Coastal Trends Report
Suffolk (Lowestoft to Languard Point, Felixstowe)
RP022/S/2011
February 2011
Title here in 8pt Arial (change text colour to black)
i
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
Email: [email protected]
www.environment-agency.gov.uk
© Environment Agency 2011
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:
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or our National Customer Contact Centre: T:
03708 506506
Email: [email protected].
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Easton Marshes
(Photo: Environment Agency)
Glossary
Accretion
The accumulation of sediment on a beach by the action of
natural forces or as a result of artificial structures
Bathymetry
The topographic relief of the seabed
Beach recharge
Artificial process of replenishing a beach with material from
another source
Berm crest
Ridge of sand or gravel deposited by wave action on the
shore just above the normal high water mark
Coastal Squeeze
The reduction in habitat area that can arise if the natural
landward migration of a habitat under sea level rise is
prevented by the fixing of the high water mark, e.g. a sea
wall
Erosion
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
FCP
Foreshore Change Parameter – a score of foreshore
steepening or flattening
Foreshore
The area of beach lying between high water and low water
Foreshore rotation
Foreshore steepening or flattening resulting in the
convergence or divergence of high and low water marks
Groyne
Shore protection structure built perpendicular to the shore;
designed to trap sediment
Longshore drift
Movement of sediment along the shoreline
MHWS
level of Mean High Water Spring tides
MLWS
level of Mean Low Water Spring tides
MSL
Mean Sea Level
Ness
A large low-lying foreland or promontory of mobile sands or
shingles attached to the foreshore
SANDS
Shoreline and Nearshore Database - software developed by
Halcrow for the analysis of beach profile data
SMP
Shoreline Management Plan. A high level strategy plan for
managing flood and erosion risk for a particular stretch of
coastline
Soft defences
Engineering options which are non-rigid (like sea walls) and
which work with the natural coastal processes of wave
action and sediment movement
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Suffolk
Coastal Trends Analysis
1.0
INTRODUCTION.................................................................................................................... 1
1.1
COASTAL MONITORING ...................................................................................................... 1
1.2
ANALYSIS METHODOLOGY ................................................................................................ 1
2.0
STUDY AREA ....................................................................................................................... 3
3.0
ANALYSIS............................................................................................................................. 6
3.1
OUTLINE TIDAL OBSERVATIONS ....................................................................................... 6
3.2
DETAILED OBSERVATIONS ................................................................................................ 8
3.3
3.2.1
Lowestoft to Kessingland ...................................................................................... 8
3.2.2
Kessingland to Southwold ..................................................................................... 9
3.2.3
Walberswick to Dunwich ..................................................................................... 11
3.2.4
Dunwich Heath to Thorpeness ............................................................................ 11
3.2.5
Thorpeness to Orfordness Lighthouse ................................................................ 11
3.2.6
Southern Orfordness ........................................................................................... 13
3.2.7
Shingle Street to Bawdsey Manor ....................................................................... 14
3.2.8
Felixstowe Ferry to Landguard Point................................................................... 15
TRENDS ANALYSIS MAPS.......................................................................................... 16 - 35
Appendix 1 – DETAILED RESULTS .................................................................................................... 36
Appendix 2 – REFERENCES............................................................................................................... 39
ii
© Crown copyright and database rights 2011 Ordnance Survey 100024198. ©
copyright and/or database rights 2011. All rights reserved.
Environment Agency
Map 1 – Shoreline Management Plan 2 boundaries (2011)
iii
1.0
Introduction
1.1
Coastal Monitoring
The Shoreline Management Group (SMG) based within the Environment Agency’s (Anglian Region)
Flood and Coastal Risk Management section has undertaken regular strategic coastal monitoring of
the Anglian coast since 1991.
The Anglian Coastal Monitoring programme is now coming to the end of its phase VII (2006/07 to
2010/11) programme which has collected a variety of data including;
•
•
•
•
•
Annual aerial photographs
Bi-annual strategic topographic beach surveys (winter and summer) at 1km intervals
Bathymetric surveys (extension of beach survey lines out to approximately 10m depth offshore)
Continuous wave and tide recording (nearshore and offshore). As part of Phase VII this included
a suite of five offshore, and twenty nearshore continuous wave and tide recorders.
Scheme specific beach topographic surveys at closer intervals
Beach topographic profiles have been undertaken at 1km intervals, twice yearly in summer and in
winter, along the coast since 1991. Generally speaking the main aspect 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 often of particular interest to coastal managers.
The positional accuracy of the Anglian Coastal Monitoring profiles is +/-0.05m vertical and +/-0.02m
horizontal.
Now, with a continuous record of nearly twenty years of beach topographic data, it is therefore
possible to analyse these to determine reasonably robust initial indicators of longer-term trends and
the Shoreline Management Group have produced a number of Coastal Trends Reports for Anglian
region which tie in with the Shoreline Management Plan boundaries (see Map 1).
This report is an updated version of the Suffolk Coastal Trends (2007) analysis, now incorporating
data up to and including summer 2010 with trends recalculated to reflect this new data.
Our scheme specific monitoring addresses more local sea defence scheme requirements in greater
detail at a variety of locations along the coast. More in-depth analysis at key locations such as at
Southwold to Benacre and at East Lane, Bawdsey has taken place. These reports often analyse more
of the beach profile, for example above high water using in-house software and incorporates the use
of historic OS maps. These reports are also available from the SMG with more key area analyses
being undertaken as and when required.
The new Phase VIII monitoring commencing in April 2011 and running to 2016 will link with the
national coastal monitoring programme providing improved levels and intensities of topographic and
bathymetric data. There will also be more emphasis on habitat monitoring through aerial and LiDAR
survey.
1.2
Analysis methodology
The profile data presented in this report is mainly in the form of tide level analysis and movement of
the foreshore between high and low water together with aerial photography between 1991 and 2010.
Tide level analysis and the temporal changes to the beach foreshore and gradient looks at the
corresponding lateral movement of the high and lower water marks over time. This data was analysed
using a function of ‘SANDS’ software with tidal parameters, derived from harmonic analysis, supplied
by Gardline Environmental Ltd. The foreshore represents the intertidal region between the highest
and lowest tide level and in this report the area between the MHWS (Mean High Water Spring) and
MLWS (Mean Low Water Spring) level is used.
1
This analysis gives mean rates of erosion or accretion trends for each profile along with the degree of
foreshore steepening or flattening.
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 on page 16. Positive Foreshore
Change Parameter (FCP) values indicate a beach system advancing seaward and negative values
show a system retreating landwards. The individual FCP numbers indicate flattening, steepening or
no rotation.
Figure 1 below demonstrates the principals of beach profile change – mean erosion/accretion and
beach gradient – over time.
Figure 1 – Conceptual diagram of a beach profile showing shoreline advance/retreat and foreshore change parameter
However, there is uncertainty in predicting coastal trends particularly where cyclical processes are
involved and added to this are other uncertainties such as sea level rise. There are also areas where
anthropogenic influences such as groynes and beach recharge will affect the overall trend of a profile.
2
2.0
Study Area
This report covers the Suffolk coastal frontage from Lowestoft south pier, to Felixstowe Landguard
Point, on the northern bank of the Stour/Orwell estuary – a total length of 72km. The area is based
upon the Shoreline Management Plan (SMP) boundary area for Suffolk (sub-cell 7). The remainder
of the Suffolk coast, north of Lowestoft harbour lies within the North East Norfolk and North Suffolk
SMP (sub-cell 6).
This stretch of coast is characterised by soft eroding cliffs, shingle beaches and coastal lagoons
(broads) and includes the estuaries of the Blyth, Alde and Ore, and Deben. The soft materials of the
coastline make it easily eroded and increasingly vulnerable to the long term impacts of climate
change. The majority of the coast is natural and as a result beaches have been able to behave
naturally and roll back in response to natural processes.
Longshore drift of beach material dominates much of this coastline resulting in unique shingle features
such as Orfordness, at 16km long, one of the largest shingle spits in Europe; and Benacre Ness, a
large mobile shingle beach which is steadily migrating northwards against the predominant net
southerly drift at a rate of around 30m/yr (May, 2003).
Lowestoft and Felixstowe are the two major urban centres in Suffolk and have been defended against
coastal erosion with extents of sea wall and groynes for many years. Work on the South Felixstowe
scheme was completed in October 2008 and consisted of T-shaped rock groynes and beach recharge.
The Central Felixstowe scheme with additional rock groynes and beach recharge between Jacob’s
Ladder and the War Memorial is due to be started in 2011.
In addition to this some of the smaller isolated towns and villages have a long standing tradition of
coastal defence such as Southwold and Aldeburgh. Southwold’s sea defences were updated in 2006
to include new rock groynes and beach recharge.
Suffolk has a long history of coastal change with many storm and flooding events recorded over the
centuries. The most notable being the great storm of January 1953 where flooding occurred on a
large scale around the entire east coast of England with records showing that 40 people lost their lives
in Suffolk mostly in the town of Felixstowe. There is also a long history of gradual coastal erosion of
the cliffs with a number of villages documented as being lost to the sea over the centuries. The most
famous of these is the village of Dunwich, once one of the most important East Anglian ports during
the early Middle Ages.
Beach management practices with soft engineering options have also been utilised along this stretch
of coast. Reprofiling (by bulldozer) of the Dunwich to Walberswick shingle ridge following storm
events used to be employed to protect the area of grazing marsh behind it. Similarly at Easton Broad
reprofiling of beach sediments was undertaken to protect the lagoon and freshwater habitat. Such
practices have recently ceased due their relative unsustainability and the lack of available sediment in
the ridges. These frontages are now being left to roll back naturally in response to coastal processes
and predicted sea level rise. However, shingle recycling works to recharge the neck at Slaughden are
continuing. This scheme has used sediment from the neighbouring Sudbourne beach on Orfordness
since 2002 to add sediment to beaches further north around the Martello Tower and at the neck
where beach levels are receding.
This study has looked at the coastline only and has not analysed data collected further inland beyond
the mouths of the estuaries. A total of 74 strategic beach profiles along the Suffolk coast at roughly
1km intervals collected since 1991 have been included. Further site specific studies have been
undertaken including more intensive scheme monitoring and which are available from the Shoreline
Management Group.
3
© Crown copyright and database rights 2011 Ordnance Survey 100024198. ©
copyright and/or database rights 2011. All rights reserved.
Environment Agency
Map 2 – Suffolk frontage profile locations (north)
4
© Crown copyright and database rights 2011 Ordnance Survey 100024198. ©
copyright and/or database rights 2011. All rights reserved.
Environment Agency
Map 3 – Suffolk frontage profile locations (south)
5
3.0
Analysis
3.1
Outline tidal observations
Table 1 below and Figure 2 on page 7 show the general trend of results of the 74 strategic profiles
from Lowestoft south pier to Felixstowe Landguard Point used in the tide level analysis. Two profiles
were shown as ‘no trend’ – S2A1 at the Knolls, Felixstowe Ferry where mobile sandbars at low water
do not give a meaningful result and at S2B4 East Lane, Bawdsey where erosion at the profile location
has outstripped the ability to survey in that location. Appendix 1 lists the full results in more detail.
Mean
Trend
Foreshore
Gradient
Defences at
profile location
Accretion
No Change (+/- 0.2 m/yr)
Erosion
No trend
Flattening
Steepening
No rotation
No trend
Hard defences
Natural defences#
1
No. of profiles Percentage
24
32
14
19
34
46
2
3
25
34
13
17
34
46
2
3
21
28
53
72
Table 1 – general results of analysis showing mean trends, foreshore gradients and alongshore defences by number of profiles
and percentage
The majority of the Suffolk coast (72 per cent of profiles) is natural and not artificially held by defences
of any kind. As a result beaches have been able to behave naturally and roll back in response to
natural processes. Along the developed sections of coast at Lowestoft, Southwold and Felixstowe
beaches are backed by concrete sea walls with groynes and are more constrained in their response.
Of the 74 profiles, nearly half (46 per cent) show a general erosion trend over the last 19 years. The
most significant trend of erosion was observed along the cliffs from Kessingland (south of Benacre
Ness) to Covehithe and Easton Bavents, just to the north of Southwold. The highest erosion rate
along this stretch was at Covehithe cliffs (SWD2) at -5.7m/yr. Other significant erosion trends were
apparent at the southern end of shingle spit at Orfordness and the low cliffs at Bawdsey.
A similar percentage of profiles (46 per cent) have shown no significant rotational change and most of
these are attributed to the profiles with natural defences. A third of profiles showed a flattening trend,
although a flattened profile does not necessarily equate to an accretional trend.
Nearly a third of profiles (32 per cent) did show an accretion trend. There were four main areas of
accretion; at Lowestoft; North Kessingland where accretion is attributed to Benacre Ness’s northerly
migration; north Orfordness/Slaughden and at Shingle Street. The most significant accretion rate at
North Kessingland (SWE8) was 16.9 m/yr.
The following section offers a description of the results of the analysis as well as graphically showing
the trends overlaid onto a suite of aerial photographs that were taken during summer 2010. All trends
and rates expressed relate to changes of the foreshore between MHWS and MLWS.
#
includes cliffs, dunes, shingle beaches and areas of ‘beach management’ where beaches, generally fronting low-lying land,
have undergone some intervention in the form of mechanical sediment redistribution occurring at some stage during the
monitoring period
6
SWE8 –
Benacre Ness
accretion rate
of 16.9 m/yr
2
0
Accretion/erosion trend (m/yr)
Lowestoft
Covehithe
Walberswick
Thorpeness
Orfordness
Bawdsey
Felixstowe
MLWS
MSL
S2B1 –
Shingle Street
accretion rate
of 4.6 m/yr
6
MHWS
4
-2
-4
-6
SWF8
SWE1
SWE2
SWE3
SWE4
SWE5
SWE6
SWE7
SWE8
SWE9
SWE10
SWD1
SWD2
SWD3
SWD4
SWD5
SWD6
SWD7
SWD8
SWD9
SWD10
SWD11
S1C1
S1C2
S1C3
S1C4
S1C5
S1C6
S1C7
S1B1
S1B2
S1B3
S1B4
S1B5
S1B6
S1B7
S1B8
S1A1
S1A2
S1A3
S1A4
S1A5
S1A6
S1A7
S1A8
S1A9
S1A10
S1A11
S1A11A
S2C6
S2C7
S2C8
S2C9
S2C10
S2C11
S2C12
S2C13
S2C14
S2B1S
S2B1
S2B2A
S2B3A
S2B4
S2B5
S2B6
S2B7
S2A1
S2A2
S2A3
S2A4
S2A5
S2A6
S2A7
S2A8
Figure 2 – graph of erosion/accretion trends for Suffolk 1km profiles from Lowestoft to Felixstowe showing MHWS, MSL and MLWS
7
3.2
Detailed observations
3.2.1 Lowestoft to Kessingland
SWF8 – Lowestoft South Pier. There is a significant variability between winter and summer profiles
prior to 1997, therefore 1992 – 1997 data has been discounted. The profile is located a few metres
south of the pier and is complicated by the presence of a rock beach retention groyne which
crosses the profile near the base of the foreshore. The profile shows a steepening trend from 1997
to 2010 with MHWSs moving onshore by an average of 15m. Mean erosion rate of -1.8 m/yr.
SWE1 – Lowestoft Claremont Pier. Significant accretion trends at all levels with no beach rotation.
Water levels have moved offshore by around 40m. The mean rate is 2.6 m/yr.
SWE2 – Lowestoft Rectory Road. Significant accretion trends at all levels particularly at MHWS,
which has moved offshore by around 65m to produce a steepened profile. Mean rate of 3.5 m/yr.
SWE3 – Lowestoft Pakefield Road. A significant accretion trend up to summer 2002 followed by a
period of erosion to winter 2008. Levels are now showing accretion again from 2008 with a
noticeable flattened profile due to greater increase at MLWS. Profile shows an overall mean
accretion trend of 3.6 m/yr.
SWE4 – Pakefield All Saints Road. Cyclical trend at all levels with accretion to 2003 followed by
another period of erosion to give a mean accretion trend of 0.5 m/yr.
SWE5 – Pakefield Arbor Lane. Moderate erosion trends at all levels with mean rate of -1.3 m/yr.
SWE6 – Pakefield, Pontin’s Holiday Camp. Variable trend pattern resulting in a mean erosion
trend of -0.3 m/yr.
SWE7 – Kessingland Heathland Caravan Park. Strong erosion trend from 1991 to summer 2002
followed by a period of sharp accretion of around 45 – 50m at all levels to 2010. Aerials show that
this is due to the northerly migration of Benacre Ness building the beach outwards. The mean
erosion value of -0.8 m/yr is therefore misleading.
SWE8 – A massive accretion trend is evident from 1992 to 2005 with water levels moving around
250m offshore, an average rate of around 20m/yr. The trend then levels off and becomes slightly
erosional from 2005 to 2010. This is due to the widest point of the ness, the apex, having passed
north of this profile in the past few years. The mean trend is 16.9 m/yr with a steepened profile.
This is by far the most significant accretion on the Suffolk coast, the full extent of this accretion
goes off the chart in figure 2.
May (2003) quoted a ness migration rate of around 30m/yr. However, our aerial analysis between
1992 and 2010 suggests that the rate might be at least twice this figure with the apex of the ness
moving northwards by around 1.5 km in 19 years.
SWE9 – Kessingland beach. This profile shows steep accretion rates up to 1999 followed by an
erosional trend of -5 m/yr to 2010, a landward movement of around 60m and which clearly shows
the effect of the passing ness system.
SWE10 – Kessingland Beach Holiday Village. Significant steady erosional trend of -3.4 m/yr as
the lower part of the ness migrates northwards with no rotation in beach levels. Water levels have
retreated landwards by around 50m.
8
1992
© Crown copyright and database rights 2011 Ordnance Survey 100024198. ©
copyright and/or database rights 2011. All rights reserved.
2010
Environment Agency
Figure 3 - Benacre Ness at Kessingland migrating northwards against a net southerly drift. Significant changes in position
and morphology are shown between 1992 and 2010 aerials
3.2.2 Kessingland to Southwold
SWD1 – Benacre Denes. Strong erosional trend of -2.7 m/yr with landward movement of water
levels by around 35m since 1996. There is no rotation in beach levels.
SWD2 – Boathouse Covert. A huge erosional trend of -5.7 m/yr with water levels moving onshore
by around 100m since 1992. This is by far the most significant erosional trend along the Suffolk
coastal frontage.
9
SWD3 – Covehithe cliffs. Significant erosional trends of -3.1 m/yr. Erosion seems to have slowed
down since 1998 with evidence of beach flattening.
SWD4 – Covehithe cliffs. Significant erosion at -3.8 m/yr with no beach rotation. These cliffs have
retreated by around 68m in the period 1992 to 2010.
SWD5 – Easton Wood. Significant erosion at all levels to give a mean erosional trend of -3.4 m/yr
with slight profile flattening.
SWD6 – Easton Marshes cliffs. Steep erosion to 1997 followed by moderate and cyclical patterns
of erosion and accretion giving a total mean erosional trend of -1.8 m/yr.
SWD7 – Easton Bavents cliffs. Moderate erosion rates to 2004 followed by a slight period of
accretion giving a mean trend of -2.1 m/yr.
SWD8 – Southend Warren. This profile is located just to the north of the limit of the Southwold sea
wall where private works have been carried out to combat the outflanking of the sea wall by the
eroding cliffs. Concrete tripods are also located on the beach in front of the cliff face. There are
fluctuations in the movement of water levels probably due to these works. However, there is a
mean moderate erosional trend of -2.2 m/yr.
© Environment Agency copyright and/or database rights 2011. All rights reserved.
Figure 4 – Historic changes to Easton Bavents cliffline, north of Southwold, from 1884 to 2009
10
SWD9 – North Parade, Southwold. Highly variable beach levels with no overall significant trend
thus showing a mean trend of no movement.
SWD10 – Gun Hill, Southwold. Cyclical patterns of erosion and accretion within an overall
moderate accretion trend of 1.9 m/yr. There is definite beach flattening with MHWSs moving 50m
offshore since 1997.
SWD11 – North Pier Southwold. Highly variable beach levels with no overall significant trend
giving a mean trend rate of 0.4 m/yr with beach flattening.
[A detailed study of the area between Benacre Denes (SWD1) to Walberswick (S1C2) is available
as a Coastal Trends and Beach Morphology Report, (March 2010)].
3.2.3 Walberswick to Dunwich
S1C1 – South Pier, Walberswick. Cyclical periods of erosion and accretion within an overall low
erosional trend of -1.4 m/yr with water levels moving by around 50m on and offshore. 2010 levels
are 50m further onshore than 1998 levels.
S1C2 – Corporation Marshes, Walberswick. Small and steady accretional trend of 0.5 m/yr with no
beach rotation.
S1C3 – Walberswick. Significant erosion trend of -2.2 m/yr with slight beach flattening.
S1C4 – Dunwich. Stable frontage, no movement.
S1C5 – Dunwich. Mean trend of 0.4 m/yr due to steady accretion since 2005. No beach rotation.
S1C6 – Dunwich, East Friars House. Slight erosional trend of -0.3 m/yr although since 2003 levels
have shown a slight accretion trend.
S1C7 – Dunwich, Cliff House Caravan Park. No movement, stable frontage.
3.2.4 Dunwich Heath to Thorpeness
S1B1 – Dunwich Heath. Moderate erosion at all levels. Mean trend is -1.3 m/yr with slight beach
steepening.
S1B2 – Dunwich Heath. Slight accretion trend to 2000 followed by a significant erosion trend of -3
m/yr to 2010. However, there is no rotation in beach levels.
S1B3 – Minsmere. Highly variable beach levels at all levels within a slowly accreting trend of 0.5
m/yr with no beach rotation.
S1B4 – Minsmere Haven. Moderate erosion trends at all levels. A more accelerated rate of
erosion is evident from 2001, giving a mean trend of -1.3 m/yr.
S1B5 and S1B6 – Sizewell. Data from both profiles shows erosion to 1999/2000 followed by a
period of accretion to 2010, resulting in no overall movement in trends.
S1B7 – Sizewell Hall. Slight accretion at all levels. Mean trend of 0.3 m/yr.
S1B8 – Thorpeness. Fairly stable beach with no overall movement.
3.2.5 Thorpeness to Orfordness Lighthouse
S1A1 – Thorpeness. Very dynamic beach showing overall accretion to 2001 followed by a period
of relative erosion to 2010 with beach levels returning to landwards of their 1991 position. This has
resulted in a mean trend of no movement.
11
2010
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1992
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Just to the north of this profile an area of emergency beach protection works has just taken place.
Storms in June 2010 swept sediment out to sea revealing gabion baskets (put in place in the 1970s
to protect the coast) and erosion of an unprotected cliff face further north. Works consisted of the
placement of sand/shingle filled geotextile bags to form a new toe at the foot of the existing
defences along with new rock-filled wire baskets laid above the extended toe to the top of the crest.
Figure 5 – Changes in beach morphology at Thorpeness – 1992 to 2010
S1A2 – Thorpeness. Moderate rates of erosion at all levels with no beach rotation. Mean trend of
-0.8 m/yr.
S1A3 – Aldeburgh. Moderate erosional trend of -1 m/yr with no foreshore steepening.
S1A4 – Aldeburgh. Slight accretion at all levels, greater at MHWS to give a slightly steepened
profile. Overall trend is 0.2 m/yr.
S1A5 – Aldeburgh. High accretion trend to 1997 at all levels. The beach is very dynamic with
subsequent years showing periods of erosion and accretion. The overall trend is slightly
accretional at 0.4 m/yr.
S1A6 – Martello Tower, Slaughden. No movement. No significant trend apparent.
[N.B. Slaughden scheme profiles (not analysed in this report) immediately to the north and south of
S1A6 all show moderate erosional trends].
12
S1A7 – Slaughden. Stable beach showing moderate accretion at all levels with some beach
flattening. Mean trend is 1 m/yr.
S1A8 – Orfordness. Beach levels were very stable to 2000. Following this a period of steep
accretion occurred at 2 m/yr to 2010.
S1A9 – Orfordness. Significant accretion of 2.9 m/yr with no foreshore steepening. Water levels
have accreted 60m further offshore in the 1991 to 2010 period.
S1A10 – Orfordness. Moderate accretion of 1.3 m/yr with no foreshore steepening.
© Environment Agency copyright and/or database rights 2011. All rights reserved.
Figure 6 – Historic changes in beach morphology at Orfordness between 1884 to 2010
S1A11 and S1A11A – Orfordness. Both profiles originate at the same point on Orfordness
adjacent to the apex of the ness where the orientation of the coast changes to SSE. Both profiles
show significant erosional trends of -1.6 and -3.3 m/yr respectively although no foreshore
steepening is apparent. S1A11 has retreated by 35m at MHWS and S1A11A by 72m since 1991.
S2C6 – Orfordness lighthouse. Significant erosion of -3.6 m/yr but no foreshore steepening is
apparent. MHWSs have retreated by 62m since 1991.
13
3.2.6 Southern Orfordness
S2C7 – Orfordness. Moderate erosion of -1.2 m/yr with signs of slight foreshore steepening.
S2C8 – Orfordness. Slight erosional trend of -0.3 m/yr but no foreshore steepening.
S2C9, S2C10, S2C11 and S2C12 – Orfordness.
between 0.1 and 0.6 m/yr, with no beach rotation.
All profiles show small accretional trends,
S2C13 and S2C14 – Orfordness. Slight to moderate accretion (0.3 to 0.8 m/yr) with no foreshore
steepening representing a very stable beach.
3.2.7 Shingle Street to Bawdsey Manor
S2B1S – Shingle Street North. No overall movement. Sediment moving south from the tip of
Orfordness bypasses the mouth of the Ore and either merges with the ness at Shingle Street or
joins the mobile sand bar features visible at low water. Although there was an accretional spike
around 2003 water levels have returned to their previous constant levels giving no apparent trend
of accretion or erosion.
S2B1 – Shingle Street. Significant accretion trend of 4.6 m/yr with no foreshore steepening.
MHWSs have moved 80m further offshore since 1991 giving the second highest accretion trend
along the Suffolk frontage.
1992
2010
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Figure 7 – Changes in beach morphology at Shingle Street and the southern tip of Orfordness 1992 to 2010
14
S2B2A – Shingle Street beach. Cyclical pattern of trends with a period of erosion to 1998 followed
by a period of accretion to 2006. There then appears to be another period of erosion to 2010
giving an overall trend of no movement.
S2B3A – Bawdsey Beach. Strong erosional trend of -2.2 m/yr with some foreshore steepening.
MHWSs have receded by 36m since 1991.
S2B4 – East Lane Bawdsey. There are few data points recorded at this location due to the beach
at this transect having now mostly disappeared and there is therefore no trend.
S2B5 – Bawdsey Beach. Strong erosion at all levels since 1997 with slight beach flattening to give
a mean erosional trend of -1.8 m/yr.
S2B6 and S2B7 – Bawdsey Beach and Bawdsey Manor. Slight erosional trends of less than -0.2
m/yr.
[More information on the detailed trends at Bawdsey from S2B1S to S2B7 can be found in the
Bawdsey Beach Morphology Report (2010)].
3.2.8 Felixstowe Ferry to Landguard Point
S2A1 – Felixstowe Ferry, The Knolls. As with S2B1S sediment bypassing the mouth of the Deben
forms the Knolls, a series of mobile, transient sand/shingle bars. This results in high profile
variability due to their rapid redistribution following storm events (English Nature, 2002). There is
therefore no meaningful trend at this location.
S2A2 – Felixstowe, The Dip. Very small erosional trend of -0.2 m/yr.
S2A3, S2A4, S2A5 and S2A6 – Felixstowe, Jacobs Ladder to south of the pier. This section of
coast is protected by hard defences of rock groynes and concrete sea wall. Moderate erosion
trends for all profiles of between -0.4 to -0.8 m/yr. S2A3 shows no movement at MHWS.
S2A7 – Felixstowe, Manor End. Slight to moderate accretion trend (0.6 m/yr) mainly due to a
sharp accretion spike in winter 2009 as a result of beach recharge works between the groynes, as
part of the South Felixstowe scheme completed in 2008.
S2A8 – Felixstowe, Landguard Point. Moderate accretion trends at all levels giving a mean trend
of 1.3 m/yr and slight beach flattening.
15
3.3
Trends analysis maps
The following section displays the mean trends of all profiles together with the Foreshore Change
Parameter – a score of foreshore steepening or flattening – overlaid onto 2010 aerial photographs.
Figures 8 and 9 below give a key to interpreting the trends analysis maps.
Figure 8 – Foreshore change classification system (adapted from Halcrow, 1988). The change is indicated in red
16
(FCP)
Figure 9 – Key to trends analysis maps
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35
Appendices
Appendix 1 – Detailed results
Profile
Name
SWF8
SWE1
SWE2
SWE3
SWE4
SWE5
SWE6
SWE7
SWE8
SWE9
SWE10
SWD1
SWD2
SWD3
SWD4
SWD5
SWD6
SWD7
SWD8
SWD9
SWD10
SWD11
S1C1
S1C2
S1C3
S1C4
S1C5
S1C6
S1C7
S1B1
S1B2
Location
Lowestoft South Pier
Lowestoft Claremont Pier
Lowestoft Rectory Road
Lowestoft Pakefield Road
Pakefield All Saint's Road
Pakefield Arbor Lane
Pakefield Pontin's Holiday Camp
Kessingland Heathland Caravan Park
North Kessingland
Kessingland beach
Kessingland beach holiday village
Benacre Denes
Boathouse Covert
Covehithe cliffs
Covehithe cliffs
Easton Wood
Easton Marshes cliffs
Easton Bavents cliffs
Southend Warren
North Parade, Southwold
Gun Hill, Southwold
North Pier Southwold
South Pier Walberswick
Corporation Marshes Walberswick
Walberswick
Dunwich
Dunwich
Dunwich, East Friars House
Dunwich, Cliff House Caravan Park
Dunwich Heath
Dunwich Heath
Defence
seawall and groyne
seawall and groyne
seawall and groyne
seawall and groyne
seawall and groyne
cliffs
cliffs
cliffs
sea wall
sea wall
dunes
dunes/shingle barrier
cliffs
cliffs
cliffs
cliffs
cliffs
cliffs
cliffs
seawall and groyne
seawall and groyne
dunes
dunes
shingle bank managed
shingle bank managed
shingle bank no longer managed
shingle bank no longer managed
cliffs
cliffs
cliffs
sand/shingle bank
Metres per year
MHWS
MSL
MLWS
-0.80
-1.79
-2.74
2.56
2.74
2.41
4.16
3.43
2.88
3.29
3.50
3.98
0.37
0.51
0.51
-1.46
-1.35
-1.13
-0.37
-0.18
-0.29
-1.28
-0.91
-0.18
17.74 17.41
15.55
-5.07
-5.00
-5.00
-3.43
-3.36
-3.43
-2.66
-2.66
-2.70
-5.73
-5.73
-5.51
-3.36
-3.39
-2.66
-3.83
-3.83
-3.72
-3.65
-3.58
-2.96
-2.04
-1.83
-1.46
-2.34
-2.12
-1.93
-2.34
-2.26
-2.04
-0.29
-0.22
0.07
1.53
1.79
2.34
-0.29
0.15
1.46
-1.53
-1.46
-1.17
0.47
0.55
0.55
-2.37
-2.30
-1.93
0.01
-0.02
0.04
0.40
0.40
0.44
-0.37
-0.33
-0.22
0.04
0.07
-0.07
-1.20
-1.28
-1.42
-1.17
-1.20
-1.20
Mean
Rate
-1.8
2.6
3.5
3.6
0.5
-1.3
-0.3
-0.8
16.9
-5.0
-3.4
-2.7
-5.7
-3.1
-3.8
-3.4
-1.8
-2.1
-2.2
-0.1
1.9
0.4
-1.4
0.5
-2.2
0.0
0.4
-0.3
0.0
-1.3
-1.2
FCP
Score
-6
5
4
6
6
-4
-5
-4
4
-5
-5
-5
-5
-4
-5
-4
-4
-4
-4
-2
6
-2
-4
5
-4
0
5
-4
0
-6
-5
Notes
data from summer 1997 onwards
no rotation
no rotation
ness migrating northwards
data from summer 1998 onwards
no rotation
data from summer 1996 onwards
no rotation
no rotation
no movement
no rotation
no movement
no rotation
36
S1B3
S1B4
S1B5
S1B6
S1B7
S1B8
S1A1
S1A2
S1A3
S1A4
S1A5
S1A6
S1A7
S1A8
S1A9
S1A10
S1A11
S1A11A
S2C6
S2C7
S2C8
S2C9
S2C10
S2C11
S2C12
S2C13
S2C14
S2B1S
S2B1
S2B2A
S2B3A
S2B4
S2B5
S2B6
S2B7
S2A1
S2A2
Minsmere
Minsmere Haven
Sizewell
Sizewell
Sizewell Hall
Thorpeness
Thorpeness
Thorpeness
Aldeburgh
Aldeburgh
Aldeburgh
Slaughden, Martello Tower
Slaughden
Orfordness
Orfordness
Orfordness
Orfordness
Orfordness
Orfordness lighthouse
Orfordness
Orfordness
Orfordness
Orfordness
Orfordness
Orfordness
Orfordness
Orfordness
Shingle Street north
Shingle Street
Shingle Street Beach
Bawdsey Beach
Bawdsey Beach
Bawdsey Beach
Bawdsey Beach
Bawdsey Manor
Felixstowe Ferry, the Knolls
Felixstowe, The Dip
dunes
dunes
dunes backed by Sizewell bank
dunes backed by Sizewell bank
cliffs
cliffs
shingle beach
shingle beach
shingle ridge
sea wall and groynes
sea wall
sea wall and groynes
shingle bank
shingle bank
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle
shingle bank
shingle bank
shingle backed by embankment
shingle backed by embankment
rock hard point
cliffs
cliffs
revetments and old timber groynes
shingle backed by sea wall
sea wall and groynes
0.58
-1.31
0.04
-0.22
0.18
-0.07
0.15
-0.80
-0.95
0.26
0.58
-0.02
0.88
1.02
2.81
1.28
-1.61
-3.21
-3.58
-1.06
-0.33
0.55
0.29
0.18
0.11
0.29
0.77
0.11
4.67
0.22
-2.01
0.51
-1.31
0.07
-0.15
0.29
-0.07
0.07
-0.88
-1.02
0.15
0.47
-0.07
0.91
1.10
2.85
1.20
-1.61
-3.29
-3.58
-1.06
-0.29
0.58
0.33
0.22
0.15
0.33
0.80
0.18
4.64
0.07
-2.19
0.51
-1.31
0.29
-0.04
0.33
-0.04
0.07
-0.73
-1.06
0.15
0.26
-0.15
1.13
1.20
2.96
1.39
-1.53
-3.36
-3.54
-1.35
-0.29
0.62
0.37
0.29
0.18
0.26
0.80
-0.01
4.60
0.11
-2.37
-2.01
-0.18
-0.18
-1.86
-0.18
-0.22
-1.64
-0.11
-0.18
-0.15
-0.18
-0.22
0.5
-1.3
0.1
-0.1
0.3
-0.1
0.1
-0.8
-1.0
0.2
0.4
-0.1
1.0
1.1
2.9
1.3
-1.6
-3.3
-3.6
-1.2
-0.3
0.6
0.3
0.2
0.1
0.3
0.8
0.1
4.6
0.1
-2.2
0.0
-1.8
-0.2
-0.2
0.0
-0.2
5
-5
1
0
6
0
0
-5
-6
4
4
0
6
6
6
6
-5
-6
-5
-6
-5
5
5
6
0
5
5
0
5
0
-6
no rotation
no rotation
no movement
no movement
no movement
no movement
no rotation
no movement
no rotation
no rotation
no rotation
no rotation
no movement
no rotation
no rotation
no movement
no rotation
no movement
no data
-4
0
0
0
no movement
no movement
no trend
no movement
37
S2A3
S2A4
S2A5
S2A6
S2A7
S2A8
Felixstowe Jacobs Ladder
Felixstowe Undercliffe Rd East
Felixstowe Town Hall
Felixstowe South of Pier
Felixstowe Manor End
Felixstowe Landguard Point
sea wall and groynes
sea wall and groynes
sea wall and groynes
sea wall & T-shaped rock groyne
sea wall & T-shaped rock groyne
dunes and shingle
-0.07
-0.33
-0.29
-0.84
0.66
1.24
-0.80
-0.33
-0.58
-0.80
0.66
1.35
-0.77
-0.47
-0.26
-0.66
0.44
1.42
-0.5
-0.4
-0.4
-0.8
0.6
1.3
-1
-6
-5
-4
4
6
no rotation
38
Appendix 2 – References
Birkbeck College/University College London Joint Research School of Geological and
Geophysical Sciences, 1999. Analysis of Coastal Change: Monitoring and Modelling of
Erosion and Sedimentation along the Suffolk Coast. Shoreline Monitoring Preliminary Report.
Environment Agency
English Nature, Environment Agency, Defra, Natural Environment Research Council, 2002
Suffolk Coastal and Estuaries Coastal Habitat Management Plan. Royal Haskoning
Environment Agency, 2007. Suffolk Coastal Trends Analysis, Shoreline Management Group,
EA
Halcrow, 2001. Lowestoft to Thorpeness Coastal Process and Strategy Study, Environment
Agency
May, V J, 2003, Benacre Ness. Coastal Geomorphology of Great Britain, Geological
Conservation Review Series No 28 (V J May and J D Hansom) Joint Nature Conservation
Committee, Peterborough, pp 301 – 304
Pontee, N I, 2005, Management Implications of Coastal Change in Suffolk, UK. Maritime
Engineering 158, Issue MA2, pp 69 - 83
Royal Haskoning, 2010. Shoreline Management Plan 7, Lowestoft Ness to Felixstowe
Landguard Point, Appendix C, Review of Coastal Processes and Geomorphology. Suffolk
Coastal District Council
SANDs software by Halcrow Group Plc http://www.halcrow.com/sands
Taylor, J A, Murdoch, A P & Pontee, N I 2004, A Macroscale Analysis of Coastal Steepening
Around the Coast of England and Wales, The Geog. Journal, Vol 170, No 3, pp 179 – 188
Townend I and McLaren P 1988. Anglian Coastal Management Atlas, Sir William Halcrow &
Partners
Waveney District Council, 1998. Benacre Ness to Thorpeness Strategy/Process Study
Project Appraisal Report. Community Services Department
39