2003 and No significant evidence of foreshore rotation. SWF2, Corton Cliffs. Data shows some accretion prior to 1997 with subsequent erosion since. Little or no beach present in front of defences. Strong beach steepening trend apparent. SWF3, Corton Village. A strong erosion trend with significant foreshore steepening occurring. SWF4, Gunton Cliffs. A period of modest erosion up to 2001 followed by some degree of accretion. No significant foreshore rotational trend apparent. SWF5, Lowestoft North Denes. A variable beach with no overall trend apparent. SWF6, Lowestoft Denes Caravan Park. Some accretion prior to 1997 followed by strong erosion trend. No foreshore rotational change apparent. SWF7, Lowestoft North Beach. A highly volatile beach with no overall trend.

25 Summary With the exception of the three profiles at Gorleston beach most of this section of coast is displaying an erosion trend. This appears to be most severe in the Corton area where foreshore steepening has occurred at the Corton Cliffs and Corton Seawall beaches. Examination of historic Ordnance Survey maps revel that the cliffs north of Corton have retreated at approximately 1 metre per year prior to the construction of the timber revetment. This rate is reduced at Corton village due the presence of the early seawall, however, beach steepening here has been severe.

26 3.0 Graphical View of Results Legend to maps

27 N2B7 N2A1 N2A2 N2A Anglian Coastal Monitoring Programme Subcell 3b Plan 1 - Weybourne to Sheringham 1:12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

28 Anglian Coastal Monitoring Programme Subcell 3b Plan 2 - Sheringham to West Runton N2A N2A5 N2A6 N2A7 1:12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

29 Anglian Coastal Monitoring Programme Subcell 3b Plan 3 - Runton and Cromer N2A7-3 N3E N3E2 N3E3 1:12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

30 -5 Anglian Coastal Monitoring Programme Subcell 3b Plan 4 - Cromer and Overstrand N3E N3E N3E :12,500 N3E Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

31 Anglian Coastal Monitoring Programme Subcell 3b Plan 5 - Sidestrand N3E N3D N3D2-4 1:12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

32 0 Anglian Coastal Monitoring Programme Subcell 3b Plan 6 - Trimingham N3D N3D N3D N3D6 1:12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

33 Anglian Coastal Monitoring Programme Subcell 3b Plan 7 - Mundesley N3D N3C N3C :12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

34 Anglian Coastal Monitoring Programme Subcell 3b Plan 8 - Bacton Gas Site N3C N3C N3C :12, Km N3C6 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

35 Anglian Coastal Monitoring Programme Subcell 3b Plan 9 - Bacton and Walcot N3C N3C N3C8 +2 1:12, Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

36 Anglian Coastal Monitoring Programme Subcell 3b Plan 10 - Happisburgh N3B N3B2(HW1) :12,500 N3B3(HW26) Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

37 0 Anglian Coastal Monitoring Programme Subcell 3b Plan 11 - Bush Estate N3B4(HW47) N3B5A(HW57) N/A 0.00 N3B6A(HW77) N/A :12,500 N3B6B(HW94) Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

38 Anglian Coastal Monitoring Programme Subcell 3b Plan 12 - Sea Palling 0.00 N/A Happisburgh to Winterton This section of coast has a long history of retreat and since the monitoring programme began in 1992 there has been a major sea defence scheme along this frontage. This includes a series of nine offshore reefs and beach nourishment campaigns. For this reason trends based upon data collected along this frontage are not indicative of potential future coastal evolution and are not presented in this report. N3B6B(HW94) N/A 0.00 N3B7A(HW119) N/A 0.00 N/A 1:12,500 N3B8A(HW139) Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

39 Anglian Coastal Monitoring Programme Subcell 3b Plan 13 - Waxham 0.00 N/A Happisburgh to Winterton This section of coast has a long history of retreat and since the monitoring programme began in 1992 there has been a major sea defence scheme along this frontage. This includes a series of nine offshore reefs and beach nourishment campaigns. For this reason trends based upon data collected along this frontage are not indicative of potential future coastal evolution and are not presented in this report. N3A2A(HW171) N/A 0.00 N3A3(HW186) N/A :12,500 N3A4(HW206) Km Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

40 Anglian Coastal Monitoring Programme Subcell 3b Plan 14 - Horsey 0.00 N/A Happisburgh to Winterton This section of coast has a long history of retreat and since the monitoring programme began in 1992 there has been a major sea defence scheme along this frontage. This includes a series of nine offshore reefs and beach nourishment campaigns. For this reason trends based upon data collected along this frontage are not indicative of potential future coastal evolution and are not presented in this report. N3A5(HW224) N/A 0.00 N3A6(HW244) N/A :12, Km N3A7(HW264) Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved.

41 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 15 - Winterton N/A 0.00 N3A8(HW284) N4D1(HW304) N4D2(HW323) 1:12, Km N4D3(HW343)

42 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 16 - Hemsby (north) N4D2(HW323) N4D3(HW343) N4D4(HW349) N4C1(HW365) N4C2(HW385) 1:12, Km

43 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 17 - Hemsby (south) N4C2(HW385) N4C N4C N4C5 1:12, Km

44 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 18 - Caister N4C N4B N/A N4B N4B3 1:12, Km

45 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 19 - Yarmouth (north) N4B N4B N4B5 N4A :12, Km

46 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 20 - Gt Yarmouth N4A N4A N4A :12, Km N4A

47 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 21 - Yarmouth (south) N4A N4A N4A N4A :12, Km

48 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 22 - Gorleston SWG1 SWG SWG :12, Km SWG

49 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 23 - Hopton SWG SWF SWF :12, Km

50 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 24 - Corton SWF SWF SWF :12, Km

51 Crown copyright and database rights 2008 Ordnance Survey Environment Agency copyright and/or database rights All rights reserved. Anglian Coastal Monitoring Programme Subcell 3b Plan 25 - Lowestoft SWF SWF SWF :12, Km

52 Appendix 1 Detailed Results Number Name Defence Metres per year Mean FCP Notes MHWS MSL MLWN/S Rate Score N2B7 Weybourne MLWN used N2A MLWN used N2A N2A MLWN used N2A4 Sheringham Seawall MLWN used N2A5 Timber/conc revetment MLWN used N2A6 Timber revetment MLWN used N2A7 West Runton MLWN used N3E1 East Runton MLWN used N3E MLWN used N3E3 Cromer Seawall MLWN used N3E4 Conc dwarf wall MLWN used N3E MLWN used N3E6 Overstrand Seawall N3D1 Rock bund MLWN used N3D N3D MLWN used N3D4 Trimingham Timber & conc. revetment MLWN used N3D MLWN used N3D6 Timber revetment MLWN used N3C1 Timber revetment N3C2 Mundesley Seawall N3C3 Timber revetment MLWN used N3C4 Timber revetment N3C5 Timber revetment MLWN used - Data shows erosion post 2003 N3C6 Seawall MHWS trend misleading N3C7 Walcott Seawall MHWS trend misleading

53 N3C8 Seawall MHWS trend misleading N3B1 Timber revetment N3B2 Timber revetment (failing) MLWN used N3B3 Happisburgh Timber revetment (failed) N3B4 Seawall/recharge Variable upper beach N3B5A Seawall/recharge N3B6A Seawall/recharge N/A Recharged beach no trend N3B6B Seawall/recharge N/A Located north of reef trend unreliable N3B7A Seawall/offshore reefs/recharge N/A Located between reefs trend unreliable N3B8A Sea Palling Seawall/offshore reefs/recharge N/A Located between reefs trend unreliable N3A1 Seawall/offshore reefs/recharge N/A Located behind reefs trend unreliable N3A2 Seawall/offshore reefs/recharge N/A Located south of reefs trend unreliable N3A3 Seawall/recharge N/A Nourished beach trend unreliable erosion apparent N3A4 Seawall/recharge N/A Nourished beach trend unreliable erosion apparent N3A5 Seawall/recharge N/A Nourished beach trend unreliable erosion apparent N3A6 Seawall/recharge N/A Nourished beach trend unreliable erosion apparent N3A7 Seawall/recharge N/A Nourished beach no trend N3A8 Seawall/recharge N/A Nourished beach poor trend accretion not apparent N4D1 Seawall/recharge N4D2 Seawall/recharge Winterton Ness northerly migration N4D3 Winterton Ness Car park (?) Erosion stalled in 2004 by works at car park N4D Some accretion since 2005 N4C MLWN used N4C N4C Variable beach but some accretion apparent N4C Variable beach but some erosion apparent N4C5 Rock revetment Limited data but erosion & steepening apparent N4B1 Seawall Variable beach but strong accretion apparent N4B2 Rock bunds (reefs) N/A Rock bund at LWM, strong accretion stable since N4B3 Caister Seawall Strong erosion trend N4B Some accretion since 2002 N4B5 Seawall

54 N4A North Denes strong accretion N4A2 Seawall with natural dunes N4A3 Seawall N4A4 Great Yarmouth Seawall N4A5 Seawall N4A6 Seawall N4A7 Seawall Gt Yarmouth Outer Harbour site SWG1 Gorleston Seawall MLWN used SWG2 Seawall SWG3 Timber revetment SWG4 Timber revetment SWF1 Seawall SWF2 Timber revetment Trend unreliable major beach loss since 1998 SWF3 Corton Seawall SWF4 Seawall Accretion trend since 2000 SWF5 Seawall SWF6 Seawall Trend unreliable major beach loss since 1998 SWF7 Lowestoft Seawall Highly variable beach

55 Appendix 2 - References (1). SANDS software by Halcrow Group PLC. (2). POLTIPS software by Proudman Oceanographic Laboratory. Cambers, G, Sediment Transport and Coastal Change. East Anglian Coastal Research Programme, Report 3, University of East Anglia, Norwich, 65pp. Defra, Shoreline Management Plan Guidance: Volume 2, Appendix E Open coast SMP management boundaries. English Nature, Environment Agency, Defra, Natural Environment Research Council. North Norfolk Coastal Habitat Management Plan (CHaMP). Royal Haskoning Jan 2003 Halcrow, Kelling to Lowestoft Shoreline Management Plan: First Review. Final Report November Available from HR Wallingford Coastal Management: Mapping of Littoral Cells, report SR328 May, VJ, North Norfolk Coast. In Coastal Geomorphology of Great Britain, Geological Conservation Review Series, No. 28, (VJ. May and JD Hanson), Joint Nature Conservation Committee, Peterborough, pp Mouchel, North Norfolk Shoreline Management Plan. Environment Agency. Steers, JA, Coastal Features of England and Wales. Eight Essays, Oleander Press, Cambridge 206 pp. Taylor, JA, Murdock, AP & Pontee, NI, A macroscale analysis of coastal steepening around the coast of England and Wales. The Geog. Journal, Vol 170, No. 3, Sept 2001, pp Townend, I, Fleming C, McLaren P & Hunter-Blair A regional study of coastal morphology in 22 nd International Conference of Coastal Engineering Vol 3 American Society of Civil Engineers (ASCE), Delft The Netherlands Halcrow Anglian Coastal Management Atlas. Sir William Halcrow & Partners.

56