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Beach nourishment operations in Wales and likely
future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Oblique aerial image of Rhyl Beach
Source: Environment Agency (2008)
COUNTRYSIDE COUNCIL
FOR WALES
CCW Science Report No. 928
Contract No: 211 MFG 09
McCue, J; Pye, K; Wareing, A.
Beach nourishment operations in
Wales and likely future
requirements for beach
nourishment in an era of sea level
rise and climate change – a Pilot
Study
Final Report
May 2010
© CCGC/CCW 2010
You may reproduce this document free of charge for non-commercial and internal business
purposes in any format or medium, provided that you do so accurately, acknowledging both the
source and Countryside Council for Wales's copyright, and do not use it in a misleading context.
This is a report of research commissioned by the Countryside Council for Wales. However, the
views and recommendations presented in this report are not necessarily those of the Council and
should, therefore, not be attributed to the Countryside Council for Wales.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Report series:
Report number: CCW Science Report No. 928
Publication date:
Contract number: Contract No: 211 MFG 09
Contractor: Atkins Ltd
Contract Manager: Jonathan McCue
Title: Beach nourishment operations in Wales and likely future
requirements for beach nourishment in an era of sea level rise
and climate change – a Pilot Study
Author(s): McCue, J; Pye, K; Wareing, A.
Restrictions: None
Distribution List (core):
CCW HQ & Regional Libraries
National Library of Wales
British Library
Welsh Assembly Government Library
Scottish Natural Heritage Library
Natural England Library
Joint Nature Conservation Committee Library
The Steering Group
Rod Jones, CCW
Ceri Seaton, CCW
Nicola Rimington, CCW
Natalie Newton, Environment Agency Wales
Peter Jones, Welsh Assembly Government (WAG)
Kerry Kierle, WAG
Mark Russell, British Marine Aggregates Producers Association (BMAPA)
Ian Selby, The Crown Estate
Russell Dobbins, Aggregates Levy fund for Wales, WAG
Distribution list (others)
All Coastal Groups, via the Chair
All Welsh Coastal Local Authorities (including National Park Authorities) - Planning,
Regeneration, Tourism, Coast protection, Ecology
Welsh Assembly Government- Planning, Marine Spatial Planning, Marine Consents, Tourism,
Economic development, Green seas
Wales Coastal Forum
Wales Coastal and Maritime Partnership
Relevant Authorities Groups - Carmarthen Bay, Pembrokeshire, Cardigan Bay, Pen Llyn a’r
Sarnau, Menai Strai and Conwy Bay, Dee Estuary, Severn Estuary
Port Authorities
BMAPA members
National Trust
Internal distribution within Steering Group organisations
Recommended citation for this volume:
McCue, J; Pye, K; Wareing, A. Beach nourishment operations in Wales and likely future
requirements for beach nourishment in an era of sea level rise and climate change – A Pilot Study. CCW Science Report No. 928, CCW, Wales.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
RHAGAIR
Traethau yw un o asedau allweddol arfordir Cymru. Maent yn hollbwysig i gynnal twristiaeth
arfordirol. Yn ogystal â hyn, maent yn ategu asedau pwysig o ran gwarchod natur a'r dirwedd.
Maent hefyd yn amddiffynfa arfordirol 'naturiol', gan wasgaru ynni'r tonnau, a helpu i warchod
strwythurau naturiol a strwythurau o waith dyn y tu cefn iddynt. Fodd bynnag, mewn oes mae
lefel y môr yn codi, maent o dan fygythiad difrifol. Er enghraifft, mae amddiffynfeydd o waith
dyn sydd wedi lleihau'r cyflenwad naturiol o waddod eisoes wedi effeithio'n andwyol ar sawl un
ohonynt.
Mae'r prosiect peilot hwn yn archwilio faint o waith adfer gwaddod a allai fod yn ofynnol er
mwyn cynnal a diogelu gwerth traethau Cymru sydd mewn perygl ar hyn o bryd ac yn y dyfodol.
Mae egwyddorion cynaliadwyedd yn sail i'r astudiaeth. Gellir cyflawni hyn drwy helpu i sicrhau
cynaliadwyedd economaidd cymunedau arfordirol sy'n dibynnu ar dwristiaeth, drwy gynnal
traethau, a thirwedd o safon uchel; neu drwy wella'r amgylchedd naturiol drwy ddarparu
cyflenwad o waddod ar gyfer twyni tywod. Mae hyn yn arbennig o bwysig a pherthnasol yng
nghyd-destun Cymru gan fod Llywodraeth Cynulliad Cymru yn un o ychydig lywodraethau yn y
byd sydd â dyletswydd gyfreithiol o ran cynaliadwyedd.
Roedd y Grŵp Llywio ar gyfer y prosiect yn cynnwys Cyngor Cefn Gwlad Cymru, Llywodraeth
Cynulliad Cymru, Asiantaeth yr Amgylchedd Cymru, Ystad y Goron a Chymdeithas
Cynhyrchwyr Agregau Morol Prydain. Gyda'i gilydd mae gan y sefydliadau hyn gyfrifoldebau i
reoli'r arfordir a gwely'r môr o amrywiaeth o safbwyntiau, gan gynnwys yn rhinwedd
perchenogion tir, y dirwedd, gwarchod natur, hamdden, mynediad, cynllunio, trwyddedu, rheoli
perygl llifogydd ac arfordiroedd, ac adnoddau. Fodd bynnag, cydnabyddir bod nifer o
sefydliadau eraill y mae angen eu cynnwys yn y prosiect wrth ddatblygu i gam nesaf y gwaith, a
ariennir drwy ddyfarniad gan Gronfa Ardoll Agregau Cymru.
Nod y gwaith hwn yw helpu i osod y sail i gynnal gwaith ymgynghori ehangach ac adfer
gwaddod ar draethau.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
FOREWORD
Beaches are one of the key assets of the Welsh coast. They play a vital role in sustaining coastal
tourism. In addition, they underpin important nature conservation and landscape assets. They
also function as a 'natural' coastal defence, dissipating wave energy, and helping to protect both
natural and man made structures to their rear. However, in an era of sea level rise they are under
serious threat. For example, many are already adversely affected by manmade defences which
have reduced the natural sediment supply.
This pilot project examines the potential requirement for beach nourishment to maintain and
safeguard the value of Welsh beaches which are at current and future risk.
The study is underpinned by the principles of sustainability. This can be achieved by helping to
deliver the economic sustainability of coastal communities which rely on tourism, through
maintaining the beach asset, and high quality landscape; or by enhancing the natural
environment by providing a sediment supply for sand dunes. This is particularly important and
relevant in a Welsh context because the Welsh Assembly Government is one of only a few
governments in the world to have a legal duty with regard to sustainability.
The Steering Group for the project consisted of the Countryside Council for Wales, Welsh
Assembly Government, Environment Agency Wales, The Crown Estate, and British Marine
Aggregates Producers Association (BMAPA). Collectively these organizations have
responsibilities for management of the coastline and seabed from a variety of perspectives,
including landowner, landscape, nature conservation, recreation, access, planning, licensing,
flood and coastal risk management, and resources. It is recognised, however, that there are
numerous other organizations which need to be involved in the project going forward in the next
phase of this work, which will be funded by an award from the Aggregates Levy Fund for Wales.
This work is designed to help build the foundations on which the wider consultation and use of
beach nourishment can be based.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
iii
CONTENTS
Rhagair ....................................................................................................................................... i
Foreword ................................................................................................................................... ii
Contents .................................................................................................................................... iii
List of Tables ............................................................................................................................. v
List of Figures .......................................................................................................................... vi
Acknowledgements ................................................................................................................... ix
Crynodeb Gweithredol ............................................................................................................... x
Executive Summary ................................................................................................................. xii
1 Introduction ....................................................................................................................... 1
1.1 Scope and purpose of the project..............................................................................................1
1.2 Aims and objectives ...................................................................................................................1
1.3 Steering Group ...........................................................................................................................2
1.4 Study Limitations .......................................................................................................................3
2 The Strategic Importance of Beach Nourishment ............................................................. 4
2.1 The coastal environment ...........................................................................................................4
2.2 The importance of beaches and problems associated with beach erosion ............................5
2.3 Previous Beach Nourishment Schemes ....................................................................................6
2.4 Climate and sea level change ....................................................................................................8
2.5 Coastal tourism and beach recreation .....................................................................................9
2.6 Integrated management ...........................................................................................................10
3 Methodology .................................................................................................................... 11
3.1 Work Package 1 - Initial Beach Case Study Assessment and Meeting ...............................11
3.2 Work Package 2 – Data Review and Initial Site Analysis ....................................................12
3.3 Work Package 3 – Beach Case Study Assessment ................................................................12
4 Results – Individual Case Study Sites .............................................................................. 14
4.1 Talacre ......................................................................................................................................14
4.2 Abergele-Pensarn .....................................................................................................................17
4.3 Traeth Crugan ..........................................................................................................................21
4.4 Morfa Dyffryn ..........................................................................................................................23
4.5 Broadwater – Tywyn – Aberdovey .........................................................................................25
4.6 Tenby North Beach ..................................................................................................................28
4.7 Port Eynon ................................................................................................................................30
4.8 Swansea Bay North ..................................................................................................................32
4.9 Aberavon ...................................................................................................................................34
4.10 Porthcawl ..................................................................................................................................36
5 Discussion ........................................................................................................................ 38
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
iv
6 Conclusions and Recommendations ................................................................................ 40
6.1 Conclusions ...............................................................................................................................40
6.2 Recommendations ....................................................................................................................40
7 References ........................................................................................................................ 42
Appendix A: Eurosion Data ................................................................................................... 46
Appendix B: Site Description Summary Sheets ...................................................................... 50
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
v
LIST OF TABLES
Table 2.1 Assumed tidal levels at possible nourishment sites in Wales, taken from the 2009 Admiralty
Tide Tables. Values taken directly from the tables in bold type, values extrapolated from the
relevant Standard Port in regular type. MHW and MLW assumed to be midway between
spring and neap levels.
Table 2.2 Advance or retreat of the HAT mark, between the First Edition County Series Ordnance
Survey maps (published in 1880s and 1890s) and aerial photography flown in 2006. Table 2.3 UKCP09 predictions of future increases in relative sea level, assuming low, medium and
high emissions scenarios. Increases are relative to 2010.
Table 3.1 Selected case study sites.
Table 4.1 Initial volumes of nourishment material required at each site for the example scenario.
The design profile assumes a 20 m wide flat-topped berm at the level of HAT, sloping
down to the existing profile at an angle of 1:25, or to MTL, whichever is closer to the
HAT mark. Table 4.2 Planar areas of the defined possible nourishment areas (between HAT and MTL), and
minimum, maximum and best estimates of volumes of sediment required to maintain the
existing beach profile by 2030, 2060 and 2100 based on UKCP09 sea level rise predictions.
Minima represent the 5% values for the low emission (SRES B1) scenario, maxima represent
the 95% values for the high emissions (A1FI) scenario, and best estimates represent the 50%
values for the medium emissions (A1B) scenario. Increases are relative to 2010. N.B. The
calculations make no allowance for post-nourishment losses and re-nourishment required,
and therefore are underestimates of the total volumes of sediment which would be required.
Table 4.3 Nourishment volumes required over the period 2010 to 2030, assuming an initial
nourishment in 2010 followed by five-yearly re-nourishment campaigns to replace 50%
losses, and additional volumes required to raise the beach profile due to sea level rise, based
on minimum, maximum and best estimates from UKCP09 sea level rise predictions. Minima
represent the 5% values for the low emission (SRES B1) scenario, maxima represent the
95% values for the high emissions (A1FI) scenario, and best estimates represent the 50%
values for the medium emissions (A1B) scenario.
Table 5.1 Summary of actual and potential benefits of beach nourishment at the ten study sites.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
vi
LIST OF FIGURES
Figure 1.1 Location of possible case study areas.
Figure 2.1 Concept diagrams showing examples of ‘Good’ beaches.
Figure 2.2 Examples of ‘Good’ beaches: wide, high, wave-dissipative beaches at (a) Harlech, looking
north in August 1991; and (b) Broad Haven, west of Stackpole Warren, in March 2009.
Figure 2.3 Concept diagrams showing examples of ‘Poor’ beaches.
Figure 2.4 Example of a ‘Poor’ beach: Ffrith Beach, Rhyl, with very low beach levels, dilapidated
groynes and exposed sea wall: (a) oblique aerial photograph taken March 2008; (b) ground
photograph looking west taken February 2010.
Figure 2.5 Concept diagram showing possible alternative sources of artificial nourishment material.
After Pye (2010).
Figure 2.6 Some alternative methods of beach nourishment. After Pye (2010).
Figure 2.7 Schematic diagrams showing sediment losses following initial beach nourishment on (a) an
open-ended system, such as a straight open-coast beach, and (b) a semi-closed system, such
as a pocket beach. After Pye (2010).
Figure 2.8 Examples of previously successful beach nourishment: (a) Miami Beach, taken 2007; (b)
oblique aerial photograph of West Shore, Llandudno, taken March 2008.
Figure 2.9 Conceptual models of shoreline evolution during sea level rise: (a) Bruun’s model of
shoreline retreat in response to sea level rise, and (b) ‘Hold The Line’ model with no net
change in shoreline position or beach form in response to sea level rise.
Figure 2.10 Future sea level rise preditions from 1990 based on the DEFRA (2006) sea level rise
allowances (for south west England and Wales), and UKCP09 projections (for Holyhead,
grid cell 18745) based on the 95th percentile modelled output values (considered very
unlikely to be exceeded) for low (SRES B1), medium (SRES A1B1) and high (SRES A1FI)
emission scenarios.
Figure 4.1 Composite aerial photograph of Site 1: Gronant-Talacre, flown 15/07/2006. Also shown are
the limits of the defined possible nourishment area, the area of the previous nourishment
scheme in February and March 2003, KPAL beach profile locations, and tide lines from the
First Edition County Series Ordnance Survey maps surveyed in 1871.
Figure 4.2 Oblique aerial photographs of (a) Talacre and Point of Ayr viewed from the east, and (b) the
nourished area of the shore near the Point of Ayr Lighthouse, taken in March 2008. Source:
Northwest Coastal Group.
Figure 4.3 The beach at Talacre taken during nourishment in February-March 2003. Source:
Countryside Council for Wales.
Figure 4.4 The upper beach (a) and frontal dunes (b) at Talacre in March 2004, one year after beach
nourishment.
Figure 4.5 Cross-sectional profiles P3 to P7 at Talacre, Autumn 2007.
Figure 4.6 The upper beach and frontal dunes (a) east and (b) west of Point of Ayr Lighthouse, in
February 2010.
Figure 4.7 Composite aerial photograph of Site 2: Abergele-Pensarn, flown 15/07/2006. Also shown are
the limits of the defined possible nourishment areas, position of Conwy County Borough
Council beach cross-sectional profiles, and tide lines taken from First Edition County Series
Ordnance Survey Maps surveyed in 1872.
Figure 4.8 Oblique aerial photographs of (a) central part and (b) western end of the Abergele-Pensarn
ridge complex, March 2008. Source: Northwest Coastal Group.
Figure 4.9 Cross-sectional beach profiles across the beach at Site 2: Abergele-Pensarn, surveyed in
October 2009.
Figure 4.10 Western end of the Abergele-Pensarn ridge complex looking (a) west and (b) east, February
2010.
Figure 4.11 Composite aerial photograph of Site 3: Traeth Crugan, flown 09/06/2006. Also shown are
the limits of the defined possible nourishment areas, position of Gwynedd Council beach
cross-sectional profiles, and the tide lines taken from First Edition County Series Ordnance
Survey Maps surveyed in 1888.
Figure 4.12 Cross-sectional beach profiles across the beach at Traeth Crugan. After Faber Maunsell
(2008).
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
vii
Figure 4.13 Rock armour sea defences and upper beach at Traeth Crugan looking (a) west and (b) east, in
2006.
Figure 4.14 Composite aerial photograph of Site 4: Morfa Dyffryn, flown 15/07/2006. Also shown are
the limits of the defined possible nourishment area, positions of Gwynedd Council beach
cross –sectional profiles, and tide lines from First Edition County Series Ordnance Survey
maps surveyed in 1887.
Figure 4.15 Offset of tidal contours relative to the station on beach profiles 34 and 35 at Morfa Dyffryn.
After Pye and Saye (2005).
Figure 4.16 The dunes at Morfa Dyffryn, taken May 2007.
Figure 4.17 Composite aerial photograph of Site 5: Broadwater-Aberdovey, flown 03/06/2006. Also
shown are the limits of the defined possible nourishment area, positions of Gwynedd Council
beach cross-sectional profiles, and the tide lines taken from First Edition County Series
Ordnance Survey Maps surveyed in 1887.
Figure 4.18 (a) Removal of excess sand from area of boat ramp at Aberdovey promenade, (b)
emplacement of nourishment sand at low points in the foredunes, Aberdovey Golf Club
frontage. Source: Gwynedd Council.
Figure 4.19 Cross-sectional beach profiles between Aberdovey and Tywyn, measured on 13-14 February
1992 and 2 May 2008.
Figure 4.20 (a) Nourished area of the frontal dunes, Aberdovey Golf Club frontage, March 2007; and (b)
the beach fronting Penllyn Marshes, north of Aberdovey Golf Club, April 2008.
Figure 4.21 (a) The beach at Tywyn, showing low beach levels and damage to promenade, and (b) beach
and railway line between Tywyn and Broad Water, showing limited flood protection, both
taken May 2007.
Figure 4.22 Composite aerial photograph of Site 6: Tenby North Beach, flown 03/06/2006. Also shown
are the limits of the defined possible nourishment area, positions of Swansea and Carmarthen
Bay beach cross-sectional profiles, and the tide lines taken from First Edition County Series
Ordnance Survey Maps surveyed in 1887-8.
Figure 4.23 Cross-sectional beach profiles at Site 6: Tenby North Beach.
Figure 4.24 Tenby North Beach (a) looking north from Castle Mound, taken March 2009, (b) looking
south from the northern end, taken February 2010.
Figure 4.25 Composite aerial photograph of Site 7: Port Eynon, flown 02/06/2006. Also shown are the
limits of the defined possible nourishment area, positions of Swansea and Carmarthen Bay
beach cross-sectional profiles, and the tide lines taken from First Edition County Series
Ordnance Survey Maps surveyed in 1877-8.
Figure 4.26 The beach at Port Eynon (a) looking southwest from Horton; and (b) looking northeast from
Port Eynon. Source: Llanelli Sand Dredging.
Figure 4.27 Cross-sectional beach profiles at Port Eynon.
Figure 4.28 Composite aerial photograph of Site 8: Northwest Swansea Bay, flown 05/04/2006. Also
shown are the limits of the defined possible nourishment area, positions of Swansea and
Carmarthen Bay beach cross-sectional profiles, and the tide lines taken from First Edition
County Series Ordnance Survey Maps surveyed in 1876-8.
Figure 4.29 Cross-sectional beach profiles in Northwest Swansea Bay.
Figure 4.30 (a) Northern Swansea Bay near Black Pill (a) looking west and (b) looking east, taken
February 2010.
Figure 4.31 Composite aerial photograph of Site 9: Baglan-Aberavon, flown 02-3/06/2006 at 2m
resolution. Also shown are the limits of the defined possible nourishment area, positions of
Swansea and Carmarthen Bay beach cross-sectional profiles, and the tide lines taken from
First Edition County Series Ordnance Survey Maps surveyed in 1875-77.
Figure 4.32 Cross-sectional beach profiles between Baglan and Aberavon.
Figure 4.33 (a) The upper beach at Aberavon looking north, taken March 2009; (b) Bulldozer removing
sand from sea wall steps at Aberavon, February 2010.
Figure 4.34 (a) The beach towards the northern end of Aberavon promenade, looking south, showing
windblown sand buildup on the stepped revetment; and (b) the beach fronting the southern
end of Baglan Burrows, looking north. Photographs taken in February 2010.
Figure 4.35 Composite aerial photograph of Site 10: Porthcawl, flown 03/06/2006. Also shown are the
limits of the defined possible nourishment area, positions of Swansea and Carmarthen Bay
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
viii
beach cross-sectional profiles, and the tide lines taken from First Edition County Series
Ordnance Survey Maps surveyed in 1876.
Figure 4.36 Cross-sectional beach profiles at Porthcawl.
Figure 4.37 The beach at Sandy Bay, Porthcawl (a) looking east from the western end; and (b) looking
west from the eastern end. Photographs taken February 2010.
Figure 5.1 Licensed dredging areas in: (a) NW Region and (b) SW Region. Source: Crown Estate.
Figure 5.2 Dredging application, option and prospecting areas in the SW Region (there are currently no
areas in the NW Region). Source: Crown Estate.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
ix
ACKNOWLEDGEMENTS
We wish to thank the staff of CCW and members of the project Steering Group who have
provided information and comments during the undertaking of this Pilot Project. Particular
thanks are due to the following for provision of data and advice relating to specific sites:
Alan Williams (Coastal Engineering UK Ltd), Bob Minty (Port of Neath), Greg Guthrie (Royal
Haskoning), Paul Day (CCW), Howard Blackwood (Shore Management (Wales), and Alun
Williams (Gwynedd Council). Technical assistance in preparation of the report was provided by
Simon Blott (KPAL) and Richard Agnew (Atkins).
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
x
CRYNODEB GWEITHREDOL
Mae traethau yn adnodd naturiol, cymdeithasol ac economaidd allweddol i Gymru. Yn ogystal â
bod yn amddiffynfa arfordirol hanfodol i gymunedau lleol, ac yn fodd i gynnal cynefinoedd
naturiol allweddol o bwysigrwydd cenedlaethol a rhyngwladol, maent hefyd yn un o asedau
tirwedd a hamdden pwysicaf Cymru sy'n sail i dwristiaeth arfordirol. Er enghraifft, mae arfordir
Cymru yn hanfodol bwysig i'r diwydiant twristiaeth yng Nghymru. Yn rhanbarthau Cymru, mae
twristiaeth glan môr yn arbennig o bwysig yn y Gogledd a'r De-orllewin, lle mae'n cyfrif am
52% o wariant twristiaid. Yn 2009, daeth y gwariant sy'n gysylltiedig ag ymweliadau dros nos ar
yr arfordir i gyfanswm o tua £601 miliwn neu 43% o gyfanswm gwariant twristiaid yng
Nghymru. Yn bwysig, mae ymweliadau arfordirol yn cyfrif am 37% o'r holl ymweliadau dros
nos yng Nghymru (Llywodraeth Cynulliad Cymru, 2010). Ar y llaw arall, yn 2009/10 £6 miliwn
oedd cyllideb Llywodraeth Cynulliad Cymru ar gyfer cefnogi gwaith awdurdodau lleol Cymru o
ran amddiffynfeydd mewndirol ac arfordirol gyda'r mwyafrif yn canolbwyntio ar amddiffyn
asedau tuag at gefn yr amddiffynfeydd. Cyfradd isel o'r gyllideb hon a ddefnyddiwyd i wella
traethau.
Gan gofio'r ystadegau economaidd pwysig hyn, mae rhai heriau mawr yn ein hwynebu y dyfodol
o ran cynnal a gwella traethau. Mae codiad yn lefel y môr a newid yn yr hinsawdd yn
fygythiadau a allai fod yn ddifrifol i draethau Cymru, yn arbennig y rhai sydd o flaen
amddiffynfeydd caled. Mae traethau yn aml o dan bwysau o ganlyniad i amddiffynfeydd
cyfredol gan eu bod wedi tynnu ffynonellau gwaddod o'r system. Fodd bynnag, er mwyn ymdopi
â chodiad yn lefel y môr a chynnal traethau ar yr un lefel gymharol â'r llanw, mae angen llawer
mwy o waddod ar draethau, nad yw ar gael yn naturiol yn aml mwyach.
Yn gysylltiedig â'r uchod, mae un o'r problemau mawr y mae Cymru'n debygol o'i hwynebu yn
ymwneud â faint yn fwy o waddod y bydd ei angen yn ôl pob tebyg i adfer a chynnal traethau
iach, o ble y daw a sut y telir amdano. I geisio mynd i'r afael â'r cyntaf o'r problemau hyn,
comisiynwyd Atkins Ltd ynghyd â Kenneth Pye Associates Ltd (KPAL) gan y Grŵp Llywio i
gynnal prosiect ymchwil ddesg i ystyried y gofynion tebygol ar gyfer gwaith adfer lefelau
gwaddod dros y ganrif nesaf. Er mwyn gwneud hyn, dewiswyd sampl cynrychioliadol o 10 o
draethau Cymru a oedd yn cwmpasu'r amrywiaeth o draethau yng Nghymru.
Ar gyfer pob un o'r 10 ardal astudiaeth achos a ddewiswyd, amcangyfrifwyd ar faint o waddod
newydd y byddai ei angen i gynnal prosiect 'gwella traethau' cychwynnol, wedi'i ddilyn gan
waith adfer gwaddod bob pum mlynedd yn ystod yr 20 mlynedd nesaf, gan ragdybio bod 50% o'r
gwaddod a osodir yn cael ei golli rhwng gwaith adfer, a chan ganiatáu ar gyfer codiad
rhagdybiedig yn lefel y môr dros yr un cyfnod o amser. Mae'r amcangyfrif gorau o ran lefelau
gwaddod ar gyfer senario allyriadau canolig codiad yn lefel y môr UKCP09 yn amrywio rhwng
142,000 m3 ar Draeth Gogleddol Dinbych-y-pysgod i 2,017,000 m3 ar Draeth Aberafan.
O dan bob un o'r senarios codiad yn lefel y môr a ystyriwyd, dengys y canlyniadau ar y gofynion
posibl o ran adfer gwaddod fod lefelau adfer gwaddod cychwynnol wrth 'wella' traethau ar bob
un o'r safleoedd a nodwyd yn eithaf cymedrol. Y mwyaf ohonynt yw 641 x 103 m3 ar Draeth
Aberafan. Mae'r gofynion ar gyfer y safleoedd amfae caeëdig llai megis Traeth Gogleddol
Dinbych-y-pysgod, Traeth Crugan a Bae Porth Einion yn gymharol fach ( < 150 x 103 m3).
Mae'r lefelau sydd eu hangen i gynnal proffiliau presennol traethau ar y 10 safle yn amrywio'n
sylweddol, yn dibynnu ar hyd y draethlin, yr amrediad llanw (ac felly lled y traeth), a chyfradd y
codiad yn lefel y môr a ystyriwyd. Gan ystyried gwerth 'amcangyfrif gorau' (50fed canradd) y
senario allyriadau canolig, byddai angen y lefelau lleiaf o waddod erbyn 2100 byddai ar Draeth
Gogledd Dinbych-y-pysgod a Thraeth Crugan (24 a 30 x 103 m3 yn y drefn honno), a byddai
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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angen y lefelau uchaf yng Ngogledd Bae Abertawe a Thraeth Aberafan (614 a 541 x 103 m3 yn
y drefn honno). Nid yw'r un o'r gwerthoedd yn fawr iawn o'u cymharu â lefelau adfer gwaddod
ar gyfer cynlluniau mawr a gwblhawyd eisoes yn Lloegr, megis y rhai yn Bournemouth,
Mablethorpe - Skegness a Heacham. Fodd bynnag, dylid cofio nad yw'r cyfrifiadau 'cynnydd
lefelau' hyn yn ystyried y gwaddod a gollir a fyddai'n anochel yn dilyn gwaith adfer gwaddod
cychwynnol a'r gwaith a gynhelir wedi hynny.
Fodd bynnag, mae cyfrifiadau o werthoedd yr astudiaeth beilot ar gyfer faint o dywod y byddai
ei angen yn deillio o'r fethodoleg a ddefnyddiwyd ac maent yn debygol o newid pe câi
methodoleg wahanol ei defnyddio. Serch hynny, gellir eu hystyried yn arwydd o'r lefelau tebygol
sydd eu hangen a'r gobaith yw y caiff rhai o'r amcangyfrifon hyn eu mireinio mewn gwaith
diweddarach. Felly, bwriad y canlyniadau yw llywio cam nesaf y gwaith a gynhelir gyda rhagor
o arian gan Gronfa'r Ardoll Agregau ar gyfer Cymru. Wrth ystyried gwaith adfer gwaddod ar y
safleoedd peilot (neu leoliadau eraill lle mae angen lefelau sylweddol), rhaid ystyried yr holl
opsiynau o ran adnoddau a byddai hyn yn ffurfio elfen bwysig o'r astudiaeth arfaethedig yn y
dyfodol.
I gloi, mae'r astudiaeth beilot wedi amlygu'r manteision pwysig y gallai gwaith adfer gwaddod
eu sicrhau ac mae'n cyfiawnhau'n llwyr yr ystyriaeth fanylach o'i ddefnydd. Mae'r astudiaeth
hefyd yn dangos yn glir, mewn oes lle mae disgwyl i'r codiad yn lefel y môr gynyddu, os ydym
am gynnal traethau Cymru yn eu cyflwr presennol bydd angen dechrau ar brosiect adfer
gwaddod traethau mawr. Gallai ymgyrch o'r fath sicrhau manteision o ran cynefinoedd, y
dirwedd, gweithgareddau hamdden ac amddiffynfeydd arfordirol, ond dim ond pe bai rhagor o
arian a systemau rheoli effeithiol ar waith i alluogi hynny. Mae'r astudiaeth beilot yn argymell y
dylid cynnal rhagor o ymchwiliadau i ffynonellau gwaddod posibl ynghyd â chynnal
gwerthusiad economaidd manylach sy'n ystyried echdynnu deunyddiau, costau trafnidiaeth a'r
costau cysylltiedig sydd ynghlwm wrth gydymffurfiaeth reoliadol (asesiad o'r effaith
amgylcheddol a gwaith monitro cyn ac ar ôl y gwaith).
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EXECUTIVE SUMMARY
Beaches are a key natural, social and economic resource for Wales. They not only provide a vital
coastal defence function for local communities, and material for the maintenance of key natural
habitats of national and international importance, but they also represent one of Wales’s premier
landscape and recreational assets which underpins coastal tourism. The Welsh coast, for
example, is vitally important to the tourism industry in Wales. Within the Welsh regions, seaside
tourism is particularly important for the North and South West, where it accounts for 52% of
tourism spend. The spending associated with an overnight visit to the coast, in 2009, amounted
to around £601million or 43% of total tourism spending in Wales. Importantly, visits to the
coast account for 37% of all overnight trips in Wales (Welsh Assembly Government, 2010). By
contrast the Welsh Assembly Government’s budget for 2009/10 for supporting the work of
Welsh local authorities for both inland and coastal defence works was £6 million with the
majority being targeted on defending assets to the rear of the defences. A minimal proportion of
this budget was used to enhance beaches.
With these important economic statistics in mind, there are some major future challenges to
maintaining and enhancing beaches. Sea level rise and climate change represent a potentially
serious threat to Welsh beaches, particularly those fronting hard defences. Beaches are often
under pressure as a consequence of existing defences because they have removed sediment
sources from the system. However, to cope with sea level rise and maintain beaches at the same
relative position to the tides they need substantially more sediment which is often not now
naturally available.
Linked to the above, one of the key issues Wales is likely to face relates to how much more
sediment is likely to be required to restore and maintain healthy beaches, where will it come
from and how will it be paid for. To try and address the first of these issues Atkins Ltd together
with Kenneth Pye Associates Ltd (KPAL) were commissioned by the Steering Group to carry
out a desk based research project to consider the likely requirements for beach nourishment
operations over the coming century. To do this a representative sample of ten Welsh beaches was
chosen which encompassed the range of the Welsh beach resource.
For each of the ten selected case study areas, estimates have been made of the sediment
nourishment volumes that would be required to carry out an initial 'beach improvement' followed
by re-nourishment at 5 yearly intervals in the following 20 years, assuming that 50% of the
emplaced sediment is lost between re-nourishment events, and allowing for projected sea level
rise over the same time period. The best estimate sediment volumes for the UKCP09 medium
emissions sea level rise scenario range from 142,000 m3 at Tenby North Beach to 2,017,000 m
3
at Aberavon Sands.
The results of the potential sediment nourishment requirements under each of the sea level rise
scenarios considered, show that initial beach 'improvement' nourishment volumes at all of the
identified sites are relatively modest, the largest being 641 x 103 m
3 at Aberavon Sands. The
requirements for the smaller enclosed embayment sites such as Tenby North Beach, Traeth
Crugan and Port Eynon Bay are relatively small (< 150 x 103 m
3).
The volumes required to maintain the existing beach profiles at the ten sites vary considerably,
depending both on the length of shoreline, the tidal range (and therefore beach width), and the
rate of sea level rise considered. Considering the 'best estimate' (50th percentile) value for the
medium emissions scenario, the smallest volumes of sediment required by 2100 would be at
Tenby North Beach and Traeth Crugan (24 and 30 x 103 m
3, respectively), while the largest
volumes would be required in Swansea Bay North and at Aberavon Sands (614 and 541 x 103
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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m3, respectively). None of the values are particularly large when compared with nourishment
volumes for large schemes already carried out in England, such as those at Bournemouth,
Mablethorpe - Skegness and Heacham. It should, however, be borne in mind that these 'volume
increase’ calculations do not take into account sediment losses which would inevitably occur
following initial nourishment and each re-nourishment.
The pilot study calculated values for the amount of sand needed are, however, a product of the
methodology used and are likely to change if a different methodology was used. Nevertheless,
they can be considered indicative of the likely scale required and it is hoped to refine some of
these estimates in later work. The results therefore are intended to inform the next phase of work
which will be carried out with further funding from the Aggregates Levy Fund for Wales.
Consideration of future nourishment at the pilot sites (or other locations where significant
volumes are required) needs to consider all resource options and would form an important
element of the proposed future study.
In conclusion, the pilot study has highlighted the important benefits that beach nourishment
could provide and fully justifies the more detailed consideration of its use. The study also clearly
demonstrates that, in an era when the rate of sea level rise is expected to increase, if we want to
maintain Welsh beaches in their current condition then a major beach feeding project will be
required. Such a campaign could deliver habitat, landscape, recreational and coastal defence
benefits but only if additional finance and effective management systems were in place to enable
this to occur. The pilot study recommends that further investigations be undertaken into possible
sediment sources together with a more detailed economic appraisal, taking account not only of
material extraction and transport costs but also the associated costs of regulatory compliance
(environmental impact assessment and monitoring pre and post-works).
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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1 INTRODUCTION
1.1 Scope and purpose of the project
Atkins Limited (Atkins) were commissioned in January 2010 by the Countryside Council for
Wales (CCW) to undertake a pilot study to consider the likely future requirements for beach
nourishment operations in Wales under conditions of possible accelerated sea level rise and
climate change, with delivery of the final report by March 2010.
Beaches in Wales are important for several reasons, including as a major 'attractor' of relevance
to the tourist industry and local, regional and national economies. The Welsh Coast is vitally
important to the tourism industry in Wales. The spending associated with an overnight visit to
the coast, in 2006, amounted to around £648million (nearly 40% of total tourism spending in
Wales). Beaches are also a form of natural coastal defence relevant to flood and erosion risk
management, and as natural features and biological habitats relevant to nature conservation.
Consequently there is a requirement to assess the future threats to the sustainability of Welsh
beaches and to investigate means of managing the risks associated with possible future sea level
and climate change (Welsh Audit Office, 2009).
The potential benefits of beach nourishment include the creation of wider, more extensive areas
of 'dry beach' and a more attractive general coastal landscape, reduced rates of coastal erosion
and improved standard of coastal flood defence, reduced requirement to construct and maintain
'hard' coastal defence structures, and creation / preservation of areas or priority habitat such as
vegetated shingle and sand dunes. Factors which may limit the expansion of beach nourishment
activities include the need to ensure adequate supplies of reasonably priced, suitable sediments,
which in turn is dependent on the availability of sediment sources, transport costs, monitoring
requirements, the magnitude of future changes in sea level and climate (especially storminess
which exercises a key control of wave climate, sediment mobility and the frequency of re-
nourishment requirements), and, perhaps most importantly, the availability of future funding
which will be tied to general economic conditions. While these issues are touched on in the
present report, it is intended that they will be the subject of more detailed consideration at a later
stage in the programme.
The pilot study represents the first stage in a wider programme of work to help encourage and
facilitate the use of beach nourishment on the Welsh coast. Although beach nourishment has
been widely and extensively used as coastal management tool in many parts of the world, it has
so far been employed in Wales only on a relatively small scale. The principal purpose of the pilot
study is therefore to assess the potential contribution which increased use of beach nourishment
could make, including the potential benefits that may arise for tourism, coastal erosion and flood
risk management, and nature conservation. In addition, the study identifies factors which might
limit the adoption of this method of beach management in Wales.
This pilot study is essentially a research project undertaken prior to more detailed planning work
that would be required for the development of specific scheme proposals. The project provides a
a generic assessment and is not intended to promote offshore extraction of aggregates or any
specific coastal scheme.
1.2 Aims and objectives
The principal aim of the pilot study is to examine ten example sites where beach nourishment
might be an appropriate engineered management option over the next 20, 50 and 100 years. The
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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2
ten selected areas have been chosen to include both sand and mixed sand/shingle systems around
the coasts of North, West and South Wales and which reflect varying relative importance of
touristic / recreational, flood and erosion risk management and nature conservation interests. The
ten chosen sites are as follows (see Figure 1.1 for locations):
• Talacre;
• Abergele - Pensarn;
• Traeth Crugan;
• Morfa Dyffryn;
• Broadwater - Tywyn – Aberdovey;
• Tenby North Beach;
• Port Eynon Bay;
• Northern Swansea Bay (Black Pill to Swansea Docks);
• Aberavon Sands (eastern Swansea Bay); and
• Porthcawl (Sandy Bay and Trecco Bay).
For each site, the study aims to identify the potential benefits of, and requirements for, beach
nourishment. For the purposes of illustration and inter-site comparison, estimates are made of the
approximate volumes of material which would be required to:
(a) improve the current condition of the current beach by creating an initial upper 'dry
beach' berm, 20 m wide and tapering seawards at a gradient of 1:25 to intersect the
existing beach profile;
(b) maintain the existing beach form under condition of sea level rise over time periods
of 20, 50 and 100 years, using estimates of local sea level rise derived from data
available on UKCP09 website user interface; and
(c) maintain the existing profile under conditions of sea level rise over a period of 20
years, allowing for natural sediment losses and consequent requirements for re-
nourishment at 5-yearly intervals (an assumed 50% loss of material between re-
nourishment events).
The calculated volumes presented are provided solely as illustrations of the general magnitudes
of required sediment volumes. It is anticipated that more detailed assessment of different options
would be undertaken for scheme design purposes at specific sites.
1.3 Steering Group
In view of the short timescale available for the project, stakeholder engagement has been key to
its successful completion. Significant input has been provided by a number of the Steering Group
members, including CCW, Environment Agency Wales, The Crown Estate and British Marine
Aggregates Producers Association (BMAPA). Opinions and data have also been sought from
several coastal managers, local authority engineers, consultants, harbour authorities and others
during the course of the project. Overall management of the project has been undertaken by
Atkins Ltd with specific technical input relating to the case study sites provided by Kenneth Pye
Associates Ltd.
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1.4 Study Limitations
The original Terms of Reference recommended the assessment of data and information from a
variety of sources. The authors have embraced the considerable challenge of reviewing as much
information as possible within a very tight project timescale (6 weeks maximum) set for the
study. Within this constraint it has not been possible to obtain and utilise all types of available
data, notably Lidar data, for the chosen study sites. It is recommended that such data should be
used to produce refined nourishment requirement volume estimates in any future work.
Following internal notification of the pilot study a few concerned responses were received by
CCW with regards to potential impacts on biological habitats. It is acknowledged that the
potential impacts of beach nourishment can be both positive and negative in terms of to
biological habitats; these have not been addressed within the pilot study and would require
further investigation at a plan/design stage.
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2 THE STRATEGIC IMPORTANCE OF BEACH NOURISHMENT
2.1 The coastal environment
The rural coast of Wales is a magnificent resource for residents and visitors to enjoy, offering
spectacular coastal scenery, attractive small towns and villages, opportunities for informal land
and water based recreation and a wildlife environment of exceptional diversity and interest. The
coast is also valued for its unspoilt scenery, peace and quiet. A balance needs to be struck on the
rural coast between tranquil areas and areas supporting a large number of people and a range of
activity (Welsh Assembly Government, 2008).
The environmental quality of the Welsh coastline is reflected in the range and number of
designations and protected sites that cover the coastline of Wales, with 70% of the coastline
designated for its environmental quality. In terms of EU and international designations, many
parts of the coastal and marine environment of Wales are designated as Special Areas of
Conservation (SAC) and Marine Special Areas of Conservation due to the richness of their
benthic habitats. These areas are chosen for being the best examples in the UK for containing
habitat types and species listed in the EU Habitats Directive. Other parts of the coast are
designated as Special Protection Areas to conserve the habitats of certain rare or vulnerable birds
and regularly occurring migratory birds. The Dovey Estuary, nearAberdovey, is the only
designated Biosphere Reserve in Wales. The Biosphere reserves are areas nominated by national
governments and designated under UNESCO’s Man and the Biosphere (MAB) programme
(Welsh Assembly Government, 2008). In addition, some are priority habitats or contain listed
species under EC and international legislation.
The western coastline of Wales and generally the seabed of the Southern Irish Sea contain a
diverse range of marine habitats and species, from algae dominated rocky reefs to deep muddy
areas inhabited by burrowing animals. The rocky reefs tend to be found close to the coast in
relatively shallow water, although there are also relatively large areas offshore to the north and
west of Anglesey. Also close to the coast are extensive areas of sediment, ranging from muds to
gravels. The central part of the Southern Irish Sea (St Georges Channel) has deeper water, often
in excess of 100m and generally coarser sediments (sands and gravels). Previous studies have
also shown the seabed environment here is highly variable, and contains a diverse range of
biological communities (Robinson et al. HABMAP, 2007).
The mean spring tidal range around the coast of Wales is large, varying from just over 4 metres
in central Cardigan Bay to over 12 m in the inner Bristol Channel, with the result that beaches
and associated intertidal flats are very extensive. Tidal levels and ranges for the ten selected case
study sites are summarised in Table 2.1 All ten sites can be described as macrotidal according to
the definition of Davies (1964). The coastal orientation, and therefore exposure to wind and
wave energy, differs between the sites. Talacre and Abergele - Pensarn experience dominant
waves from the northwest, Traeth Crugan, Morfa Dyffryn and Broadwater - Aberdovey are
influenced both strong waves from north-westerly, westerly and south-westerly directions,
Tenby North Beach is affected mainly by waves from the southeast and east (some of which are
refracted offshore south-westerly waves), while Port Eynon, northern Swansea Bay, Aberavon
and Porthcawl are influenced by dominant south-westerly waves, including long-distance swell
from the as far away as the South Atlantic. Talacre, Tenby North Beach, Port Eynon Bay,
Swansea Bay North, Aberavon Sands and Porthcawl represent sand-dominated beach systems,
Abergele-Pensarn is a gravel-dominated system, while Traeth Crugan, Morfa Dyffryn and
Broadwater-Tywyn-Aberdovey are examples of mixed sand - gravel beach systems.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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2.2 The importance of beaches and problems associated with beach erosion
Beaches represent the first line of coastal defence and are of critical importance in dissipating
wave and tidal energy. They therefore exert a significant control on both erosion/ accretion
trends and water levels along the coast. All beaches are subject to change over time due to the
interaction of waves and tides, and fluctuations in the local sediment budget. Reductions in
sediment supply, or an increase in wave and/or tidal energy, can rapidly lead to falling beach
levels and recession of the shoreline (defined here as the level of the highest astronomical tide,
HAT). Alternating periods of beach erosion and accretion can occur on a variety of timescales,
ranging from seasonal (winter / summer), through decadal to centennial. Changes generally only
become significant if maintained for several decades or longer. The net movement of the HAT
line since the later 19th century at each of the ten case study sites is summarised in Table 2.2.
Abergele - Pensarn is the only site which has experienced net seaward accretion over the period,
and parts of even this site have experienced net erosion in recent decades.
Many of the sites show a spatially variable pattern of net erosion, stability and accretion over the
period, reflecting the importance of longshore sediment transport processes on many parts of the
coast; sediment eroded from the up-drift ends of sediment transport cells is frequently deposited
at the distal, down-drift ends of the cells - a fact which needs to be taken into consideration if
designing any beach nourishment scheme. The highest average rates of net shoreline recession
recorded at any of the ten site was recorded near the Point of Ayr (profile P7) at Talacre, while
the highest average rates of progradation (accretion) over the period have been experienced at the
northern end of the Aberavon Sands - Baglan site (profiles P217 & P218). At several sites,
including Tenby North Beach, Morfa Dyffryn and Traeth Crugan, the HAT line has shown little
or no net movement over the period, although is several of these instances the beaches have
steepened due to a landward movement of the low water mark (Futurecoast, 2002; Pye & Saye,
2005).
From several perspectives, a 'good beach' can be defined as one which has a relatively wide
backshore which is dry under most tidal conditions, a wide, relatively high foreshore which is
effective in dissipating wave energy, and which has a zone of sand dunes or vegetated shingle
behind the normal HAT line which provides a further reservoir of sediment which can be
released to the beach during storm conditions (Figure 2.1). Such beaches provide effective
natural coastal defences, a wide range of ecological habitats which promote biodiversity, have
high aesthetic appeal and a large 'useable' space for recreational and touristic activities. In
general, gravel (shingle) beaches are more effective in dissipating wave energy, and are less
susceptible to damage during individual storms, than beaches on which sand dominates both the
upper and lower parts of the beach. Two examples of such 'good' beaches are illustrated in Figure
2.2. Harlech Beach, located in Tremadoc Bay, provides one of the few examples in Wales where
a relatively open coast 'receptive shore' is still receiving significant supplies of sediment from
the offshore and nearshore zones, and where large parts of the frontage are either stable or
slowly accreting, despite high seasonal visitor pressure. Broadhaven in Pembrokeshire provides a
example of a smaller headland-bound 'pocket' beach which experiences a similar positive
sediment budget, resulting in a wide sandy foreshore, wide backshore and newly forming
embryo dunes and foredunes.
By the same token, 'poor beaches' may be defined as ones which are very narrow, low, frequently
wet and often backed by hard coastal defence structures (Figure 2.3). The value of such beaches
as natural coastal defences is severely limited, and costs of artificially controlling back-beach
erosion, and of maintaining an adequate level of flood protection, are often high. The presence of
vertical sea walls of other structures can itself enhance the problem of beach loss due to
accentuated wave reflection and toe scour (Figure 2.3a & b). Such beach systems are unattractive
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
6
from a visual point of view, are often un-usable for recreational / touristic purposes at high tide,
and are of limited nature conservation value. Access to the beaches from the promenade or sea
wall is often difficult. An example of such a 'poor' beach near the eastern end of Rhyl is
illustrated in Figures 2.4a & b. At this location the coastal defences run at an oblique angle to the
natural orientation of the ridges and runnels on the foreshore, creating particularly low areas
where the runnels abut the toe of the defences. This coastline has experienced long-term loss of
sediment due to restricted supply from the west and a tendency for net eastward alongshore drift.
The groyne systems along the coast are now in a state of disrepair and have limited effect. Beach
levels have fallen to a point where sheet piling at the toe of the sea wall is exposed, standing
water and/ or underlying silts and peat deposits are exposed over large areas of the beach, and
recreational appeal is severely reduced. While addition of rock armour might improve the
standard of flood protection by itself it would do little to raise beach levels or increase the
touristic and nature conservation value of the beach.
Even if artificial defences are not present, a narrow backshore and steep foreshore in front of a
naturally eroding dune cliff or shingle ridge or eroding dune cliff provides limited useable space
for recreational / tourist space and is widely to be perceived as unattractive or even dangerous
for swimmers and other users (Figures 2.3c & d).
2.3 Previous Beach Nourishment Schemes
2.3.1 Artificial beach nourishment schemes in North America, Europe and other parts of the
World
A distinction needs to be made between natural beach nourishment and artificial (or man-made)
beach nourishment (Pye, 2010). Under natural conditions beaches may be nourished with
sediment from several possible sources, including neighbouring river mouths, the offshore /
nearshore sea bed, up-drift coastal erosion, or in situ-biogenic sediment production. Artificial
nourishment may be unintentional or intentional. Examples of unintentional artificial
nourishment include the dumping of mine and quarry waste on the shore or into rivers which
subsequently transport the material to the coast, or accelerated rates of soil erosion due to de-
vegetation which result in increased rates of sediment supply to the coastal zone. Intentional
artificial beach nourishment most commonly involves the purposeful placement of material
(natural or artificial sediment) to create or replenish a beach. Beach creation involves the
construction of a beach where none-existed previously; beach replenishment (sometimes also
referred to as beach recharge or beach fill) involves the restoration or improvement of an existing
beach. Repeat placement of additional material on a beach which has already been artificially
nourished is referred to as beach re-nourishment.
It is often stated in the coastal scientific literature that the first major artificial beach
nourishment schemes were undertaken in California and New Jersey during the period 1919 -
1922, and the practice became increasing popular in the United States between the Wars.
Amongst the most significant early schemes where the creation of a recreational beach at Coney
Island in 1922 using dredgings from New York Harbour, and the creation of a large recreational
beach at Waikiki, Hawaii, in 1939 (Finkl & Walker, 2005). The first large-scale project in
Europe was undertaken on the German island of Nordeney commencing in 1951. Since that time
beach nourishment has been undertaken in many other European countries including Belgium,
Denmark, The Netherlands, France, Portugal and Spain, as well as many other parts of the world.
Several case study examples are described in Schwartz & Bird (1990) and in Appendix 1 to this
report. One of largest single schemes undertaken was at Miami Beach in Florida between 1975
and 1980, when more than 10 x 106 m3 of sediment was placed on a 20 km length of beach for
combined recreational and storm protection purposes. Other major recent schemes have been
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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undertaken as part of major construction and economic development programmes in Dubai,
China and Malaysia. In the Netherlands, beach nourishment has become the principal tool by
which a policy of 'dynamic preservation of the coastline' will be delivered. Under this policy, the
coastal profile of the Dutch coast down to a depth of -20 m, as it existed in 1990, will be
maintained by nourishment every 5 years in order to keep pace with rising sea level (Mulder et
al., 2006). The principal source of sediment will be provided by dredging of offshore areas
beyond the -20 m isobath. Regular and detailed monitoring of the beach, nearshore and offshore
areas provides a key part of the strategy (van der Lee, 2009).
In the United Kingdom, the first significant artificial sand beach nourishment schemes
undertaken primarily for recreation purposes were undertaken at Bournemouth and Portobello
(Edinburgh) in the early 1970's. Prior to this time there had only been small scale nourishments
of beaches in several places using harbour dredging, quarry and construction waste (both
sediment and rock). Since the 1970's large-scale nourishment projects using both sand and
shingle have been undertaken on several parts of the UK coast, mainly in eastern and southern
England. The main drivers have been both flood protection (e.g. Lincshore in Lincolnshire and
Heacham in Norfolk) and recreational (e.g. Bournemouth). The initial Lincshore project in the
late 1990's involved placement of approximately 7.5 x 106 m3 of coarse sand along the shore
between Mablethorpe and Skegness; subsequent annual re-nourishment requirements have
averaged about 450 x 103 m3 (Blott & Pye, 2004).
2.3.2 Artificial beach nourishment in Wales
Compared with other parts of the world, including England, previous beach nourishment
operations in Wales have been few and mostly small-scale. Dredgings from a number of small
harbours and ports have been used to nourish nearby beaches and dunes; examples include
Pwlheli, Aberdovey, Aberystwyth, Aberaeron and Neath. A small pilot study was undertaken in
2000 to examine the feasibility of using dredgings from the approach to Neath Harbour for
beneficial beach recharge; approximately 14 x 103 m
3 of sandy material was deposited offshore
from Sker Beach (Kenfig Sands) on the assumption that it would move shorewards under the
influence of natural processes (BP Chemical Ltd, 2000). Subsequently c. 6 x 103 m
3 of sand from
this source was used to nourish the north-western end of Aberavon - Baglan dunes; in 2007
approximately 115 x 103 m
3 was used to nourish the northern end of the Aberavon foreshore,
and in 2008 c. 220 x 106 m
3 was used to nourish the beach in front of Crymlyn Burrows. In 2003,
approximately 180 x 103 m
3 of dredged material (mainly sand) from the approaches to Mostyn
docks was used to nourish the beach at Talacre, east of Prestatyn.
During the early 1990's volumes of c. 100 - 150 x 103 m
3 of sand were used for beach
nourishment as part of a number of wider coastal protection schemes, including those at Llanelli,
Machynys and Llandudno West Shore. A significant proportion of the material used at Llanelli
and Machynys was reportedly sources from offshore sources. Other significant nourishment
projects, involving on or mainly cobble or gravel-sized material, were undertaken at Llandudno
North Shore, Penrhyn, Morfa Dinlle and Kinmel Bay, amongst other places, but most involved
relatively small quantities of material (generally < 15 x 103 m
3).
2.3.3 Guidance relating to beach nourishment
A number of manuals and collected conference papers have been published which provide
general guidance on strategy and specific technical aspects relating to beach nourishment. These
include Delft Hydraulics Laboratory (1987), van der Graaff et al., (1991), National Research
Council (1995), Dean (2002) and Dean & Dalrymple (2002).
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The CIRIA Beach Management Manual (Simm et al., 1996) contains a chapter on beach
recharge and discusses its role in relation to other techniques of beach management. The Manual
is currently being revised and a second edition is expected to be published later in 2010.
A review of European experience with beach nourishment, focused on engineering aspects, was
undertaken by Hamm et al. (2002), while the potential ecological effects have been reviewed by
Speybroeck et al. (2006).
Figure 2.5 presents a simple concept diagram which illustrates the main potential sources of
sediment for artificial nourishment, while Figure 2.6 summarises the main methods by which
nourishment can be undertaken. Various options for sediment emplacement exist, including
formation of a rectangular or tapered sediment wedge on part, or all, of the upper beach,
deposition of nourishment material as an offshore berm, or trickle-charging with sediment from
one end of the system (Pye, 2010). Whatever the method and form of the initial emplacement, re-
distribution of sediment is likely to occur under the influence of natural processes (Figure 2.7).
The rate at which this occurs will depend on the specific local coastal physiography and coastal
energy regime. Figure 2.8 illustrates two examples of nourishment schemes which are generally
regarded to have been successful in their objectives (Miami Beach and Llandudno West Shore).
In general, beach nourishment, whether used alone or in conjunction with other measures,
provides a more environmentally acceptable method of shoreline management than hard defence
structures in terms of landscape and visual impacts (ECUS, 2000).
2.4 Climate and sea level change
Climate change is likely to have significant impacts on the coast. Figures from the UK Climate
Impacts Programme 2009 (UKCP09) and the UK Meteorological Office indicate that:
• Mean Global temperatures could rise anywhere between 1.5°C and 5.8°C by 2080 –
between 2 and 8 times the rise already seen since 1990. In the UK, an average rise of 2-
3.5°C is anticipated.
• Winters will become wetter (20-30% wetter by 2080) and summers may become drier
(35-50% drier by 2080). Heavier rainfalls will become more frequent.
• Relative sea level will continue to rise around the UK coastline, at varying rates which
will depend party on the pattern of crustal movements, partly on actual levels of global
emissions, and partly on the nature of complex responses and interactions between the
coupled atmosphere-ocean-cryosphere systems; modelling results indicate a wide range
of possible values for the magnitude of total sea level rise, ranging for, 0.3 to 1.9 m over
the next century. Figure 2.10 indicates a comparative example of the UKCP09 scenarios
(low-medium and high emissions) compared to existing Defra guidance (2006). These
show that the sea level rise predictions will amount to less than 1m, from a base year of
1990. The H++ scenario states a sea level rise of 1.9m but unlike the low, medium and
high scenarios, no detailed information is available on how this increase will be reached.
• The potential impacts of climate change are likely to be various. An example is the
possible increase in extreme weather events such as storminess which may have the
effect of increasing flooding in low-lying areas, and increase erosion rates that could lead
to a loss of beaches. A rise in sea level would have implications for low lying lands and
coastal infrastructure. Tourism is also a contributor to climate change. The tourism
industry and visitors alike are becoming more aware of the need to reduce their carbon
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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footprints, which may well lead to an increase in demand for domestic holidays (Welsh
Assembly Government, 2008).
Bruun (1962) proposed a well-known two-dimensional model which predicts the effects of sea
level rise on beaches, assuming a closed sediment system. According to this model, a rise on sea
level will result in a lateral retreat of the high water mark by a predictable amount as sediment is
eroded from the shoreface and re-deposited on the proximal sea floor (Figure 2.9a). An
equilibrium beach profile is assumed to be maintained as coastal retreat progresses. Although
this is a simplistic model which has been widely criticised, it still provides a useful conceptual
framework.
At its simplest, beach nourishment can be considered as a method by which retreat of the
shoreline (high water mark) can be slowed or prevented and an equilibrium beach profile
maintained (to some fixed distance offshore) during sea level rise (Figure 2.9 b). In essence this
concept lies at the heart of the Dutch coastal defence policy of 'dynamic preservation of the
coastline' adopted in 1990. The volumes of sediment required to achieve this condition are likely
to be large and the costs could be high, depending on the rates of sea level rise, the location of
suitable sediment sources, and the nature of feasible transportation methods.
Estimates of possible future sea level rise for each of the 10 case study sites considered in this
study were calculated from data available via the UKCP09 website user interface. A summary of
the values obtained for three different emissions scenarios and different climate model outputs is
provided in Table 2.3.
Consideration of issues of suitable sediment sources and transport costs will be undertaken in a
later stage of the work programme. For example, nourishment schemes to protect the coastline
from the affects of climate and sea level change should themselves have a minimal negative
impact as possible on the same effect. The “carbon footprint” of the proposed nourishment
schemes will be calculated, expressed in terms of the amount of carbon dioxide, or its equivalent
of other greenhouse gasses, emitted. Both the “embedded” carbon dioxide in the materials used
and transport of those materials will be estimated. The results of this analysis will help inform
the decision-making process to select the optimal nourishment scheme design.
2.5 Coastal tourism and beach recreation
The Welsh Coast is vitally important to the tourism industry in Wales. The spending associated
with an overnight visit to the coast, in 2009, amounted to around £601million or 43% of total
tourism spending in Wales. It attracts around 3.4 million staying trips (14 million nights) each
year together with an estimated 25 million tourism day trips (Welsh Assembly Government,
2010).
The majority (78%) of seaside tourism is for leisure purposes although places such as Cardiff,
Swansea and Llandudno also attract some business tourism. Visits to the coast account for 37%
of all overnight trips in Wales - a much higher proportion than in England and Scotland where
visits account for only 20% and 13% respectively (Welsh Assembly Government, 2010). Within
the Welsh regions, seaside tourism is particularly important for the North and South West, where
it accounts for 52% of tourism spend. The direct impact of tourism amounts to an estimated
3.2% of whole-economy value added in Wales (Welsh Assembly Government, 2008).
The importance of coastal tourism is also reflected by the Welsh Assembly Government in their
‘One Wales: A progressive agenda for the government of Wales’ document which also proposes
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to construct an all-Wales coastal path as part of its plan to maintain clean, healthy and
sustainable local environments in which people can take pride (Welsh Assembly Government,
2007). Its importance is outlined within the Coastal Tourism Strategy which was identified as
one of the key national actions within the Wales Spatial Plan. The purpose of the Coastal
Tourism Strategy is to identify a clear way forward for the development of Coastal Tourism,
which realises and builds on the economic potential of the coastline of Wales whilst respecting
its environmental quality and recognising the importance of achieving community benefits.
A key recommendation of the Strategy is that proposals for tourism investment recognise and
take account of the implications of climate change impacts, particularly the increasing flood and
erosion risks, and assist with adaption to those impacts.
2.6 Integrated management
Data and information management is defined as a key pressure “theme” in Making the Most of
Wales’ Coast, the ICZM Strategy for Wales. Previous work undertaken by Atkins for CCW
(McCue, J. et al., 2008)helped CCW review what information currently exists, where data is
stored, and whether it is helpful in improving the understanding of issues such as habitat
replacement, natural evolution of landforms and the economic implications of natural shoreline
change over time.
CCW are at the forefront of ICZM in Wales and with increasing pressure on the coastal resource,
and a growing recognition that the coastline should be managed in a more strategic and co-
ordinated way, the impact of visitors on sites around the coast may result in additional
management costs to land owners and local authorities in terms of sustaining the quality of the
environment and providing facilities for visitors to enjoy a safe experience.
The proposed Action Plan set for that project (section 7) is a useful source of information and
proposed intervention with relation to the delivery of ICZM principles within Wales. Sustainable
beach solutions for the future were presented as a key area for consideration.
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3 METHODOLOGY
The project methodology has centred on 4 work packages (WP):
• WP1 – Initial Beach Case Study Assessment and Inception Meeting;
• WP2 – Data Review and Initial Site Analysis;
• WP3 – Beach Case Study Assessment; and
• WP4 – Draft and Final Reporting.
3.1 Work Package 1 - Initial Beach Case Study Assessment and Meeting
Aim: To introduce the project team, confirm the communication strategy with CCW, scope out
the approach to each Work Package, and discuss possible beach case study areas.
To assist in ensuring project completion within the tight project timescales, Atkins undertook a
rapid desk-top study of numerous potential case study sites for the project, for discussion at the
Inception Meeting on 3rd
February 2010. A preliminary set of case study criteria was adopted to
help ascertain which case studies are appropriate for further evaluation. These criteria were
developed in line with CCW's key corporate drivers.
The following sites were discussed at the Inception Meeting:
• Talacre-Gronant
• Rhyl-Prestatyn
• Abergele-Towyn
• Morfa Dinlle
• Traeth Crugan
• Llanaber-Morfa Dyffryn
• Fairbourne
• Broadwater-Tywyn-Aberdovey
• Borth-Ynyslas
• Swansea Bay (North)
• Swansea Bay (East)
• Porthcawl-Ogmore
• Rhoose-Barry Island
• Penrhyn Bay
• Nicholaston Burrows
• Oxwich Bay
Of these 16 sites, 4 were retained as pilot sites but truncated in their length (Talacre, Abergele,
Morfa Dyffryn and Porthcawl), 3 were retained in their entirety (Traeth Crugan, Broadwater-
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Tywyn-Aberdovey, Swansea Bay (North) and 3 sites were introduced (Tenby, Port Eynon Bay
and Aberavon Sands) in order to best represent a mix of sand, shingle and mixed beaches of
varying significance to nature conservation, flood risk management and tourism, geographically
spread around the Welsh coast. Therefore, the final ten selected pilot sites were defined as:
• Talacre
• Abergele - Pensarn
• Traeth Crugan
• Morfa Dyffryn
• Broadwater - Tywyn - Aberdovey
• Tenby North Beach
• Port Eynon Bay
• Northern Swansea Bay (Black Pill to Swansea Docks)
• Aberavon Sands (eastern Swansea Bay)
• Porthcawl (Sandy Bay and Trecco Bay)
3.2 Work Package 2 – Data Review and Initial Site Analysis
Aim: To collate and review existing published information of relevance and to develop and
analyse the agreed list of possible beach nourishment case study areas.
Following agreement of the case study sites at the Inception Meeting, for each site we have
developed a more detailed overview of the distribution, sedimentary character, morphology and
recent erosion / accretion status of beaches. Table 3.1 provides a summary of this information.
3.3 Work Package 3 – Beach Case Study Assessment
For the ten selected case study sites the principal methods employed in this study have been:
• Desk study evaluation of published and unpublished literature;
• Analysis of aerial photographs provided by CCW and available on Google Earth;
• Analysis of selected beach profile data previously provided by local authorities;
• Field reconnaissance visits to most of the sites;
• Analysis of sea level and climate change projection data on the UKCP09 website
userinterface (accessed via ukclimateprojections.defra.gov.uk);
• Calculation of sediment volumes based on current beach topography and predicted rates
of sea level rise; and
• Data synthesis and development of recommendations.
It was originally intended to use Environment Agency lidar data in order to assist the sediment
volume requirement calculations but unfortunately the data were not made available in time to
allow their inclusion in the study. It is therefore recommended that they be used in the next stage
of the programme.
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The volumes of sediment nourishment required with the defined sections of beach were
calculated in three ways:
(1) In order to assess the volumes required to create an improved beach', a hypothetical
initial nourishment profile was assumed, consisting of a 20 m wide flat-topped- berm
at the level of HAT, ending in a seaward gradient of 1 in 25 down to the intersection
with the existing beach profile, or, where the existing beach slope was too steep to
allow intersection with a 1 in 25 gradient, the assumed nourishment profile was taken
to end in a uniform slope down to the mean tide level (MTL). Available beach profile
data were then used to calculate the difference between the existing (most up-to-date)
beach surface and the hypothetical design profile. Each profile was assumed to
represent a length of frontage on either side, and this length multiplied by the cross-
sectional area of required nourishment to obtain the volume of required sediment fill
(no allowance being made for over-fill or losses during or after the nourishment
process)
(2) In order to assess the volumes required to maintain the profile of the existing beach
under conditions of projected sea level rise over 20, 50 and 100 year time scales, a
planar area for each beach was first defined down to mean tide level at each site
(levels being defined from the available beach profiles and 2009 Admiralty Tide
Tables for the nearest Standard or Secondary Port. Estimates of sea level rise for each
case study area and each shoreline management 'epoch' were then calculated using
information downloaded from the UKCP09 website. Values were obtained for three
emissions scenarios (low, medium and high), and representing the 5th, 50th and 90th
percentile modelled values (Table 2.3). The 'minimum' expected sea level rise was
taken to be the 5th percentile value for the low emissions scenario, while the
'maximum' expected rise was taken to be the 95th percentile for the high emissions
scenario. Values of up to 1.9m of sea level rise have been considered possible but very
unlikely by the UK Met Office, and therefore have not been considered for the
purposes of the present report. A 'best estimate' value for sea level rise was taken to be
the 50th percentile value for the medium emissions scenario (Table 2.3). Each of these
sea level rise increments was then multiplied by the planar areas specified above to
give an estimate of the volume fill requirement to maintain the existing beach form. It
should be noted that these calculations provide an under-estimate of the actual volume
of sediment which would need to be added to the beach since the volume fill
calculations take no account of losses of nourished sediment which would inevitably
occur and which would need to be compensated for in an actual scheme.
(3) In order to estimate the volume of sediment which would be required to undertake an
initial nourishment improvement scheme, and then to maintain it in the face of sea
level rise and natural erosional losses, the initial nourishment requirements from (1)
above were used in conjunction with sea level rise estimates from (2). The
assumptions were (a) an initial nourishment in 2010 (Table 4.1), (b) four subsequent
five-yearly re-nourishments, each replacing an assumed 50% loss from the previous
nourishment, and (c) minimum, best estimate and maximum values for sea level rise
by 2030, indicated in Table 4.2. These amounts were then added to produce the total
sediment volume requirements indicated in Table 4.3.
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4 RESULTS – INDIVIDUAL CASE STUDY SITES
4.1 Talacre
4.1.1 General geomorphological character
The Talacre site forms part of the eastern end of a dune-capped barrier spit system which extends
eastwards from Rhyl towards the entrance to the Dee estuary. Extensive areas of low-lying
ground, mainly representing reclaimed marshland, lie behind the barrier. Around Rhyl and
Prestatyn large areas of the former dunes have been levelled and built on. Between Gronant and
Talacre there are two main lines of dunes which converge at the western (Gronant) end. In
between is an area of lower ground occupied by deflation areas, sand sheets and low hummocky
dunes (Figure 4.1). The age of the Talacre - Gronant dune system is not well constrained by
dating, but back barrier peat deposits exposed at the eastern end of the Rhyl foreshore have been
radiocarbon-dated at 5000 - 6000 years old, suggesting that a sand and/or gravel barrier has
existed in the area at least since mid-Holocene times. The present dune and gravel barrier ridges
partially overlie and cross-cut older ridges in the Talacre area.
4.1.2 Coastal processes
This part of the North Wales coast is macrotidal with a mean spring tidal range of 7.70 m (Table
2.1). Maximum flood and ebb spring tidal velocities in the ‘Wild Road’ channel off the Point of
Ayr reach 1.5 m s-1
, resulting in strong scour and high sediment transport rates in both directions,
but with net residual drift towards the Dee estuary. The dominant waves in Liverpool Bay
approach from the west and west-northwest, but wave refraction results in a more north-westerly
approach angle along the coastal frontage between Gronant and Point of Ayr lighthouse, and
giving rise to net easterly littoral drift along the upper foreshore (Shoreline Management
Partnership, 1993, 1999; Babtie, 2001a; HR Wallingford, 2008; Wolf, 2008). The rate of
sediment supply to the Talacre area by littoral drift has been significantly diminished by the
construction of groynes and other coastal structures further west over the past 150 years.
The interaction of moderate wave energy and large tidal range gives rise to a wide multi-barred
foreshore composed mainly of medium sand. Between Gronant and Talacre the intertidal zone
decreases in an easterly direction as the WSW-ENE-trending shoreline approaches the Wild
Road low-water channel. Inter-tidal wave heights increase eastwards, resulting in greater
potential for gravel transport along the upper beach. Near Point of Ayr lighthouse the dune toe is
partially protected by a narrow gravel berm which increases in size and to form a distinct ridge at
the eastern end of the system. Exposure to the dominant westerly winds also increases eastwards
between Gronant and the Point of Ayr lighthouse, resulting in greater potential aeolian sand
transport and development of larger dunes and blowouts. To the east of the lighthouse the coastal
orientation changes to W-E and then NW-SE, with the result that the exposure to westerly winds
is reduced, and winds from the NW, N, NE, E and SE assume greater relative importance.
4.1.3 Historical shoreline change
During the 17th
and 18th
centuries there was significant accretion in the Point of Ayr area, partly
as a result of strong sediment drift from the west and partly due to seaward movement of the
Wild Road low water channel. In 1812 an embankment was constructed between the (then) Point
and Tanlan, thereby removing tidal influence from the former marshlands to the west, and in
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1844 a new metal pile lighthouse was constructed c. 800 m seaward of an earlier stone and brick
one built in 1776 (Ashton, 1920). However, landward movement of the Wild Road Channel
must have commenced shortly after 1850 and the metal pile lighthouse was replaced in 1883 by
a lightship. Today the original lighthouse stands on the foreshore approximately 120 m from the
dune toe (Figure 4.2).
Comparison of historical maps and aerial photographs (Babtie, 2001a; Pye & Saye, 2005) shows
that the dune toe between Gronant and Talacre (Profiles 3, 4 & 5 shown in Figure 4.1) has
experienced little net change between 1871 and the present day, but the eastern part of the
frontage around the Point of Ayr lighthouse has suffered significant net erosion (total retreat of
42 m at Profile 6 and 106 m at Profile 7). Much of the erosion near the lighthouse occurred after
1970 and was associated with a landward movement (>460 m) of the low water mark on the
southern side of the Wild Road channel. Erosion of the Point has been accompanied by further
accretion of sand and gravel ridges, with areas of intervening saltmarsh, at the entrance to the
Dee estuary, east of Talacre village.
4.1.4 Flood defence, nature conservation and recreational importance
The beach and dunes provide a natural flood defence for the areas of low-lying land behind,
including several caravan parks, an oil terminal and the villages of Talacre and Lower Gronant.
The study area forms part of, and/or lies adjacent to, several designated nature conservation
areas, including the Gronant Dunes and Talacre Warren SSSI (re-notified 1983), the Gronant
Dunes Local Nature Reserve, and the Dee Estuary SSSI, Ramsar Site, Special Protection Area
and Special Area of Conservation. There is also an RSPB reserve to the east of Talacre village.
Talacre beach is highly popular with recreational visitors, notably in the summer months when
pressures on the beach and dunes are high. Visitors include local residents, day-trippers and
longer-stay guests, mainly from North Wales and North-west England (Jemmett, 1999).
4.1.5 Shoreline management policy
The SMP I for coastal sub-Cell 11a. Shoreline Management Partnership, 1999a) placed this
frontage within Management Unit 4/3 (Barkby Beach to Talacre Access), for which the Preferred
Management Policy was ‘Do Nothing’. The SMP II Draft policy for this Policy Unit (now 4/4,
Halcrow, 2009) is Managed Realignment in the Short Term (0 to 20 years), Medium Term (20 –
50 years) and Long Term (50 -100 years). Under this policy it is intended that the natural defence
which the dunes provide will be maintained while allowing the dunes and Point of Ayr to evolve
naturally. Measures will continue to be taken to control the rate of dune erosion, including
possible use of beach nourishment. Strengthening and maintenance of the line of secondary
defence is recommended in the Medium and Longer Terms.
4.1.6 Previous beach nourishment
A review of coastal processes, morphological change and coast protection / flood risk
management issues along the Gronant – Talacre – Point of Ayr frontage was undertaken by
Babtie (2001a). Among the recommendations arising from this study, incorporated in the
Management Plan for the area (Babtie, 2001b), were sand nourishment of the beach along the
north-central part of the frontage and shingle nourishment along the upper beach along a 850m
section near the Point of Ayr lighthouse (areas shown in Figure 4.1). Following the development
of a Method Statement and monitoring programme (Flintshire County Council, 2003), the beach
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was nourished in February - March 2003 maintenance dredgings (mainly medium and fine sand)
from the approach channel to the Port of Mostyn. Sand was stock-piled on the upper beach prior
to re-profiling using a bulldozer (Figure 4.3). The initial nourished profile aimed to increase the
width and height of the backshore by forming a ramp reaching 6.0 m OD in front of the eroding
dune cliffs. The initial volume of sand emplaced was reported to be 176 x 103 m
3,
of which
about c. 85% was estimated to remain on the beach after 2 years (Jacobs-Babtie, 2005).
By March 2004 the modified nourished profile was still clearly evident (Figure 4.4a) although
significant quantities of sand had been blown into low areas of the frontal dunes raising their
overall level (Figure 4.4b). Sand deposited on the upper beach has continued to be blown into the
dunes and moved alongshore, resulting in a further drop in upper beach levels (Figure 4.5) and
allowing erosion of the dune toe during winter storms (Figure 4.6). It is likely that recession of
the HAT line on the open coast will resume at its former rate unless re-nourishment is
undertaken, and may accelerate in the medium to longer term if forecasts of future sea level rise
prove to be correct. However, accretion is likely to continue on the Dee estuary side of the Point
(Saye & Pye, 2005).
4.1.7 Future nourishment: potential benefits and requirements
For the purposes of the present study, preliminary consideration has been given to the
requirements for further nourishment which would assist the policy objectives identified in the
SMP II (Halcrow, 2009), and which would also provide additional nature conservation and
recreational benefits. The main potential benefits of additional nourishment in this area would
be:
• increase in foredune height / cross-sectional area / sediment volume, providing a more
effective primary flood defence and a reservoir of sand to feed the beach during major
storms – effective in the short, medium and longer term if the frontal dunes are allowed
to ‘roll back’ in the face of rising sea level and continuing erosion
• enhanced sand supply to frontal dunes and inter-dune areas, resulting in stimulation of
vegetation growth (mainly a short-term effect) and expansion of areas of bare sand,
beneficial to species such as the sand lizard
• sediment feed to the down-drift end of the system, enhancing growth of new embryo
dunes / low foredunes
• increase in area of ‘dry’ beach at high water – reduction in recreational pressure on the
beach and frontal dunes
The principal justification for further nourishment on this frontage is likely to be flood risk
management, notably the requirement to protect the village of Talacre and the BHP Billiton gas
terminal. However, nourishment could also be justified as a means by which the Talacre dune
system, which lies with the Dee Estuary SAC, could be returned to a more favourable condition
by restoring a local sediment budget similar to that which existed prior to the interruption of
sediment supply by construction of coastal defence structures further to the west.
The further nourishment scenario considered for purposes of illustration in the present study
involves creation of a 20 m wide flat-topped sand berm at the level of HAT, terminating in a
seaward slope with gradient of 1:25 until the slope meets the existing beach surface. The total
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width of the nourished profile in this instance would be 43 – 91 m. For the defined length of
shore defined, this would represent a total fill volume of 148 x 103 m
3.
The increased volumes which would be filled with sediment in order to maintain a constant
profile across the entire beach between HAT and MTL in each of the shoreline management
epochs, using estimates of sea level rise derived from the UKCP09 website, range from a
minimum of 30 x103 m
3 on a 20 year timescale to a maximum on 1 x 10
6 m
3 on a 100 year time
scale.
The volume required to maintain an initially nourished volume over 20 years from 2010, taking
into account project sea level rise and an assumed 50% loss during each 5 year period between
re-nourishments, would range from 474 to 616 x103 m
3.
These relatively large nourishment volume requirements reflect the relatively large area of beach
above MTL.
Sand for further beach nourishment may be provided by maintenance dredging of the approaches
to Mostyn Docks, although the amount available may well be less than in 2003-04 when capital
works were undertaken (channel deepening were undertaken); availability from this source will
be dependent partly on the commercial fortunes and operational requirements of the port. An
alternative source of both sand and gravel could be provided by licenced dredging areas in
Liverpool Bay. Larger quantities of gravel could be used in future to provide greater protection
for the dune toe and to create shore-parallel ridges which could act as partial wave breaks.
4.2 Abergele-Pensarn
4.2.1 General geomorphological character
The Abergele – Pensarn coastal frontage lies immediately to the east of the Llanddulas
promontory on the central part of the North Wales coast (Figure 4.7). It forms part of a large
shingle and sand barrier system which forms the seaward boundary of a large area of low-lying
land adjacent to the River Clwyd. The River originally took a meandering course through a
structurally-controlled, rock-bound embayment, and was flanked by extensive saltmarshes
(Morfa Rhuddlan), but during the 13th
century the river was artificially straightened and the
marshland was subsequently embanked and reclaimed (mostly following Act of Parliament in
1793 and 1807).
The western part of the barrier system extends from the Llanddulas headland to Fford (Kinmel
Bay) on the western side of the mouth of the River Clywd. The upper part of the active beach is
generally composed of coarse gravel and cobbles, while the lower beach consists mainly of
medium sand. Landward of the active beach is a variable width of stabilized shingle ridges
which are capped by low dunes and windblown sand sheets. Peat and formers back-barrier silts
are periodically exposed on lower parts of the foreshore, testifying to long-term retreat of the
shoreline in this area. Between Abergele, Pensarn and Tywyn the coastal shingle has mostly
been buried by development, but west of Abergele a significant width of un-developed shingle
ridges still remains (Figure 4.8).
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4.2.2 Coastal processes
The frontage is macrotidal with a mean spring tidal range of 7.02 m (Table 2.1). The flood tide
runs in an easterly direction approximately parallel to the coast at maximum spring tide
velocities of c. 0.6 m s-1
, while the ebb tide runs in the opposite direction with peak spring
velocities of c. 0.5 m s-1
. The dominant waves approach from WNW and NW directions;
modelling results have indicated 10 and 100 year Hs values of 4.13 m and 4.75 m, respectively
(HR Wallingford, 1993; Shoreline Management Partnership, 1999a). The net direction of
transport for both sand and shingle is easterly, although modelling has suggested significant
variations in potential sediment drift rates along the frontage, being close to zero at Ty Crwn and
c. 16 x 103 m
3 at Pensarn promenade (HR Wallingford, 1993). This reflects the greater shelter
offered to the western part of the system by the Llanddulas promontory. East of Pensarn where
the shoreline orientation presents a smaller oblique angle to the north-westerly waves the
potential drift rate declines to c. 4 x 103 m
3. Ridges and runnels on the mid and lower foreshore
are oriented approximately perpendicular to the dominant waves, with the result that longshore
drift rates of sand on the lower foreshore are limited. Periodic changes in the positions of the
ridges and runnels, the landward ends of which abut obliquely against the natural shingle ridge
and artificial sea defences, cause alternating episodes of upper shoreface stability and erosion.
Prior to the 20th
century, this coastal frontage received a generous supply of shingle from erosion
of the boulder clay cliffs to the east of Penmaen Rhos Head, between Llanddulas and Old
Colwyn (Ashton, 1920). Some shingle was also supplied by erosion of limestone outcrops and
dumping of quarry waste at Llanddulas. However, during the late 19th
and 20th
centuries
construction of sea defences between Old Colwyn and the coast east of Llanddulas progressively
reduced the rate of sediment supply and easterly transport. Erosion of the shore in front of the
municipal waste tip at Llanddulas, immediately east of the case study frontage, had become
severe by 1960 and in the following 20 years a range of measures were implemented to control
it, including training works at the mouth of the River Dulas, and groynes on the east side of the
river. Bunding of the shingle within the groyne bays was undertaken in the 1980’s and a rock
revetment was built in front of the tip between 1988 and 1980, with further additions in 1991 and
1998. The construction of sea defences along the A55 frontage further west during the late
1970’s and early 1980’s further reduced the sediment supply to areas down-drift. However,
construction of a new promenade near Abergele - Pensarn Station, and a new rock revetment at
Tywyn following the 1990 storm surge, created a barrier to eastward drift of shingle away from
the case-study frontage. Only recently has easterly drift been re-established (Coastal Engineering
UK, 2008).
4.2.3 Historical shoreline change
Comparison of historical maps suggests that the shingle beach at Abergele west prograded
seawards between 1870 and 1960. However, the accretionary trend changed to one of erosion
with the commencement of the Llanddulas sea defences after 1960. Analysis of beach profile
data for the period 1968-90 led Lee (2005) to conclude that the western and eastern ends of the
Abergele – Pensarn ridge complex experienced net erosion while the central section experienced
net accretion, although changes in beach plan were relatively minor. Analysis of data for the
period 1997 – 2004 showed a spatially variable pattern of shingle volume change and a slight net
overall loss, with the greatest net loss occurring at the western end of the system. No significant
change in the barrier crest position was detected, indicating that retreat due to over-washing had
not been important during the period, with most of the sediment loss being accounted from by
beach face erosion.
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Beach profiles in the stable central part of the frontage generally show a more gently sloping
gradient than at the eroding western end and in front of the Abergele - Pensarn promenade at the
eastern end (Figure 4.9). Erosion at the western end of the system is beginning to presents a
threat to the flood wall at the western end of the caravan park (Costal Engineering UK, 2008).
The edge of the vegetated shingle in this area is marked by a 1 m high cliff which shows clear
evidence of active recession (Figure 4.10). The cliff edge along the line of unprotected vegetated
shingle now lies c. 8m landward of the line of rock revetment just to the west, and the width of
vegetated shingle has been reduced to less than 5 m in places (Figure 4.8b). Unless action is
taken, the erosion front is likely to impinge on the flood wall within 5 years. However, as noted
by Lee (2005), construction of further hard defences in this area would be likely to extend the
problem of erosion in an easterly direction (down-drift); consequently; beach nourishment may
present a better management alternative.
4.2.4 Flood defence, nature conservation and recreational importance
As noted above, the vegetated beach ridge plain is backed by a 1.5 m high floodwall (constructed
after the February 1990 storm surge), a service road, the North Wales coastal path and cycle-
way, and a caravan park, behind which run the Chester to Holyhead railway line and the A55
trunk road.
Pensarn Beach was notified as a SSSI in 1977 for its SD1 pioneer shingle communities and SD8
more stable vegetation communities. The ridge complex represents c. 13% of the total resource
of vegetated shingle in Wales (University of Newcastle, 2000); loss of vegetated shingle area at
Hen Wrynch is therefore a matter of importance.
The beach is fairly heavily used for recreational purposes, including seasonal occupants of
several caravan parks in the Tywyn - Pensarn - Abergele - Llanddulas area.
4.2.5 Shoreline management policy
The SMP1 recognised that maintenance of the shingle bank between Hen Wrych and Pensarn
(Management Unit No. 3/4) is essential for any future strategy for coastal defence in this area,
and beach replenishment was identified as an option for future consideration (Shoreline
Management Partnership, 1999a). The SMP2 preferred policy for the Llanddulas - Pensarn
frontage (included in Policy Unit 2.3) during all three epochs is also ‘Hold The Line’, involving
beach maintenance and improvement (Halcrow, 2009). Owing the presence of the railway
embankment and A55 behind the beach there is little scope for the beach system to retreat
landwards under conditions of accelerated sea level rise. Over a 100 year timescale the beach
system may therefore become ‘squeezed’, with resulting loss of habitat, unless intervention
measures are implemented.
4.2.6 Previous beach nourishment
Although there dumping of quarry waste at Llanddulas may inadvertently led to some
nourishment of the beach between Hen Wrych and Pensarn, there is no record of deliberate
previous nourishment of this frontage.
4.2.7 Future nourishment: potential benefits and requirements
Following the 1990 storm surge and large-scale breach in the defences at Towyn, HR
Wallingford (1993) examined the defence options and concluded that shingle beach
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nourishment, combined with secondary flood walls set back behind the beach crest, could
provide a feasible solution. Three options were identified:
(1) Re-nourishment of an open shingle beach with 80 x 103 m
3 of gravel-size material from
the nearby Raynes Quarry every 5 years
(2) Re-nourishment with a system of 19 rock groynes to slow the rate of longshore sediment
drift and to stabilise the beach
(3) Re-nourishment with breakwaters placed on the lower beach near the sand / shingle
boundary (crest height of 6.0 m OD and a length of 2500 m) to stabilise the beach
Lee (2005) concluded that only the first option offered the opportunity for amelioration of
habitat loss while minimising the effect on coastal processes, but this option would require a
long-term commitment for re-nourishment and might in the long-term prove considerably more
expensive than the other options involving structures. However, to date no significant
nourishment has been undertaken.
The principal potential benefits of beach nourishment in this area would be:
• stabilization of the shoreline and enhancement of the shingle beach as the primary sea
defence, thereby reducing pressure on secondary defences and reducing flood and erosion
risk to existing assets, including regional transport infrastructure (main railway line and
trunk road)
• reduction / cessation of loss of priority habitat (vegetated shingle); potential creation of
new habitat
• recreational / touristic benefit by increasing area of ‘dry beach’, maintaining security of
tourist accommodation (caravan parks), and maintenance of the North Wales Coastal
Path and cycleway
For the purposes of this study, a scenario has been considered in which a 20 m wide shingle
berm at the level of HAT is created, terminating in a constant gradient down to MTL level.
Based on 2009 beach profile data, the overall nourishment width would vary from 52 to 121 m,
resulting in a total required fill volume of 430 x 103 m
3.
In order to maintain the 2009 beach area and cross-sectional profiles between HAT and MTL,
taking account of projected sea level rise, over a 20 year timescale the minimum sediment fill
volume would be 4 x 103 m
3 and the maximum requirement over 100 years would be 136 x 10
3
m3 (no allowance being made for sediment losses).
To undertake initial nourishment and maintain an equivalent volume over a period of 20 years
would require between 1.29 and 1.31 x 106 m
3 of sediment.
The main requirement for sediment nourishment of the upper beach will be gravel, potential
sources of which include nearby limestone quarries. However, further investigation is required to
assess its suitability in terms of angularity / roundness and durability. Naturally occurring known
sources of rounded gravel are unlikely to be able to satisfy the volumes required.
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4.3 Traeth Crugan
4.3.1 General geomorphological character
Traeth Crugan represents the western part of a larger bay-head barrier beach system which links
the rock head of Carreg y Defaid in the west and the former bedrock island of Carreg yr Imbill
in the east. The eastern part of the beach is known as Pwlheli South Beach, represents a former
spit system which has grown eastwards to attach itself to Carreg y Imbil. The western part of the
barrier is very narrow and the periodic exposure of back-barrier deposits on the lower
beachprovide evidence of long-term coastal retreat in this area (Figure 4.11). Almost the entire
length of this part of the frontage is protected by rock armour and the beach consists mainly of
cobles, gravel and coarse sand. A gravel-armoured scar forms an intertidal exposure 400 - 600 m
offshore. Behind the rock armour revetments is an artificial embankment which protects a large
area of low-lying land (the Afon Penrhos floodplain) from tidal flooding. The beach in this area
consists of a steep upper beach and a more gently sloping lower foreshore (Figures 4.12 & 4.13).
The width of the barrier increases and becomes more sandy in an easterly direction. The plan
form of the beach shows a slight bulge in the central-eastern part of Traeth Crugan due to long-
term net accumulation of sediment in this area (Figure 4.11). A change to erosion along this part
of the shoreline after the mid 1970's resulted in the placement of additional rock armour which
has 'fossilized' the shoreline position, with resultant steepending of the fronting beach in recent
decades.
Further east, the average gradient of the beach reduces and an upper beach berm becomes more
pronounced. (Figure 4.12). Dunes up to 12 m high occur between the promenade at Pwlheli
South Beach and Carreg y Imbil. The dunes provide an important semi-natural flood defence for
a large area of residential property which lies between the dunes and Pwlheli harbour. Since the
1970's the morphology and sediments along the entire Traeth Crugan - Pwlheli South Beach
frontage have been significantly affected by beach management measures and dune restoration
works associated with the promenade re-development at Pwlheli West End. The shoreline of
Traeth Crugan has been progressively hardened as the beach erosion front has moved eastwards
over time.
4.3.2 Coastal processes
The area experiences a macrotidal regime (mean spring tidal range of 4.50 m) and is exposed to
refracted waves which approach Tremadoc Bay mainly from the southwest. Inter-annual and
shorter-term fluctuations in beach profiles are governed principally by storm sequencing in
Tremadoc Bay (Neill et al., 2008). The general net sediment drift direction along the upper beach
is from west to east, with drifted material passing around Carreg yr Imbill and being deposited at
the entrance to Pwlheli harbour where it poses a problem for navigation (Faber Maunsell, 2008).
4.3.3 Historical shoreline change
At the extreme western end of the beach the high water mark has receded landwards by 10 - 30
m since 1888, but along the central and eastern parts of the frontage there has been little net
change, with slight net seaward movement of the high water mark along the western part of the
Pwlheli Golf Club frontage and further east.
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4.3.4 Flood defence, nature conservation and recreational importance
The Traeth Crugan beach and associated structures are important in providing coastal flood
protection to the Afon Penrhos lowlands and the adjacent Pwlheli Golf Club. The western
hinterland is relatively undeveloped but is crossed by the A499 Pwlheli to Abersoch Road.
Flooding of this area could potentially affect the flood protection status of the western part of
Pwlheli.
Traeth Crugan falls within the Pen Llyn a'r Sarnau SAC and the foreshore forms part of Myndd
Tir Y Cwmwd A'r Glannau At Garrey Yr Imbill SSSI. The main biotope present is Mobile gravel
with sparse infauna but the site is important for the occurrence of the amphipod
Pectenogammarus planicrurus with coarse sand and fine gravel deposits which occur on the mid
to upper beach (Webb et al., 2010).
Pwlheli South Beach is popular with local residents and tourists during the summer months, but
the coarser grained and more distal parts of Traeth Crugan are of less importance in this respect.
4.3.5 Shoreline management policy
A study by Posford Duvivier (1996) into problems of erosion along the Traeth Crugan - Pwlheli
Golf Club frontage concluded that Hold the Line was the best policy option and that recycling of
dredgings from Pwlheli harbour to nourish the beach offered the bests solution. The first
Northern Cardigan Bay Shoreline Management Plan (Gwynedd Council, 2002) also identified a
policy of Hold the Line for the Traeth Crugan frontage but, in the light of comments received
from CCW during the consultation phase, recognised the need for a strategic appraisal of defence
options to be carried out. CCW were of the opinion that Hold the Line is sustainable only in the
short-term and that longer term other options, including Managed Realignment, might have to be
considered. A further review of the management options by Faber Maunsell (2008) also
concluded that, while sediment recycling / beach nourishment should be continued in the short to
medium term, plans should be made for removal and/ or realignment of defences in the medium
to longer term. The preferred option under the SMPII review, currently being undertaken by
Royal Haskoning, has not yet been announced.
4.3.6 Previous beach nourishment
In 2002, following a serious storm, the beach was nourished using capproximately 35 x 103 m
3
of dredgings from Pwlheli harbour and approach channel. Delivery to the beach was
accomplished using land-base plant. A repeat operation was carried out in February and March
2007. The short-term effects of the nourishment were to raise upper beach levels and to increase
the availability of sand for wind-blown transport to the back-beach area. However, following the
initial nourishment in 2002 beach levels gradually returned to their previous levels by 2007.
Following re-nourishment levels were again increased but have since fallen again and are likely
to continue to fall in future years as sand is lost both onshore (by wind action) and alongshore
(by wave-induced littoral drift).
4.3.7 Future beach nourishment: potential benefits and requirements
As noted above, continued beach nourishment at Traeth Crugan would remove the need for
construction of new rock armour defences and would provide time in which detailed plans for
managed realignment and/ or removal of existing defences can be made. Addition of sediment
would increase the usable recreational area of the beach and potentially increase the extent of
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suitable habitat for species such as Pectenogammarus planicrurus if suitably coarse-sized
material is used.
For the purposes of illustration in the present study, creation of a 20 m dry beach berm and with
slope down to existing mean tide level would create a sediment fill would create a total
nourished width of beach of 28 - 39 m and an overall fill volume of 68 x 103 m
3 (Table 4.1). In
order to maintain the existing (2006) beach profile in the face of sea level rise, a minimum of 2 x
103 m
3 would be required on a 20 year timescale and a maximum volume of 59 x 10
3 m
3 would
be required over 100 year timescale (Tables 4.2). In order to maintain the existing period over a
20 year period, allowing for a 50% volume loss in each 5 year period between re-nourishment
operations, a volume of 206 to 210 x 103 m
3 of sediment would be required, depending on the
rate of sea level rise.
While maintenance dredging of the entrance to Pwlheli harbour is likely to supply sufficient
material to satisfy the nourishment requirements in the short term (20 years), there is likely to be
an increasing short-fall in the medium and longer term which would need to be satisfied from
sources further afield (offshore or onshore). Continued recycling of sediment dredged from
Pwlheli Harbour and placement on the beaches to the west could also likely to add to a problem
of sediment starvation at Abererch and other beaches to the east, creating a sediment demand that
could only be satisfied by supply from offshore or other onshore sources.
4.4 Morfa Dyffryn
4.4.1 General geomorphological character
Morfa Dyffryn is a cuspate feature which has formed to seaward of a mid-Holocene cliff-line
(Figure 4.14). The name of the area arises from the extensive area of former marshy ground
which extends west and north from the village of Dyffryn Ardudwy. Today the system consists
of a dune-capped sand and gravel barrier on its western side and a large area of back-barrier
sand-flat which formerly was covered in large marsh by salt, brackish and freshwater marsh. The
main barrier beach links Shell Island (Mochras) in the north with the upland coast near Llanaber
in the south, but is broken near Tal y Bont where the Afon Ysgethin enters the sea. Shell Island
is an outlier of glacial till from which a gravel ridge (Sarn Badric) extends offshore for several
kilometres (Coastal Geomorphology Partnership, 2000). Wave erosion of the till cliffs at Shell
Island has supplied sediment for a small spit system which extends in a northeasterly direction
towards the entrance to estuary of the Afon Artro. The flanks of the Artro estuary behind the
Mochras spit are fringed by active saltmarsh which was more extensive before reclamation and
creation of the Llanbedr Airfield (now dis-used).
Morfa Dyffryn is significant for its extensive development of sand dunes and associated
blowouts. It represents one of the most active sand dune fields in the United Kingdom and is
characterized by transgressive dunes which in places are more than 15 m high. Towards the
landward side of the dune field the dunes are generally better vegetated and less active. To
seaward of the dunes is mixed sand and shingle beach which today is relatively narrow. Areas of
eroded till and former soil horizons are periodically exposed on parts of the beach near Shell
Island.
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4.4.2 Coastal processes
The Morfa Dyffryn coast is macrotidal but the mean spring tidal range is only 4.30 m, resulting
in a narrower intertidal zone than those found on some other parts of the Welsh coast. The main
coastal orientation runs almost transverse to the prevailing south-westerly winds and dominant
waves, with the result that potential rates of wind-blow sand transport are high but the potential
for longshore sediment transport is relatively low, although historical there has been slow net
northward movement of sediment. In recent decades rates of northerly sediment drift have been
reduced by a variety of ad hoc measures undertaken to protect the caravan parks and other
developed frontages along the southern part of the coastal frontage. Little or no sand appears to
be supplied to the coast from the offshore zone at the present time. North of Shell Island the
shore orientation is almost parallel to the south-westerly winds and waves, with the result that
potential longshore sediment transport rates are higher. However, wind exposure on the northern
side of Shell Island is much reduced and dune development is on a much smaller scale than on
the southern side where very large composite parabolic parabolic dunes occur.
4.4.3 Historical shoreline change
Evidence from historical maps and aerial photographs indicates that since 1887 the high water
mark has shown almost no movement at Shell Island but has receded by up to 20 m at the
southern end of the system (Table 2.2). However, monitoring of beach profiles established by
Gwynedd Council has demonstrated there has been little movement of the HAT and MHWS tide
lines in the south since 1992, although a slight landward movement of the MHWNT and MTL
tidal offsets is indicated (Figure 4.15). The beach has consequently become narrower, slightly
steeper and more stony.
4.4.4 Flood defence, nature conservation and recreational importance
The dune belt forms a barrier against tidal flooding for the low-lying marshy land, railway line
and coastal settlements behind.
The dune system is of high nature conservation importance, notably for its wide range of dune
landforms and habitats, including active transgressive dunes and slacks formed in blowout
depressions (Figure 4.16). The area was established as a National Nature Reserve in 1962 and
forms part of the Morfa Dyffryn SSSI, the Harlech a Morfa Dyffryn SAC, the Pen Llyn a'r
Sarnau SAC and the Snowdonia National Park.
The area is popular with visitors in the summer months and a number of caravan parks and
camping sites are located adjacent to and within the area. The location is especially popular with
naturists.
4.4.5 Shoreline management policy
The preferred policy identified in the SMPI was 'Do Nothing' (Gwynedd Council, 2003). The
preferred policy identified in SMPII has not yet been announced but is likely to be No Active
Intervention.
4.4.6 Previous beach nourishment
There are no records of previous beach nourishment at Morfa Dyffryn.
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4.4.7 Future beach nourishment requirements and benefits
If left to its own devices, the main NW - SE shoreline is likely to continue to erode, probably at
an accelerating rate if there is a significant increase in the rate of sea level rise or an increase in
storminess (Pye & Saye, 2005). Owing to the high degree of wind exposure, a significant
proportion of the eroding beach sediment will be transferred landwards into the dune system
rather than being moved offshore by wave action, thereby acting to accelerate the rate of
shoreface recession. Shell Island will continue to act as a relative hard point; there may be an
increase in the rate of cliff erosion in this area but the amounts of sediment released are unlikely
to large enough to have a significant effect on the rate of shoreline recession, especially to the
south. A combination of wind and wave winnowing of the beach sediments will increase the
tendency towards a stony beach which will in the longer term act to self-regulate the rate of
shoreline recession but which will produce a beach which is less visually attractive from a
recreational / touristic perspective. The potential benefits which might arise from sand beach
nourishment would therefore to slow the rate of shoreface recession in the short to medium term
and to maintain a more appealing beach character. Increased availability of sediment for wind
transport would enhance the existing mobile dunes and encourage their landward movement;
however, the effectiveness of aeolian transport on this coast means that the positive effects of
nourishment on the beach per se are likely to be short-lived.
The calculated volume of sediment required to create a 20 m flat-topped berm at HAT level,
terminating in a uniform slope down to MTL, would be 369 x 103 m
3. The resulting total width of
initially nourished beach would vary from 62 m to 163m.
Maintaining the existing beach in the face of sea level l rise would require a minimum volume of
14 x 103 m
3 to be filled with sediment over 20 years, and a maximum volume of 400 x 10
3 m
3
over a 100 year time scale. To undertake an initial 'improvement' nourishment and maintain it
over 20 years in the face of sea level rise, allowing for 50% losses between 5 yearly
nourishments, would require 1.12 x 106
m3 to 1.18 x 10
6 m
3 of sediment
nourishment and re-
nourishment.
4.5 Broadwater – Tywyn – Aberdovey
4.5.1 General geomorphological character
The Broadwater - Aberdovey open coast frontage comprises two main coastal barrier systems
centred on an upland area formed of bedrock and glacial till at Tywyn (Figure 4.17). The
northern barrier, which is shingle-dominated, extends northwards from Tywyn towards another
bedrock headland at Tonfanau. Behind this barrier is an extensive area of lowland which forms
part of the Afon Dysinni valley, Prior to reclamation in the 16th to 18th centuries much of this
areas represented an active intertidal estuary, but tidal exchange is now regulated through an
artificial channel at Dysinni Bridge. The Broadwater lagoon represents a shallow remnant of a
once-much larger area of tidal flat and saltmarsh
The barrier to the south of Twywn consists of a mixture of sand and shingle, reinforced by
placed slate blocks along the Pen-Llyn marshes frontage. The shingle ridge is generally smaller
than the ridge north of Tywyn but non-the-less forms a significant part of the flood-defence
between Tywyn and Aberdovey Golf Club. The ridge is backed by a small area of dunes at the
Tywyn end and by a much larger dune system at the southern end. A large part of the southern
dune area is occupied by Aberdovey Golf Club and a caravan park. To seaward of the shingle
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ridge and dunes is a relatively flat, low sandy foreshore. Along the central and northern part of
the beach the sand cover is thin and overlies back-barrier peat and silt deposits which are
periodically exposed. There presence provides evidence of long-term barrier retreat (Pye & Blott,
2006).
4.5.2 Coastal processes
The mean spring tidal range in the area is about 4.30 m (Table 2.1), resulting in a exposure of a
moderately wide foreshore at low tide. Flood tidal currents are directed northward, sub-parallel
to the coast, while slightly weaker ebb-currents are directed southwards. A more complex flow
pattern occurs close to the entrance to the Dyfi estuary in the south.
The general orientation of the coastline lies at a slight oblique angle to the prevailing south-
westerly winds and dominant waves. Net sediment drift directs are subject to considerable
variability in response to alternating periods of dominance by south-westerly and north-westerly
waves. The long-term net drift direction to the north of Tywyn is northerly, while south of
Tywyn it is southerly. The artificially protected frontage at Tywyn now forms a slight 'headland'
and effective littoral drift divide. Sediment accumulation still takes place at the distal ends of the
drift system near the Dysinni entrance and in front of the promenade at Aberdyfi (Figure 4.18).
4.5.3 Historical shoreline change
Comparison of historical maps and aerial photographs has indicated that since 1887 there has
been very little change in the position of the back-beach at Tywyn but the undefended / lightly
defended coast immediately to the north and south of the town has retreated by 20 - 40 m (Table
2.2). Significant net accretion (up to 152 m) has occurred near the mouth of the Afon Dysinni
and at the southern end of the Aberdovey Golf Course frontage (up to 77m). The net result has
been the formation of two shallow bays centred on a 'hinge point' at Tywyn.
Monitoring of beach profiles since 1992 by Gwynedd Council has shown a continuing slow fall
in beach levels and retreat of the dune toe along the open coast part of the Aberdovey Golf Club
frontage. (Figure 4.19). Beach levels and the volume of shingle on the upper beach along the
Pen-llyn marshes frontage have also been falling although the position of the backshore has not
changed due to the presence of slate blocks which were placed in the 1970's and 1980's.
4.5.4 Flood defence, nature conservation and recreational importance
The Tywyn to Aberdoveyshingle and sand barrier provides a semi-natural flood defence for the
low-lying area of Pen-lyn marshes and for the Cambrian coast railway which runs along its
landward edge (Figure 4.20b). The Tywyn to Aber Dysynni shingle barrier provides the main
flood defence for northern parts of Tywyn, the Broadwater lagoon and the lower Dysinni valley.
North of Tywyn the Cambrian coast railway line runs very close to the beach and is protected
only by the shingle beach and a low line of rock armour (Figure 4.21b). At Tywyn itself there a
variety of hard defence structures, including a concrete faced promenade and groynes, which
have fallen into a state of disrepair (Figure 21a). A defence improvement scheme is currently
underway and will involve the construction of a detached headland breakwater, new rock
groynes, rock revetment and improvements to the sea wall (Atkins, 2009).
The area is of high conservation importance, including, or lying adjacent to, several designated
areas: the Llyn Peninsula a'r Sarnau SAC, Broadwater SSSI, Dyfi SSSI, Snowdonia National
Park and Dyfi Estuary Biosphere Reserve. The barrier north of Tywyn contains a significant area
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of vegetated shingle and the Aberdovey dunes contain a variety of significant dune habitats and
vegetation communities.
Both Aberdovey and Tywyn are popular with day trippers and longer term holiday visitors.
Aberdovey Golf Club attracts a significant number of visitors from throughout the UK and
overseas, notably North America.
4.5.5 Shoreline management policy
The SMPI (Gwynedd Council, 2003) identified a preferred policy option of Retreat for the
Aberdovey Golf Course and Pen Llyn Marshes frontage, and suggested the construction of a set
back flood defence bund to protect the railway, coast road and other infrastructure from flooding.
The Environment Agency Wales have agreed to maintain the defences along the Pen-llyn section
for a period of 25 years (until approximately 2030). Gwynedd Council and Aberdovey Colf Club
are currently collaborating to slow the rate of recession of the Golf Club dune frontage under a
policy of what amounts to Managed Realignment.
The SMP1 preferred policy for the Tywyn to Broadwater frontage was Hold the Line on account
of the need to protect residential property in Tywyn itself, the proximity of the railway line, and
the practical and cost issues likely to be associated with the establishment of set-back defences
across a long section of the Dysinni valley.
The SMPII preferred policies, which are being developed by Royal Haskoning, have at the time
of writing not been announced but are most likely to be Hold the Line for the Tywyn to
Broadwater frontage and No Active Intervention or Managed Realignment for the Pen-Llyn to
Aberdyfi frontage.
4.5.6 Previous beach nourishment
Ad hoc nourishment of the beach at Tywyn has been undertaken in the past, chiefly following
storm damage to the promenade and groynes, using a variety of materials including imported
shingle and cobbles from on-shore sources and construction waste. However, there are no
records of large-scale sand importation.
Since the early 1990's Gwynedd Council has carried out an annual sand shift which involves
removal of excess sand from Aberdovey dock, and the adjoining area of the promenade, and
deposition of the material at low points in the frontal dunes along the Aberdovey Golf Club
frontage. The excess sand at Aberdovey creates problems for navigation into the dock and
requires periodic clearing of wind-blown sand from the promenade, road and adjoining
properties. Excess material (mainly sand but with some shingle) is removed by digger (Figure
4.18a) and truck-hauled along the beach to selected points of deposition (Figure 4.18b). The
objectives have been to infill low points in the frontal dunes where storm tide ingress is possible
and to construct a continuous line of relatively high dunes slightly inland of the present dune toe,
thereby allowing for the natural long-term trend of coastal recession. The total amount of
material moved annually has varied, depending on the quantity of excess sediment in the
licenced removal area, but has typically been in the range of 10 - 20 x 103 tonnes (7.5 - 15 x 10
3
m3). Wind erosion of the emplaced sand has been reduced by covering the nourished sand
surface with brashings (Figure 4.20a). Temporary fencing and warning notices have also been
employed to encourage the establishment of vegetation.
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4.5.7 Future beach nourishment requirements and benefits
The ongoing Tywyn coastal defences improvement scheme includes plans for small-scale beach
nourishment adjacent to the new detached headland breakwater. The principal purpose of the
nourishment is to prevent draw-down of sediment from adjoining areas of more exposed beach
and accumulation in the lee of the breakwater. The sources of material have yet to been
confirmed, but may include a combination of cobbles from an onshore quarry source and
dredged sand from Pwlheli harbour entrance channel.
For the purposes of illustration in the present project, a hypothetical nourishment scheme along
the entire shore from the Dysinni to Aberdovey has been considered in order to illustrate the
volumes of sediment which would be required for a larger-scale, 'strategic' nourishment scheme.
Construction of a 20 m wide, flat-topped berm at HAT level has been assumed, terminating
along the southern part of the frontage (south of Tywyn) in a 1:25 seaward slope and along the
naturally steeper northern part (north of Tywyn) in a uniform slope down to MTL. The resulting
total width of nourished beach in this instance would range from 23 m to 100 m, with a total
required sediment volume of 491 x 103 m
3.
To maintain the existing beach form along the entire frontage in the face of future sea level rise
would require infilling with sediment of an additional volume of between 18 x 103 m
3 and 502 x
103 m
3 (no allowance being made for sediment losses due to erosion).
Creation of an initial nourished profile and subsequent maintenance of the same profile in the
face of sea level rise over a 20 year period would require emplacement of between 1.49 and 1.56
x 106 m
3 of sediment, assuming 50% losses between 5-yearly re-nourishments.
Any nourishment scheme along this frontage would require importation of a range of sediment
types, including gravel, cobbles and sand. Current and likely future dredging volumes from the
small harbours around Cardigan Bay would be unlikely to satisfy the demand for a large or long-
term scheme. Relatively proximal onshore quarry sources might be able to satisfy the
requirement for cobble sized material but are unlikely to be able to satisfy the requirement for
coarse gravel (shingle) and sand.
4.6 Tenby North Beach
4.6.1 General geomorphological character
Tenby North Beach is a small bay-head beach located to the northwest of Castle Moundand
south of First Point (Figure 4.22). Tenby Harbour is located at the southern end. The beach is
backed by steep slopes with a seawall at its foot (Figures 4.23 & 4.24). In the southern part of the
bay the low-tide beach is relatively wide (> 250 m) but low (below 1 m OD) and has a gentle
gradient. Consequently there is no high tide 'dry beach'. At the northern end the low tide beach is
less than 100 m wide but the back-beach is much higher, reaching 5 m OD. However, the width
of the high tide dry-beach varies from 0 to only 10m. A large rock (Gosker Rock) separates the
wider, flatter southern part of the beach from the narrower, steeper northern part. The beach is
composed almost entirely of medium well-sorted sand with only localised rock outcrops and
ephemeral patches of shingle.
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4.6.2 Coastal processes
The tidal range in the area is large, exceeding 7.5 m on mean spring tides (Table 2.1). Owing to
the easterly orientation of the beach it is sheltered from the direct force of south-westerly waves,
although waves from this direction are refracted around St Catharine's Island and are able to
reach the shore. Shorter period, steeper waves approach the shore directly from the east and
northeast. Sediment movement occurs mainly in an onshore-offshore direction due to fluctuating
wave conditions, although there is some limited longshore drift in both directions.
4.6.3 Historical shoreline change
The position of the back-beach has shown virtually no movement since 1887 (Table 2.2) The
mean low water mark has shown a net landward movement in the northern part of the bay during
this period but has moved seawards slightly in the central and southern parts (Figure 4.21).
4.6.4 Flood defence, nature conservation and recreational importance
Owing to the steeply rising nature of the ground to the west, the beach itself has little importance
in terms of flood protection although it serves a coast protection function by breaking wave
energy and reducing the pressure on the seawalls at the cliff toe. In time, future sea level rise will
reduce the width of the available dry beach width and tourist amenity. In addition this will act to
create a positive feedback loop with accelerated beach draw down as waves are reflected from
the sea wall at the back of the beach, leading to instability and ultimate failure of the wall in due
course.
The beach lies within, or adjacent to, the Tenby Cliffs and St Catharine's Island SSSI, the
Carmarthen Bay SAC and the Pembrokeshire Coast National Park.
Tenby is one of the most popular holiday destinations in Wales, attracting large numbers of long-
stay visitors from other parts of the United Kingdom and Europe. The North Beach is
approximately 1 km long and is the smaller of two main beaches at Tenby. The larger South
Beach extends over a distance of 2 km to the southwest of St Catharine's Island as far as Giltar
Point and retains a greater width of dry beach at high tide. However, it is generally less sheltered
than the north beach and potentially more hazardous for bathing and other recreational activities.
The small available area of dry sand area on the North Beach at high tide results in high densities
of visitors and limits the provision of traditional beach activities. Two other small areas of high
tide dry beach occur, one within the harbour and the other adjacent to Castle Hill.
4.6.5 Shoreline management policy
The preferred policy identified for the North Beach in the SMP1 was Hold the Line (Shoreline
Management Partnership, 1999b); this is also the preferred policy identified in the SMP2
currently in preparation by Halcrow (2010).
4.6.6 Previous beach nourishment
There are no records of previous beach nourishment on Tenby North Beach.
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4.6.7 Future beach nourishment: potential benefits and requirements
The principal potential benefit of beach nourishment would be to increase the area of the high
tide dry beach available to recreational users. Increased beach width and elevation would also
increase the capacity of the beach to dissipate storm wave energy, thereby reducing the
requirements for maintenance of the back-beach sea wall and creating the possibility of embryo
dunes at the less heavily used northern end of the beach. However, excessive beach nourishment
could cause potential problems of sedimentation within the harbour area.
The limits of the hypothetic nourishment considered for illustration purposes in this study are
shown in Figure 4.22; these exclude the harbour area but otherwise extend seawards to the mid-
tide level. The total width of beach which would require initial nourishment in the considered
example would vary from 63 to 80 m, creating an initial dry beach at HAT level along
approximately 900 m of the back-beach. This would more than quadruple the existing area
available for recreational use at high tide, allowing an increase in visitor numbers and comfort.
The total volume of sandy sediment required to achieve the initial nourishment profile would be
relatively modest (46 x 103 m
3).
The additional volume which would need to filled with sand in order to maintain the existing
beach profile / area under conditions of future sea level rise would vary from a minimum of 2 x
103 m
3 over 20 years to 45 x 10
3 m
3 over 100 years. The volume of sediment required to carry
out the initial nourishment and subsequently maintain the average beach level in the face of sea
level rise over the next 20 years, allowing for losses of 50% of the material placed in the initial
nourishment and each subsequent 5 yearly re-nourishment, would range between 140 and 146 x
103
m3, depending on the rate of sea level rise.
There is only limited opportunity to nourish the more northerly parts of the beach using small-
scale dredgings from the harbour, and it is likely that the bulk of any nourishment material
would need to be brought from further away (e.g. dredgings at Burry Port) or from offshore
sources (e.g. Nobel Banks).
4.7 Port Eynon
4.7.1 General geomorphological character
Port Eynon Bay, located on the south coast of the Gower, is a relatively small rock-bound
embayment which lies between the rocky headlands of Port Eynon Point in the west and Oxwich
Point in the east. (Figure 4.25) The distance between the two headlands across the mouth of the
bay is approximately 4 km. The bay has an asymmetric plan form with a mainly sand beach in
the west and an exposed rock shore platform in the east. The back of the bay is fringed by sand
dunes which are locally protected by small-scale sea defences. The land behind the beach rises
fairly steeply towards the villages of Port Eynon and Horton. The toe of the slope deposits has
been cliffed in the past by wave action at a time when fronting dunes were absent. At the
western and eastern ends of the beach, rock scars are exposed on the mid and lower foreshore,
but in the middle of the bay the beach is normally sandy down to the low tide mark. Beach levels
are lower at the western (Port Eynon) end of the bay where the backshore is now very narrow
and periodically absent altogether. The backshore width increases towards the eastern end of the
bay although the foreshore width becomes narrower in that direction.
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4.7.2 Coastal processes
Port Eynon Bay experiences a large tidal range (MSTR of 8.4 m), with the result that a wide
foreshore is exposed at low tide (Table 2.1). The bay is influenced by refracted waves from the
southwest and by waves approaching directly from the south and southeast. Evidence suggests a
long-term net sediment drift in an easterly direction across the upper beach. Offshore movement
of sediment from the upper beach into the deeper water of the bay occurs during storms, with
onshore movement of material leading to re-building of the beach during fair weather periods.
Material moves offshore during exceptionally large storms may be moved into very deep water
from which it cannot be returned by fair-weather waves.
4.7.3 Historical shoreline change
Comparison of historical maps and aerial photographs has shown that since 1877 the HAT line
has moved inland by 24 m at the Port Eynon end of the Bay but has moved seawards by 4 m at
the Horton end. For most of the 20th century much of the bay had a sandy backshore and
relatively high overall beach levels (Figure 4.26), but since the 1990's beach levels have fallen,
resulting in a narrower backshore and more extensive exposure of rock scars and patches of
gravel. Monitoring of beach profile levels by Swansea Bay Coastal Group since 1999 has shown
a steady decline in beach levels although the position of the back-beach line has not changes
significantly (Figure 4.27).
4.7.4 Flood defence, nature conservation and recreational importance
Owing to the generally rising nature of the land behind the beach and dunes are of limited
importance in terms of flood risk prevention. There are also relatively few properties at risk from
erosion.
The area falls within, or lies adjacent to, several designated areas, including the Gower Coast
SSSI, the Gower Area of Outstanding Natural Beauty, and the South Wales Limestone Coast
SAC.
Port Eynon Bay is popular as a recreational area for residents of the wider Swansea area and with
tourists to the Gower from other parts of the UK.
4.7.5 Shoreline management policy
The SMP1 preferred policy for the whole shoreline was 'Hold the Line' (Shoreline Management
Partnership, 2001) but the preferred policy identified in the draft SMPII document is 'No Active
Intervention'.
4.7.6 Previous beach nourishment
There are no records of previous beach nourishment in Port Eynon Bay.
4.7.7 Future beach nourishment: potential benefits and requirements
The reduction in beach extent, particularly of the dry backshore, in Port Eynon Bay is having a
detrimental effect on the visual appearance of the bay and on its attractiveness to visitors.
Continues loss of sand would worsen the situation as inter-tidal rock exposures become more
extensive and as increased erosion pressure is put on the dunes and artificial defences at the back
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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of the beach. The main potential benefits of beach nourishment would therefore be in terms of
landscape quality and amenity value.
Owing to the relatively small size of the bay, the total volume of sand required to create a 20 m
wide high topped berm at HAT level along the defined length of shore would be only 152 x 103
m3. However, the total width of nourished beach would be relatively large (128 to 149 m) on
account of the gentle overall beach gradient.
The volume which would nee to be filled with sediment in order to maintain the existing beach
form in the face of sea level rise would range from a minimum of 5 x 103
m3 to a maximum of
124 x 103 m
3. The volume of sediment required to initially nourish the beach and then to
maintain it over a 20 year period, allowing for sea level rise and erosional losses of 50% between
each re-nourishment, would be 460 - 477 x 103 m
3.
The nearest potential source of nourishment sand would be the licenced dredging area on
Helwick Bank. Alternative longer-term potential sources would be the Nobel Banks area of
Carmarthen Bay and other licensed dredging areas in the Bristol Channel. In the short-term
beneficial use might be made of dredgings from locations such as the entrance to Burry Port
harbour.
4.8 Swansea Bay North
4.8.1 General geomorphological character
Swansea Bay is a large macrotidal embayment with a mean spring tidal range of 8.5 m at
Swansea (Table 2.1). There is weak residual anticlockwise tidal circulation in the northern part
of the bay. The western side of the Bay is defined by the upland area of the Gower Peninsula but
the northern side is characterised by a relatively wide coastal plain which has now been
extensively built on. A dune-capped barrier beach system with back-barrier marshlands formed
in this area during the mid to late Holocene, fed by landward movement of sediments from the
floor of Swansea Bay, but supply of sediment over the past century has been low.
The entire shoreline between Mumbles and Swansea Docks is protected by artificial defences.
Remnants of the former dune system, now cut off from the sea, occur between Lower Sketty and
Brynmill. Small areas of actively forming dunes occur on the seaward side of the sea defences
between the University and County Hall. This area forms a natural sink for windblown sand
which causes periodic problems when it is blown onto the cycleway, promenade and A4067
trunk road behind.
4.8.2 Coastal processes
The north-western part of the bay between Black Pill and Swansea Docks (Figure 4.28) is
sheltered from south-westerly winds and waves and winds / waves from the south and south-east
exert the greatest influence. Wave energy at the shoreline is low except during easterly and
south-easterly gales. Longshore sediment transport rates on the upper foreshore are low, but the
evidence suggests an overall slight net easterly drift. The beach between the University and
County Hall has a relatively wide backshore with incipient dune development, while the beach to
the southwest of the University has a narrower backshore and a narrow belt of older, degraded
dunes (Figure 4.30).
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4.8.3 Historical shoreline change
Evidence from historical maps and aerial photographs indicates that the western end of the study
frontage has experienced net landward movement of the HAT line of 20 - 41 m since 1876,
whereas there has been up to 84 m of seaward movement at the eastern end, mainly due to land
reclamation (Table 2.2). Monitoring of beach profiles since 1999 has shown a slight overall fall
in levels at the western end, although the position of the HAT line has not changed (Figure 4.29).
There has been little change at the eastern end of the system.
4.8.4. Flood defence, nature conservation and recreational importance
As noted above, the entire shoreline of northern Swnsea Bay is backed by hard defences. The
beach and narrow belt of dunes to seaward of the defences provide additional protection. The
hinterland is generally low-lying and contains significant infrastructure, including the A4067
road, Swansea University, Morriston Hospital, and the rugby / cricket club.
The dunes at Black Pill are included within the Black Pill SSSI but the reminder of the area is
not currently covered by nature conservation of heritage designations.
The beach is a popular recreational area for local residents and University students but Swansea
is not a major holiday destination.
4.8.5 Shoreline management policy
The preferred policy for this frontage identified in both the SMPI (Shoreline Management
Partnership, 2001) and the draft SMP II being prepared by Halcrow (2010) is 'Hold the Line'.
4.8.6. Previous beach nourishment
Excess sand from removed from the upper beach and dunes between Sketty and County Hall,
and cleared from the promenade, cycleway and road after southerly gales, has been used to
nourish the beach further to the south-west, between Black Pill and Oystermouth, where beach
levels are low.
4.8.7 Future beach nourishment: potential benefits and requirements
The coastal defences along this part of northern Swansea Bay may come under increased
pressure if there is a significant future increase in the rate of sea level rise, and/ or storminess.
Given the limited scope to move the defences landward, and the need to protect high asset land,
there will be a requirement to improve the defences in future years. This could be done either by
construction of higher sea walls, placement of rock armour, addition of new beach material, or a
combination of these. Enhancement of the beach through nourishment would potentially reduce
the standard to which artificial defences have to be constructed / maintained, retain high visual
landscape quality, and enhance the recreational / toursitic value to both local residents and
outside visitors. An improved beach could, combined with other improvements, significantly
increase the appeal of Swansea as a tourist and conference destination.
By way of example, the volume of sediment required to construct a 20 m wide flat-topped berm
along the defined frontage would be 345 x 103 m
3. The width of nourished beach would range
from 91 to 128 m. Problems of wind-blown sand invasion onto the promenade and road could
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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be avoided either by the use of coarse sand and/ or the placement of sand-trapping barriers along
the top of the beach.
Maintenance of the existing beach form in the face of rising sea level over the next 20 - 100
years would require additional sediment to fill a volume ranging from 49 x 103 m
3 to 1.16 x 10
6
m3. The volume of sediment required to carry out the initial nourishment improvements, and
then to maintain it by re-nourishment at 5 yearly intervals over a 20 year period, has been
calculated to be 1.08 to 1.24 x 106 m
3.
Potential sources of sand for nourishment would be maintenance dredgings from Swansea, Neath
and Port Talbot harbours (subject to sediment quality standards being attained), and licensed
offshore dredging area sin the Bristol Channel and Carmarthen Bay.
4.9 Aberavon
4.9.1 General geomorphological character
Aberavon Sands extend between Port Talbot outer harbour and the entrance to the Neath estuary
on the north-eastern side of Swansea Bay (Figure 4.31). Historically the area to landward was an
area of low-lying dunes and marshes formed during the mid to late Holocene period, but it has
been significantly modified by human activities during the Industrial and Post-Industrial periods.
A large residential urban area (Port Talbot and Sandfields) occupies the area behind the southern
and central parts of Aberavon Sands, while the area behind the northern part of the beach at
Baglan is occupied mainly by factories and warehouses. A sea wall and promenade, protected by
rock revetment at the southern end, runs the entire length of the Port Talbot frontage. Begond the
northern end of the sea wall there is a relatively short section of rock armour and gabions, but the
frontage of Baglan Burrows is undefended.
4.9.2 Coastal processes
Eastern Swansea Bay has a large tidal range (MSTR of 8.7), resulting in exposure of a wide
beach at low tide. Tidal current velocities are relatively low, with a slight residual anti-clockwise
circulation in northern Swansea Bay. Aberavon Sands has a high degree of exposure to wind and
waves from the southwest, and to a lesser extent from the south. The net sediment littoral drift
direction is northerly. Port Talbot Outer Harbou effectively acts as a groyne which limits the
movement of sediment from areas further south; the harbour itself also acts a as a sediment trap
and requires periodic dredging. Consequently the southern part of Aberavon Beach is starved of
sediment and experiences net loss of material to areas further north.
4.9.3 Historical shoreline change
Historical maps and aerial photographs show that the HAT mark has retreated landwards along
the southern Port Talbot frontage by 30 - 48 m since 1876 (Table 2.2), but along the Baglan
frontage the HAT line has moved seawards by up to 900m. Accretion in the northern areas has
been associated within the infilling of the former Baglan Bay after construction of training walls
to fix the entrance channel into the River Neath. Similar accretion has occurred on the northern
side of the Neath estuary at Crymlyn Burrows (Figure 4.31).
Monitoring of beach profiles by Swansea Bay Coastal Group since 1999 has shown a slight
overall fall in levels along most of the Port Talbot frontage, with some continued accretion at the
Baglan end (Figure 4.32). The dune frontage at the southern end of Baglan Burrows shows
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small-scale cliffing and significant blowout development, partly due to wave erosion and partly
to heavy recreational pressure. Recent storm-erosion of the dune front has also affected Crymlyn
Burrows, and sand eroded from both sides of the estuary has shown a tendency to invade the
trained channel, creating a requirement for enhanced maintenance dredging.
4.9.4 Flood defence, nature conservation and recreational importance
The primary flood defence along the Port Talbot urban frontage is provided by hard defences (a
stepped seawall and rock revetment in the south; Figure 4.33). However, the condition of he
artificial defences may be compromise din the future of beach levels continue to drop. This is
likely to be a particular problem at the sediment starve Port Talbot docks end of the system
(Figure 4/33a). Along the central and northern parts of the defended frontage the beach levels
fluctuate in response to storm conditions and periodic problems are currently encountered with
excessive sand build-up on the upper beach and lower parts of the stepped sea wall. Current
management policy is to draw such excess sand back down the beach using plant in order to
prevent further problems of wind-blown sand encroachment onto the promenade (Figures 4.33b
& 4.34a). Falling beach levels along the southern end of the undefended Baglan Burrows
frontage will lead to further dune erosion and degradation in this area (Figure 4.34b).
4.9.5 Shoreline management policy
The preferred policy option for the Port Talbot frontage identified in both the SMP I and SMP II
is 'Hold the Line'.
4.9.6 Previous beach nourishment
Sand dredged from the Neath estuary harbour approaches has been used on a number of
occasions to nourish the beach and dunes on both sides of the estuary, at Baglan and Crymlyn.
However, there are no records of nourishment having been undertaken further south on the Port
Talbot beach frontage.
4.9.7 Future beach nourishment requirements and benefits
A future shoreline management policy of 'Hold the Line' will require maintenance and possible
improvements to the hard defences. However, if beach levels continue to fall, and there is an
increase in relative sea level rise and/ or storminess, this will become increasingly difficult to
achieve unless beach nourishment is undertaken.
For purposes of illustration, creation of a 20 m wide flat-topped berm at HAT level along the
entire defined frontage would require a total sediment volume of 641 x 103
m3.
This would
involve a total nourished width of 74 - 155 m, depending on the existing beach slope.
Maintenance of the existing beach form in the face of sea level rise would require sediment
infilling of a volume ranging from 228 x 103 m
3 to 1.02 x10
6 m
3 over time periods of 20 to 100
years.
In order to create the initial improved nourished profile and then to maintain it by 5-yearly re-
nourishment would require 1.97 to 2.10 x 106 m
3 of sediment.
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Potential sources of sandy sediment for nourishment include maintenance dredgings from Neath,
Swansea and Port Talbot harbour approaches, and licenced offshore aggregate extraction areas in
the Bristol Channel.
4.10 Porthcawl
4.10.1 General geomorphological character
The Porthcawl area has a number of small sandy bays which are bounded by rocky
promontories. The two bays considered in this study (Sandy Bay and Trecco Bay, Figure 4.35)
are the two most heavily used beaches or recreational purposes.
Sandy Bay is bounded on the west by Porthcawl Point, the harbour wall and a former railway
embankment along which a road now runs. The back of the beach is defined by the Coney Island
amusement park at the western end and by a belt of sand dunes at the eastern end. The eastern
side of the bay is defined by a further bedrock outcrop at Rhych point. Trecco Bay is bounded on
its western side by Rhych Point and on its eastern side by Newton Point. The back of the beach
is flanked by a large static caravan park. Both beaches can be described as 'bay-head' or 'pocket'
beaches.
4.10.2 Coastal processes
Porthcawl experiences the largest tidal range of all the sites considered (MSTR = 8.9 m, Table
2.1). However, owing to the relatively steep gradient of the beaches (Figure 4.36), the exposed
width at low tide is not a large as might be expected.
Both beaches are exposed to wave action from the southwest, although some protection is
afforded by the rocky promontories on either side. Under fair weather conditions sediment is
moved landwards, while during severe storms there is some offshore movement. Trecco Bay is
slightly more exposed than Sandy Bay and therefore more susceptible to sand movement. There
appears to be little exchange of sediment between the bays or with neighbouring pocket beaches
to the west and east.
4.10.3 Historical shoreline change
Historical maps and aerial photographs shown that the HAT line has not moved significantly
since 1876 at the western end of Sandy Bay, but there has been seaward movement of about 15
m at the eastern end where a ridge of dunes has developed (Figure 4.35; Table 2.2). By contrast,
in the central part of Trecco Bay the HAT line has retreated landwards by 48m since 1876.
Beach profile monitoring by Swansea Bay Coastal Group has shown that beach levels in both
bays have fluctuated since 1999 but there has been no significant overall change (Figure 4.36).
At the present time the backshore is very narrow, and at times virtually absent, at the western end
of Sandy bay and in much of Trecco Bay, although a significant width remains at the eastern
end of Sandy Bay (Figure 4.37). The restricted area of dry beach at high tide provides a
significant constraint on the recreational use of the two beaches.
4.10.4 Flood defence, nature conservation and recreational importance
The beach and dunes in Sandy Bay form a significant part of the flood defence for a small area
of low-lying land in the hinterland. Trecco Bay is backed by naturally rising land.
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The two beaches are not currently covered by conservation designations but the important
Merthyr Mawr NNR (important for its dune system) lies only a short distance to the east.
Porthcawl is a major recreational and holiday destination for residents of South Wales and
neighbouring areas (especially Cardiff and Bridgend).
4.10.5 Shoreline management policy
The SMPI identified a preferred policy of 'Hold the Line' or possibly 'Advance the Line' subject
to development proposals. The draft SMPII proposes 'Hold the Line' for both bays.
4.10.6 Previous beach nourishment
There are no records of beach nourishment in sandy bay and Trecco Bay although nourishment
has been reported to have been undertaken in rest Bay, to the west, during the 1980's. Much of
the material was eroded within a few years and has not been replaced.
4.10.7 Future beach nourishment requirements and benefits
It is of major economic importance to the town of Porthcawl to maintain, and if possible
enhance, the quality of its tourist beaches. In the future, it is likely that the beaches will be
increasingly squeezed between rising sea level and a fixed back-beach 9either natural rock
outcrops or hard defences. Beach therefore provides a potential means of allowing the useable
beach area to be maintained while the position of the back-beach remains fixed.
In the example where a flat-topped 20 m wide berm at HAT level is created, a total sediment
volume of 159 x 103
m3 of sandy sediment would be required. Maintenance of the existing beach
form would require sediment infilling of between 11 - and 251 x 103
m3 of sediment over time
periods of 20 to 100 years. Creation of the initial 'improved' profile by nourishment, followed by
maintenance over a 20 year period using re-nourishment at 5 yearly intervals, would require a
total of 488 - 521 x 103 m
3 of sediment, assuming 50% losses between nourishment episodes.
Potential sources of sand for future nourishment include harbour dredgings and licenced offshore
aggregate areas in the Bristol Channel.
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5 DISCUSSION
The results of the potential sediment nourishment requirements under each of the scenarios
considered, and for all ten case study sites, are summarised in Tables 4.1, 4.2 and 4.3.
Table 4.1 shows that initial beach 'improvement' nourishment volumes at all of the identified
sites are relatively modest, the largest being 641 x 103 m
3 at Aberavon Sands. The requirements
for the smaller enclosed embayment sites such as Tenby North Beach, Traeth Crugan and Port
Eynon Bay are relatively small (< 150 x 103 m
3).
The volumes required to maintain the existing beach profiles at the ten sites vary considerably,
depending both on the length of shoreline, the tidal range (and therefore beach width), and the
rate of sea level rise considered. Considering the 'best estimate' (50th percentile) value for the
medium emissions scenario, the smallest volumes of sediment required by 2100 would be at
Tenby North Beach and Traeth Crugan (24 and 30 x 103
m3, respectively), while the largest
volumes would be required in Swansea Bay North and at Aberavon Sands (614 and 541 x 103
m3, respectively - Table 4.2). None of the values are particularly large when compared with
nourishment volumes for large schemes already carried out in England, such as those at
Bournemouth, Mablethorpe - Skegness and Heacham. It should, however, be borne in mind that
these volume increase calculations do not take into account sediment losses which would
inevitably occur following initial nourishment and each re-nourishment.
Table 4.3 summarises the estimated nourishment volumes which would be required to carry out
an initial 'beach improvement' nourishment followed by re-nourishment at 5 yearly intervals in
the following 20 years, assuming that 50% of the emplaced sediment is lost between re-
nourishment events, and allowing for projected sea level rise over the same time period. The best
estimate sediment volumes for the medium emissions scenario range from 142 x 103 m
3 at Tenby
North Beach to 2017 x 103 m
3 at Aberavon Sands. The question of where such larger quantities
of sediment could be sources from warrants more detailed consideration in later stages of the
work programme.
Table 5.1 indicates, for the ten locations, where beach re-nourishment has been used as beach
management practice in the past, and if this has been deemed successful or not. For future
management it also includes the appropriate factors that it could be used for, namely for flood
and coastal erosion defence purposes, habitat remediation / creation and to benefit coastal
tourism and recreation.
As discussed in section 2.3.2, dredgings from a number of small harbours and ports have been
used to date in order to nourish nearby beaches and dunes. Examples include Pwlheli,
Aberdovey, Aberystwyth, Aberaeron and Neath. If any future recharge were to take place at the
pilot sites (Swansea Bay North and Aberavon Sands) or any other sites where significant
volumes are required, existing dredge licences, or even currently un-licenced resources that have
as yet not been used to provide re-nourishment material to Welsh beaches may become a viable
option from which to source material.
Therefore, these sources should be investigated on greater detail and Figures 5.1 and 5.2 show
existing dredge sites, licensed by The Crown Estate in the Bristol Channel and Irish Sea
respectively. Of the aforementioned harbours from which dredging have been used to source re-
nourishment, Neath is indicated on Figure 5.1 as the other harbours are located within Cardigan
Bay, more distant from both Bristol Channel and Irish Sea dredge sites. However, we would
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
39
envisage that the costs and the potential benefits of nourishment at selected sites should be
subjected to more detailed investigation of resource distribution and composition combined with
economic appraisal, taking account not only of material extraction and delivery costs but also the
associated costs of regulatory compliance (environmental impact assessment and monitoring pre
and post-works).
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
40
6 CONCLUSIONS AND RECOMMENDATIONS
6.1 Conclusions
This pilot study has considered ten sites around the Welsh coast where beach nourishment has or
has not been previously used as a beach management tool. Talacre, Traeth Crugan, and parts of
Swansea Bay north and Aberavon Sands have undergone various scales of recharge with varying
degrees of success. Talacre is the largest scheme to have been undertaken and has produced
significant benefits over the succeeding six year period.. However, beach nourishment generally
does not provide a one-off solution to a coastal defence or habitat recreation issues issue, and
beach levels at Talacre have now fallen to a point where further re-nourishment needs to be
considered.
It is concluded that beach nourishment is an under-used method of beach management in Wales
compared with many other parts of the world, and that considerable benefits could arise if greater
use is made of the technique in future. Beaches form an important first line of coastal defence
and healthy beaches can contribute significantly to coastal erosion and flood risk management by
dissipating wave and tidal energy and thereby reducing the requirements for capital and
maintenance expenditure on hard defences. Beach nourishment also offers significant
environmental and landscape benefits when compared with traditional hard engineering works.
Evidence from many other parts of the work also shows that beach nourishment can be an
important catalyst for economic development of an area and can play an important role in
stimulating tourism.
6.2 Recommendations
Based on the work undertaken in this Pilot Study, the following recommendations are made:
• Further consideration should be given to identifying potential sources of different
grading of potential nourishment material; resources of coarse sand, fine gravel,
medium gravel and cobble are of particular interest, and potential sources include
both the sea bed and inland quarries.
• Further work should be undertaken to characterise the particle size, colour and
mineralogical properties of Welsh beaches in order to ensure that naturally
occurring sediment are matched as closely as possible with suitable nourishment
materials.
• More detailed evaluation should be undertaken at some of the Pilot Study sites
using Lidar data to provide more accurate quantification of the present beach
morphology and the volumes of nourishment material required.
• The ecological effects of nourishment in the short, medium and longer term
should be investigated in more detail so that the most appropriate nourishment
methodologies for particular sites can be identified.
• The costs and the potential benefits of nourishment at selected sites should be
subjected to more detailed economic appraisal, taking account not only of
material extraction and transport costs but also the associated costs of regulatory
compliance (environmental impact assessment and monitoring pre and post-
works).
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
41
• The “carbon footprint” of the proposed nourishment schemes should be
calculated. The results of this analysis will help inform the decision-making
process to select the optimal sustainable nourishment scheme design.
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
42
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Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
46
APPENDIX A: EUROSION DATA
Previous Beach Nourishment Schemes from elsewhere in Europe (Eurosion, 2004).
Number Country Case study Coastal type Policy Measure
1. Belgium De Haan Sedimentary macrotidal
(Sandy beaches and
dunes)
Hold the line Seawall / Nourishment
2. Belgium Zeebrugge-Knokke
Heist
Sedimentary macrotidal
(Sandy beaches and
dunes)
Hold the line Seawall / Groynes /
Harbour breakwater /
Nourishment
3. Bulgaria Shabla-Krapetz Soft Rock
Sedimentary microtidal
(Sandy beaches)
Hold the line /
Managed
realignment
Seawall / Dyke
4. Cyprus Dolos-Kiti Sedimentary microtidal
(Shingle beaches)
Limited
intervention / Do
nothing
Harbour breakwater /
Groynes / Detached
breakwater / Revetment
5. Denmark Hyllingebjerg-
Liseleje
Soft rock
Sedimentary microtidal
(Sandy beaches)
Hold the line Slope protection /
Groynes / Detached
breakwater /
Nourishment
6. Denmark Køge bay Sedimentary microtidal
(Sandy beaches and
dunes)
Move seaward /
Hold the line
Groynes / Dyke / Filter
tubes
7. Denmark Western coast of
Jutland
Sedimentary microtidal
(Sandy beaches and
dunes)
Hold line /
Managed
realignment / Do
nothing / Limited
intervention
Groynes / Detached
breakwater / Revetment/
Nourishment / Dune
protection
8. Estonia Tallin Soft Rock
Sedimentary microtidal
(sandy & shingle
beaches, narrow
vegetated shores,
artificial coastline)
Hold the line /
Limited
Intervention
Revegetation forestry /
Nourishment / Seawall /
Slope protection
9. Finland Western coast of
Finland
Soft Rock
Sedimentary microtidal
(sandy & shingle
beaches, saltmarsh)
Do nothing None
10. France Aquitaine coast Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line
/Limited
intervention
Revegetation / Seawall /
Revetment / Groynes
11. France Chatelaillon Sedimentary macrotidal
(sandy beach)
Hold the line /
(Move seaward)
Seawall / Groynes (past)
Nourishment
12. France Haute-Normandie Soft Rock
Sedimentary macrotidal
(shingle beaches)
Do Nothing / Hold
the line / Managed
realignment
Groynes / Nourishment
13. France Rémire–Montjoly
(French Guyana)
Hard Rock
Sedimentary macrotidal
(sandy beaches)
Do nothing
(Limited
intervention-
future)
Future: Breakwater /
Nourishment
14. France Rhône delta Sedimentary microtidal
(delta, sandy beaches
and dunes)
Hold the line / Do
Nothing / Limited
intervention
Groynes / Seawall /
Breakwater / Revetment
/ Nourishment / Wind
trap Sand ripping
15. France Sables d’Olonne Hard Rock
Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line Seawall / Beach drainage
16. Germany Elbe estuary Sedimentary macrotidal
(estuary, saltmarsh)
Hold the line Dyke / Revetment /
Saltmarsh creation /
Polder / Groynes /
Saltmarsh Drainage
17. Germany Isle of Sylt
(Isles Schleswig-
Holstein)
Soft Rock
Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line /
Managed
realignment
Revetment / Seawall /
Rif Enhancement /
Groynes / Nourishment
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
47
Number Country Case study Coastal type Policy Measure
18. Germany Rostock Soft Rock
Sedimentary microtidal
(sandy beaches and
dunes)
Hold the line /
Limited
intervention
Groynes / Revetment /
Seawall / Revegetation /
Nourishment
19. Greece Lakkopetra Sedimentary microtidal
(sandy beaches)
Limited
intervention
Detached breakwater
20. Greece Mesollogi lagoon
area
Sedimentary microtidal
(sandy beaches and
dunes, saltmarsh)
Hold the line Groynes
21. Ireland Rosslare Soft Rock
Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line Groynes / Revetment /
Nourishment
22. Ireland Rossnowlagh Soft Rock
Sedimentary macrotidal
(sandy beaches and
dunes)
None
(Locally Hold the
line)
Revetment
(Future: dune
nourishment)
23. Italy Cirqaccio-
Ciracciello
(Isle of Procida)
Soft Rock
Sedimentary microtidal
(sandy beach)
Hold the line Beach drainage /
Breakwater
24. Italy Giardini-Naxos
(Isle of Sicily)
Hard Rock
Sedimentary microtidal
(sandy beach)
Hold the line Groynes / Seawall /
Detached breakwater /
Nourishment
25. Italy Goro mouth- Po
delta
Sedimentary microtidal
(delta, sandy beaches
and dunes)
Limited
intervention /
Hold the line
Nourishment / Groynes /
Revetment / Dune
rebuilding
26. Italy Lu Littaroni -
La Liccia
(Isle of Sardinia)
Hard Rock
Sedimentary microtidal
(sandy beaches and
dunes)
Do nothing None
27. Italy Marina di Massa -
Marina di Pisa
Sedimentary microtidal
(sandy beaches,
artificial coastline)
Hold the line Seawall / Groynes /
Detached breakwater /
Submerged breakwater /
Nourishment
28. Italy Marina di Ravenna-
Lido Adriano
Sedimentary microtidal
(sandy beaches and
dunes)
Hold the line Seawall / Submerged
breakwater / Detached
breakwater / Groynes /
Jetty / Nourishment
29. Italy Marinella di
Sarzana
Sedimentary microtidal
(sandy beaches)
Hold the line Groynes / Detached
breakwater / Jetty /
Artificial island /
Nourishment
30. Italy Vecchia Pineta Sedimentary microtidal
(sandy beaches and
dunes)
Hold the line Submerged breakwater /
Nourishment / Beach
Drainage
31. Latvia Gulf of Riga Sedimentary microtidal
(delta, sandy beaches
and dunes, narrow
vegetated shores)
Limited
intervention /
Hold the line
Forest plantation /
Seawall / Revetment /
Nourishment
32. Lithuania Klaipeda Soft Rock
Sedimentary microtidal
(sandy beaches and
dunes, narrow
vegetated shores)
Limited
intervention
Forest plantation /
Nourishment
33. Malta Xemxija -
Ghajn Tuffieha
Soft Rock
Sedimentary microtidal
(sandy beaches)
Do nothing /
Limited
intervention
Revegetation
34. The Netherlands Holland coast Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line Nourishment / Groynes
35. The Netherlands Wadden Sea islands Sedimentary macrotidal
(sandy beaches and
dunes)
Limited
intervention /
Hold the line / Do
nothing
Groynes / Revetment /
Nourishment / Cross-
shore dam
36. The Netherlands Western Scheldt
estuary
Sedimentary macrotidal
(estuary, saltmarsh)
Hold the line /
Move seaward
Nourishment /
Revetment / Groyne /
Pier protection
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
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48
Number Country Case study Coastal type Policy Measure
37. Poland Hel peninsula Soft Rock
Sedimentary microtidal
(sandy beaches and
dunes)
Hold the line Groynes / Seawall /
Nourishment
38. Poland Western Coast of
Poland
Soft Rock
Sedimentary microtidal
(sandy beaches and
dunes)
Hold the line / Do
nothing
Seawall / Groynes /
Nourishment /
Revegetation
39. Portugal Azores
(Azores Islands)
Hard Rock Hold the line Harbours / Marinas /
Slope stabilisation
40. Portugal Cova do Vapor Soft Rock
Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line Nourishment / Groynes /
Seawall
41. Portugal Estela Sedimentary macrotidal
(sandy beaches and
dunes)
Limited
intervention
Dune nourishment /
Sand ripping / Wind trap
/ Sand bags
42. Portugal Vagueira-Mira Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line /
Managed
realignment
Groynes / Jetty /
Nourishment
43. Portugal Vale do Lobo Soft Rock
Sedimentary macrotidal
(sandy beaches and
dunes)
Hold the line Revetment /
Nourishment
44. Romania Danube delta Sedimentary microtidal
(delta, sandy beaches
and dunes)
(Hold the line)
Do Nothing
Jetty / Groynes /
Nourishment
45. Romania Mamaia Sedimentary microtidal
(sandy beaches and
dunes)
Limited
intervention /
Hold the line
Detached breakwater /
Nourishment
46. Slovenia Slovenian coast Hard Rock
Soft Rock
Sedimentary microtidal
(shingle beaches,
saltmarshes, artificial
coastline)
Hold the line /
Limited
intervention /
Move seaward
Seawall / Submerged
breakwater / Dyke
47. Spain Can Picafort
(Isle of Mallorca)
Sedimentary microtidal
(sandy beaches and
dunes)
Limited
intervention
Nourishment
48. Spain Castellón Sedimentary microtidal
(sandy & shingle
beaches, dunes)
Hold the line Groynes / Detached
breakwater /
Nourishment
49. Spain Ebro delta Sedimentary microtidal
(delta, sandy beaches
and dunes)
Limited
intervention /
Hold the line /
(Managed
relignment)
Dune nourishment /
Wind traps /
Revegetation / Beach
Drainage
50. Spain El Médano
(Canary Islands)
Sedimentary macrotidal
(sandy beaches and
dunes, narrow
vegetated shores)
Do nothing /
Limited
intervention
Dune nourishment /
Revegetation
51. Spain Gross Hard Rock
Sedimentary macrotidal
(sandy beaches)
Hold the line Jetty / Nourishment
52. Spain Mar Menor Sedimentary microtidal
(sandy beaches and
dunes)
Hold the line /
Limited
intervention
Groynes / Nourishment
53. Spain Sitges Hard Rock
Sedimentary microtidal
(sandy beaches)
Hold the line Groynes / Detached
breakwater / Seawall /
Artificial island /
Nourishment
54. Sweden Falsterbo peninsula Sedimentary microtidal
(sandy beaches and
dunes)
Do nothing Seawall /
Groynes(Future:
revegetation /
nourishment)
55. Sweden Ystad Sedimentary microtidal
(sandy beaches and
Hold the line Groynes / Seawall /
Dune plantation /
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
49
dunes) Geotextile
Number Country Case study Coastal type Policy Measure
56. United
Kingdom
Essex estuaries Sedimentary macrotidal
(estuary, saltmarsh,
shingle beaches)
Hold the line /
Managed
realignment / Do
nothing
Seawall / Revetments /
Embankment / Groynes /
Polder / Nourishment
57. United
Kingdom
Holderness coast Soft Rock
Sedimentary macrotidal
(sandy and shingle
beaches)
Hold the line /
Do nothing
Groynes / Seawall /
Revetment
58. United
Kingdom
Humber estuary Sedimentary macrotidal
(estuary, saltmarsh)
Hold the line /
(Managed
realignment)
Embankment /
Revetment / Seawall /
Tidal flat recreation
59. United
Kingdom
Luccombe-
Blackgang
(Isle of Wight)
Soft Rock
Sedimentary macrotidal
(shingle beaches)
Managed
realignment /
Hold the line / Do
nothing
Seawall / Revetment /
Groynes / Nourishment /
Slope stabilisation
60. United
Kingdom
South Downs
(Sussex)
Soft Rock
Sedimentary macrotidal
(shingle beaches)
Hold the line /
Managed
realignment
Seawall / Groynes /
Nourishment
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
50
APPENDIX B: SITE DESCRIPTION SUMMARY SHEETS
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site – Talacre Unitary Authority: Sir y Fflint – Flintshire
Length of Coastline: 2900m
Current SMP2 Policy: Hold-the-line
Coastal Management Overview This North/North-west facing coastline has a large unspoiled expansive sandy foreshore backed by gently sloping
dunes which graduate into a low-lying backshore. To the east there are shingle banks and dune ridges with large
quantities of aeolian sand between which lie tidal channels and developing saltmarsh. The shingle banks are formed
primarily from drifted beach nourishment material. Further east at Talacre Warren are two dune ridges with dune
slacks. Located behind these dunes is the Prestatyn Gutter canal which discharges to the western frontage of the
dunes.
Coastal Processes and Geomorphology Assuming no inlet was established on the North Wales shoreline, this area would be likely to gradually silt up
because of the available sediment within the Dee estuary, with subsequent re-formation of saltmarsh
geomorphology. The limit of the flooding would be constrained by the original cliff-line of the estuary. The majority
of sand material is either retained by coastal defences or contributes to the significant accretion of material at the
Point of Ayr, where it forms an expansive intertidal zone, and subsequently material to be used in the development
of the Talacre Sand Dunes.
Coastal Protection and Flood Risk This section of shoreline has been defended over the last 100 years, and with no defences there would be significant
flooding of the low-lying land as there is no natural form of defence either in front of or behind the present
embankment. With no secondary defences in place this inundation could extend behind Talacre, resulting in a
dramatic change in the shoreline form and position.
Natural and Historic Environment Issues Designated areas include: Ramsar The Dee Estuary (Wales); SPA The Dee Estuary (Wales); SAC Dee Estuary /
Aber Dyfrdwy; SSSI Dee Estuary / Aber Afon Dyfrdwy; and Gronant Dunes & Talacre Warren SSSI.
Beach Recreational Issues Gronant Dunes is an area of sand dunes and foreshore that stretch to the Point of Ayr, Talacre. This area has
outstanding wildlife and it is a site of Special Scientific Interest. Both Gronant and Talacre Dunes are popular with
holidaymakers and local residents.
Governance Issues The Crown Estate licenses nearby dredge sites that may prove a possible source of future recharge material although
the management and provision of the material is currently less clear. Material may also be available from Mostyn
Docks.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 148,080
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
504,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
531,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site - Abergele Unitary Authority: Conwy – Conwy
Length of Coastline: 2700m
Current SMP2 Policy: Hold-the-line
Coastal Management Overview This stretch of the coastline is North/North-west facing, with Pensarn beach situated centrally, between Rhyl to the
east and Colwyn Bay to the west. The beach is generally a combination of sand and shingle.
Coastal Processes and Geomorphology East of Abergele the three controlling headlands at Rhos Point, Tan Penmaen Head and Llanddulas would
experience a moderate degree of erosion. To the west, from Abergele to Prestatyn, the shoreline would take a more
linear form. This would cause the shoreline to become more normal to the approaching wave direction thus
ultimately reducing the net sediment transport rate along the frontage. Accretion toward the Point of Ayr would
consequently be reduced.
Coastal Protection and Flood Risk A revetment and seawall in places, originally constructed 1845-48, re-furbished 1906, defends the entire frontage
with an additional flood embankment protecting the Abergele to Towyn frontage from inundation. Following in
destruction in the 1990 storms, the seawall and rock revetment was rebuilt in 1993, at Towyn. At Kinmel Bay,
beach recharge and groynes have acted as a drift barrier and advanced the shoreline seaward. A shingle bank fronts
the wall to the east of Abergele with dunes to landward and low-lying hinterland. Bars and troughs in the sand
foreshore migrate eastward across the frontage influencing cycles of erosion / accretion. The developed frontage
beach is constrained in places by railway and trunk roads, though is well-developed between this infrastructure.
Natural and Historic Environment Issues Designated areas include three SSSIs: the Traeth Pensarn; Llanddulas Limestone and Gwrych Castle Wood; the
Coed y Gopa.
Beach Recreational Issues Pensarn beach is important for recreational activities such as Windsurfing and Canoeing. The developed frontage is
a tourist destination.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 429,709
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
68,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
1,301,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site – Traeth Crugan Unitary Authority: Gwynedd – Gwynedd
Length of Coastline: 2730m
Current SMP1 Policy: Hold-the-line
Coastal Management Overview This area of South-east facing coastline has a backshore characterised by a single, narrow sand dune ridge. The
height of the dune is generally 3 - 5 m and the crest width is approximately 3 - 4 m. Much of the dune system is
poorly vegetated. At the low water mark, patches of clean sand, shingle and boulders are apparent, while at high
water this gives way to a cleaner ground of gravel and coarse sand.
Coastal Processes and Geomorphology Erosion of the sand dunes at Traeth Crugan and Pwllheli Golf Club are providing sand, which accretes eastwards by
littoral drift along the Pwllheli promenade. There is, however, ongoing loss to this frontage as material by-passes
Carreg yr Imbill and is deposited in the harbour mouth. There is a problem with siltation of the inner harbour at
Pwllheli and this is thought to be due to the low tidal current velocities through the harbour entrance. Although the
sea bed is generally free of silt outside the harbour entrance, the eroding glaciogenic cliffs to the west of the harbour
are a source of suspended silt and mud. Continued protection of the dunes at Traeth Crugan and Pwllheli Golf Club
would eventually result in a reduced supply of sand to the promenade area of Pwllheli south beach and as a
consequence the areas that are currently accreting are likely to experience erosion. Continued sea level rise and a
breach in the dunes at Morfa Garreg due to the reduced supply of sediment could result a new outlet to the sea to the
east of Carreg yr Imbill.
Coastal Protection and Flood Risk The sand dunes at Traeth Crugan and Pwllheli Golf Club are subject to local erosion and are protected in places by
stretches of rock revetment.
Natural and Historic Environment Issues This area of coastline is undeveloped, with designated sites; the Pen Llyn a'r Sarnau / Lleyn Peninsula and the
Sarnau SAC, and the Mynydd Tir Y Cwmwd A'r Glannau At Garreg Yr Imbill SSSI.
Beach Recreational Issues This area is important recreationally for the golf course users and also for sea anglers. The lagoon at Traeth Crugan
also has a lagoon which sits within a string of banks and reefs which form an arc offshore which has a very diverse
bivalve fauna.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 68,159
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
30,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
210,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site – Morfa Dyffryn Unitary Authority: Gwynedd – Gwynedd
Length of Coastline: 6800m
Current SMP1 Policy: Do Nothing
Coastal Management Overview This South-west facing coastline has an extensive dune foreland, begining at Llanaber and has grown northwards
and incorporated within itself the former moraine island of Mochras. Between Llanaber and Morfa Dyffryn there is
sand beach overlying peat beds, fringed with dunes on its outer margin.
Coastal Processes and Geomorphology In areas of the beach, the underlying peat is exposed and eroding, thereby causing permanent loss in beach volume
since the eroded peat will disperse from the area. There is a large-scale northwards sediment transport pathway
throughout most of Cardigan Bay. This longshore movement of sediment has generally been considered to
contribute to the northwards prolongating spits and structures including Morfa Dyffryn. The accreting sediment is
attributed largely to that sourced by erosion of the glacigenic cliffs in the southern part of Cardigan Bay. Along the
southern coast of the Lleyn Peninsula, littoral drift is generally to the east, with widespread erosion of the glacigenic
cliffs and sand dune systems contributing to the sediment supply. If beach nourishment is not undertaken, in the
short term it is possible that material released from erosion of the dunes capping the ridge, and the breakdown of the
ridge itself, would feed Morfa Dyffryn to the north, temporarily halting erosion of the dune system there. However,
when the supply of sand and shingle diminishes, further erosion of Morfa Dyffryn dunes would be expected, with
the eroded material being deposited on the foreshore.
Coastal Protection and Flood Risk With present management practices, the small sections of defended coastline (Llanaber Point, the caravan parks at
Sunnysands, Islawrfordd and Barmouth Holiday Village) are likely to remain as hard spots resisting landward
movement and effectively becoming promontories as the shoreline to either side migrates landwards. The
promontories would effectively reduce northwards littoral drift of material, resulting in a smaller supply of sand to
Morfa Dyffryn resulting in erosion of the Morfa Dyffryn dunes.
Natural and Historic Environment Issues Designated sites include: Morfa Harlech a Morfa Dyffryn SAC; Morfa Dyffryn NNR; Morfa Dyffryn SSSI;
Snowdonia National Park; Pen Llyn a'r Sarnau / Lleyn Peninsula and the Sarnau SAC.
Beach Recreational Issues Part of the beach is an officially recognised naturist area. The beach is also known for dolphin sightings.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 369,486
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
202,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
1,144,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site - Broadwater-Tywyn-
Aberdovey Unitary Authority: Gwynedd – Gwynedd
Length of Coastline: 8300m
Current SMP1 Policy: Retreat south of Twywn, hold-the-line north of Twywn to Broadwater
Coastal Management Overview This coastline is South-west facing with a combination of sandy and pebbly beaches. The area is a mixture of
developed and undeveloped with Tywyn town and a golf course, along with undeveloped areas around.
Coastal Processes and Geomorphology This area of the coast is eroding between Tywyn and Club House Aberdovey / accretion East of Aberdovey.
Coastal Protection and Flood Risk There is a groyne field in front of Tywyn / Shingle ridge in place, sandy beach backed by dunes or Penllyn marshes.
Natural and Historic Environment Issues Sites include Pen Llyn a'r Sarnau / Lleyn Peninsula and the Sarnau SAC; Broadwater SSSI; Dyfi SSSI; Snowdonia
National Park; Dunes part of Dovey SSSI within Pen Llyn A’R SAR.
Beach Recreational Issues This area is important for recreation e.g. fishing, sailing, surfing and other water sports off Aberdovey harbour.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 491,394
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
257,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
1,518,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site - Tenby Unitary Authority: Sir Benfro – Pembrokeshire
Length of Coastline: 800m
Current SMP2 Policy: Hold-the-line
Coastal Management Overview This part of the coastline has sandy beaches backed by rocky cliffs. Carmarthen Bay within which Tenby is situated
is a storm-dominated bay, which has been cut largely into softer Carboniferous rocks, in particular mudstones of the
Carboniferous Coal Measures. Resistant Carboniferous Limestones form headlands on the Gower Peninsula, and at
Tenby and Giltar Point. Millstone Grit forms cliffed promontories between Tenby and Ragwen Point.
Coastal Processes and Geomorphology Carmarthen Bay, as a whole is a sink for sediments. This is due to its position sheltered from the main tidal streams.
Sediment cover, predominantly sandy, is up to 10 metres thick in the centre of the Bay, thinning towards the
shoreline. The Bay contains a fairly constant volume of sediment, which is reworked during storms, with no major
exchange of sediment between the Bay and the Bristol Channel or Celtic Sea. Varying rates of cliff retreat around
the western end of Carmarthen Bay, due to differential erosion of rocks of varying resistance, is responsible for the
current topography of headlands and bays. Carboniferous sandstones and limestones form headlands, but mudstone-
rich beds within the Carboniferous Coal Measures and Millstone Grit have been susceptible to greater erosion and
recession. Very little sand is derived from erosion of sandstones on this coastline. Most sand released from cliff
erosion will be stored locally on the beaches, or washed into Carmarthen Bay by storm wave currents. There is a
small net littoral drift to the east within the western part of Carmarthen Bay.
Coastal Protection and Flood Risk Much of the open-cliffed coastline is undefended, with defences being restricted to the settlements of Tenby,
Saundersfoot, Wisemans Bridge, Amroth and Pendine, with few implications for the rest of the coastline. These
defences will not significantly affect the future shoreline evolution. The construction of the railway embankment
across the Ritec estuary aided the development and stabilisation of South Beach Tenby. The presence of the railway
embankment will limit the scope for retreat of the sand dunes here.
Natural and Historic Environment Issues Designated areas include the following: SSSI Lydstep Head To Tenby Burrows; National Park Pembrokeshire
Coast; SAC Carmarthen Bay and Estuaries / Bae Caerfyrddin ac Aberoedd; SSSI Tenby Cliffs and St. Catherine's
Island.
Beach Recreational Issues Tenby beach is a popular tourist destination which is used for Canoeing, Sailing and Sea Angling.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 45,964
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
24,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
142,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site – Port Eynon Unitary Authority: Abertawe – Swansea
Length of Coastline: 1200m
Current SMP1/2 Policy: No Active Intervention
Coastal Management Overview Port Eynon is a very popular tourist resort. Port Eynon Point, to the south west of the bay, is the most southerly
point of the Gower Peninsula. The bay is also in the area of outstanding natural beauty with sandy beaches and rock
pools.
Coastal Processes and Geomorphology The coastline is backed by dune systems within the embayments, e.g. Oxwich Bay and Port-Eynon Bay. The
orientation of the bays, as illustrated by soft sediments, has been due to incident wave climate over longer periods of
time. The resistant geology of the cliffs throughout this frontage is a fundamental control upon both large-scale and
local-scale development. The Carboniferous Limestone rocky headlands are local controls because they act to
refract and diffract incident waves, creating weak drift reversals. This means that the larger embayments, e.g.
Oxwich Bay, along this coastline are generally stable and experience limited net drift. Oxwich Point also provides
some shelter to the western part of this shoreline. These cliffs have a very low potential recession rate and therefore
significant change along the cliffed shoreline is not expected over the next century.
Unfortunately, both Port Eynon and Horton beaches have suffered in the last ten years from denudation of their sand
cover. A large proportion of the sand on the coast is likely to have been derived by wave action from the shoreface.
There has been large scale dredging of sand from Helwick Bank and it is possible that the dredging of sands from
Helwick Bank may influence sand budgets on the coast, such as at Port Eynon Bay.
Coastal Protection and Flood Risk Much of the open-cliffed coastline is undefended, with defences being restricted to individual embayments. Where
defences are present, principally in the form of seawalls or revetments (such as in Port Eynon, Oxwich, Caswell, and
Langland Bays), they protect localised areas from erosion but with few implications for the rest of the coastline.
Natural and Historic Environment Issues Designated areas include the following: SAC Limestone Coast of South West Wales / Arfordir Calchfaen De
Orllewin Cymru; SSSI Gower Coast: Rhossili to Porteynon; AONB Gower; SSSI Horton, Eastern And Western
Slade; SSSI Oxwich Bay; SAC Gower Ash Woods / Coedydd Ynn Gwyr; NNR Oxwich.
Beach Recreational Issues This area is popular for sailing, surfing, and has boat launching facilities.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 151,636
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
66,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
467,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site – Swansea (North) Unitary Authority: Abertawe – Swansea
Length of Coastline: 4900m
Current SMP1/2 Policy: Hold-the-line
Coastal Management Overview This area of coast is a large, sweeping, curving, sandy bay with the headland at Mumbles as the focal point to the
West. Apart from the cliffs which occur near Mumbles, the rest of the coastline is low lying.
Coastal Processes and Geomorphology The seabed east of Swansea Bay comprises mainly bedrock, with locally thin accumulations of sand and gravel.
Extensive areas of rock are exposed across the channel off the South Glamorgan coast where there are maximum
stresses on the seabed due to the tidal currents. Closer to shore near Swansea Bay, Helwick and Nash Sands form
banner banks reflecting changes in the orientation of the coastline. These banks provide limited protection to the
coastline from open-ocean wave activity. Overall, the plan shape of Swansea Bay is dominantly a south to south-
west facing bay bounded on either side by broadly east-west trending hard rock coasts composed primarily of early
Carboniferous limestones. Rates of transport of sand and gravel are likely to have been lower than those of the
cliffed coasts of the Gower and South Glamorgan because Swansea Bay has been largely sheltered from westerly
storms and weaker ebb-currents. Swansea Bay is generally a sink for sediments.
Coastal Protection and Flood Risk As a whole, there has been significant human interference within Swansea Bay, where reclamation, slag dumping,
dredging, navigation works, and sand winning have all had an influence upon its recent evolution. The estuaries
within the Bay have been heavily modified through human development. Within the Afan Estuary, there are no
saltmarshes or mudflats, with sand occupying virtually the whole system. The upper part of the Neath Estuary is
extensively reclaimed and industrialised, with docks and considerable navigational dredging. The dredging of
sediments from the river channels has impacted on the distribution of sands and muds in the bay to date and it is
likely that the cessation of dredging in the River Neath would influence sand and mud accumulation in the central
part of Swansea Bay. The Swansea Barrage, built between 1989 and 1992, now limits the flux of bedload sediments
transported by tidal processes.
Natural and Historic Environment Issues The Blackpill SSSI is the only designated area on this stretch of the coastline.
Beach Recreational Issues Sea uses in this area include leisure craft for sailing and fishing from Oystermouth/Mumbles, Swansea-Cork Ferry
and commercial craft using Swansea, Port Talbot and Neath docks.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 344,832
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
614,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
1,144,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site - Aberavon
Unitary Authority: Castell-nedd Port Talbot - Neath Port Talbot
Length of Coastline: 4800m
Current SMP1/2 Policy: Hold-the-line
Coastal Management Overview Aberavon, to the East of Swansea Bay is a highly industrialised area of coast characterised by heavy industry around
Port Talbot including the Corus (margam) steel works, whose tall apparatus and chimneys are clearly visible from
the beach. The coastline here is straight, in contrast to the curved coast which can be seen further west, and has a
high, hilly backdrop, particularly in the Port Talbot area. The Neath and Tawe fault valleys emerge betwen the hills.
There are extensive coastal dune systems to the South-east at Kenfig, Margam and Crylyn Burrows.
Coastal Processes and Geomorphology The coastal plain widens particularly around Port Talbot, which is built on former sand dunes. These are still
apparent around the very extensive Kenfig and Margam Burrows although the latter helps cover waste from the steel
works. The Tawe and Neath rivers reach the coast, the latter forming a minor estuary of mud and sand flanked by
sand dunes including Crymlyn Burrows.
Coastal Protection and Flood Risk In the 1950s many of the sand dunes of Aberavon Beach disappeared as part of the development of the Sandfields
estate. During this development, a 1.25 mile sea defence wall was built. This is also fronted by a rock revetment.
Natural and Historic Environment Issues One designated area exists to the north of this area of coastline; Crymlyn Burrows SSSI.
Beach Recreational Issues Averavon Beach is a favourite with surfers.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 640,784
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
541,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
2,017,000
Beach nourishment operations in Wales and likely future requirements for beach nourishment in an era of
sea level rise and climate change – a Pilot Study
Beach Management Case Study Site - Porthcawl Unitary Authority: Pen-y-bont ar Ogwr – Bridgend
Length of Coastline: 1400m
Current SMP1/2 Policy: Hold-the-line
Coastal Management Overview This area is characterised by a flat coastal plain around Porthcawl with low rocky headland and sandy enclosed
beaches. Much of the coastline is composed of relatively resistant cliffs and rock platforms, which have
experienced little movement over the centuries. Porthcawl is an urban area with a large caravan site at Trecco Bay,
and a golf course.
Coastal Processes and Geomorphology There has been significant modification to this shoreline as a result of human interference. Much of the area of
dunes has since been significantly modified and built up, so little of the originally morphology remains. Merthyr-
mawr Warren is an extensive sand dune system nestled in a natural cove between Porthcawl and the River Ogmore.
Although most of the sand contained within this system is relict, the dunes having built up over the last 6,000 years,
there is still an active interchange between the beach and dunes. The cliffs at Porthcawl and between Ogmore River
and Nash Point would continue to be dominated by low rates of erosion. The foreshore could be subjected to
narrowing under increased storm wave activity as landward movement of the beaches is constrained by the backing
cliffs. Some local coastal protection works exist in the form of seawalls and revetments between Hutchwns Point
and Porthcawl Point. Overall, there is no notable trend of either accretion or erosion of beaches, though some
beaches, such as in Trecco Bay, Porthcawl, have seen erosion in recent years.
Coastal Protection and Flood Risk Climate change may threaten low lying land with flooding in the future. Porthcawl waterfront is also proposed for
substantial regeneration as part of the 7 Bays Project. The Planning Guidance outlines proposals that will result in
the regeneration of Porthcawl's Waterfront, stretching from Cosy Corner and the harbour in the south, to Trecco Bay
in the east. The plan includes the construction of new sea defences, enabling regeneration of the area to take place
and whilst also helping to protect over 440 existing properties which may be at the risk of flooding.
Natural and Historic Environment Issues Close by designated areas to the east of this shoreline include the Kenfig / Cynffig SAC, and the Merthyr Mawr
SSSI.
Beach Recreational Issues The sea here is used for swimming and surfing.
Future Beach Nourishment Implications
Nourishment Volume (m3)
Initial volume of nourishment material required 159,268
Volume of sediment required to maintain the existing beach profile for sea
level rise to 2100 (medium emissions scenario)
133,000
Volume of sediment required by 2030, assuming an initial re-nourishment
in 2010 and five-yearly re-nourishment campaigns to replace 50% losses
501,000
Tables
Site Station used fortidal levels HAT MHWS MHW MHWN MTL MLWN MLW MLWS LAT CD MSTR
Site 1 : Gronant-Talacre Hilbre Island 5.21 4.07 3.17 2.27 0.22 -1.83 -2.73 -3.63 -4.62 -4.93 7.70Site 2 : Abergele-Pensarn Colwyn Bay 4.77 3.70 2.85 2.00 0.24 -1.66 -2.49 -3.32 -4.23 -4.10 7.02Site 3 : Traeth Crugan Pwllheli 3.41 2.66 1.91 1.16 0.32 -0.54 -1.19 -1.84 -2.42 -2.44 4.50Site 4 : Morfa Dyffryn Barmouth 3.31 2.56 1.81 1.06 0.20 -0.64 -1.19 -1.74 -2.23 -2.44 4.30Site 5 : Broadwater-Aberdovey Aberdovey 3.31 2.56 1.81 1.06 0.17 -0.44 -1.09 -1.74 -2.32 -2.44 4.30Site 6 : Tenby North Beach Tenby 4.95 3.90 2.85 1.80 -0.01 -1.50 -2.55 -3.60 -4.53 -4.50 7.50Site 7 : Port Eynon Mumbles 5.50 4.30 3.10 1.90 0.05 -1.90 -3.00 -4.10 -5.08 -5.00 8.40Site 8 : Northwest Swansea Bay Swansea 5.50 4.50 3.35 2.20 0.16 -1.90 -2.95 -4.00 -5.00 -5.00 8.50Site 9 : Baglan-Aberavon Port Talbot 5.80 4.60 3.40 2.20 0.22 -1.70 -2.90 -4.10 -5.17 -5.20 8.70Site 10 : Porthcawl Porthcawl 5.80 4.60 3.40 2.20 0.01 -2.00 -3.15 -4.30 -5.32 -5.30 8.90
Elevations relative to Ordnance Datum (in metres)
Table 2.1 Assumed tidal levels at possible nourishment sites in Wales, taken from the 2009 Admiralty Tide Tables. Values taken directly from the tables in bold type, values extrapolated from the relevant Standard Port in regular type. MHW and MLW assumed to be midway between spring and neap levels.
Profile Period Advance (+) Average Rateor Retreat (-) of Change(m) (cm/year)
Site 1 : Gronant-Talacre P3 1871-2006 -18 -13P4 1871-2007 0 0P5 1871-2008 +14 +10P6 1871-2009 -53 -39P7 1871-2010 -107 -79
Site 2 : Abergele-Pensarn P45 1872-2006 +58 +43P46 1872-2006 +90 +67P47 1872-2006 +66 +49P48 1872-2006 +40 +30P49 1872-2006 +12 +9
Site 3 : Traeth Crugan P70 1888-2006 +3 +3P71 1888-2006 0 0
Site 4 : Morfa Dyffryn P34 1887-2006 -18 -15P35 1887-2006 -19 -16P36 1887-2006 -4 -3P37 1887-2006 0 0P38 1887-2006 0 0
Site 5 : Broadwater-Aberdovey P3 1887-2006 +25 +21P4 1887-2006 +152 +128P5 1887-2006 +39 +33P6 1887-2006 -21 -18P7 1887-2006 -7 -5P8 1887-2006 0 0P9 1887-2006 0 0P10 1887-2006 0 0P11 1887-2006 -37 -31P12 1887-2006 -8 -6P13 1887-2006 +77 +65
Site 6 : Tenby North Beach P12 1887-2006 0 0P13 1887-2006 0 0
Site 7 : Port Eynon P103 1877-2006 -24 -18P104 1877-2006 +4 +3
Site 8 : Northwest Swansea Bay P206 1876-2006 -41 -31P207 1876-2006 -24 -19P208 1876-2006 -22 -17P209 1876-2006 0 0P210 1876-2006 +84 +65
Site 9 : Baglan-Aberavon P217 1875-2006 +898 +685P218 1875-2006 +723 +552P219 1875-2006 +115 +88P220 1875-2006 -30 -23P221 1875-2006 -48 -36
Site 10 : Porthcawl P237 1876-2006 0 0P238 1876-2006 +20 +15P240 1876-2006 -62 -48
Table 2.2 Advance or retreat of the HAT mark, between the Firest Edition County Series Ordnance Survey maps (published in 1880s and 1890s) and aerial photography flown in 2006.
Site UKCP09grid cell
2030 2060 2100Low Emissions Scenario (SRES B1 Storyline)Site 1 : Gronant-Talacre 18964 5.2 (2.2 - 8.1) 14.5 (6.3 - 22.8) 30.0 (12.9 - 47.1)Site 2 : Abergele-Pensarn 18961 5.1 (2.2 - 8.0) 14.4 (6.2 - 22.5) 29.7 (12.6 - 46.8)Site 3 : Traeth Crugan 19976 5.2 (2.4 - 8.1) 14.7 (6.6 - 22.9) 30.3 (13.3 - 47.5)Site 4 : Morfa Dyffryn 20184 5.3 (2.5 - 8.2) 14.9 (6.8 - 23.2) 30.8 (13.8 - 47.9)Site 5 : Broadwater-Aberdovey 20800 5.5 (2.7 - 8.4) 15.4 (7.3 - 23.6) 31.6 (14.6 - 48.8)Site 6 : Tenby North Beach 23048 6.1 (3.3 - 9.0) 16.9 (8.8 - 25.1) 34.3 (17.3 - 51.4)Site 7 : Port Eynon 23259 6.1 (3.3 - 9.1) 17.0 (8.8 - 25.2) 34.4 (17.4 - 51.5)Site 8 : Northwest Swansea Bay 23261 6.1 (3.3 - 9.0) 16.9 (8.8 - 25.2) 34.4 (17.3 - 51.5)Site 9 : Baglan-Aberavon 23263 6.1 (3.3 - 9.0) 16.9 (8.8 - 25.1) 34.3 (17.3 - 51.4)Site 10 : Porthcawl 23470 6.2 (3.3 - 9.1) 17.0 (8.9 - 25.2) 34.5 (17.5 - 51.6)
Medium Emissions Scenario (SRES A1B Storyline)Site 1 : Gronant-Talacre 18964 6.3 (2.6 - 10.1) 17.7 (7.1 - 28.4) 36.7 (14.4 - 59.0)Site 2 : Abergele-Pensarn 18961 6.3 (2.4 - 10.0) 17.6 (6.8 - 28.3) 36.4 (14.0 - 58.7)Site 3 : Traeth Crugan 19976 6.4 (2.6 - 10.1) 17.9 (7.2 - 28.6) 37.0 (14.7 - 59.3)Site 4 : Morfa Dyffryn 20184 6.5 (2.7 - 10.2) 18.2 (7.5 - 28.8) 37.4 (15.1 - 59.8)Site 5 : Broadwater-Aberdovey 20800 6.6 (2.9 - 10.4) 18.6 (7.9 - 29.3) 38.3 (16.0 - 60.6)Site 6 : Tenby North Beach 23048 7.2 (3.5 - 11.1) 20.1 (9.4 - 30.9) 41.0 (18.7 - 63.4)Site 7 : Port Eynon 23259 7.3 (3.5 - 11.0) 20.2 (9.5 - 30.9) 41.1 (18.8 - 63.4)Site 8 : Northwest Swansea Bay 23261 7.3 (3.5 - 11.0) 20.1 (9.5 - 30.8) 41.0 (18.7 - 63.4)Site 9 : Baglan-Aberavon 23263 7.2 (3.5 - 11.1) 20.1 (9.4 - 30.9) 41.0 (18.7 - 63.4)Site 10 : Porthcawl 23470 7.3 (3.6 - 11.0) 20.2 (9.5 - 30.9) 41.2 (18.8 - 63.5)
High Emissions Scenario (SRES A1FI Storyline)Site 1 : Gronant-Talacre 18964 7.7 (2.9 - 12.5) 21.7 (8.1 - 35.3) 44.9 (16.5 - 73.2)Site 2 : Abergele-Pensarn 18961 7.6 (2.8 - 12.4) 21.4 (7.8 - 35.0) 44.5 (16.1 - 72.9)Site 3 : Traeth Crugan 19976 7.8 (3.0 - 12.5) 21.8 (8.2 - 35.4) 45.2 (16.8 - 73.6)Site 4 : Morfa Dyffryn 20184 7.9 (3.1 - 12.6) 22.1 (8.5 - 35.7) 45.6 (17.3 - 74.0)Site 5 : Broadwater-Aberdovey 20800 8.0 (3.3 - 12.8) 22.5 (9.0 - 36.1) 46.5 (18.1 - 74.9)Site 6 : Tenby North Beach 23048 8.6 (3.8 - 13.4) 24.0 (10.4 - 37.6) 49.2 (20.8 - 77.5)Site 7 : Port Eynon 23259 8.7 (3.9 - 13.5) 24.1 (10.5 - 37.7) 49.3 (20.9 - 77.6)Site 8 : Northwest Swansea Bay 23261 8.7 (3.9 - 13.4) 24.1 (10.5 - 37.7) 49.2 (20.8 - 77.6)Site 9 : Baglan-Aberavon 23263 8.6 (3.8 - 13.4) 24.0 (10.4 - 37.6) 49.2 (20.8 - 77.5)Site 10 : Porthcawl 23470 8.7 (3.9 - 13.5) 24.1 (10.6 - 37.7) 49.3 (21.0 - 77.7)
Increase in mean sea level from 2010 (cm)50% value (5-95% range in brackets)
Table 2.3 UKCP09 predictions of future increases in relative sea level , assuming low, medium and high emissions scenarios. Increases are relative to 2010.
Beach nourishment options in Wales and likely future requirements for beach nourishment in an era of sea level rise and climate change
Table 3.1 Selected case study sites.
Criteria Talacre Abergele Traeth Crugan Morfa Dyffryn Broadwater-Tywyn-Aberdovey
GEOGRAPHY Open coast or estuarine?
Estuarine Open Coast Open Coast Open Coast Open Coast
Eroding or accreting?
The majority of sand material is either retained by coastal defences or contributes to the significant accretion of material at the Point of Ayr, where it forms an expansive intertidal zone, and subsequently material to be used in the development of the Talacre Sand Dunes.
Source of material is relict – sediment supply through re-working of shoreline deposits. East of Abergele the three controlling headlands at Rhos Point, Tan Penmaen Head and Llanddulas would experience a moderate degree of erosion.
Erosion of the sand dunes at Traeth Crugan and Pwllheli Golf Club are providing sand, which accretes eastwards by littoral drift along the Pwllheli promenade. There is ongoing loss to this frontage as material by-passes Carreg yr Imbill and is deposited in the harbour mouth. There is a problem with siltation of the inner harbour at Pwllheli and this is thought to be due to the low tidal current velocities through the harbour entrance. Although the sea bed is generally free of silt outside the harbour entrance, the eroding glaciogenic cliffs to the west of the harbour are a source of suspended silt and mud.
In areas of the beach, the underlying peat is exposed and eroding, thereby causing permanent loss in beach volume since the eroded peat will disperse from the area. There is a large-scale northwards sediment transport pathway throughout most of Cardigan Bay.
Eroding between Tywyn and Club House Aberdovey / Accretion East of Aberdovey
COASTAL DEFENCES Material? This beach has a large unspoiled expansive sandy
foreshore backed by gently sloping dunes which graduate into a low-lying backshore.
The beach is generally a combination of sand and shingle. At the low water mark, patches of clean sand, shingle and boulders are apparent, while at high water this gives way to a cleaner ground of gravel and coarse sand.
Sandy beach overlying peat beds. A combination of sandy and pebbly beaches.
Hard or soft defences?
Large sandy beach with shallow gradient / shingle ridge. Considerable tidal range backed throughout by dunes.
Revetment (and wall in places) originally constructed 1845-48, re-furbished 1906. New revetment in places built in 1993 following 400m breach at Towyn in 1990. Shingle bank fronts wall to east of Abergele with dunes to landward and low-lying hinterland. Bars and troughs in sand foreshore migrate eastward across frontage influencing cycles of erosion / accretion.
The backshore is characterised by a single, narrow sand dune ridge. The height of the dune is generally 3 - 5 m and the crest width is approximately 3 - 4 m. Much of the dune system is poorly vegetated. The sand dunes at Traeth Crugan and Pwllheli Golf Club are subject to local erosion and are protected in places by stretches of rock revetment.
Sandy beach backed by dunes . Outcropping of shingle ridge down to Llanaber/ timber breastwork and rock revetment in front of caravan park 1km north. Down to Llanaber, railway line is built against the shoreline and protected by rock armour / Concrete promenade in front of railway line at Llanaber, fronted by rock revetment
Groyne field in front of Tywyn / Shingle ridge in place, sandy beach backed by dunes or Penllyn marshes
MANAGEMENT ISSUES Developed or undeveloped coast?
Undeveloped but caravan park, golf course and villages of Talacre and Gronant in the hinterland
Developed frontage tourist destination, beach constrained in places by railway and trunk roads though well-developed between this infrastructure.
Undeveloped along the whole coast line. Largely undeveloped - Four caravan parks, Llanaber village and railway line along part of the frontage
Mixed - Tywyn town and golf course.
Cross council boundary coverage?
Sir y Fflint - Flintshire Conwy – Conwy Gwynedd – Gwynedd
Gwynedd – Gwynedd Gwynedd North of Estuary
ENVIRONMENTAL ISSUES Designated or non-designated?
Dee Estuary SSSI and Gronant Dunes & Talacre Warren SSSI. Gronant Dunes and Talacre Warren are part of the proposed Dee Estuary SAC and the proposed extension to the Dee Estuary SPA and Ramsar Site.
SSSI: Traeth Pensarn SSSI: Llanddulas Limestone And Gwrych Castle Wood SSSI: Coed Y Gopa
Designated sites: Pen Llyn a'r Sarnau / Lleyn Peninsula and the Sarnau SAC, and the Mynydd Tir Y Cwmwd A'r Glannau At Garreg Yr Imbill SSSI.
SAC: Morfa Harlech a Morfa Dyffryn NNR: Morfa Dyffryn SSSI: Morfa Dyffryn National Park: Snowdonia SAC: Pen Llyn a'r Sarnau / Lleyn Peninsula and the Sarnau
Dunes part of Dovey SSSI within Pen Llyn A’R SAR
Important for recreation and access?
Both Gronant and Talacre Dunes are popular with holidaymakers and local residents. Beach access through dunes and car park.
Pensarn beach is important for recreational activities such as Windsurfing and Canoeing. Beach access over mainline railway.
This area is important recreationally for the golf course users and also for Sea Anglers. The lagoon at Traeth Crugan also has a lagoon which sits within a string of banks and reefs which form an arc offshore which has a very diverse bivalve fauna.
Part of the beach is an officially recognised naturist area, one kilometre in length. The beach is also known for regular sightings of dolphins.
Fishing, sailing and watersports off Aberdovey harbour.
Beach nourishment options in Wales and likely future requirements for beach nourishment in an era of sea level rise and climate change
Table 3.1 (cont’d) Selected case study sites.
Criteria Tenby (North) Port Eynon Swansea Bay (North) Aberavon Porthcawl GEOGRAPHY Open coast or estuarine?
Open Coast Open Coast Estuarine / Open Coast Open Coast / Estuarine Estuarine / Open Coast
Eroding or accreting?
Varying rates of cliff retreat around the western end of Carmarthen Bay, due to differential erosion of rocks of varying resistance, is responsible for the current topography of headlands and intervening bays. Carboniferous sandstones and limestone form headlands, but mudstone-rich beds within the Carboniferous Coal Measures and Millstone Grit have been susceptible to greater erosion and recession.
The cliffs between Worms Head and Port Eynon Point, around Oxwich Point and between Great Tor and Mumbles Head will be dominated by very low rates of erosion.
Rates of transport of sand and gravel are likely to have been lower than those of the cliffed coasts of the Gower and South Glamorgan because Swansea Bay has been largely sheltered from westerly storms and weaker ebb-currents. Swansea Bay is generally a sink for sediments.
Much of this coastline is composed of relatively resistant cliffs and rock platforms, which have experienced little movement over the centuries. Overall, there is no notable trend of either accretion or erosion of beaches, though some beaches, such as in Trecco Bay, Porthcawl, have seen erosion in recent years.
COASTAL DEFENCES Material? Resistant Carboniferous Limestones form headlands such as
Worms Head and Burry Holms on the Gower Peninsula, and at Tenby and Giltar Point. Millstone Grit forms cliffed promontories between Tenby and Ragwen Point.
The resistant early Carboniferous limestone geology will constrain the future broad-scale configuration of this rocky cliffed coast. These cliffs have a very low potential recession rate and therefore significant change along the cliffed shoreline is not expected over the next century. Due to the exposure of these rocky shorelines and the lack of contemporary sediment input there would not be any significant new sediment accumulations.
The seabed east of Swansea Bay comprises mainly bedrock, with locally thin accumulations of sand and gravel. Extensive areas of rock are exposed across the channel off the South Glamorgan coast where there are maximum stresses on the seabed due to the tidal currents. Overall, the plan shape of Swansea Bay is dominantly a south to south-west facing bay bounded on either side by broadly east-west trending hard rock coasts composed primarily of early Carboniferous limestone.
This is a highly industrialised area of coast. The coastal plain widens particularly around Port Talbot, which is built on former sand dunes.
This area is characterised by a flat coastal plain around Porthcawl with low rocky headland and sandy enclosed beaches.
Hard or soft defences?
4 km of sandy beaches. Very little sand is derived from erosion of sandstones on this coastline. Most sand released from cliff erosion will be stored locally on the beaches, especially within pocket beaches, or will be washed into Carmarthen Bay by storm wave currents. Rock clasts (pebbles and shingle) liberated by rock falls generally remain on the adjacent rock platforms in the short term. Clay released from erosion of mudrocks will be carried by storm and tidal currents into the outer Bristol Channel. Much of the open-cliffed coastline is undefended, with defences being restricted to the settlements of Tenby, Saundersfoot, Wisemans Bridge, Amroth and Pendine, with few implications for the rest of the coastline.
Much of the open-cliffed coastline is undefended, with defences being restricted to individual embayments. Where defences are present, principally in the form of seawalls or revetments (such as in Port Eynon, Oxwich, Caswell, and Langland Bays), they protect localised areas from erosion but with few implications for the rest of the coastline.
Sand (mud?), wide intertidal area, wood fences to retain sand on the western side bay / Seawall and concrete revetment on the northern side then harbour jetty Closer to shore near Swansea Bay, Helwick and Nash Sands form banner banks reflecting changes in the orientation of the coastline. These banks provide limited protection to the coastline from open-ocean wave activity.
In the 1950s many of the sand dunes of Aberavon Beach disappeared as part of the development of the Sandfields estate. During this development, a 1.25 mile sea defence wall was built. This is also fronted by a rock revetment.
Rocky coast on western side with coves / sandy beach alternated with headlands / concrete promenade / jetty harbour / four small fishtail groynes / sandy beach backed by dunes to the east / rocky platform in front of Ogmore. There has been significant modification to this shoreline as a result of human interference. Much of the area of dunes has since been significantly modified and built up, so little of the originally morphology remains.
MANAGEMENT ISSUES Developed or undeveloped coast?
Tenby is developed with undeveloped land around. Port Eynon is largely undeveloped with a small residential area and camping and caravan park.
Heavily developed This is a highly industrialised area of coast characterised by heavy industry around Port Talbot.
Developed - Town, golf course, caravan park
Cross council boundary coverage?
Sir Benfro – Pembrokeshire Abertawe - Swansea Abertawe – Swansea Castell-nedd Port Talbot - Neath Port Talbot
Pen-y-bont ar Ogwr - Bridgend
ENVIRONMENTAL ISSUES Designated or non-designated?
SSSI: Lydstep Head To Tenby Burrows National Park: Pembrokeshire Coast SAC: Carmarthen Bay and Estuaries / Bae Caerfyrddin ac Aberoedd SSSI: tenby cliffs and st. Catherine's island
SAC: Limestone Coast of South West Wales / Arfordir Calchfaen De Orllewin Cymru SSSI: Gower Coast: Rhossili To Porteynon AONB: Gower SSSI: Horton, Eastern And Western Slade SSSI: Oxwich Bay SAC: Gower Ash Woods / Coedydd Ynn Gwyr NNR: Oxwich
SSSI: Blackpill, Swansea SSSI: Crymlyn Burrows SAC: Kenfig / Cynffig SSSI: Merthyr Mawr
Important for recreation and access?
Tenby is a very busy UK holiday resort during summer. Caravan and Camping park. Access beach, watersport Averavon Beach is a favourite with surfers.
The sea here is used for swimming and surfing.
Profile Shoreline length Existing profile Design profile Required Additional Nourishment Total nourishment Assumedrepresented by area to MTL area to MTL nourishment area required volume required volume required nourishment
profile (m) (m2) (m2) width (m) (m2) per profile (m3) for site (m3) profile slopeSite 1 : Gronant-Talacre P3 408 183 202 43 20 8139 148080 1:25
P4 756 219 266 59 47 35169 1:25P5 712 245 306 72 61 43431 1:25P6 671 295 353 91 58 38833 1:25P7 365 231 292 68 62 22508 1:25
Site 2 : Abergele-Pensarn P46 1306 98 316 121 218 284997 429709 Slope to MTLP47 385 101 162 52 60 23301 Slope to MTLP48 498 101 200 69 100 49618 Slope to MTLP49 466 125 279 103 154 71793 Slope to MTL
Site 3 : Traeth Crugan P70 612 35 74 28 39 24163 68159 Slope to MTLP71 1079 50 90 39 41 43996 Slope to MTL
Site 4 : Morfa Dyffryn P34 897 74 128 62 55 48935 369486 Slope to MTLP35 1607 165 220 122 55 88303 Slope to MTLP36 1245 149 284 163 136 168948 Slope to MTLP37 1133 162 218 120 56 63300 Slope to MTL
Site 5 : Broadwater-Aberdovey P4 270 129 169 69 40 10817 491394 1:25P5 633 126 178 79 52 32616 1:25P6 806 104 185 93 81 65210 1:25P7 1241 89 186 100 97 120550 Slope to MTLP8 987 93 151 76 58 57042 Slope to MTLP9 670 79 141 70 63 41988 Slope to MTLP10 691 75 130 63 55 37981 Slope to MTLP11 1082 34 92 39 58 62599 Slope to MTLP12 1218 32 67 23 35 42551 Slope to MTLP13 656 71 101 45 31 20041 Slope to MTL
Table 4.1 Initial volumes of nourishment material required at each site for the example scenario. The design profile assumes a 20 m wide flat-topped berm at the level of HAT, sloping down to the existing profile at a angle of 1:25, or to MTL, whichever is closer to the HAT mark.
Profile Shoreline length Existing profile Design profile Required Additional Nourishment Total nourishment Assumedrepresented by area to MTL area to MTL nourishment area required volume required volume required nourishment
profile (m) (m2) (m2) width (m) (m2) per profile (m3) for site (m3) profile slopeSite 6 : Tenby North Beach P12 347 62 132 63 70 24291 45964 Slope to MTL
P13 425 192 243 80 51 21673 Slope to MTLSite 7 : Port Eynon P103 508 307 461 149 153 77908 151636 Slope to MTL
P104 704 293 398 128 105 73728 Slope to MTLSite 8 : Northwest Swansea Bay P206 768 298 412 99 114 87565 344832 1:25
P207 979 332 460 125 128 125261 1:25P208 934 424 444 128 20 18589 1:25P209 1103 372 429 106 57 62604 1:25P210 996 346 397 91 51 50813 1:25
Site 9 : Baglan-Aberavon P217 641 311 355 74 44 28296 640784 1:25P218 1055 343 419 96 76 80427 1:25P219 1078 295 474 128 179 192948 1:25P220 767 327 484 128 158 120739 1:25P221 860 246 500 155 254 218374 1:25
Site 10 : Porthcawl P237 418 320 396 83 76 31794 159268 1:25P238 234 384 454 117 70 16417 1:25P240 700 338 496 142 159 111056 1:25
Table 4.1 continued.
Site Planar areaof proposednourishment Minimum Best Maximum Minimum Best Maximum Minimum Best Maximum
(x103 m2) Estimate Estimate EstimateSite 1 : Gronant-Talacre 1373 30 86 172 86 243 485 177 504 1005Site 2 : Abergele-Pensarn 187 4 12 23 12 33 65 24 68 136Site 3 : Traeth Crugan 81 2 5 10 5 14 29 11 30 59Site 4 : Morfa Dyffryn 540 14 35 68 37 98 193 75 202 400Site 5 : Broadwater-Aberdovey 670 18 44 86 49 125 242 98 257 502Site 6 : Tenby North Beach 58 2 4 8 5 12 22 10 24 45Site 7 : Port Eynon 160 5 12 22 14 32 60 28 66 124Site 8 : Northwest Swansea Bay 1498 49 109 201 132 301 565 259 614 1163Site 9 : Baglan-Aberavon 1319 44 95 177 116 265 496 228 541 1022Site 10 : Porthcawl 323 11 24 44 29 65 122 56 133 251
Sea level rise by 2030 (cm) Sea level rise by 2060 (cm) Sea level rise by 2100 (cm)Volumes of sediment required to maintain the existing beach profile (x103 m3)
Table 4.2 Planar areas of the defined possible nourishment areas (between HAT and MTL), and minimum, maximum and best estimates of volumes of sediment required to maintain the existing beach profile by 2030, 2060 and 2100 based on UKCP09 sea level rise predictions. Minima represent the 5% values for the low emission (SRES B1) scenario, maxima represent the 95% values for the high emissions (A1FI) scenario, and best estimates represent the 50% values for the medium emissions (A1B) scenario. Increases are relative to 2010. N.B. The calculations make no allowance for post-nourishment losses and re-nourishment required, and therefore are underestimates of the total volumes of sediment which would be required.
Site Initial Four renourishments Volumes required to maintain
nourishment assuming 50% losses
(x103 m3) every five years Minimum Best Maximum Minimum Best Maximum
(x103 m3) Estimate EstimateSite 1 : Gronant-Talacre 148 296 30 86 172 474 531 616Site 2 : Abergele-Pensarn 430 859 4 12 23 1293 1301 1312Site 3 : Traeth Crugan 68 136 2 5 10 206 210 215Site 4 : Morfa Dyffryn 369 739 14 35 68 1122 1144 1177Site 5 : Broadwater-Aberdovey 491 983 18 44 86 1492 1518 1560Site 6 : Tenby North Beach 46 92 2 4 8 140 142 146Site 7 : Port Eynon 152 303 5 12 22 460 467 477Site 8 : Northwest Swansea Bay 345 690 49 109 201 1084 1144 1235Site 9 : Baglan-Aberavon 641 1282 44 95 177 1966 2017 2099Site 10 : Porthcawl 159 319 11 24 44 488 501 521
existing beach profile (x103 m3)
Total volume of sediment
required by 2030 (x103 m3)
Table 4.3 Nourishment volumes required over the period 2010 to 2030, assuming an initial nourishment in 2010 followed by five-yearly renourishment campaigns to replace 50% losses, and additional volumes required to raise the beach profile due to sea level rise, based on minimum, maximum and best estimates from UKCP09 sea level rise predictions. Minima represent the 5% values for the low emission (SRES B1) scenario, maxima represent the 95% values for the high emissions (A1FI) scenario, and best estimates represent the 50% values for the medium emissions (A1B) scenario.
Table 5.1 Summary of actual and potential benefits of beach nourishment at the ten study sites.
Has beach nourishment been used to date?
If so, has it been thought a success?
Actual or potential benefits of beach nourishment
Flood and coastal erosion risk management
Habitat creation/ remediation
Tourism and recreation
Talacre
Abergele - Pensarn
Traeth Crugan
Morfa Dyffryn
Broadwater - Tywyn – Aberdovey
Tenby North Beach
Port Eynon Bay
Northern Swansea Bay (Black Pill to Swansea Docks)
Aberavon Sands (eastern Swansea Bay)
Porthcawl (Sandy Bay and Trecco Bay)
Figures
Figure 1.1 Location of possible case study areas.
Tenby NorthBeach Port
Eynon NorthwestSwansea Bay
Baglan-Aberavon
Porthcawl
Broadwater-Aberdovey
TalacreAbergele-Pensarn
MorfaDyffryn
TraethCrugan
MHW
MLW
embryodunes
sanddunes
WAVE DISSIPATION
WIND TRANSPORT
(a) Soft defences, sand only Flood protection:Recreational use:Biodiversity/nature conservation:Visual appearance/landscape quality:Beach access:
Moderate/GoodGoodGoodGoodGood
Wide forshore, gently sloping
Wide backshore,with drying beach
MHW
MLW
vegetated shingle
sanddunes
sand
sandWAVE DISSIPATION
LIMITED WIND TRANSPORT
(b) Gravel upper beach,sand lower beach
Flood protection:Recreational use:Biodiversity/nature conservation:Visual appearance/landscape quality:Beach access:
Moderate/GoodModerate/GoodGoodGoodModerate/Good
Wide forshore, gently sloping
Wide, high backshore,with drying beach
activeshingle
Figure 2.1 Concept diagrams showing examples of ‘Good’ beaches.
sand
sand
sand
gravel
Figure 2.2 Examples of ‘Good’ beaches: wide, high, wave-dissipative beaches at (a) Harlech, looking north in August 1991; and (b) Broad Haven, west of Stackpole Warren, in March 2009.
(a)
(b)
(a) Low beach levelsfronting sea wall
thin sandlayer
MHW
MLW
exposed back-barriersand/ peat deposits
scourhole
no high tide‘dry beach’
HIGH DEGREE OFWAVE REFLECTANCE
sea wall
Flood protection:Recreational use:Biodiversity/nature conservation:Visual appearance/landscape quality:Beach access:
PoorPoorPoorPoorPoor
(b) Low beach levelsfronting rock armour
thin sandlayer
MHW
MLW
exposed back-barriersand/ peat deposits
REDUCED WAVEREFLECTANCE
sea wall/revetment
Flood protection:Recreational use:Biodiversity/nature conservation:Visual appearance/landscape quality:Beach access:
ModeratePoor/DangerousPoorPoorPoor
angularrock armour
(c) Narrow beach fronting eroding sand dunes
Flood protection:Recreational use:Biodiversity/nature conservation:Visual appearance/landscape quality:Beach access:
PoorPoorPoorModerateModerate
Figure 2.3 Concept diagrams showing examples of ‘Poor’ beaches.
MHW
MLW
LIMITED WAVE DISSIPATION
narrow foreshore
very narrowbackshore
narrow erodingforedune
landward movementof dunes
(d) Narrow beach fronting narrow shingle barrier
Flood protection:Recreational use:Biodiversity/nature conservation:Visual appearance/landscape quality:Beach access:
PoorPoorModerateModerateModerate
MHW
MLW
LIMITED WAVE DISSIPATIONvery narrowbackshore
shingle bermwith narrow crest
retreat by washoverand breaching
relativelynarrow foreshore
infilling over back-barriersaline lagoons and
burial of marshback-barrier depositsexposed on foreshore
sand
sand
back-barrier deposits
gravel
Figure 2.4 Example of a ‘Poor’ beach: Ffrith Beach, Rhyl, with very low beach levels, dilapidated groynes and exposed sea wall: (a) oblique aerial photograph taken March2008; (b) ground photograph looking west taken February 2010.
(a)
(b)
Figure 2.5 Concept diagram showing possible alternative sources of artificial nourishment material. After Pye (2010).
marina
river
Solid rock upland
Dominantwave
approach
10
9
8
7
6
5
43
2
1
11
1234567891011
Port and harbour dredging (captial and maintenance)Inland quarry (hard and soft rock)Inland quarry (unconsolidated gravel and/or sand)Excavation for buildings and infrastructureIndustrial waste productsNearshore sea bed borrow pitNearshore banks (ebb tidal delta shoal)Proximal offshore zone (>20 m depth)Distal offshore depositsNeighbouring beach depositsDowndrift sediment sink - sediment recycled
coastal plain
Figure 2.6 Some alternative methods of beach nourishment. After Pye (2010).
marineinputs
landinputs
longshoretrickle-feed
road
truck haul beach deposit
offshore deposit (subtidal berm)
conveyor transport excavationsite
conveyor deposit
dredger pipe
dredger
‘rainbow’deposition
Hydraulicnourishment
landward movement of sediment by natural processes
SEA LAND
Key
nourishment material
initial beach
dune nourishment deposits (usually truck ortractor/trailer haul)
t0
t1
t2
t3
Figure 2.7 Schematic diagrams showing sediment losses following initial beach nourishment on (a) an open-ended system, such as a straight open-coast beach, and (b) a semi-closed system, such as a pocket beach. After Pye (2010).
Landward transfer losses(aeolian transportand/or washover)
“spead out”losses
offshorelosses
Dominantwave
approach
“spead out”losses
(a)
limited losses offshore
Landward lossesto dunes
t0t1
t2t3sediment spreads out but little is lost from the system
gravel concentrated on backshore
sand moves to nearshore
(b)
sediment losses due to longshore
drift
Dominantwave
approach
Key
nourishment material (t1)
initial beach (t0)
seaward position of beach after time period (t2)
seaward position of beach after time period (t3)
headland
headland
Figure 2.8 Examples of previously successful beach nourishment: (a) Miami Beach, taken 2007; (b) oblique aerial photograph of West Shore, Llandudno, taken March 2008.
(a)
(b)
Mean sea level 2Mean sea level 1
Shorelineposition 1
Shorelineposition 2
(a) Simple 2-D Bruun ModelNatural retreat, no nourishment
t1
t2
sea level rise
erosion distance
Mean sea level 1sea level rise
Mean sea level 2
t1t2
(b) ‘Hold The Line’Large-scale nourishment required
No change inshoreline position
Figure 2.9 Conceptual models of shoreline evolution during sea level rise: (a) Bruun’s model of shoreline retreat in response to sea level rise, and (b) ‘Hold The Line’ model with no net change in shoreline position or beach form in response to sea level rise.
Erosion
Accretion
Wholeprofile
accretion
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
Sea
leve
l ris
e (m
)
DEFRA (2006)
UKCP09 - low emissions 95%ile
UKCP09 - medium emissions 95%ile
UKCP09 - high emissions 95%ile
Figure 2.10 Future sea level rise preditions from 1990 based on the DEFRA (2006) sea level rise allowances (for south west England and Wales), and UKCP09 projections (for Holyhead,grid cell 18745) based on the 95th percentile modelled output values (considered very unlikely to be exceeded) for low (SRES B1), medium (SRES A1B1) and high (SRES A1FI) emission scenarios.
308500 309000 309500 310000 310500 311000 311500 312000 312500 313000383000
383500
384000
384500
385000
385500
386000
LowerGronant
Talacre
Point of AyrLighthouse
Figure 4.2 Oblique aerial photographs of (a) Talacre and Point of Ayr viewed from the east, and (b) the nourished area of the shore near the Point of Ayr Lighthouse, taken in March 2008. Source: Northwest Coastal Group.
(a)
(b)
Figure 4.3 The beach at Talacre taken during nourishment in February-March 2003.Source: Countryside Council for Wales.
(a)
(b)
Figure 4.4 The upper beach (a) and frontal dunes (b) at Talacre in March 2004, one year after beach nourishment.
(a)
(b)
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600 700
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600 700
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600 700
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600 700
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600 700
Elev
atio
n (m
OD
)
Chainage (m)
Figure 4.5 Cross-sectional profiles P3 to P7 at Talacre, Autumn 2007.
P3 P4
P5 P6
P7
Figure 4.6 The upper beach and frontal dunes (a) east and (b) west of Point of Ayr Lighthouse, in February 2010.
(a)
(b)
291000 291500 292000 292500 293000 293500 294000 294500 295000 295500 296000377500
378000
378500
379000
379500
380000
P45
P46P47
P48P49
R. Dulas mouth
Pensarn
Abergele
HenWrych
Figure 4.8 Oblique aerial photographs of (a) central part and (b) western end of the Abergele-Pensarn ridge complex, March 2008. Source: Northwest Coastal Group.
(a)
(b)
-4
-2
0
2
4
6
8
-50 0 50 100 150 200 250 300 350 400 450
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
-50 0 50 100 150 200 250 300 350 400 450
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
-50 0 50 100 150 200 250 300 350 400 450
Elev
atio
n (m
OD
)
Chainage (m)
-4
-2
0
2
4
6
8
-50 0 50 100 150 200 250 300 350 400 450
Elev
atio
n (m
OD
)
Chainage (m)
P46 P47
P48 P49
Figure 4.9 Cross-sectional beach profiles across the beach at Site 2 : Abergele-Pensarn , surveyed in October 2009.
Figure 4.10 Western end of the Abergele-Pensarn ridge complex looking (a) west and (b) east, February 2010.
(a)
(b)
234000 234200 234400 234600 234800 235000 235200 235400 235600 235800 236000 236200 236400332000
332200
332400
332600
332800
333000
333200
333400
333600
333800
334000
P70
P71
-2
-1
0
1
2
3
4
5
6
7
8
9
00105005-
Chainage (m)
Ele
vati
on
(m
)
-2
-1
0
1
2
3
4
5
6
7
8
9
00105005-
Chainage (m)
Ele
vati
on
(m
)
Spring 1996 Spring 1997 Autumn 1997 Spring 1998 Autumn 1998 Spring 1999 Autumn 1999Spring 2000 Autumn 2000 Spring 2001 Autumn 2001 Spring 2002 Autumn 2002 Spring 2003Autumn 2003 Spring 2004 Autumn 2004 Spring 2005 Autumn 2005 Spring 2006
Figure 4.12 Cross-sectional beach profiles across the beach at Traeth Crugan.After Faber Maunsell (2008).
Profile P70
Profile P71
Figure 4.13 Rock armour sea defences and upper beach at Traeth Cruganlooking (a) west and (b) east, in 2006.
(a)
(b)
Composite aerial photograph of Site 4 : Morfa Dyffryn, flown 15/07/2006. Also shown are thelimits of the defined possible nourishment area, positions of Gwynedd Council beach cross‐sectional profiles, and tide lines from First Edition County Series Ordnance Survey mapssurveyed in 1887.
Figure 4.15 Offset of tidal contours relative to the station on beach profiles 34 and 35 at Morfa Dyffryn. After Pye and Saye (2005)
0
20
40
60
80
100
120
140
160
180
200
S19
92
A19
92
S19
93
A19
93
S19
94
A19
94
S19
95
A19
95
S19
96
A19
96
S19
97
A19
97
S19
98
A19
98
S19
99
A19
99
S20
00
A20
00
S20
01
A20
01
S20
02
A20
02
S20
03
Dis
tanc
e fro
m S
tatio
n (m
)
Year/Season
PROFILE 34
HAT
MHWST
MHWNT
MTL
0
20
40
60
80
100
120
140
160
180
200
S19
92
A19
92
S19
93
A19
93
S19
94
A19
94
S19
95
A19
95
S19
96
A19
96
S19
97
A19
97
S19
98
A19
98
S19
99
A19
99
S20
00
A20
00
S20
01
A20
01
S20
02
A20
02
S20
03
Dis
tanc
e fro
m S
tatio
n (m
)
Year/Season
PROFILE 35
HAT
MHWST
MHWNT
MTL
Figure 4.15 continued.
0
20
40
60
80
100
120
140
160
180
200
S19
92
A19
92
S19
93
A19
93
S19
94
A19
94
S19
95
A19
95
S19
96
A19
96
S19
97
A19
97
S19
98
A19
98
S19
99
A19
99
S20
00
A20
00
S20
01
A20
01
S20
02
A20
02
S20
03
Dis
tanc
e fro
m S
tatio
n (m
)
Year/Season
PROFILE 36
HAT
MHWST
MHWNT
MTL
0
20
40
60
80
100
120
140
160
180
200
S19
92
A19
92
S19
93
A19
93
S19
94
A19
94
S19
95
A19
95
S19
96
A19
96
S19
97
A19
97
S19
98
A19
98
S19
99
A19
99
S20
00
A20
00
S20
01
A20
01
S20
02
A20
02
S20
03
Dis
tanc
e fro
m S
tatio
n (m
)
Year/Season
PROFILE 37
HAT
MHWST
MHWNT
MTL
Figure 4.16 The dunes at Morfa Dyffryn, taken May 2007.
(a)
(b)
255000 255500 256000 256500 257000 257500 258000 258500 259000 259500 260000 260500 261000295000
295500
296000
296500
297000
297500
298000
298500
299000
299500
300000
300500
301000
301500
302000
302500
303000
303500
304000
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
0 250 500 750 1000
Figure 4.18 (a) Removal of excess sand from area of boat ramp at Aberdovey promenade, (b) emplacement of nourishment sand at low points in the foredunes, Aberdovey Golf Club frontage. Source: Gwynedd Council.
(a)
(b)
-1
0
1
2
3
4
5
6
7
8
-50 0 50 100 150 200 250 300
Elev
atio
n (m
OD
)
Chainage (m)
May-08
Feb-92
Figure 4.19 Cross-sectional beach profiles between Aberdovey and Tywyn, measured on 13-14 February 1992 and 2 May 2008.
P3-1
0
1
2
3
4
5
6
7
8
-50 0 50 100 150 200 250 300
Elev
atio
n (m
OD
)
Chainage (m)
May-08
Feb-92
P4
-1
0
1
2
3
4
5
6
7
8
-50 0 50 100 150 200 250 300
Elev
atio
n (m
OD
)
Chainage (m)
May-08
Feb-92
P5-1
0
1
2
3
4
5
6
7
8
-50 0 50 100 150 200 250 300
Elev
atio
n (m
OD
)
Chainage (m)
May-08
Feb-92
P6
-1
0
1
2
3
4
5
6
7
8
-50 0 50 100 150 200 250 300
Elev
atio
n (m
OD
)
Chainage (m)
May-08
Feb-92
P7-1
0
1
2
3
4
5
6
7
8
-50 0 50 100 150 200 250 300
Elev
atio
n (m
OD
)
Chainage (m)
May-08
Feb-92
P8
Figure 4.20 (a) Nourished area of the frontal dunes, Aberdovey Golf Club frontage, March 2007; and (b) the beach fronting Penllyn Marshes, north of Aberdovey Golf Club, April 2008
(a)
(b)
Figure 4.21 (a) The beach at Tywyn, showing low beach levels and damage to promenade, and (b) beach and railway line between Tywyn and Broad Water, showing limited flood protection, both taken May 2007.
(a)
(b)
212800 213000 213200 213400 213600 213800 214000 214200200200
200400
200600
200800
201000
201200
201400
201600
P12
P13
CastleMound
Tenby
FirstPoint
-4
-2
0
2
4
6
8
10
12
-50 0 50 100 150 200 250 300 350
Elev
atio
n (m
OD
)
Chainage (m)
Profile 12
08/10/1999 22/03/200010/10/2000 04/04/200126/10/2001 26/04/200215/10/2002 07/10/200314/04/2004 30/09/200428/06/2005 04/07/200620/06/2007 21/05/200801/05/2003 14/05/1999
-4
-2
0
2
4
6
8
10
12
-50 0 50 100 150 200 250 300 350
Elev
atio
n (m
OD
)
Chainage (m)
Profile 13
08/10/1999 22/03/200010/10/2000 04/04/200129/10/2001 26/04/200215/10/2002 07/10/200314/04/2004 30/09/200428/06/2005 04/07/200620/06/2007 21/05/200801/05/2003 14/05/1999
Figure 4.23 Cross-sectional beach profiles at Site 6 : Tenby North Beach.
Figure 4.24 Tenby North Beach (a) looking north from Castle Mound, taken March 2009, (b) looking south from the northern end, taken February 2010.
(a)
(b)
246400 246600 246800 247000 247200 247400 247600 247800 248000 248200 248400184200
184400
184600
184800
185000
185200
185400
185600
185800
P103
P104
Port EynonPoint
Port Eynon
Horton
Figure 4.26 The beach at Port Eynon (a) looking southwest from Horton; and(b) looking northeast from Port Eynon. Source: Llanelli Sand Dredging.
(a)
(b)
-4
-2
0
2
4
6
8
10
12
14
-50 0 50 100 150 200 250 300 350 400 450 500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 103
29/09/1999 03/03/200008/09/2000 11/03/200125/09/2001 03/04/200216/09/2002 19/08/200316/03/2004 08/09/200427/04/2005 01/06/200613/06/2007 02/07/200811/03/2003 10/04/1999
-4
-2
0
2
4
6
8
10
12
14
-50 0 50 100 150 200 250 300 350
Elev
atio
n (m
OD
)
Chainage (m)
Profile 104
29/09/1999 03/03/200008/09/2000 11/03/200125/09/2001 03/04/200216/09/2002 19/08/200316/03/2004 08/09/200427/04/2005 01/06/200613/06/2007 02/07/200811/03/2003 10/04/1999
Figure 4.27 Cross-sectional beach profiles at Port Eynon.
261500 262000 262500 263000 263500 264000 264500 265000 265500 266000 266500 267000190000
190500
191000
191500
192000
192500
193000
P206
P207
P208
P209P210
0 250 500 750 1000
Scale (m)
Swansea
LowerSketty
BlackPill
SwanseaUniversity
WestPier
Brynmill
-4
-2
0
2
4
6
8
10
12
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 206
08/04/1999 02/10/199911/03/2000 01/09/200008/03/2001 07/10/200102/04/2002 09/09/200202/09/2003 24/03/200414/09/2004 10/05/200508/06/2006 30/05/200710/06/2008 17/03/200309/06/1998
-4
-2
0
2
4
6
8
10
12
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 207
31/03/1999 03/10/199911/03/2000 01/09/200008/03/2001 07/10/200102/04/2002 09/09/200202/09/2003 24/03/200414/09/2004 10/05/200508/06/2006 31/05/200710/06/2008 17/03/200310/06/1998
Figure 4.29 Cross-sectional beach profiles in Northwest Swansea Bay.
-4
-2
0
2
4
6
8
10
12
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 208
30/03/1999 16/09/199901/03/2000 31/08/200008/03/2001 04/10/200102/04/2002 09/09/200202/09/2003 24/03/200414/09/2004 10/05/200508/06/2006 30/05/200710/06/2008 17/03/200310/06/1998
-4
-2
0
2
4
6
8
10
12
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 209
30/03/1999 16/09/199901/03/2000 31/08/200008/03/2001 02/10/200103/04/2002 19/09/200202/09/2003 26/03/200414/09/2004 09/05/200531/05/2006 30/05/200710/06/2008 27/03/200310/06/1998
Figure 4.29 continued.
-4
-2
0
2
4
6
8
10
12
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 210
30/03/1999 16/09/199901/03/2000 31/08/200008/03/2001 24/09/200103/04/2002 19/09/200226/08/2003 26/03/200413/09/2004 04/05/200512/06/2006 31/05/200711/06/2008 01/04/200310/06/1998
Figure 4.29 continued.
Figure 4.30 (a) Northern Swansea Bay near Black Pill (a) looking west and (b) looking east, taken February 2010.
(a)
(b)
271000 271500 272000 272500 273000 273500 274000 274500 275000 275500187000
187500
188000
188500
189000
189500
190000
190500
191000
191500
192000
192500
193000
193500
0 250 500 750 1000
P217
P218
P219
P220
P221
0 250 500 750 1000
Scale (m)
Port Talbot
BaglanBurrows
CrymlynBurrows
Baglan
Aberavon
River Neath
-4
-2
0
2
4
6
8
10
12
14
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 217
12/04/1999 22/09/199917/03/2000 05/09/200015/03/2001 08/10/200116/04/2002 23/09/200209/09/2003 29/03/200417/09/2004 17/05/200518/07/2006 05/06/200730/06/2008 01/04/200301/07/1998
-4
-2
0
2
4
6
8
10
12
14
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 218
12/04/1999 22/09/199917/03/2000 05/09/200015/03/2001 08/10/200108/04/2002 23/09/200209/09/2003 29/03/200417/09/2004 17/05/200518/07/2006 04/06/200709/06/2008 01/04/200301/07/1998
Figure 4.32 Cross-sectional beach profiles between Baglan and Aberavon.
-4
-2
0
2
4
6
8
10
12
14
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 220
05/04/1999 22/09/199902/03/2000 04/09/200007/03/2001 25/09/200104/04/2002 23/09/200220/08/2003 16/03/200407/09/2004 17/05/200505/06/2006 01/06/200709/06/2008 01/04/200311/06/1998
-4
-2
0
2
4
6
8
10
12
14
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 219
05/04/1999 22/09/199902/03/2000 05/09/200007/03/2001 25/09/200104/04/2002 23/09/200220/08/2003 16/03/200407/09/2004 17/05/200505/06/2006 01/06/200709/06/2008 01/04/200311/06/1998
Figure 4.32 continued.
-4
-2
0
2
4
6
8
10
12
14
-100 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Elev
atio
n (m
OD
)
Chainage (m)
Profile 221
05/04/1999 22/09/199902/03/2000 04/09/200007/03/2001 25/09/200104/04/2002 23/09/200220/08/2003 16/03/200407/09/2004 17/05/200505/06/2006 01/06/200709/06/2008 01/04/200311/06/1998
Figure 4.32 continued.
Figure 4.33 (a) The upper beach at Aberavon looking north, taken March 2009;(b) Bulldozer removing sand from sea wall steps at Aberavon,February 2010.
(a)
(b)
Figure 4.34 (a) The beach towards the northern end of Aberavon promenade, looking south, showing windblown sand buildup on the stepped revetment; and (b) the beach fronting the southern end of Baglan Burrows, looking north. Photographs taken February 2010.
(a)
(b)
281400 281600 281800 282000 282200 282400 282600 282800 283000 283200 283400 283600 283800 284000176000
176200
176400
176600
176800
177000
177200
177400
177600
0 200 400 600 800
P237P238
P240
Porthcawl
PorthcawlPoint
TreccoBay
SandyBay
NewtonPoint
RhychPoint
NewtonBurrows
Newton
-4
-2
0
2
4
6
8
10
12
14
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
Elev
atio
n (m
OD
)
Chainage (m)
Profile 237
28/03/1999 18/09/199911/03/2000 07/09/200009/03/2001 26/09/200105/04/2002 17/09/200229/08/2003 18/03/200421/09/2004 25/05/200520/06/2006 06/06/200704/06/2008 18/03/200316/06/1998
-4
-2
0
2
4
6
8
10
12
14
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
Elev
atio
n (m
OD
)
Chainage (m)
Profile 238
28/03/1999 18/09/199911/03/2000 07/09/200014/03/2001 26/09/200108/04/2002 17/09/200215/09/2003 18/03/200423/09/2004 01/06/200520/06/2006 06/06/200704/06/2008 12/03/200316/06/1998
Figure 4.36 Cross-sectional beach profiles at Porthcawl.
-4
-2
0
2
4
6
8
10
12
14
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
Elev
atio
n (m
OD
)
Chainage (m)
Profile 240
09/04/1999 18/09/199913/03/2000 07/09/200009/03/2001 26/09/200105/04/2002 17/09/200213/08/2003 10/03/200423/09/2004 01/06/200520/06/2006 06/06/200704/06/2008 12/03/200316/06/1998
Figure 4.36 continued.
Figure 4.37 The beach at Sandy Bay, Porthcawl (a) looking east from the western end; and (b) looking west from the eastern end. Photographs taken February 2010.
(a)
(b)
CHART H:LICENSED DREDGING AREAS FOR THENORTH WEST REGION
04 0
0 W
03 3
0 W
03 0
0 W
54 00 N
53 30 N
331
392393 A
B
12M
ileTerritorial Sea
Limit
6M
ileF
ishingLim
it
457
PRESTON
MORECAMBE
FLEETWOOD
BLACKPOOL
SOUTHPORT
LIVERPOOL
BARROW-IN-FURNESS
GRANGE-OVER-SANDS
SCALE : 1:500,000
NOTE: NOT TO BE USED FOR NAVIGATION
CEMEX UK Materials Ltd.(Mersey Sand Supplies - Tel. 01512 071 886)
193/1 (A) 193/2 (B)
Norwest Sand & Ballast Co.(Mersey Sand Supplies - Tel. 01512 071 886)
175/1 (A)175/2 (B) 393
Tarmac Marine Dredging Ltd.(Tel. 01243 817 200)
195/1 (A) 195/2 (B)331392
Westminster Gravels Ltd. (Tel. 01489 885 933)
457 (From 01/07/2010)
DATE: APRIL 2010
From 01/07/2010
CHART G:LICENSED DREDGING AREAS FOR THESOUTH WEST REGION
04 0
0 W
03 3
0 W
03 0
0 W
04 3
0 W
51 00 N
385
391
377 379 381
51 30 N476
6M
ileFi
shin
gLi
mit
472
England / Wales Boundary
373*
470/1470/2
BUDE
SWANSEA
CARDIFF
NEWPORT
WATCHET
LLANELLI
MINEHEAD
CAMARTHEN
PORTHCAWL
ILFRACOMBE
WESTWARD HO!
BURNHAM-ON-SEA
WESTON-SUPER-MARE
SCALE : 1:600,000
NOTE: NOT TO BE USED FOR NAVIGATION
British Dredging Ltd.(Tel. 023 8072 0200)
379385
CEMEX UK Marine Ltd.(Tel. 023 8072 0200)
472
Hanson Aggregates Marine Ltd.(Tel. 023 8082 8200)
377 470/2391 472470/1
Llanelli Sand Dredging Ltd.(Tel. 01489 885 933)
373 (Dormant)476
Tarmac Marine Dredging Ltd.Formerly United Marine Dredging Ltd.(Tel. 01243 817 200)
381 470/2470/1 472
DATE: APRIL 2010
Awaiting relicensing*Licence
Figure 5.1 Licensed dredging areas in: (a) NW Region and (b) SW Region.Source: Crown Estate.
(b)
(a)
CHART F:
486/5
455 459
6M
ileFi
shin
gLi
mit
04 3
0 W
04 0
0 W
03 3
0 W
03 0
0 W
51 30 N
51 00 N
England/Wales Boundary486/3
486/2486/1486/4
486
SWANSEA
CARDIFF
NEWPORT
WATCHET
LLANELLI
MINEHEAD
CAMARTHEN
PORTHCAWL
ILFRACOMBE
WESTWARD HO!
BURNHAM-ON-SEA
WESTON-SUPER-MARE
DATE: APRIL 2010
SCALE : 1:600,000
NOTE: NOT TO BE USED FOR NAVIGATION
British Dredging Ltd.(Tel. 023 8072 0200)
486/1 486/3 486/5 486/2 486/4
Severn Sands Ltd.(Tel 01633 258589)
455459
Hanson Aggregates Marine Ltd.(Tel. 023 8082 8200)
486/1 486/3 486/5486/2 486/4 Tarmac Marine Dredging Ltd.United Marine Dredging Ltd.(Tel. 01243 817200)
486/1 486/3 486/5486/2 486/4
DREDGING APPLICATION, OPTION AND PROSPECTING AREAS FOR SOUTH WEST REGION
Application AreaPre Application AreaOption or Prospecting Area
Figure 5.2 Dredging application, option and prospecting areas in the SW Region (there are currently no areas in the NW Region). Source: Crown Estate.
Recommended