Historic Environment Guidance for the Offshore Renewable Energy ...

Historic EnvironmentGuidance

for theOffshore Renewable

Energy Sector

Prepared by Wessex Archaeology Ltd for COWRIEJanuary 2007

www.offshorewind.co.uk

This report was commissioned by COWRIE (Collaborative Offshore Windfarm Research Intothe Environment). COWRIE is a registered Charity set up to raise awareness andunderstanding of the potential environmental impacts of the UK offshore windfarmprogramme. It was created following the completion of the second licensing round for UKoffshore windfarms, and is funded by developers’ non-refundable option fees. The Charitycarries out three inter-related strands of work: Data Management, Education andCommunication, and Generic Environmental Research.

This report provides generic guidance in relation to the survey, appraisal and monitoring of thehistoric environment during the development of offshore renewable energy projects in theUnited Kingdom. It covers both the marine and coastal environments and those areas furtherinland likely to be affected by such developments.

The guidance is intended to promote the development of best practice in relation to the marinehistoric environment for the offshore renewable energy sector. It is also intended to promotean understanding of the conservation issues arising from the impacts of offshore renewableenergy projects on the historic environment, and in this way develop capacity amongstdevelopers, consultants and contractors.

i

Prepared by Wessex Archaeology Ltd for COWRIE

January 2007

Historic Environment Guidancefor the

Offshore Renewable Energy Sector

ii

© COWRIE Ltd, January 2007

ISBN-13: 978-0-9554279-1-6ISBN-10: 0-9554279-1-6

Preferred way to cite this report:Wessex Archaeology Ltd (January 2007). Historical Environment Guidance for the OffshoreRenewable Energy Sector. Commissioned by COWRIE Ltd (project reference ARCH-11-05).

Published by COWRIE Ltd.

Copies available from:www.offshorewind.co.ukE-mail: [email protected]

Photographs: © Wessex Archaeology Ltd

Design: Naturebureau International, 36 Kingfisher Court, Hambridge Road, Newbury RG14 5SJ, UKwww.naturebureau.co.uk

This publication (excluding the logos and images) may be re-used free of charge in any format ormedium. It may only be re-used accurately and not in a misleading context. The material must beacknowledged as COWRIE Ltd copyright and use of it must give the title of the source publication.Where third party copyright material has been identified, further use of that material requirespermission from the copyright holders concerned.

Contact details:Wessex Archaeology Ltd, Portway House, Old Sarum Park, Salisbury SP4 6EB, UKRef: 62890

http://www.offshorewind.co.uk

http://www.naturebureau.co.uk

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Executive Summary ............................................................................................................................ vAcknowledgements ......................................................................................................................... xiii

1 Introduction ................................................................................................................................... 11.1 Background.............................................................................................................................. 11.2 The importance of the marine historic environment ................................................................. 21.3 Archaeological principles ......................................................................................................... 5

The precautionary principle ...................................................................................................... 4In situ preservation ................................................................................................................... 7‘Polluter pays’ and developer-funding ..................................................................................... 7Archives and publication .......................................................................................................... 7Public interest .......................................................................................................................... 8

2 Possible Effects of Offshore Renewable Energy Development on the Marine and CoastalHistoric Environments ................................................................................................................... 92.1 Overview .................................................................................................................................. 92.2 Types of site ............................................................................................................................. 9

Wrecks and wreckage .............................................................................................................. 9Coastal heritage ..................................................................................................................... 11Prehistoric deposits and artefacts ......................................................................................... 11

2.3 Environments ......................................................................................................................... 112.4 Landscapes, seascapes and ‘setting’ .................................................................................... 122.5 Cumulative effects ................................................................................................................. 15

3 Development Processes ............................................................................................................. 163.1 Archaeology and the development process ........................................................................... 163.2 Consent processes for offshore renewable energy schemes ................................................ 173.3 Consents and other obligations relating to the historic environment ..................................... 18

Protection of Wrecks Act 1973............................................................................................... 18Ancient Monuments and Archaeological Areas Act 1979 ...................................................... 19Protection of Military Remains Act 1986 ................................................................................ 19Merchant Shipping Act 1995 .................................................................................................. 20Treasure and other archaeological finds ................................................................................ 20Human remains ...................................................................................................................... 20Ordnance and firearms........................................................................................................... 20

3.4 Risk management .................................................................................................................. 21

4 Sources of Historic Environment Advice and Information ....................................................... 224.1 Advice .................................................................................................................................... 22

Curators ................................................................................................................................. 22Consultants and contractors .................................................................................................. 23Other archaeological interests ............................................................................................... 23

4.2 Information ............................................................................................................................. 25Information provided by developers ...................................................................................... 25Information from other sources .............................................................................................. 26

5 Environmental Impact Assessment ........................................................................................... 27

6 Scoping and Archaeological Appraisal ...................................................................................... 31

7 Baseline Studies .......................................................................................................................... 33

8 Acquiring, Processing and Interpreting Marine Geophysical and Geotechnical Data ........... 368.1 Overview ................................................................................................................................ 368.2 Surveying wrecks and debris ................................................................................................. 368.3 Surveying seabed prehistory .................................................................................................. 378.4 Survey design ........................................................................................................................ 38

Contents

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9 Identifying Impacts and Assessing Effects ............................................................................... 41

10 Forms of Mitigation ..................................................................................................................... 4310.1 Overview ............................................................................................................................... 4310.2 Prevention or avoidance ........................................................................................................ 4310.3 Reduction .............................................................................................................................. 4410.4 Remedying or offsetting ........................................................................................................ 45

11 Frameworks for Mitigation ......................................................................................................... 4511.1 Conditions of consent ........................................................................................................... 4511.2 Written Schemes of Investigation .......................................................................................... 4511.3 Protocols for Unexpected Discoveries .................................................................................. 46

12 Monitoring .................................................................................................................................... 47

Further Reading.................................................................................................................................. 48

Glossary ............................................................................................................................................. 51

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Wessex Archaeology Ltd was commissioned byCOWRIE Ltd. to produce a generic guidancenote on the survey, appraisal and monitoring ofthe historic environment during the developmentof offshore renewable energy projects in theUnited Kingdom. The guidance is applicable tothe marine environment, which comprises theUK Territorial Seas and Renewable Energy Zone(the area adjacent to the territorial waters withinwhich renewable energy schemes can beinstalled). It also applies to the coastalenvironment adjacent to any development,encompassing the inter-tidal area, coastalmargin and those areas further inland likely to beaffected by offshore renewable energydevelopments.

The guidance note incorporates the results of adesk-based review of existing guidance andother sources of information relating to thesurvey, assessment and monitoring of thehistoric environment during offshoredevelopment. It builds upon similar guidancedeveloped for the marine aggregates industry(BMAPA/English Heritage, April 2003).

The guidance note is intended to promote thedevelopment of best practice in relation to themarine historic environment for the offshorerenewable energy sector. It is also intended topromote an understanding of the conservationissues arising from the impacts of offshorerenewable energy projects on the historicenvironment, and in this way develop capacityamongst developers, consultants and contractors.

The guidance note is aimed at all:• the offshore renewable energy sector;• environmental consultants involved in

offshore renewable energy development;• archaeological consultants and contractors

involved in offshore renewable energydevelopment;

• regulatory authorities and bodies;• national and local curators; and• the wider public.

Wessex Archaeology Ltd has attempted tostructure the document in a manner whichprovides a logical narrative, and which reflectsthe stages at which archaeologicalconsiderations have to be addressed.

References to other sources of information areincluded in the text where applicable, and anextensive list of further reading and keydocuments is included at the end of the document.

The importance of the historicenvironment

The United Kingdom has been inhabited atvarious times during the last 700,000 years bymodern humans and their predecessors. Theevidence of this inhabitation forms a rich anddiverse national asset that is often described asthe historic environment.

The attractive natural resources to be foundalong waterways and around the coast meantthat much past human activity was centred onthese areas of the landscape through seafaringand other maritime activities, or by living at andusing the coast. In addition, lower sea levelsrelating to glacial periods resulted in theexposure of areas of the seabed, creatinghabitats that were exploited by humans.Potentially rich deposits of prehistoricarchaeological and palaeoenvironmental materialcan therefore be expected on and beneath theseabed and coastal margins of the UK.

The importance and potential of the UK’smarine historic environment, as part of the widerhistoric environment, is clearly understood, as isthe need to protect it. However, the content,area by area, of marine historic environment ofthe UK is often largely unknown and as yetpoorly documented, and the need for primarysurvey and research is widely accepted.

Fundamental principles applicable toarchaeological sites and remains

The artefacts, sites and deposits that make upthe marine and coastal historic environment arefragile and non-renewable, and to ensure theirconservation a number of general principles areapplicable to these sites and materials. These are:• The use of the precautionary principle, the

aim of which is to prevent damage to sitesand material by proactively putting in placeprotective measures, rather than having toattempt to repair damage after it has occurred.

• The assumption that archaeological sitesshould be subject to as little disturbance as

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possible, and should preferably, bepreserved in situ.

• The requirement, where preservation in situ isnot practicable or reasonable, for disturbanceto be offset by appropriate and satisfactoryprovisions to mitigate the effects of disturbance.

• The requirement to create and deposit anaccessible archive of the results of allarchaeological investigations to ensure the‘preservation by record’ of this non-renewable resource.

Range and types of site

In terms of the range of site types that are likelyto be affected by offshore renewable energydevelopments, shipwrecks enjoy perhaps thehighest public profile. Watercrafts haveprobably been used in UK waters since theMesolithic period and records exist for morethan 30,000 maritime casualties in UK waters.

Other evidence of millennia of human coastal andmaritime activity includes fish traps, salt-makingsites, the remains of inundated or erodedsettlements, reclamation and flood defence works,military infrastructure, wharves and hards,shipbuilding sites, and navigational features.

Prehistoric material can be found re-depositedin sands, gravels and other sediments laid downby former rivers as well as in situ on former landsurfaces and within fine-grained and peatydeposits.

Impacts and effects upon the historicenvironment

The impacts of offshore renewable energyschemes on the historic environment arise fromthe construction of foundations for turbines andother infrastructure, and from laying power andcontrol cables. Primary impacts include cableploughing, piling and excavation, whilstconstruction vessels may have secondaryimpacts when jacking-up or anchoring.

Similar impacts can be expected closer to shoreand within the inter-tidal zone where the sitesand materials comprising the historicenvironment are likely to be particularly denseand complicated. On coastal land, activitiesassociated with cable laying and with the

construction of shore-side infrastructure arelikely to be the principal causes of impact.

The clearest effects of offshore renewableenergy developments are those that are direct,where the primary footprint of a developmentimpact coincides wholly or partly with thefootprint of an archaeological site or deposit.Indirect effects may arise where the directimpact has effects beyond its primary footprint,implicating archaeological sites or deposits thatlie some distance away. Cumulative effects areindividually minor but collectively significantincremental changes or effects that result froma scheme in combination with otherdevelopments and activities in the same areaand are likely to manifest themselves in themedium or long-term.

The non-renewable character of the historicenvironment is such that physical impacts andtheir effects are usually permanent andnegative, especially in respect of physicalremains in their original context. Positive effectsmay be identified if a scheme can consolidateor safeguard sites that would otherwise havebeen disturbed. Excavation, recording,conservation of artefacts and structures, andthe deposition of a publicly-accessible archivemay also be seen as positive outcomes, butthey have to be gauged against the underlyingprinciple that preservation in situ is preferable.Analysis, publication and other forms ofdissemination to scholarly and more generalaudiences can be seen as positive effectsbecause they create new knowledge andawareness that can help to offset physicaldestruction. The effects of a scheme upon thehistoric environment must be considered in theenvironmental impact assessment and planningof the scheme, and measures put in place tomitigate adverse effects.

Landscapes, seascapes and ‘setting’

It is increasingly recognised that the entire formof our present environment, even featureswhose main processes are entirely natural, hasbeen structured by human actions andperceptions. The concepts of ‘setting’,‘landscape’ and ‘seascape’ are becomingincreasingly important considerations inaddressing the effects of schemes on the

Historic Environment Guidance for the Offshore Renewable Energy Sector

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terrestrial and marine historic environments, andtheir application is being developed as part ofthe assessment process throughout the UK.

Archaeology and the developmentprocess

The historic environment is best dealt withthrough a process which is most effective whenit is woven through the other strands of anyscheme or development. The process-basedcharacter of development-led archaeology hasbecome recognised in the following series ofwell-established stages:• archaeological appraisal;• desk-based assessment;• archaeological field evaluation;• mitigation;• monitoring;• post-fieldwork assessment;• analysis;• publication and dissemination;• archive preparation and deposition.

The relation between the stages of thearchaeological process and the stages ofdevelopment can vary according to thedevelopment and the scope of eacharchaeological stage.

It has become clear to archaeologists anddevelopers alike that consideration of thehistoric environment should start early in thedevelopment process and be maintainedthroughout. The early advice of national andlocal curators will be important in establishingthe content and timing of these stages.

Adherence by developers to archaeologicalprocesses will help to identify, quantify andavoid risks to the scheme arising from thehistoric environment.

Sources of archaeological advice andinformation

There is a wide variety of sources ofarchaeological advice and information availableto offshore renewable energy developers.

The regulatory authorities that decide whetherconsent is to be granted are advised, in respectof the historic environment, by national

archaeological curators and by archaeologicalcurators in local authorities.

The curators are a key source of advice fordevelopers in respect of the marine elements ofeach scheme and it is strongly advised thatdevelopers consult the relevant curators asearly in any project as possible, preferably notlater than the scoping phase, and maintainregular communication with the curatorthereafter. Within the EIA process, curatorialauthorities will also provide developers withscoping advice where requested, and willengage in subsequent discussions about theconduct of EIA, the results of investigations, andthe appropriateness of possible mitigationmeasures.

Archaeological curators will not carry out any ofthe archaeological studies or investigations thatcontribute to EIA. The developer will beresponsible for carrying out such studies,usually by commissioning an archaeologicalcontractor or consultant. Developers shouldensure that the archaeological consultants/contractors they use have skills and knowledgeappropriate to advising on offshore renewableenergy schemes.

A range of primary and secondary sources ofinformation about the historic environment isavailable from sources such as the NationalMonuments Record, local authority HistoricEnvironment Records, the UK HydrographicOffice, the Receiver of Wreck, and national andlocal museums.

Developers themselves hold important primarydata about the historic environment in the formof the geophysical and geotechnical data theyacquire as part of the engineering and EIA process.

Other sources of information are available anddevelopers should be guided in this regard bythe archaeological consultant/contractor.

EIAEnvironmental Impact Assessment (EIA)requires consideration of the historicenvironment. Consequently, decisions regardingconsent, and any conditions that are to beattached to such consent, can be expected totake account of any likely significant effects on

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the historic environment identified by EIA,including the mitigation that is proposed.

The detail of the regulatory route being taken inrespect of an offshore renewable energyscheme will be important in identifying therelevant archaeological curators. It is especiallyimportant to note that a combination of bothnational and local curators is likely to becomeinvolved, each with their own remits. Moreover,multiple national and local curators might beinvolved because schemes traverse territorialboundaries, because of regional arrangements,and because of thematic specialisms (e.g. builthistoric environment, terrestrial archaeology,maritime archaeology).

The detail of the consent processes is also likelyto be important in correlating relevant guidanceand policies in respect of the historicenvironment, and in identifying possiblestakeholders and consultees. An understandingof the specific remits of archaeological curatorsmay also help in structuring historic environmentelements of the Environmental Statement, sothat aspects of the baseline, assessment ofeffects and proposed mitigation reflect theirparticular involvement.

The refinement of, or changes to scheme detailswill affect their archaeological assessment asmuch as any other study, so it is essential thatdevelopers keep their archaeologicalconsultants/contractors appraised of changes ina timely fashion.

Early integration of archaeologists within thedevelopment team will help to identify theadded value that can be achieved in respect ofthe historic environment through reference toother studies being carried out as part of theEIA process.

There are a number of options for incorporatingthe historic environment within the Environ-mental Statement, and this should be viewed asan important consideration in designing the EIA.The conduct of EIA will probably be speedier if,at the outset, the developer, the consultantspreparing the ES and any specialist archaeo-logical consultants have a clear understanding ofthe structure that the ES is to take.

Several commentaries have noted that it isessential that the methodology used in variouselements of the EIA process is made explicit,including the use of terminology. Clearexpositions of the methodologies that areadopted for gauging the magnitude of impactson the historic environment, importance ofarchaeological receptors, significance of effectsand so on are likely to be a key factor inachieving an adequate EIA.

Scoping

Developers of offshore renewable energyschemes should anticipate that the historicenvironment is likely to be identified as a keyissue by the scoping exercise, although thedetail will depend on the nature of the project,its location and its environment.

Although archaeological appraisal by thecurators is likely to be prompted by the scopingreport, there is nothing to stop developers fromcontacting curators pre-scoping for informaladvice.

Whether an archaeological contractor/consultant is employed at the scoping stage orsubsequently, the developer and theirenvironmental and engineering team shouldestablish at an early stage the expected scopeof communication between their archaeologicalcontractor/consultant and the archaeologicalcurators.

The scoping phase also represents anopportunity for developers to integrate theirarchaeological contractor/consultant within theiroverall environmental and engineering team.

Baseline studies

The coarse nature of much of the informationrelating to the marine historic environment oftenmakes it appropriate to define relatively broadStudy Areas for the baseline study.

Where available, reference should be made toStrategic Environmental Assessments, marineHistoric Landscape Characterisation or otherregional overviews, rather than seeking to writethe entire history of a sea area.


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The baseline study should identify all the knownelements of the historic environment that maybe impacted by the scheme, the most obviousof which are likely to be the sites that aresubject to statutory or planning designation, orother forms of quasi-legal registration, includingProtected Wrecks, Scheduled Monuments,Listed Buildings, Conservation Areas and so on.There are also likely to be a considerablenumber of other wrecks, monuments andfindspots whose locations are known more orless precisely.

Beyond this ‘known’ archaeological heritage,the marine and coastal historic environment ischaracterised by a far wider ‘potential’ heritage.This is taken to mean features and sites that arelikely to be present, but which have not yet beenfound, and which will be as susceptible tosignificant effects as the ‘known’ heritage.Potential sites will encompass the full range ofperiods and site types, from wrecks to coastalstructures to submerged prehistoric sites.Geophysical and geotechnical surveys can playa large part in reducing potential by establishingthe actual presence or absence of sites withinan area, and by refining the extent of further‘potential’.

Importance

Baseline studies will have to ascribe importanceto both the ‘known’ and ‘potential’archaeological heritage as a basis for thesubsequent assessment of significant effects.Even where elements of the historicenvironment are ‘known’ it can be difficult toascribe importance, partly because thecharacter of a ‘known’ feature will often beobscured because it is buried, and partlybecause the archaeological importance of anyfeature is rooted in the intellectual enquiries ofthe discipline. For many archaeological sites,their importance will depend on what is broughtto them by investigation.

There are a number of schemas available forascribing importance to archaeological sites,and baseline studies should be transparent andconsistent in bringing these to bear. It should benoted that references to different forms ofdesignation as a proxy for importance, as is

common in respect of species and habitats, willnot suffice in an archaeological context.

Survey design

Geophysical and geotechnical data gathered foroffshore renewable energy schemes as part ofthe design process or to inform EIA topics suchas seabed ecology are very important toassessing the effects of offshore renewableenergy schemes on the historic environment.

To enable these surveys to provide data thatsupports historic environment analysis, it isimportant that archaeological objectives are anintegrated component of planning geophysicaland geotechnical surveys from the outset. Earlyconsultation between the developer andarchaeological curators, preferably including thedeveloper’s archaeological consultant/contractor and geophysical or geotechnicalcontractor, is therefore essential.

Ideally, geophysical and geotechnical surveysshould be informed by prior desk-based studies,which should have identified known features andkey deposits that can then be targeted. Equally,the overall historic environment baseline shouldincorporate the results of geophysical andgeotechnical surveys, so the subsequentassessment is based as firmly as possible ondata relating to the site, rather than on broadergeneralisations from existing records andsecondary sources.

Surveys should be carried out to a single datumand co-ordinate system. All survey data,including navigation, should be acquireddigitally in industry-standard formats. Careshould be taken to maintain the orientation andattitude of sensors on line. Trackplots should becorrected for layback and made available indigital (GIS) form.

Geophysical and geotechnical data

Sidescan sonar survey should be carried out atfrequency, range and gain settings capable ofresolving all objects that have a relief of morethan 0.5m above the seabed throughout thesurvey area.

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For archaeological purposes, true sidescan ispreferable to multibeam pseudo-sidescan.Sidescan sonar data should be made availablein the form of raw, un-mosaiced files in asuitable proprietary format.

Magnetometer survey should be carried outusing a caesium gas or equivalent systemcapable of resolving anomalies of 5 nanoTeslasand above.

Multibeam survey should be carried out using asystem capable of achieving an effective cell/bin size better than 1m. Use of a beam-formingsystem is preferred.

Sub-bottom (shallow seismic) survey is likely tobe the most productive tool in seeking tounderstand the prehistory of the seabed, as itcan show the deposits, cuts and surfaces of theprevious architecture of the land, and of thesequences through which it changed. Surveyline and cross-line spacings and orientationsshould be sufficient to resolve the extents andcharacteristics of the principal Quaternarydeposits.

Ideally, shallow seismic survey should besupported by borehole or vibrocore surveys, toconfirm the sediments that have given rise tothe acoustic reflections seen using geophysics.Archaeological interest in boreholes andvibrocores will be confined to Quaternarydeposits, especially fine-grained materialindicative of low energy deposition, and peatyhorizons indicative of vegetated land surfaces.

Sediment horizons that have been identified asbeing of archaeological interest on the basis ofgeophysical data and/or geotechnicalengineering logs should be targeted by thearchaeological assessment of borehole andcore samples, or by the recovery of furtherborehole or vibrocores.

Assessing effects

The coincidence of development activities andthe known and potential archaeological heritagecan be established by mapping the footprint ofthe scheme onto the results of the baselinestudy. The assessment of the significance of theresultant effects will usually be carried out by

correlating impacts upon receptors with theimportance of the receptor.

Classifications of importance, impact and thesignificance of effect, combined within a matrixoffer a transparent methodology, and may alsoenable cross-correlation with effects arisingfrom other environmental topics. However,many such schemes have been designed fordealing primarily with other environmentaltopics and their application to the historicenvironment may be inappropriate. Morequalitative, textual descriptions of effects maybe more sympathetic to the characteristics ofthe historic environment and to the currentstate of knowledge and understanding, andwill result in an assessment that is moreadequate overall.

Where effects are assessed, it should be madeclear whether the assessment is withoutmitigation, or whether it assumes theimplementation of the mitigation proposed inthe Environmental Statement (ES).

EIA should identify beneficial effects as well asadverse effects. For the historic environment,beneficial effects such as improved access orthe contribution to new knowledge that arisesfrom investigation are likely to depend on theimplementation of mitigation measures. Asabove, beneficial effects that have beendesigned-in to the scheme can be highlighted,but beneficial effects that are subject tounconfirmed measures should be dealt withmore cautiously.

Gaps in data or methodology should behighlighted where uncertainty remains aboutknown or potential sites, about importance,about impacts, or about effects.

Mitigation

Mitigation can take place at various stagesduring the project life and for each scheme willbe based primarily on the measures proposed inthe EIA. Some mitigation may be implementedpre-submission or pre-consent. There may be arequirement to implement mitigation measures,such as exclusion zones around archaeologicalsites and features, during the project designstage. Other measures may be required during


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the construction, operation anddecommissioning of a scheme.

Mitigation measures applicable toarchaeological sites generally take three forms:• prevention or avoidance;• reduction;• remedying or offsetting.

Government policy and international bestpractice favour the preservation in situ ofnationally important archaeological remains.Preservation in situ also has a practicaladvantage to offshore renewable energydevelopments in that it reduces the risk to thedeveloper of having to support site excavationand removal, and the subsequent stages ofinvestigation (e.g. post-fieldwork assessmentand publications).

The avoidance of known sites can be achievedthrough the implementation of archaeologicalexclusion zones, which preclude development-related activities within their extents, aroundeither discrete sites or more extensive areasidentified in the EIA.

Although the details of mitigation measures willdiffer from scheme to scheme, two generalmeasures are likely to be encountered amongconsent conditions. These are the production of:• a Written Scheme of Investigation (WSI);• a Protocol for Unexpected Discoveries.

The WSI is a document which sets out when,how and why archaeological mitigationmeasures recommended in the ES are to beimplemented for any given scheme. It is an

overall framework for archaeological mitigationand/or monitoring during the construction,operation and decommissioning of the scheme.

Unexpected archaeological material or sites maybe encountered during works associated withconstruction, operation or decommissioning.The Protocol for Unexpected Discoveries is aformal mechanism for intercepting and reportingsuch accidental discoveries and aims to reduceany adverse effects of the development uponthe marine historic environment by enabling therapid, convenient and effective reporting ofdiscoveries or recovered material by scheme staff.

Monitoring

The provision made by a developer forimplementing mitigation measures will need toinclude measures to ensure that theimplementation is effective.

A programme of monitoring is likely to beincluded in the WSI, and may include periodicreporting on adherence to exclusion zones andthe results of watching briefs. Measures shouldalso be put in place to establish whetherindirect, secondary and cumulative impactsoccur, and are mitigated, as predicted.

For monitoring to have any value in mitigatingsignificant effects it will have to beaccompanied by a scheme of adaptivemanagement. Mechanisms must be put in placeto allow the results of monitoring programmesto inform subsequent development activitiesthroughout the construction, operation anddecommissioning of the scheme.

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This report was commissioned by COWRIE Ltd.Wessex Archaeology Ltd would like to thankDr Carolyn Heeps of The Crown Estate, SarahFowler and Chloe Delgery of NaturebureauInternational, and Dr Chris Pater of EnglishHeritage for their co-operation and supportduring the compilation of this guidance note.

Wessex Archaeology Ltd would also like tothank all those who provided comment and

Acknowledgements

feedback on the various drafts of the document,and whose input has contributed substantiallyto the final form and content of the guidance.

John Gribble and Dr Antony Firth of WessexArchaeology Ltd compiled this document andKaren Nichols prepared the illustrations. Theproject was managed for Wessex ArchaeologyLtd by John Gribble.

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1.1 Background

1.1.1 In recent decades the exploitation of themarine environment of the United Kingdom (UK),particularly seabed resources, has grownrapidly with the development of the offshorehydrocarbon and aggregate extractionindustries. Most recently, as part of theGovernment’s commitment to meetingrenewable energy targets, the development ofoffshore renewable energy schemes hasadded a new dimension to the use of theseabed of the UK.

1.1.2 Seabed developments of any sort havethe potential to have significant effects on thearchaeological sites and materials that make upthe historic environment. The coast and seabedof the UK are particularly rich in archaeologicalsites and materials, which need to beconsidered during the course of any seabeddevelopment.

1.1.3 As part of its work to raise awareness andunderstanding of the potential environmentalimpacts of the UK offshore renewable energyprogramme COWRIE has commissioned thisHistoric Environment Guidance. The aim of thedocument is to provide archaeological adviceand guidance to current and prospectiveoffshore renewable energy sector developers,thereby promoting best practice and theprotection of the marine historic environment.

1.1.4 It is also worth noting that a valuablecontribution to the understanding of the marineand coastal historic environment is made byoffshore renewable energy developers as aresult of seabed surveys and other datagenerated during the course of development.

1.1.5 This guidance document has beenprepared on behalf of COWRIE and should beread in conjunction with the other sources ofinformation to which it refers. The advicepresented here reflects current knowledge andunderstanding, both of which are undergoingrapid change in relation to the marine historicenvironment. Also subject to change is thelegislative situation, due to reviews of bothheritage protection, and the framework ofmarine management.

1.2 The importance of themarine historic environment

1.2.1 For more than 700,000 years the UnitedKingdom has been inhabited at various times bymodern humans and their predecessors. Theevidence of this inhabitation is a rich anddiverse national asset that is often described asthe historic environment, which includes:• Direct physical traces of human activity,

including human remains and artefacts,activity sites, structures and buildings, theremains of ships and aircraft, and their setting.

THE MARINE BILL AND THE HISTORIC ENVIRONMENT

The Government is committed to drafting a Marine Bill to provide a new legislativeframework for the seas that will balance conservation, energy and environment needs.The key elements of a Marine Bill are expected to include a system of Marine SpatialPlanning, a reformed system for licensing marine activities, improvements to marinenature conservation (including Marine Protected Areas), and the possible formation of aMarine Management Organisation. All of these elements are likely to include new orrevised provision for the marine historic environment. The Marine Bill will have theprinciples of sustainable development at its core, and contribute to the Government’sstrategic goals for the marine environment, which include increasing ‘understanding ofthe marine environment, its natural processes and our cultural marine heritage and theimpact that human activities have upon them’ (Defra, 2006).

HERITAGE REVIEW

The Government is currently conducting a review of marine heritage protection, which islikely to propose changes to the law in respect of matters such as statutory site protectionand the reporting of discoveries. A White Paper that includes a chapter on UK marineheritage is expected in Spring 2007.

11111 Introduction

2

• Former land surfaces, deposits and featuresfrom which evidence of previous humanenvironments can be interpreted.

• Landscapes and seascapes whose form andmeaning have been shaped by humanactivity.

1.2.2 Archaeological material from before thelast ice age (known as the Devensian GlacialMaximum) occurs in many parts of the UK andcan reveal details of human evolution and socialdevelopment. Stone tools, butchered animalbone, and associated deposits can be foundwhich date to the following periods:• Lower Palaeolithic (>700,000 to 245,000

Before Present (BP))• Middle Palaeolithic (245,000 to 50,000 BP)• Early Upper Palaeolithic (50,000 to 18,000 BP).

1.2.3 After the retreat of the Devensian icesheet, which started about 18,000 years ago,the UK was re-inhabited by Late UpperPalaeolithic (12,500 to 10,000 BC), Mesolithic(10,000 to 4,000 BC) and later prehistoricpeoples. Since then, there has been a constanthuman use of the land and the sea, through tothe present day.

1.2.4 As huge quantities of water were taken upin ice sheets by a succession of glaciationsduring the last 700,000 years, large areas ofwhat is now seabed were exposed as dry land.This provided inhabitable land surfaces thatwere exploited and utilised by humans. Duringinterglacial periods, and particularly after theend of the last ice age, these landscapes andthe archaeological evidence they containedwere inundated as the sea level rose. Lying onand beneath the seabed of the UK, therefore,are potentially rich deposits of prehistoricarchaeological and palaeoenvironmentalmaterial.

1.2.5 The attractive natural resources foundalong waterways and the coast meant thatmuch early human activity was centred on theseareas of the landscape. As early as 7,500 BC,simple watercraft were being used in andaround the UK. The rise in sea level saw theterrestrial link with mainland Europe severedapproximately 8,000 BC and since thenmaritime transport has played a central role inthe history and development of the UK.Millennia of seafaring has resulted in vastnumbers of shipwrecks in UK waters, the study

Figure 1. Lower, Middle and Early Upper Palaeolithic timelines

For hundreds of thousands of years, much of the seabed around the UK would have formed inhabitable land that wouldonly have been inundated at the peaks of interglacial warm stages. Throughout this time, the principal evidence ofhuman activity is flint hand axes and flakes, which have usually been re-deposited within former river sediments.Recent discoveries are, however, pointing to the continued survival of in situ activity sites at the present coast andoffshore, complete with butchered bone and a range of palaeo-environmental evidence.


3

Figure 2. Late Upper Palaeolithic, Late GlacialMesolithic and Neolithic timelines

After the last (Devensian) glacial maximum, the climatewarmed and sea-levels rose swiftly. Sea-level was stillabout 50m lower than today when the UK started to be re-occupied, meaning that the key cultural developments ofour predecessors would have taken place on land that isnow submerged (curve from Streif, 2004).

Figure 3. Maritime timeline

Although there are very numerous records of ships sunk in the 19th and 20th centuries, the remains of boats and shipsdating back to at least the Bronze Age have been found around the coast of the UK.

of which can provide fascinating insights intotrade, communication, combat, technology,industry, economics, and many other aspects oflife and society from the Mesolithic to moderntimes. In the 20th century, the wrecks of morethan a thousand aircraft have added to themarine historic environment.

1.2.6 It is true to say that the marine historicenvironment of the UK is still largely unknownand as yet poorly documented, and the need forfundamental survey and research is widelyaccepted. However, the importance and potentialof the marine historic environment, as part ofthe wider historic environment is clearly under-stood, as is the need to protect it as part of theUK’s rich cultural and archaeological heritage.

Introduction

4

Figure 4. Coastal timeline

A very wide range of artefacts and sites are to be found at the coast, often in very close proximity to each other. Animalbone, flint and metal tools, pottery might be just stray losses, or they might point to the presence of denser activity. Thewaterlogged conditions often found at the coast can lead to the survival of ancient timber structures such as fish traps,trackways and ‘Seahenge’. Palaeo-environmental evidence can survive also, including submerged forests, peaty formerlandsurfaces, and even human footprints. In more recent times, coastal sites include hulked and wrecked ships, militaryinstallations and crashed aircraft.

INSTITUTE OF FIELD ARCHAEOLOGISTS –ARCHAEOLOGICAL PRINCIPLES

The Institute of Field Archaeologists (IFA) is the professionalorganisation representing archaeologists and others involved inprotecting and understanding the historic environment in the UK.In view of the fact that the archaeological heritage of the UK is a‘finite, vulnerable and diminishing resource’ the IFA has adopted aCode of Conduct which sets out professional and ethical standardsexpected of members.

The fundamental principles of the Code applicable to archaeologicalinvolvement in offshore renewable energy development are asfollows:

• The archaeologist shall adhere to the highest standards ofethical and responsible behaviour in the conduct ofarchaeological affairs.

• The archaeologist has a responsibility for the conservation ofthe archaeological heritage.

• The archaeologist shall conduct his/her work in such a waythat reliable information about the past may be acquired, andshall ensure that the results be properly recorded.

• The archaeologist has responsibility for making available theresults of archaeological work with reasonable dispatch.

Further information regarding the IFA, and the full text of the Codeof Conduct is available at: http://www.archaeologists.net/modules/icontent/


http://www.archaeologists.net/modules/icontent

5

UNITED NATIONS CONVENTION ON THE LAW OF THE SEA (1982)

Article 303 of the United Nations Convention on the Law of the Sea refers to archaeological and historical objects found at seaand places a duty on signatory States to protect this material.

The full text of UNCLOS is available at:

http://www.un.org/Depts/los/convention_agreements/texts/unclos/UNCLOS-TOC.htm

UNESCO CONVENTION ON THE PROTECTION OF THE UNDERWATER CULTURAL HERITAGE (2001)

The UNESCO Convention on the Protection of the Underwater Cultural Heritage created an international legal framework toregulate underwater cultural heritage in domestic and international waters. The Convention also provides that States Party shalluse the best practicable means to prevent or mitigate any adverse effects that might arise from activities under its jurisdictionincidentally affecting underwater cultural heritage. ‘Activities incidentally affecting underwater cultural heritage’ means activitieswhich are not directed at underwater cultural heritage but may physically disturb or otherwise damage underwater culturalheritage nonetheless.

The Annex to the Convention reflects the ICOMOS Charter (see below), setting out rules and standards for conducting marinearchaeological investigations.

The Convention has not been signed by the UK, but the UK has signalled its support for many of the principles set out in theConvention, including the rules set out in the Annex.

The full text of the Convention is available at: http://www.unesco.org/culture/laws/underwater/html_eng/conven2.shtml

THE ICOMOS CHARTER (1996)

The ICOMOS Charter on the Protection and Management of Underwater Cultural Heritage aims to encourage the protection andmanagement of underwater cultural heritage in inland and inshore waters, in shallow seas and in the deep oceans and is aresponse to the peculiar attributes and circumstances of underwater cultural heritage.

The Charter attempts to provide decision-makers, such as curators, and archaeologists with criteria for assessing and managingmarine archaeological projects, and is important as a statement of international best practice with regard to the investigation ofunderwater cultural heritage.

The full text of the Charter is available at: http://www.international.icomos.org/under_e.htm

1.3 Archaeological principles

1.3.1 The artefacts, sites and deposits thatmake up the marine and coastal historicenvironment are fragile and non-renewable. Forthe whole of prehistory, archaeological materialis the only record of human activity on andaround these islands. Even in periods for whichwe have documents, maps and photographs,there is no substitute for the actual physicalremains of human action.

1.3.2 Care and attention in the managementand protection of the historic environment isessential. This generation is answerable not onlyto the present, but will also be held to accountby future generations for how it manages andprotects this heritage. To ensure theconservation of the marine and coastal historicenvironment a number of general principles areapplied by archaeologists whether they areacting as curator, consultant or contractor.

1.3.3 The archaeological principles that animatecurrent UK practice have developed over manyyears, arising partly from the historicaldevelopment of archaeology itself, and partlyfrom developments in the environmental andconservation sciences of which archaeology ispart. These principles enjoy wide currency, andfind particular expression in several internationallegal frameworks applicable to archaeologygenerally, and marine archaeology in particular.The guidance provided in this document seeksto give practical effect to these principles indeveloping offshore renewable energy schemes.

The precautionary principle

1.3.4 The precautionary principle is one of thekey principles shared by the historicenvironment and other environmental concerns.The principle is highlighted by the UKGovernment as a mechanism for achievingsustainable development in its strategydocument, Securing the Future (2005).

Introduction

http://www.un.org/Depts/los/convention_agreements/texts/unclos/UNCLOS-TOC.htm

http://www.unesco.org/culture/laws/underwater/html_eng/conven2.shtml

http://www.international.icomos.org/under_e.htm

6

Figure 5. Key principles

Archaeology combines the pursuit of knowledge with the conservation of physical evidence, all within a public arena.This has given rise to a series of key principles that inform archaeology in the development process.


In Situ preservation

1.3.7 As a general rule, archaeological sitesshould be subject to as little disturbance aspossible, and should ideally be preserved.Government policy (Securing the Future (2005)and PPG 16) sets out a presumption in favour ofthe preservation in situ of nationally importantarchaeological remains. The same principle iscentral to a number of internationalarchaeological conventions such as the VallettaConvention (see text box). Avoidance of sitesand material should therefore be the preferredmeans of mitigation in offshore developmentcontexts.

1.3.8 Where preservation in situ is notpracticable it is an accepted principle of nationaland international policy that disturbance ofarchaeological sites or material should be offsetby appropriate and satisfactory provision tomitigate the effects of disturbance. Thispractice, sometimes referred to as ‘preservationby record’ often comprises excavation,recording, recovery of artefacts, structures andor samples, and analysis. Such work also entailsarchiving and publication (see below).

1.3.5 In relation to the historic environment, theapplication of this principle by the offshorerenewable energy sector will result indevelopment activities being planned andimplemented on the basis of the carefulevaluation of available evidence regarding thehistoric environment, whilst acknowledgingareas of uncertainty and being responsive toincreased knowledge about the historicenvironment. The precautionary principle shouldbe applied when, on the basis of the evidenceavailable at the time of decision-making:• there is good reason to believe that the

historic environment may be subject toharmful effects; and

• the level of scientific uncertainty about theconsequences or likelihood of these effects issuch that risk cannot be assessed withsufficient confidence to inform decision-making.

1.3.6 The aim of the application of theprecautionary principle is the prevention ofdamage to the environment by proactivelyputting in place protective measures, rather thanhaving to attempt to repair damage (which maybe irreversible) after it has occurred.

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THE VALLETTA CONVENTION (1992)

The European Convention on the Protection of the ArchaeologicalHeritage was signed at Valletta in 1992. It was ratified by the UKGovernment in 2000 and came into force in 2001.

The Convention contains provisions, amongst others for theidentification, protection and integrated conservation ofarchaeological heritage, whether situated on land or under water,and promotes high standards for all archaeological work.

The Convention makes the conservation and enhancement of thearchaeological heritage one of the goals for planning policies forsignatories, and sets guidelines for the funding of archaeologicalwork and the dissemination of the results of this work.

The provisions of the Convention reflect current practice in the UKwith regard to the protection and recording of archaeology duringdevelopment. In particular, Articles 5 and 6 contain provisionsapplicable to the funding of development-led archaeology – theconcept of ‘user pays’ – whilst Articles 7 and 8 deal with thecollection and dissemination of information generated byarchaeological work.

The full text of the convention is available at:

http://www.coe.int/t/e/cultural_co-operation/heritage/archaeology/2Convention.asp

Introduction

‘Polluter pays’ and developer-funding

1.3.9 The ‘Polluter pays’ principle is thepremise that whoever causes pollution orenvironmental damage should be responsiblefor making good the damage. In archaeology,the principle takes effect through developer-funding, whereby archaeological investigationsthat are instigated by schemes proposed by adeveloper are funded by that developer.Developer-funding encompasses all aspects ofinvestigation and its consequences, includinganalysis, conservation, archiving andpublication.

Archives and publication

1.3.10 As archaeological sites and materials arenon-renewable and all intrusive archaeologicalinvestigations are essentially destructive,‘preservation by record’ is only effective if theresulting record is returned to the public arenaby dissemination. The responsibility todisseminate archaeological results arises directlyfrom involvement in the investigative process.

1.3.11 Archives are generally understood tocomprise the entire archaeological recordresulting from investigation. This includes thematerial archive of finds and objects, and allassociated documents and survey data,whether written, drawn or photographic, in hardcopies or in electronic format.

1.3.12 Dissemination is understood to includethe deposition of an archive of the results of theassessment, evaluation, mitigation and/ormonitoring works, prepared according to currentprofessional standards and deposited with aregistered museum. It is only through such practicethat the destructive effects of development, andof investigations prompted by development, canbe considered to have been mitigated.

1.3.13 In addition, there is a responsibility toensure that where the results of any work areconsidered to be substantial contributions toarchaeological knowledge, theory, method ortechnique that these are disseminated throughpublication. Publication ensures that informationand results are made available to a wideaudience, both professionally and among thegeneral public.

http://www.coe.int/t/e/cultural_co-operation/heritage/

8

1.3.14 It is important that developers recognisefrom the outset that they will be responsible forcreating and depositing an archive of the resultsof archaeological investigations that stem fromtheir development, and that they will also haveto provide for publication of significantdiscoveries or investigations. Even where nodamage has been incurred, there is likely to bean extensive archive arising from thearchaeological assessment of developmentproposals, including geophysical andgeotechnical data and the results of desk-basedstudies. Arrangements for the deposition of thearchive – including material, digital and hardcopy elements – should be made with anappropriate repository at an early stage.


Public interest

1.3.15 The historic environment is the culturalpatrimony of the people of the UK. As such,seabed developers have a responsibility toensure that their activities do not undulydamage or compromise this national asset. Thepublic interest is also protected by transparencyin the development process and engagementwith the public during the consent process, andsubsequently by adding archaeological resultsto national and local records.

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2 Possible Effects of Offshore Renewable EnergyDevelopment on the Marine and Coastal HistoricEnvironments

2.1 Overview

2.1.1 The clearest effects of offshore renewableenergy developments are those that are direct,where the primary footprint of a developmentimpact coincides wholly or partly with thefootprint of an archaeological site or deposit.The direct impacts related to the construction,operation and decommissioning of offshorerenewable energy schemes can thereforeinclude:• Direct damage to structures, features,

deposits and artefacts.• The disturbance or destruction of

relationships between structures, features,deposits and artefacts, and their widersurroundings.

2.1.2 Indirect effects may arise where the directimpact has effects beyond its primary footprint,implicating archaeological sites or deposits thatlie some distance away. In the marine andcoastal environment, water quality, currents andsediment transport may transmit the effects of adevelopment to elements of the historicenvironment lying a considerable distance fromthe immediate footprint of the scheme. Seabedscour around foundations or cables, changes tolocal current patterns, or changes to sedimentmovement may have impacts beyond theimmediate area of the construction activities.While these effects are harder to predict thandirect impacts, it should be possible to identifythem during the Environmental ImpactAssessment through the integration of thearchaeological assessment with other studiessuch as coastal processes, for example.

2.1.3 Effects can also arise from secondaryimpacts, that is to say, from activities that occuras part of the development process but mightnot be considered to be part of thedevelopment as such. Examples might includeanchorages for construction vessels, or accessroads and compounds for the installation ofonshore cables.

2.1.4 The direct, indirect, primary andsecondary effects of development on the historicenvironment are usually negative, especially inrespect of physical remains in their originalcontext. Positive effects may be identified if ascheme can consolidate or safeguard sites that

would otherwise have been disturbed.Excavation, recording, conservation of artefactsand structures, and the deposition of a publicly-accessible archive may be seen as positiveoutcomes, but they have to be gauged againstthe underlying principle that preservation in situis preferable. Analysis, publication and otherforms of dissemination to scholarly and moregeneral audiences can also be seen as positiveeffects because they create new knowledge andawareness that can help to offset physicaldestruction.

2.1.5 The non-renewable character of thehistoric environment is such that physicalimpacts are usually permanent. The positiveeffects of investigation and recording will betemporary unless proper provision is made forarchive deposition and publication.

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Figure 6. Effects

Different types of effect can arise from impacts attributable to offshore renewable schemes, which can be categorisedin terms of the pathways that are taken.

11

2.1.6 Physical impacts on the historicenvironment are often of short duration. Effectsarise immediately and catastrophically fromconstruction if no provision has been made formitigation. Where construction has impactedonly a part of an archaeological site or feature(by piling, for example), medium or long termeffects may occur in respect of the material thathad hitherto survived the immediate impact ofconstruction. Where effects of medium andlong duration are anticipated, proper provisionmust be made for monitoring their onset andoutcomes.

2.2 Types of site

2.2.1 The potential effects of offshorerenewable energy developments on the historicenvironment are outlined below in terms of:• archaeological site types and themes; and• the physical environment they affect.

Wrecks and wreckage

2.2.2 In terms of the range of site types that arelikely to be affected by offshore renewableenergy developments, shipwrecks enjoyperhaps the highest public profile. As notedabove, watercraft of various sorts have probablybeen used in UK waters since the Mesolithicperiod. Records exist for more than 30,000maritime casualties in UK waters, but it isestimated that as many as 500,000 wrecks,including aircraft may in fact lie on the coastand seabed of the UK. More ephemerally,distributions of artefacts lost or thrownoverboard can indicate anchorages, shippingroutes or battle sites.

Coastal heritage

2.2.3 Often less widely known or publicisedthan wrecks, other evidence of millennia ofhuman coastal and maritime activity are to befound on the seabed, inter-tidal zone, foreshoreand coastal margins. This evidence includes fishtraps, salt-making sites, the remains ofinundated or eroded settlements, reclamationand flood defence works, military infrastructure,wharves and hards, shipbuilding sites, andnavigational features.

Prehistoric deposits and artefacts

2.2.4 Prehistoric material dating from thePalaeolithic periods can be found re-depositedin sands, gravels and other sediments laid downby former rivers. It is increasingly recognisedthat early prehistoric material can also be foundin situ in offshore areas, notwithstanding themassive processes that have accompaniedglaciation and sea-level change. Prehistoricmaterial from all periods up to Iron Age andRoman times can be found nearer to the shore,in inter-tidal areas, and beneath areas of coastalland reclaimed in Medieval and later periods.

Possible Effects of Offshore Renewable Energy Development on the Marine and Coastal Historic Environments

Figure 7. Types of site

The range of features of the historic environment that canbe affected by offshore renewable schemes is very diverse.

12


2.3.4 On coastal land, activities associated withcable laying and with the construction of shore-side infrastructure – together with associatedcompounds and access roads – are likely to bethe principal causes of impact. The potential forshipwrecks might be thought to be less than atsea, but many of the most significant ship findshave been found within reclaimed coastal land.The potential for prehistoric material in depositssealed by reclamation is also high, and there willbe potential for traces to survive of many formsof coastal activity – industrial, agricultural andmilitary – from the Roman period, throughMedieval and Post-medieval times, to the presentday. As well as buried remains, the historicenvironment of coastal land may includeupstanding structures such as ancient seadefences, buildings and historic landscapefeatures.

2.4 Landscapes, seascapes and‘setting’

2.4.1 Traditionally, frameworks for managing thehistoric environment have focused on individualsites and monuments. Archaeologists’ concernshave always been broader than this and severalconcepts, including those of ‘landscape’ and‘setting’ have been used to enable aconsideration of the archaeological heritage togo beyond the focus on individual sites. Theseattempts by archaeologists to engage withmonuments within their surroundings hascoincided with a wider recognition of thecontribution that the physical remains of oldthings can make to what is valued in anenvironment. It is now increasingly recognisedthat the entire form of our present environment,even features whose main processes areentirely natural, has been structured by humanactions and perceptions.

2.4.2 ‘Setting’ starts with a monument or groupof associated monuments, and draws attentionto the importance of their geographical contextto understanding and appreciating thoseparticular monuments. ‘Landscape’ takes anopposite tack, being concerned with the overallgeography of a place and the role of historicalactivity in its formation and survival, of whichindividual monuments and features are a physical– though often unrecognised – manifestation.

2.3 Environments

2.3.1 The sites and materials described aboveoccur in a range of marine (sub-tidal and inter-tidal) and terrestrial environments, which aresubject to different types of impact in thecourse of offshore renewable energydevelopment.

2.3.2 In offshore areas, scheme impacts arisefrom the construction of foundations forturbines and other infrastructure, and fromlaying power and control cables. Cableploughing, piling and excavation are among theprimary impacts, while construction vesselsmay have secondary impacts when jacking-upor anchoring.

2.3.3 Closer to shore and within the inter-tidalzone, scheme impacts are likely to arise fromcable laying and from the activities of cablelaying vessels. It should be recognised that thehistoric environment of the coastal margin islikely to be particularly dense and complicated:the coast forms a natural hazard to shipping; itwill also have supported specific coastalactivities; and the build up of prehistoric layersmay have considerable time-depth.

13

2.4.3 Although ‘setting’ may be driven stronglyby visual considerations, it can also encompasstopography and historic land use. ‘Setting’ maybe used as a way of addressing the intentions ofthe people who built or were otherwiseresponsible for the original siting of themonument, or it may be used to address thepeople whose appreciation of a monument inthe present day might be degraded by a changeto that setting. Similarly, it can be important todistinguish between the interpretations oflandscapes that were meaningful to people inthe past, and the contribution that historicfeatures make to landscapes perceived in thepresent.

2.4.4 In terms of offshore renewable energyschemes, ‘setting’ and ‘landscape’ may be keyconsiderations in addressing the effects of thescheme on land. These effects may arise fromscheme elements that are actually on land –overhead cables, sub-stations and other aspectsof terrestrial infrastructure – but also fromscheme elements which are at sea but can beperceived from land, such as offshore renewableenergy turbines. Hence the setting of features ofthe historic environment situated on the coast –cliff top forts, historic quaysides, designedlandscapes that look out to sea – may beaffected by development offshore, as may bethe overall character of a historic coastallandscape. The effects of offshore elements of ascheme on the historic environment on land maybe barely perceptible, but such an assessmentshould be a conclusion, not a premise.

2.4.5 The concepts of ‘setting’ and ‘landscape’become harder to apply to the historicenvironment in fully marine areas – i.e. sites andfeatures that are wholly sub-tidal. Althoughneither concept is reducible to visualperception, their appreciation is driven to largedegree by the physical form and influence ofmonuments. Moreover, the causal relationshipbetween marine features and their surroundingsis sometimes less direct than on land.Prehistoric features – whether they are artefact-rich sites, or deposits whose interest is palaeo-environmental – need not signify the presenceof an entire landscape; the prehistoric depositsthat are found at many offshore locations areoften fragmentary and comprise elements ofmany successive land surfaces. Although often

of high importance in their own right, the degreeto which any particular fragment constitutes a‘submerged landscape’ will be debatable.Equally, the causality that links a wreck to itssurroundings may have to be examined andestablished, rather than assumed. In landscapeterms, there could be a marked differencebetween, for example, the wreck of a collier lyingon the route that its fellow colliers traded overdecades or centuries, and the wreck of a ‘blowin’ whose relationship with its surroundings is asaccidental as the tragedy of its loss.

2.4.6 The relationships between marine sitesand their surroundings are starting to beaddressed in a way that can help inform theirmanagement in the context of offshorerenewable energy schemes, but these are stillearly days. The concept of ‘seascape’ hasconsiderable currency, but its use is directed atvisual considerations and predominantly withthe way that the sea is viewed from land.

2.4.7 Seascape characterisation wasdeveloped seminally in Wales by CountrysideCouncil for Wales (2001), to add additionalinformation to existing land-based landscapeassessments. It centres on the perceivedcharacter of coastal landscapes, and mapsareas to relate specific areas of sea to specificareas of coastal landscape, in effect to createcoastal zone spatial planning units based onscenery. The concept takes into account bothland to sea and sea to land perspectives. InWales Seascape Characterisation should becomplete at a regional scale by the end of 2007,and the concepts are being applied to spatialplanning for offshore renewable energydevelopments. In Scotland similar work forScottish Natural Heritage (Scott et al. 2005) hasbeen used in spatial planning for offshorerenewable energy schemes.

2.4.8 Recent DTI guidance (2005) explains theconcepts and applications of seascape to theplanning, siting and design of offshorerenewable energy schemes. Although nospecific survey or application is made to themarine historic environment this is implicit as acomponent of the total scenic environment. Thekey feature of seascape characterisation is theestablishment of broad-brush spatial planningunits, based on the variation in seascape


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HISTORIC LANDSCAPE CHARACTERISATION

The aim of Historic Landscape Characterisation is to characterisethe current appearance of the historic urban and rural environmentswithin a given area, and to use this information to manage changewithin the historic landscape.

England’s national HLC programme is co-ordinated by EnglishHeritage and is now more than half complete. Information on specificprojects is available from English Heritage:

(http://www.english-heritage.org.uk),

the Countryside Agency:

(http://www.countryside.gov.uk) or from the relevant local authority.

English Heritage has recently sought to extend HLC to the sea,through the England’s Historic Seascapes Project. One pilot area(Liverpool Bay) has been completed and four more pilots are inprogress. Further details can be found at:

http://www.english-heritage.org.uk/server/show/nav.8684

In Wales the compilation of the Register of Historic Landscapes inWales has been underway since 1998. The Welsh Register is amaterial consideration in the planning process, the application ofwhich is covered in published guidance (see Further Reading below)and with the ASIDOHL methodology for assessment the significanceof the impacts of development on historic landscape areas.Information can be obtained from Cadw:

(http://www.cadw.wales.gov.uk), the Countryside Council for Wales(http://www.ccw.gov.uk) or regional and local planning authorities.

Scotland’s HLC programme, ‘Historic Landuse’, has been developedby Historic Scotland (http://www.historic-scotland.gov.uk/) and theRoyal Commission on the Ancient and Historical Monuments ofScotland (http://www.rcahms.gov.uk). Further information can beobtained from either of these organisations or from regional andlocal planning authorities.

Figure 8. Types of environment

Offshore renewable schemes have impacts across a range of environments from land to sea, all of which need to beaddressed in assessing likely effects on the historic environment.

http://www.english-heritage.org.uk

http://www.countryside.gov.uk

http://www.english-heritage.org.uk/server/show/nav.8684

http://www.cadw.wales.gov.uk

http://www.ccw.gov.uk

http://www.historic-scotland.gov.uk/

http://www.rcahms.gov.uk

15

character between one area and another. As theconcept develops more detailed and specificstudies and methodological principles shoulddevelop to deal with specific aspects of theseareas, including the historic component.

2.4.9 Other conceptions of seascape such asmarine Historic Landscape Characterisation(HLC) (see text box) are attempting to draw outthe contribution of historical processes to thephysical characteristics of the coast and seabedin the present day. In respect of fully marinefeatures of the historic environment, theunderstanding of how they relate to theirsurroundings, how as a whole they constitutethe marine historic environment, and how theserelationships are affected by renewable energyschemes, are going to be areas ofmethodological development for several yearsto come.

2.5 Cumulative effects

2.5.1 Cumulative effects are those individuallyminor but collectively significant effects thatresult from a project in combination with otherprojects and activities. Cumulative effects areincremental changes to the environment and arelikely to manifest themselves in the medium orlong-term. They are thus potentially moredifficult to predict than other impacts on thehistoric environment.

2.5.2 The difficulty in assessing cumulativeeffects on the marine historic environment iscompounded by the general lack of detailedknowledge of the known and potentialarchaeological resource offshore and an as-yetembryonic understanding of how significantthe incremental effects of marine developmentmay be.

2.5.3 A firm knowledge and understanding ofthe marine historic environment within an areamay only arise at the point that archaeological

studies and investigations are conducted byindividual developers of offshore renewableenergy schemes. As acknowledged by guidanceon other topics, it may be advantageous forcompanies promoting offshore renewableenergy schemes within a region to collaboratewith each other, and with marine developers inother sectors, to address cumulative effects onthe historic environment.

2.5.4 Some context for the assessment ofcumulative effects has been provided by theregulatory authorities that are responsible forthe overall programme for offshore renewableenergy in the UK, as a result of the SEADirective (2001/42/EC). As in the EIA Directive,the SEA Directive includes the archaeologicalheritage among the elements of the environmentthat must be addressed. Accordingly, a SEAwas commissioned by the Government ahead ofthe Round 2 offshore renewable energy leasingprocess, and the DTI has extended its SEAs foroil and gas to also include offshore renewableenergy schemes in recent cases. The DTI SEAshave included technical reports on prehistoricarchaeology and maritime archaeology (seehttp://www.offshore-sea.org.uk/site/scripts/sea_archive.php).

2.5.5 Although SEAs may provide a startingpoint for the assessment of possible cumulativeeffects within a region, they are also constrainedby current lack of knowledge and understandingof the historic environment. There is, as yet, noestablished methodology for addressingcumulative effects on the marine historicenvironment, and this is consequently anotherarea where innovation is to be expected.

2.5.6 In considering the cumulative effects ofoffshore renewable energy schemes on thehistoric environment, attention should be paid tothe measures through which any such effectsare to be monitored, and what provisions are toapply if cumulative adverse effects prove to besignificant.


http://www.offshore-sea.org.uk/site/scripts/

16

3.1 Archaeology and thedevelopment process

3.1.1 Several processes that have directrelevance to the historic environment intertwinein the development of an offshore renewableenergy scheme:• Development will be subject to one or more

consent procedures, through which licencesto carry out the works are sought fromGovernment.

• The consent process will be accompanied byan Environmental Impact Assessment (EIA)process, through which the developer has toconsider and mitigate any adverse implicationsof the scheme for the environment.

• A process of design will take place, seekingto optimise the scheme for its purpose giventhe constraints upon it.

• A site investigation process will be carriedout to provide data upon which the designand environmental assessment processescan be based.

• All of these strands will take place withinprocesses of project and financialmanagement, to ensure that the progress ofthe scheme is efficient, and remains viable.

All of these processes are staged, iterative andincremental, and typically involve many partiesacting on behalf of the scheme’s sponsors.

3.1.2 Consideration of the historic environmentis far from incidental to all of these processes.On the one hand, unforeseen archaeologicalproblems can be time consuming andexpensive, and threaten key aspects of schemedesign or the award of consent. On the otherhand, the historic environment can be dealt withadequately without incurring unreasonable costsif it is considered in the course of the processesoutlined above.

3.1.3 Consequently, the historic environment isalso best dealt with through a process, which ismost effective when it is woven through theother strands. Over the last couple of decades,the process-based character of development-led archaeology has become recognised in aseries of well-established stages ofinvestigation, namely:• archaeological appraisal;• desk-based assessment;

• archaeological field evaluation;• mitigation;• monitoring;• post-fieldwork assessment;• analysis;• publication and dissemination;• archive preparation and deposition.

3.1.4 The relation between these stages of thearchaeological process and stages ofdevelopment processes can vary according tothe development and to the scope of eacharchaeological stage. The advice of national andlocal curators will be especially important inestablishing the content and timing of thesestages (see Section 5 below for informationabout curators)

3.1.5 Archaeological appraisal is the stage atwhich curators are first alerted to a scheme, atwhich point they will identify the key issues forthe historic environment raised by the scheme,and the measures that they would expect to betaken to address them. It is clearlyadvantageous to all parties if the curators areable to carry out their appraisal as early aspossible, as appraisal will enable thesubsequent stages to be targeted effectively.

3.1.6 Generally, in the context of offshorerenewable energy schemes, desk-basedassessment and non-intrusive forms of fieldevaluation (by walkover or marine geophysicalsurvey, for example) are commonly conductedto inform EIA, before applications for consentare submitted. If intrusive field evaluation isrequired in order to establish the presence andimportance of sites that may be critical indetermining consent or the conditions thatmight apply, these will also have to occur beforesubmission. Where intrusive evaluation is lesscritical to consent but will inform the detaileddesign of mitigation measures of the schemeitself, then it may be deferred post-consent.

3.1.7 Mitigation measures will generally have tobe carried out between consent and the start ofconstruction, or at least to be formally in placeby that time. Monitoring will accompanyconstruction and operation, for the duration ofthe process identified as requiring monitoring.Post-fieldwork assessment is a key stage, atwhich point the overall content and value of

3 Development Processes

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PLANNING POLICY GUIDANCE

In England PPG16: Archaeology and Planning (Department of the Environment 1990) setsout the Secretary of State’s policy on archaeological remains in England. It acknowledgesthe fragile and finite nature of such remains, and states that the desirability of preservationof archaeological remains and their settings is a material consideration within the planningprocess. PPG16 provides that there is a presumption in favour of the preservation in situ ofnationally important archaeological remains, and that where such preservation is not justifiedit is reasonable for planning authorities to require the developer to make appropriate andsatisfactory provision for excavation and recording of remains.

English Heritage made the following statement in ‘England’s Coastal Heritage’ (1996):

Although it remains government policy not to extend the Town and Country Planning systemto the territorial sea, the principles set out in … PPG16 … should be applied to the treatmentof sub-tidal archaeological remains in order to secure best practice.

In Northern Ireland planning law is used to regulate archaeology. Government policy onplanning, archaeology and the built heritage is presented in Planning Policy Statement 6(Department of the Environment Northern Ireland, 1999) and while the Planning Order (NorthernIreland) 1991 has application only to the low water mark, the principles of Planning PolicyStatement 6 can be extended to the seabed.

National Planning Policy Guidelines (NPPGs) set out Government policy on nationallyimportant land use and other planning matters in Scotland. NPPG5 Archaeology and Planningsets out policy on how archaeological remains and discoveries should be handled. Theguidance is aimed at planning authorities in Scotland, and is also of direct relevance todevelopers, owners, statutory undertakers, government departments, conservationorganisations and others whose actions have a direct physical impact upon the natural orbuilt environment (Scottish Office 1994a).

The Planning Advice Note: Archaeology – the Planning Process and Scheduled MonumentProcedures (PAN 42) gives more detailed advice on planning procedures and the separatecontrols over scheduled monuments (Scottish Office 1994b).

Welsh Office Circular 60/96 – Planning and the Historic Environment: Archaeology – providesadvice on the handling of archaeological matters within the planning system in Wales. Itsupplements guidance in Planning Guidance (Wales): Planning Policy 1996.

archaeological investigations are reviewed, as abasis for recommendations for analysis andpublication. Finally, as discussed above, thearchive – including the material archive of anyartefacts and structures recovered by fieldwork– will have to be prepared and deposited.

3.1.8 A key finding, by archaeologists anddevelopers alike, is that consideration of thehistoric environment should start early in thedevelopment process, and be maintainedthroughout.

3.2 Consent processes for offshorerenewable energy schemes

3.2.1 As a result of the current regulatorysituation for marine development, variousconfigurations of consents for offshorerenewable energy schemes are possible. Foroffshore renewable energy schemes, two mainroutes for consent have been identified.Following one route, applications in respect ofUK territorial waters and the Renewable EnergyZone (REZ) can be made under the Electricity

18


Act (EA) 1989, which also requires consentsunder the Food and Environment Protection Act(FEPA) 1985 and the Coast Protection Act (CPA)1949. These applications can be made to theDepartment for Trade and Industry, which willliaise with the Defra/DfT Marine Consents andEnvironment Unit (MCEU) in respect of FEPAand CPA consents. Under the second route,applications in respect of UK territorial waters(but not the REZ) can be made under theTransport and Works Act (TWA) 1992. Consentunder the CPA is not required if the TWA route isfollowed, but a FEPA licence will still be required.

3.2.2 An Environmental Impact Assessment islikely to be required irrespective of theconsenting route that is chosen, as therequirements of the EIA Directive have beenapplied in whole or in part to the Electricity Act,Transport and Works Act and Coast ProtectionAct, and information equivalent to an EIA isrequired as a result of FEPA licensing policy.

3.2.3 EIA requires consideration of thearchaeological heritage. Consequently decisionsregarding consent, and any conditions that areto be attached to such consent, may takeaccount of any likely significant effects on thehistoric environment arising from proposedoffshore renewable energy schemes.

3.2.4 Other consents are likely to be required.In particular, planning permission under theTown and Country Planning Acts (TCPA) may berequired for onshore elements. Under the TWAroute, the developer can seek ‘deemed’planning permission, whereas under the EAroute, planning permission will have to besought separately. An EIA may be required tosupport the application for planning permission,whether it is to be ‘deemed’ or soughtseparately. The DTI advises that the developershould make early contact with the appropriateLocal Planning Authority (LPA) as to theenvironmental information that the LPA are likelyto require, and notes that developers canexpect to have planning conditions imposed tocontrol and mitigate the impact of onshoreelements. Archaeology is a materialconsideration in the TCPA process, and thereare explicit policies in respect of the historicenvironment both nationally and in LPAdevelopment plans.

3.2.5 The detail of the regulatory route beingtaken in respect of a particular offshorerenewable energy scheme will be important inidentifying the relevant archaeological curators(see below). It is especially important to note thata combination of both national and local curatorsis likely to become involved, each with their ownremits. Moreover, multiple national and localcurators might be involved because schemestraverse territorial boundaries, because ofregional arrangements, and because of thematicspecialisms (e.g. built historic environment,terrestrial archaeology, maritime archaeology).

3.2.6 The detail of the consent processes isalso likely to be important in correlating relevantguidance and policies in respect of the historicenvironment, and in identifying possiblestakeholders and consultees. An understandingof the specific remits of archaeological curatorsmay also help in structuring historic environmentelements of the Environmental Statement, sothat aspects of the baseline, assessment ofeffects and proposed mitigation to reflect theirparticular involvement.

3.3 Consents and otherobligations relating to the historicenvironment3.3.1 Where a scheme impinges on a historicasset subject to statutory designation, then aspecific consent or licence under the relevantAct may also be required.

Protection of Wrecks Act 1973

3.3.2 Under the 1973 Act, shipwrecks andwreckage of historical, archaeological or artisticimportance within UK territorial waters can beprotected by way of designation. Once a wreckhas been designated it is an offence to carry outcertain activities in a defined area surroundingthe site, except where a licence for thoseactivities has been obtained from theGovernment.

3.3.3 Administration of this Act and associatedlicenses is the responsibility of English Heritagein England, Historic Scotland in Scotland, Cadw:Welsh Historic Monuments in Wales and theEnvironment and Heritage Service in Northern

19

Ireland. Requests for further information orapplications for licences should be directed tothe relevant national curator (see below).

3.3.4 Presently designated wrecks in UK watersrange in date from the Middle Bronze Age to the20th century. Where a wreck is located that isconsidered worthy of designation the relevantSecretary of State is required to consultappropriate advisors prior to designation.However, developers should be aware that it isalso possible, where a wreck or wreck materialof importance is discovered during the course ofa development, for such a site to be designatedin an emergency.

Ancient Monuments andArchaeological Areas Act 1979

3.3.5 Monuments that are of nationalimportance can be protected by being added tothe schedule of monuments protected under theAncient Monuments and Archaeological AreasAct 1979. It is an offence to damage, or to carryout a range of specified activities on such a‘scheduled monument’, unless a license forthese activities has been obtained from therelevant authority, in the form of ‘scheduledmonument consent’.

3.3.6 ‘Monument’ is a wide term that coversmany types of archaeological site, includingbuildings, structures, works, excavations andtheir sites. Monument can also mean the site ofany vehicle, vessel, aircraft or other movablestructure. The 1979 Act can therefore also beused to protect wrecks and has been used toprotect other forms of nationally importantmonuments along the foreshore and belowMean Low Water. The Act is applicable to thelimit of the UK Territorial Sea.

3.3.7 In Northern Ireland, comparable provisionis made under the Historic Monuments andArchaeological Objects (Northern Ireland) Order1995.

Protection of Military Remains Act 1986

3.3.8 The primary purpose of the Protection ofMilitary Remains Act 1986 is to protect theresting places of military personnel fromunauthorised disturbance. It allows the Ministry

of Defence (MOD) to protect vessels and aircraftthat were in military service when they were lostor wrecked. The MOD can designate any suchnamed vessel lost after 4 August 1914 as a‘protected place’, even if the position of thewreck is not known. In addition, the MOD candesignate as a ‘controlled site’ any such wreckwhose position is known. In the case of a wreckprotected as a ‘controlled site’ no more than200 years must have elapsed since its loss. Ineither case it is not necessary to demonstratethe presence of human remains in order for awreck to be designated.

3.3.9 Access is not prohibited at a ‘protectedplace’, but it is an offence to tamper with,damage, move or remove items from such awreck without a licence. However, access,salvage and excavation are all prohibited on‘controlled sites’, except where a licence forrestricted activities has been obtained from theMOD.

3.3.10 The remains of all aircraft that have beenlost in military service are automaticallyclassified as ‘protected places’ by the Act.Applications for licences in respect of aircraftlost in military service can be sought from theCentral Casualty Section of the RAF PersonnelManagement Agency.

3.3.11 The Protection of Military Remains Act1986 also includes a prohibition on excavationfor the purpose of discovering whether any

Development Processes

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place comprises any remains of an aircraft orvessel lost in military service, except inaccordance with a licence.

Merchant Shipping Act 1995

3.3.12 The Merchant Shipping Act 1995 is not aform of designation, but it will affect offshorerenewable energy schemes if, in the course ofsite investigations or construction, any materialis recovered which falls within the definition of‘wreck’. All wreck has an owner, and theMerchant Shipping Act sets out the procedurefor returning recovered wreck to the owner ortheir successor. The Receiver of Wreck has tobe notified of all recovered wreck, and will seekto identify the original owner so that it can beclaimed. Ownership of unclaimed wreck fromwithin territorial waters vests in the Crown or ina person to whom rights of wreck have beengranted. Unclaimed wreck from beyondterritorial waters is returned to the finder.

3.3.13 The Receiver of Wreck has a duty toensure that finders who report the wreck receivean appropriate salvage payment. In the case ofmaterial considered to be of historic orarchaeological importance, a suitable museumwill be asked to purchase the material at thecurrent market valuation. The finder will receivethe net proceeds of the sale as a salvagepayment. If the right to, or the amount of,salvage cannot be agreed, either betweenowner and finder or between competing salvors,the Receiver of Wreck will hold the wreck untilthe matter is settled, either through amicableagreement or by court judgement.

Treasure and other archaeologicalfinds

3.3.14 In England, Wales and Northern Ireland,all finders of gold and silver objects that areover 300 years old – including groups of coinsfrom the same findspot – are under a legalobligation in terms of the Treasure Act 1996 toreport such items to a Coroner for the district inwhich they were found. Base-metalassemblages found after 1 January 2003 alsoqualify as Treasure if they are of prehistoric date.

3.3.15 In Scotland all objects whose originalowner or rightful heir cannot be identified ortraced are the property of the Crown. TheCrown Office, overseen by the ScottishExecutive claims bona vacantia (or ownerlessgoods) and acting on behalf of the nation claimsall archaeological finds and historic objects.Finders of archaeological objects are requiredto report their finds to the Treasure TroveSecretariat. A Treasure Trove Advisory Panelappointed by the Scottish Ministers providesadvice to the Crown Office on matters relatingto treasure trove(http://www.treasuretrovescotland.co.uk).

3.3.16 In England and Wales, there is also avoluntary scheme for reports of all forms ofarchaeological find, known as the PortableAntiquities Scheme(PAS – http://www.finds.org.uk/index.php).

Human remains

3.3.17 If human remains – including crematedremains – are discovered in the course of siteinvestigations or construction, they must not beexhumed unless a license has been obtainedunder the Burial Act 1857. The Department ofConstitutional Affairs is responsible for burials inEngland, and it advises that anyone disturbingburied remains accidentally is advised to leavethe remains in place and to contact themimmediately. The responsibility for burials inWales rests with the Welsh Assembly, and inScotland the Scottish Executive is responsible.

Ordnance and firearms

3.3.18 If suspected ordnance is discovered atsea or in inter-tidal areas, record its position andcontact HM Coastguard. Do not attempt tomove it. Although ordnance may be of historicinterest, the health and safety of employees andthe public take precedence.

3.3.19 Any firearms and ammunition (e.g.machine guns or hand guns from crashedmilitary aircraft) are likely to be subject to theFirearms Acts. Ammunition should be regardedas ordnance, irrespective of its size; it may beunstable if moved and extremely hazardous.

http://www.treasuretrovescotland.co.uk

http://www.finds.org.uk/index.php

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3.4 Risk Management

3.4.1 Aside from the formal requirements ofdevelopment consents, EIA, historicenvironment designations and relatedobligations, adherence by developers toarchaeological processes will help to identify,quantify and avoid risks to the scheme arisingfrom the historic environment.

3.4.2 As noted above, features of the historicenvironment are widespread and diverse. Thelocation of many features is not known,particularly in the marine environment.Consequently, there is a risk that archaeologicalmaterial might be discovered in the course ofsite investigations, during construction, orduring operation. Such discoveries can have a

big effect on development because of thephysical constraints they place on activity,because of the public interest that may arise,and because of the financial consequences ofhaving to deal with the unforeseen issue.

3.4.3 The risk of significant impacts arising fromthe historic environment will be reduced byobtaining firm information on known andpotential sites, and by putting measures in placeto address discoveries if they occur. Theseprecautions will normally be achieved byfollowing the archaeological procedures set outin this guidance. However, it is worth noting thatin some circumstances, prudent riskmanagement may warrant archaeologicalinvestigations over and above those strictlyrequired for the purpose of consents.

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4.1 Advice

4.1.1 There is a wide variety of sources ofarchaeological advice and information availableto offshore renewable energy developers. It isimportant to make the distinction between thosesources that can provide archaeological adviceand those that hold archaeological information.However, some of the public authorities thatprovide advice also maintain important sourcesof information.

Curators

4.1.2 The regulatory authorities that decidewhether consent is to be granted are advised, inrespect of the historic environment, by nationalarchaeological curators and by archaeologicalcurators in local authorities. Advice fromarchaeological curators can also be sought bydevelopers, to make sure that the proposals, forwhich they are seeking consent, and theenvironmental assessment of those proposals,are appropriately informed.

4.1.3 In their advice to regulators, and tooffshore renewable energy developers,archaeological curators will be directed by theirstatutory remit and by published policies andguidance (see Further Reading below). Whereavailable, their advice will also be guided byStrategic Environmental Assessments.

4.1.4 Responsibility for the historic environmentis a devolved matter, so each home country hasits own national curator. The national curatorshave responsibility for the historic environmentin territorial waters, including statutoryprotection. The national curators are a keysource of advice for developers in respect ofthe marine elements of each scheme.

National Curators

English Heritage Maritime Archaeology TeamFort Cumberland, EastneyPortsmouth PO4 9EFTel: 023 9285 6700Fax: 023 9285 6701Email: [email protected]

English Heritage has a regional structure ofoffices. Developers are encouraged to establish

4 Sources of Historic Environment Advice and Information

contact with the relevant office. Contact detailsof the regional offices can be found at:www.english-heritage.org.uk

Historic ScotlandLongmore House, Salisbury PlaceEdinburgh EH9 1SHTel: 0131 668 8600Fax: 0131 668 8899www.historic-scotland.gov.uk

CadwPlas Carew, Unit 5/7 Cefn CoedParc NantgarwCardiff CF15 7QQTel: 01443 33 6000Fax: 01443 33 6001Email: [email protected]

Historic Environment Services Northern IrelandWaterman House5–33 Hill StBelfast BT1 2LATel: 01443 33 6000Fax: 01443 33 6001www.doeni.gov.uk

Local Curators

Association of Local GovernmentArchaeological Officers (ALGAO)http://www.algao.org.uk

4.1.5 Curatorial advice regarding the terrestrialand inter-tidal aspects of offshore renewableenergy developments should also be soughtfrom the relevant local governmentarchaeological officer, usually within the localgovernment heritage or environment service. Akey role of local government archaeologicalofficers is to advise local planning authorities,so it is particularly important that offshorerenewable energy developers seek advice fromlocal curators if any aspect of their schemerequires planning permission.

4.1.6 Major agencies and land holders such asthe National Trust, Defence Estates andNational Parks also employ archaeologists, whomay also be an important source of advice if

www.historic-scotland.gov.uk

www.english-heritage.org.uk

www.cadw.wales.gov.uk

www.doeni.gov.uk

http://www.algao.org.uk

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elements of an offshore renewable energyscheme fall within their purview.

4.1.7 Within the EIA process, curatorialauthorities will provide developers with scopingadvice where requested, and will engage insubsequent discussions about the conduct ofEIA, the results of investigations, and theappropriateness of possible mitigationmeasures. Archaeological curators will, in duecourse, advise the regulator about theadequacy of Environmental Statements, themerits of consent, and any conditions that mightbe considered necessary. It is strongly advisedfor developers to consult the relevant curatorsas early in any project as possible, preferablynot later than the scoping phase, and tomaintain regular communication with the curatorthereafter.

4.1.8 Although archaeological curators will beable to provide guidance to developers,together with some information, they will notcarry out any of the archaeological studies orinvestigations that contribute to EIA. Thedeveloper will be responsible for carrying outsuch studies, usually by commissioning anarchaeological contractor or consultant.

4.1.9 Developers are advised to consult the IFAYearbook for the details of archaeologicalcontractors/consultants with suitable previousexperience.

Consultants and contractors

4.1.10 Offshore renewable energy developerscan obtain independent archaeological adviceby employing an archaeological consultant and/or contractor. Generally speaking, anarchaeological consultant will guide thedeveloper through archaeological aspects of theentire proposal whereas an archaeologicalcontractor will carry out specific studies orinvestigations.

4.1.11 There are numerous private andcharitable organisations across the UK that canprovide professional archaeological services.Additionally, some engineering andenvironmental consultancies employprofessional archaeologists in-house and areable to provide such services.

4.1.12 Developers should ask potentialarchaeological consultants/contractors todemonstrate that they have skills andknowledge appropriate to advising on offshorerenewable energy schemes.

Other archaeological interests

4.1.13 There is a wide range of otherorganisations and individuals whose interest inarchaeology and the historic environmentshould be considered during offshore renewableenergy developments. Some may own or have

IFA MEMBERSHIP AND IFA REGISTERED ARCHAEOLOGICALORGANISATIONS

Membership of the Institute of Field Archaeologists provides a measure ofthe professional and ethical standards to which archaeological consultantsand contractors ascribe. Individual archaeologists can qualify at a variety ofcorporate levels, each of which requires adherence to the IFA’s Code ofConduct and other by-laws.

The IFA’s Registered Archaeological Organisation (RAO) scheme extendsthese obligations to companies. Organisations registered with the IFA arecommitted to meeting IFA standards; they have formally resolved to carryout their work in line with the IFA Code of Conduct and other by-laws; theirarchaeological work is controlled by a Member of the Institute (MIFA); andtheir status as a registered organisation is reviewed annually by the IFA.

Further information can be found at:

http://www.archaeologists.net/modules/icontent/index.php?page=22

http://www.archaeologists.net/modules/icontent/index.php?page=22

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Material type NMRs HERs UKHO CROs RoW PAS Mus MODWreck data ✔ ✔ ✔ ✔

Documented shipping losses ✔ ✔

Military Remains ✔

Sites and Monuments ✔ ✔

Finds (including wreck) ✔ ✔ ✔ ✔

Listed Buildings ✔ ✔

Historic Maps ✔ ✔

Historic Charts and Sailing Instructions ✔ ✔ ✔

Aerial Photographs ✔ ✔

Secondary Sources ✔ ✔

Key:NMRs = National Monuments Records maintained by English Heritage, Royal Commission on the

Ancient and Historical Monuments of Scotland (RCAHMS), Royal Commission on theAncient and Historical Monuments of Wales (RCAHMW), Environment and HeritageService, Northern Ireland.

HERs = Historic Environment Records (formerly Sites and Monuments Records – SMRs)maintained by Local Authorities.

UKHO = UK Hydrographic Office, Wreck Index and ArchiveCROs = County Record OfficesRoW = Receiver of WreckPAS = Portable Antiquities SchemeMus = National and local museumsMOD = Ministry of Defence

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interests in specific sites or wrecks, while othersmay have a more general concern for marinearchaeology and the historic environment. Thisencompasses both the public concerned with aparticular scheme because it may directly affectthem – including national and local NGOsrepresenting historic environment interests –and the wider public.

4.1.14 The transparent and public nature of theoffshore renewable energy application andlicensing process allows anyone with an interestin a particular proposal to make arepresentation. Developers are thereforestrongly advised to ensure that a wide range ofinterests related to the historic environment isconsidered at an early stage in preparing theirapplication.

4.2 Information

4.2.1 Archaeological and historical informationrequired for the baseline study and impactassessment phase of offshore renewableenergy developments can be obtained from thefollowing sources.

Information provided by developers

4.2.2 A key source of primary informationrelating to the historic environment of anyoffshore renewable energy project is that likelyto be held or acquired by developers themselves.

4.2.3 In archaeological terms, the mostimportant information that is often held byoffshore renewable energy developers is thegeophysical and geotechnical data that theyacquire as part of the engineering and EIAprocess. For marine areas, this data is likely tobe the most recent, most direct and highestquality data that is available to archaeologists.The usefulness to archaeologists of thedeveloper’s geophysical and geotechnical datawill depend on the detail of the survey designand specification.

4.2.4 It is best practice to obtain archaeologicaladvice in the course of developingspecifications for geophysical and geotechnicalsurveys, even if the primary purpose of suchsurveys is to acquire engineering or ecologicaldata. The acquisition, processing andinterpretation of geophysical and geotechnicaldata is considered in greater detail below.

4.2.5 Another important set of information thatdevelopers hold is the detail of the schemeitself. Plans showing all the proposed elementsof the scheme: structures; cables; sub-stations;compounds; access routes and so on will beneeded to establish the study area for whicharchaeological data must be obtained, and anyspatial coincidence between elements of thescheme and elements of the historicenvironment. Sections and levels may be veryimportant in establishing whether schemeelements will penetrate horizons that arearchaeologically sensitive. Textual descriptionsof construction processes will help in identifyingimpacts, in assessing their effects, anddesigning effective mitigation measures.

Sources of Historic Environment Advice and Information

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4.2.6 The refinement of schemes will affect theirarchaeological assessment as much as anyother study, so it is essential that developerskeep their archaeological consultants/contractors appraised of changes in a timelyfashion, and archaeological consultants/contractors should ensure that they are keptinformed.

4.2.7 The developer is also likely to be a goodsource of other information that has a bearingon the historic environment and its assessment.Numerous studies that are commissioned in thecourse of developing offshore renewableschemes are relevant to archaeologists.Geological interpretations will help set theoverall context within which the presence orpotential for Quaternary or Holocene depositscan be gauged. Hydrological andsedimentological studies may indicate the

scope for disturbance to archaeologicalfeatures beyond the immediate footprint ofconstruction. Visual assessments may indicatethe envelope within which the setting ofarchaeological features is affected. Earlyintegration of archaeologists within thedevelopment team will help to identify theadded value to be obtained from other studies.

Information from other sources

4.2.8 A range of primary and secondary sourcesof information about the historic environment isavailable. The main data sources for the differenttypes of historic and archaeological material aresummarised in the table below, but othersources do exist, and developers will be guidedin this regard by the archaeological consultant/contractor.

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5.1 As noted above, the possible effects of anoffshore renewable energy scheme on thehistoric environment may be considered byregulators in determining whether a scheme isto receive consent, or in deciding whatconditions might apply. The presence ofelements of the historic environment may haveimplications for the design of a scheme, eitherbecause additional statutory consents arerequired, or because of the constraints theyplace on construction. The risk of incurringcosts and delays as a result of unexpectedlydiscovering an important archaeological site inthe course of construction is also likely to be anincentive to careful consideration of the historicenvironment when developing a scheme.

5.2 In addition to all these powerful motives,however, is the specific requirement to addressthe historic environment – the architectural andarchaeological heritage and landscape – as partof Environmental Impact Assessment. Therequirements of EIA are defined in EuropeanCouncil Directive on Environmental Assessment85/337/EEC (amended in 1997 by Directive 97/11/EC) and the Directive has been incorporatedinto UK law through a series of sectoralregulations and policies. In practice, EIA hasrapidly emerged as the central process forconsidering the historic environment for all thereasons set out above, as well as for satisfyingEIA regulations themselves.

5.3 It is important, nonetheless, to recall thatEIA is only a partial mechanism for addressingthe historic environment. Although EIAanticipates all stages of the development of ascheme – from construction through operationto decommissioning – EIA itself ceases at thepoint an application is submitted. Where the EIAprocess is being relied upon to arrange historicenvironment provision for the entire duration ofa scheme, it is important that the EIA itselfincludes details of the implementationmechanisms that are to be employed in post-submission discussions with regulators, indetailed design, in the course of construction,and in monitoring thereafter. The responsibilityfor ensuring that consideration of the historicenvironment outlasts the EIA rests with both thedeveloper and the regulator.

5.4 The general application of EnvironmentalImpact Assessment to offshore renewableenergy developments is discussed in detail inDTI (2004) and CEFAS (2004) guidancedocuments, though only limited guidance isprovided in respect of the historic environment.There is, however, a considerable body ofpractice relating to the historic environment inEIA on terrestrial developments both in the UKand on the Continent, and an increasing body ofpractice relating to EIA and the marine historicenvironment.

5 Environmental Impact Assessment

27

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5.5 The following Guiding Principles for CulturalHeritage in EIA have been proposed (see box):

5.6 The process of EIA culminates in thepublication of an Environmental Statement (ES).As a result of the complexity of consentsrequired for marine development, applicationsfor some marine schemes (including someRound 1 offshore renewable energy schemes)have been accompanied by multipleEnvironmental Statements, each reflecting thespecific scope of the consent being sought.Happily, for Round 2 offshore renewable energyschemes, the DTI has indicated that only one ESnormally need be submitted to cover all of theconsents applied for, provided that the scope ofthe ES is sufficient to embrace all theenvironmental issues that each consent can beexpected to consider.

5.7 Although there may be only one ES, thereare a number of options for incorporating thehistoric environment within its pages. Theconduct of EIA will probably be speedier if, atthe outset, the developer, the consultantspreparing the ES and any specialistarchaeological consultants have a clearunderstanding of the structure that the ES is totake. It is common for the historic environment –as with other topics – to be addressed in astand-alone Technical Report. The ES may theninclude only a summary of the Technical Report,with the Technical Report submitted as anappendix. Alternatively, the whole content of theTechnical Report might be incorporated withinthe text of the ES as a ‘historic environmentchapter’. A further alternative is to split thebaseline, assessment and mitigation sections ofthe historic environment topic into separate

GUIDING PRINCIPLES FOR CULTURAL HERITAGE IN EIA

1. Cover all aspects of cultural heritage.

2. Integrate cultural heritage expertise into all stages of EIA, from screening throughto implementation.

3. Describe the project requiring assessment clearly and in sufficient detail toallow identification of all impacts that could affect the cultural heritage.

4. Define a suitably large study area to allow a clear understanding of the culturalheritage and the extent of potential impacts upon it.

5. Undertake all cultural heritage surveys and investigations to a high standardso as to ensure a full understanding of the nature and significance of the resourceand to allow informed decisions to be taken.

6. Assess all beneficial and adverse impacts on cultural heritage, including direct,indirect, temporary, permanent and cumulative effects.

7. Evaluate the significance of any impacts on the cultural heritage resource totake account of both the intrinsic value of the resource and how much it will bechanged. Use relevant international, national and local legislation and policy toexplain the significance, and make explicit the basis for any statementsconcerning value or importance.

8. Consider the likely effects on cultural heritage assets of alternative scenarios,including doing nothing.

9. Consider a variety of approaches to mitigation, including design modification,appropriate investigation and recording measures. Make provision forunforeseen effects. Propose realistically achievable mitigation measures andfully monitor and document any agreed actions, including responsibility fortheir implementation.

10. Ensure all communication relating to cultural heritage in EIAs is clear, focusedand accessible to the non-specialist. Archive and index all documentation in aclearly traceable manner.

Jones et al. 2006


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sections, which are integrated with all of theother environmental topics in baseline,assessment and mitigation chaptersrespectively.

5.8 There is also a variety of ways to structure ahistoric environment Technical Report,irrespective of the model adopted for the ESoverall. Depending on the details of the schemeand of consent processes, it may beappropriate to divide the treatment of thehistoric environment by environment (offshore;inter-tidal; onshore), by theme (wrecks;prehistory; coastal heritage), or by investigativemethod (desk-based study; geophysical survey;geotechnical survey). No two EnvironmentalStatements need be alike, so long as theircoverage of the historic environment isadequate.

5.9 A key consideration is the way in whichspecialist historic environment advice isincorporated into the ES. Again, there are anumber of alternatives. In some cases, historicenvironment sections are prepared by non-specialists. In other cases, historic environmentspecialists are responsible only for theTechnical Report, with the relevant text withinthe ES being compiled by an environmentalconsultant on the basis of the Technical Report.In other cases, the ES text might be drafted byan historic environment specialist, or at least besubject to checking by an historic environmentspecialist. As above, the key measure iswhether the ES is adequate, thoughcommentators have noted that the quality ofEnvironmental Statements in respect of thehistoric environment is usually better wherespecialists have been employed.

Environmental Impact Assessment

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5.10 A clear finding of several commentarieshas been that it is essential that themethodology used in various elements of theEIA process is made explicit, including the useof terminology. It may be useful to include aglossary of terms within the historic environmentassessment.

5.11 Even the terms ‘impact’ and ‘effect’ canbe a source of confusion. For the purposes ofthis guidance, ‘impact’ is taken to mean thephysical coincidence of a development activityand an element of the historic environment,whether it occurs through mechanical, chemicalor biological processes. ‘Effect’ is taken tomean the consequence for the historicenvironment, taking account of the change inthe public value of the historic environment thatresults from the impact, as well as the physicalchange. Hence the significance of an effect willbe a product of both the magnitude of theimpact, and the public importance of thehistoric environment asset that is impacted.

5.12 The historic environment is made up ofphysical features, but the value or importance ofsuch features arises from the attributions thatare given to them by current (and, we anticipate,future) populations. Although it is common toregard the physical elements of the historicenvironment (wrecks; monuments; artefacts) asthe ‘receptors’ that may be impacted bydevelopment, some attention is now turning topeople as receptors, focusing on the degree to

which peoples’ enjoyment or awareness of thehistoric environment might be impacted bydevelopment. The identification of people asreceptors may be important in addressingterrestrial, above-ground features including thebuilt heritage and issues relating to setting andlandscape/seascape. However, it should beacknowledged that physical components of thehistoric environment, both in the ground and onthe seabed, may be receptors of impactsirrespective of whether any person is yet awareof them at the time of impact, and theconsequent adverse effect on the historicenvironment may be significant nonetheless.

5.13 Clear expositions of the methodologiesthat are adopted for gauging the magnitude ofimpacts, importance of receptors, significanceof effects and so on are likely to be a key factorin achieving an adequate EIA. Effectiveassessment will require that suchmethodologies are tailored specifically to thecharacteristics of the historic environment.However, there will also be a need to ensurethat methodologies are consistent and can beassimilated with the methodologies forassessing other environmental topics.Consequently, EIA methodologies may bedriven by the overall requirements of thedeveloper and their environmental consultants,rather than by historic environment specialists.In such cases, the appropriateness of themethodologies to the historic environmentshould be checked and confirmed explicitly.

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6 Scoping and Archaeological Appraisal

6.1 ‘Scoping’ is the EIA stage at which thedeveloper may ask the regulator for their formalopinion on what should be included within theES, and in most cases this will be the firstcontact between developer, curator andarchaeologist. Developers will normally submit ascoping report to the regulator, which will setout the scheme details in outline, and also setout what the main environmental issues arethought to be and what will be done toinvestigate them in the course of EIA. As with allother environmental issues, preparation of thescoping report is a useful mechanism forprompting archaeological appraisal by therelevant curators, with a view to obtainingformal opinions on what the historicenvironment component of EIA shouldcomprise.

6.2 Developers of offshore renewable energyschemes should anticipate that the historicenvironment is likely to be identified as a keyissue by the scoping exercise, although thedetail will depend on the nature of the project,its location and its environment.

6.3 Although scoping reports frequentlyaddress the historic environment, there isconsiderable variety in how this is done.Scoping and the initial archaeological appraisalcan ‘set the tone’ for the relationship betweendevelopers and archaeological curators, so it isimportant that all parties make sure that theyare well-informed about the developmentactivities that might implicate the historicenvironment, and the background ofarchaeological data and policy. Scoping reportson the historic environment are sometimesprepared by environmental consultants who arenot specialists on the topic. However, it may beadvantageous for the developer to commissiona specialist consultant even for this early stage,as a background of experience in dealing withthe actual effects of offshore renewable energyschemes on the historic environment mayenable both developer and curators to achieve arealistic understanding of each others’responsibilities and concerns.

6.4 Although the curators’ archaeologicalappraisal is likely to be prompted by thescoping report, there is nothing to stopdevelopers from contacting curators pre-

scoping for informal advice. Both national andlocal curators usually maintain websites thatprovide the background to their role andresponsibilities, and there is an extensive rangeof published guidance available. Early contact isto be encouraged.

6.5 The formal opinion provided by curators inresponse to the scoping report will be a keydocument in specifying the scope of EIA inrespect of the historic environment. If anarchaeological contractor/consultant is to becommissioned after the scoping phase, it isessential that they have access to theseopinions at an early stage.

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• opportunities for conducting combined siteinvestigations;

• opportunities to design-out archaeologicalissues.

6.9 An iterative process of discussion betweendevelopers and their archaeological consultant/contractor regarding the scheme design shouldreduce or eliminate possible archaeologicalconstraints on the scheme and developmentimpacts on the historic environment. Thisshould result in benefits for the developer interms of savings of time and money while at thesame time optimising the preservation of thehistoric environment within the scheme area.

6.10 Whilst the archaeological contractor/consultant will want to receive a detailed finalplan of the scheme as early as possible, so thatthey can tailor their assessment accordingly, ithas to be recognised that in many cases thedesign of an offshore renewable energy schemewill be informed by conclusions reached in thecourse of the EIA. While this does mean thatthere is scope to design-out archaeologicalissues by changing layouts and cable positions,for example, care has to be taken to ensure thatdesign changes do not go outside theparameters of the archaeological assessment inrespect of, for example, geophysical survey.

6.11 The overall matter of how to balance theparameters of an EIA with flexibility in schemedesign is now often addressed in terms of the‘Rochdale Envelope’ of a scheme. Put simply,the Rochdale Envelope is a series of projectedmaximum extents to the development for whichthe significant effects are assessed. Thedetailed design of the scheme can then varywithin this envelope without rendering the EIAinadequate. The scope of archaeologicalassessment will need to reflect discussionsregarding the Rochdale Envelope of thescheme.

6.6 Whether an archaeological contractor/consultant is employed at the scoping stage orsubsequently, the developer and theirenvironmental and engineering team shouldestablish at an early stage the expected scopeof communication between their archaeologicalcontractor/consultant and the archaeologicalcurators. Normally, all communication will takeplace through the developer or theirenvironmental consultant, but somecommentators have suggested that the benefitsof ongoing and constructive dialogue –especially in areas where archaeologicalassessment methodologies are still developing– may require a greater level of communicationbetween contractor/consultant and curator thanis often the case.

6.7 The scoping phase provides an opportunityto obtain archaeological curators’ formalopinions on some problematic areas of marinearchaeological assessment. In particular,opinions could be sought on:• How extensive should Study Areas be?• What forms of field evaluation are expected

as part of EIA?• What levels of analysis are expected as part

of EIA?• What framework should be adopted for

ascribing importance to receptors?• What framework is likely to be advocated for

implementing mitigation?

6.8 The scoping phase also represents anopportunity for developers to integrate theirarchaeological contractor/consultant within theiroverall environmental and engineering team.This integration will be useful in achieving arange of practical arrangements that are likely toimprove the overall efficiency of the project, tosubmission of the ES and beyond. Integration islikely to facilitate:• data management;• access to other relevant specialist reports;


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7 Baseline Studies

7.1 The foundation of the EIA process is thecollection of baseline data. These are used toassess the environmental character of the arealikely to be affected by a development and toidentify relevant natural and human processesor factors which may change or influence thecharacter of the area. The historic environmentbaseline study equates with the process of‘desk-based assessment’ that is broadlyrecognised in other forms of development-related archaeology. Desk-based assessmenthas been defined in the IFA Standard andGuidance for Archaeological Desk-basedAssessment (1999) as:

a programme of assessment of the known orpotential archaeological resource within aspecified area or site on land, inter-tidal zone orunderwater. It consists of a collation of existingwritten, graphic, photographic and electronicinformation in order to identify the likely character,extent, quality and worth of the known or potentialarchaeological resource in a local, regional,national or international context as appropriate.

7.2 In general the objectives of the historicenvironment baseline study are to:• Provide an overview of the historic

environment in the area associated with thedevelopment, based on existingarchaeological records and secondarysources;

• Highlight known features, including sites andareas subject to statutory protection, thatmay be impacted by the proposed scheme;

• Summarise the potential for the presence ofhitherto unknown sites that may be impactedby the development;

• Comment on the importance of known andpotential sites; and

• Set out the statutory, planning and policycontext relating to the historic environment inthe development area.

7.3 The coarse nature of much of theinformation relating to the marine historicenvironment often makes it appropriate todefine one or more relatively broad Study Areasfor the baseline study. For maritime sites suchas wrecks and casualties, a broad Study Areawill help capture possible sites for whichpositional information is poor. For prehistoricmaterial, a broad Study Area that encompassesadjacent coastlines can draw in sites on landthat provide context for the former terrestrialarchaeological and palaeo-environmentaldeposits that may occur offshore.

7.4 The choice of Study Area will have toencompass the full extent of possible impacts,including indirect and secondary effects. At thesame time however, overly extensive areas willdraw in large volumes of data that are likely toprove irrelevant. The delineation of a Study Areahas therefore, to be carefully balanced foroptimal results.

7.5 Baseline studies carried out in the course ofEIA for other environmental issues are likely togenerate results that are relevant to assessing

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impacts of the scheme upon the historicenvironment. Sediment transport studies andvisual assessments in particular may be used tocheck that impacts on the historic environmentoutside the immediate footprint of constructionhave been adequately addressed. Equally, thehistoric environment baseline may inform thegeological baseline, and landscapeassessments.

7.6 The archaeological baseline should be clearin acknowledging the specific difficulties ofinterpreting the marine historic environment,which arise from weaknesses in availableknowledge and understanding. The baselineshould also address the characteristics of thetypes of site that fall within the scheme footprintsuch as:• The scope for prehistoric sites to be highly

concentrated or diffuse;• The high quality of survival of inter-tidal and

shoreline coastal sites;• The fact that wrecks may occupy an

extended area beyond the confines of anyremaining hull; and

• The potential for stray items lost or thrownoverboard to indicate preferred sea routesthrough the centuries.

The differences in former topography,bathymetry, geology and seabed type acrossthe development area should also be addressed,with a view to characterising variation inarchaeological potential arising from patterns ofhuman activity or from differential preservation.

7.7 The baseline is likely to cover the entirerange of human history, in terms of terrestrial, ofcoastal and of maritime activity. Although thefocus must be on the detail of the scheme, thecurrent level of archaeological knowledge andunderstanding is such that broadergeneralisations will also be required. Whereavailable, reference should be made to SEAs,marine Historic Landscape Characterisation orother regional overviews rather than seeking towrite the entire history of a sea area.

7.8 The baseline study should identify all theknown elements of the historic environment thatmay be impacted by the scheme. Of these, themost obvious are likely to be the sites that aresubject to statutory or planning designation, or

other forms of quasi-legal registration, such asProtected Wrecks, Scheduled Monuments,Listed Buildings, Conservation Areas,Registered Battlefields and so on. There is alsolikely to be a considerable number of otherwrecks, monuments and findspots whoselocations are known more or less precisely.

7.9 Beyond this ‘known’ archaeologicalheritage, the marine and coastal historicenvironment is characterised by a far wider‘potential’ heritage, which must also beaddressed by baseline studies. ‘Potential’ istaken to mean here that there are featurespresent that have not yet been found, but thefact that they have yet to be found does notmean that they are any less susceptible tosignificant effects than the ‘known’ heritage.Potential sites will encompass the full range ofperiods and site types, from wrecks to coastalstructures to submerged prehistoric sites.Geophysical and geotechnical surveys can playa large part in reducing potential by establishingthe actual presence or absence of sites within anarea, and by refining the extent of further‘potential’. A wide range of archaeological data,historic maps, documentary and secondarysources can be used in conjunction withgeophysical and geotechnical results in seekingto map archaeological potential.

7.10 ‘Potential’ will also need to be addressedby baseline studies in respect of features thatare clearly present but whose origin andcharacter cannot be determined from theavailable evidence. Of particular concern are thelarge numbers of indeterminate seabedanomalies that arise from geophysical survey, orare listed within monument and wreck indexesas anomalies or fishermen’s net fastenings. Alarge proportion of these are likely to prove to beof non-archaeological interest, being geologicalexposures, bed features or modern debris.Among their number, however, may be somehighly important sites. The cost of investigatingeach anomaly by diver or ROV is likely to beprejudicial to the overall scheme, especially priorto consent. Consequently, the baseline study willneed to be explicit about how such anomaliesare to be regarded for the purpose of assessingthe scheme’s effects, indicating eitherprecautionary mitigation or the conduct offurther investigation at a later stage.

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Baseline Studies

Figure 9. Known and potential

The historic environment includes features on a spectrum that ranges from ‘known’ to ‘potential’. Different types ofevidence – all with their own particular characteristics – have to be used in combination to arrive at an adequateassessment.

7.11 Baseline studies will have to ascribeimportance to both the ‘known’ and ‘potential’archaeological heritage as a basis for thesubsequent assessment of significant effects.Even where elements of the historic environmentare ‘known’ it can be difficult to ascribeimportance, partly because the character of the‘known’ feature will often be obscured becauseit is buried, and partly because thearchaeological importance of any feature isrooted in the intellectual enquiries of the

discipline. For many archaeological sites, theirimportance will depend on what is brought tothem by investigation. There are a number ofschemas available for ascribing importance toarchaeological sites, and baseline studies shouldbe transparent and consistent in bringing theseto bear. It should be noted that references todifferent forms of designation as a proxy forimportance, as is common in respect of speciesand habitats, will not suffice in an archaeologicalcontext.

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8.1 Overview

8.1.1 Geophysical and geotechnical data areusually gathered for offshore renewable energyschemes as part of the design process or toinform EIA topics such as seabed ecology. Asnoted above, these data are very important toassessing the effects of offshore renewableenergy schemes on the historic environment.Geophysical and geotechnical surveys are likelyto be among the most expensive and time-consuming elements of preparing an offshorerenewable energy scheme, both in terms ofsurvey fieldwork – which is subject to weatherand other operational vagaries – and theprocessing of huge volumes of resulting data.

8.1.2 There are several options to consider inseeking the overall integration of archaeologicalobjectives with geophysical and geotechnicalsurveys, within the overall context of developinga scheme. In early examples of archaeologicalassessment of marine development, it was notunusual for geophysical and geotechnicalsurveys to be entirely completed beforearchaeological interests were considered.Although there would still be scope forarchaeologists to make use of the resultingdata, the utility of the data for archaeologicalpurposes could be limited, especially where keymaterial – such as samples from boreholes –had already been discarded. To enable thesesurveys to provide data that supports historicenvironment analysis, it is important thatarchaeological objectives are an integratedcomponent of planning geophysical andgeotechnical surveys from the outset. It shouldbe noted that surveys only designed to fulfilengineering objectives to aid site evaluation donot directly equate with a survey strategynecessary to inform historic environmentexamination.

8.1.3 Ideally, geophysical and geotechnicalsurveys should be informed by prior desk-based studies, which should have identifiedknown features and key deposits that can thenbe targeted. Equally, the overall historicenvironment baseline should incorporate theresults of geophysical and geotechnicalsurveys, so the subsequent assessment isbased as firmly as possible on data relating tothe site, rather than on broader generalisations

from existing records and secondary sources. Itmay, however, be difficult to achieve the desiredintegration within an EIA programme, especiallyif surveys are hampered by weather. In practice,the incorporation of geophysical andgeotechnical surveys within offshore renewableEIAs has been achieved in a variety ofconfigurations. It may be advisable to seek theviews of archaeological curators if, foroperational reasons, the historic environmentbaseline is to be submitted before there hasbeen an opportunity to interpret geophysicaland geotechnical results.

8.1.4 Marine geophysical surveys can – withcare – be carried out over inter-tidal areas whenthe tide is high, providing a degree of overlapwith terrestrially-based techniques such asreviewing historic and modern air photographs,and carrying out walkover surveys.Geotechnical surveys can directed to fullymarine, to inter-tidal and to fully terrestrialareas, though the methods used will varyaccording to the operational requirements ofeach environment. On land, conventionalarchaeological techniques such as fieldwalking,terrestrial geophysics, test-pitting andevaluation trenching can all be employed.Guidance on the application of these techniquescan be obtained from national and localcurators.

8.2 Surveying wrecks and debris

8.2.1 The known and potential archaeologicalresource of ship and aircraft wrecks, and otherforms of historic maritime material, as identifiedby the prior desk-based studies requirecorroboration by data derived from geophysicaland geotechnical surveys.

8.2.2 Sidescan sonar survey can be used toobtain an image of wrecks and related debris ofall periods that lie (at least in part) above thesurface of the seabed. On previously knownwrecks, sidescan can confirm their presenceand provide information on their position,extent, and apparent character. Sidescan datacan also be reviewed in the search forpreviously unknown wrecks and features.Sidescan continues to be the pre-eminent toolfor identifying wrecks from wide area surveys.

8 Acquiring, Processing and Interpreting MarineGeophysical and Geotechnical Data

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8.2.3 Multibeam bathymetric survey can beused to obtain a high density of quantitativedata from wreck sites. The data can beespecially useful in seeking to identify wreckson the basis of their documented dimensions,and as a basis for subsequent survey by diversor Remote Operated Vehicle (ROV). Multibeamsurvey can be used to some degree when tryingto check for wrecks within an area, especially ifthe wreck is has considerable height or isindicated by a seabed feature such as scour ora ridge. Although multibeam data is quantitative,it is generally less dense than the qualitativedata provided by sidescan, which means thatmultibeam is generally inferior to sidescan incharacterising known wrecks or checking forthe presence of as yet unknown wrecks.However, the use of multibeam and sidescandata combined in a suitable visualisationpackage can be a very powerful combination.

8.2.4 Magnetometer data may help tocharacterise known wrecks by providing dataon the amount of ferrous material present(indicating whether a ship has a wooden ormetal hull, for example). Magnetic anomaliesmay also indicate the presence of as yetunknown ferrous material that is buried andtherefore not visible to sidescan. In the contextof offshore renewable energy schemes,magnetometer surveys are unlikely to beconducted at line densities sufficient to identifyall the anomalies within an area, and so are notappropriate as a tool for prospecting for wreckson their own. However, they can be a useful andrelatively inexpensive adjunct to sidescansurveys, even though the line spacing may berelatively wide.

8.2.5 It may be difficult using sub-bottom(boomer, pinger, chirp) surveys to resolve theoften shallow deposits that occur even onknown wrecks. However, in some instances afortunately-placed line of shallow seismic datacan help confirm the presence of a wreck that isbarely visible on the surface. Sub-bottomsurvey can help in assessing the potential forwrecks to be present by identifying deposits orburied features – such as now-buried but once-navigable channels – within which wrecksmight survive.

8.3 Surveying seabed prehistory

8.3.1 Geophysical and geotechnical methodscan be used in combination to addressprehistoric deposits.

8.3.2 Bathymetric survey, using single beam ormultibeam systems, can be used to establishthe basic framework for gauging the presenceof prehistoric material. The height of theseabed, in conjunction with secondary sourcesrelating to sea level rise, sets the broadparameters for when that area of seabed mighthave been exposed, and therefore inhabitable.Bathymetric survey may also indicate thetopography of the land surface that wasinundated, but in many cases the formertopography will have been buried, eroded orotherwise masked by a variety of processes, sobathymetry alone may be an unreliable guide.

8.3.3 Sub-bottom (shallow seismic) survey islikely to be the most productive tool in seekingto understand the prehistory of the seabed, as itcan show the deposits, cuts and surfaces of theprevious architecture of the land, and of thesequences through which it changed. Ideally,shallow seismic survey should be supported byborehole or vibrocore surveys, to confirm thesediments that have given rise to the acousticreflections seen using geophysics. Wherepossible, horizons that have been identified asbeing of archaeological interest on the basis ofgeophysical data should be targeted byboreholes and cores. Where an appropriatearchaeologically-informed methodology isemployed, samples from boreholes and corescan provide direct evidence of palaeo-environmental conditions and may be suitable

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for scientific dating. Such samples may alsocontain direct evidence of human inhabitation.

8.3.4 If a suitable methodology is employed,grab sampling of the seabed may provideevidence of the presence or absence ofprehistoric artefactual material at or just belowthe surface of the seabed. Grab sampling hasalso been used to map the extent of deposits ofprehistoric archaeological interest such as peat,if they outcrop on the seabed.

8.3.5 Although sidescan survey is of limited usein addressing prehistoric material, it cansometimes reveal geological outcrops that havea bearing on archaeological potential. Sidescantraces of bedforms can also be used to helpmap former topographies and their subsequentmodification.

8.4 Survey design

8.4.1 Although geophysical and geotechnicaldata are also an important primary source ofinformation about the historic environment, theirvalue in this respect can only be realised ifarchaeological objectives are added to theengineering or other environmental purposes forwhich the surveys are instigated.

8.4.2 Early consultation between the developerand archaeological curators, preferablyincluding the developer’s archaeologicalconsultant/contractor and geophysical orgeotechnical contractor, is essential to ensurethat archaeological considerations are takeninto account in planning geophysical andgeotechnical surveys.

8.4.3 Geophysical and geotechnical surveysshould be informed by such desk-basedarchaeological information as is available at thetime of the survey. Surveys should cover theentire extent of the scheme, to include cableroutes to shore as well as the principaldevelopment area.

8.4.4 As best practice, archaeological surveyshould always be incorporated with the primarygeophysical and geotechnical surveys. Thespecification of the geophysical andgeotechnical surveys (e.g. line spacing andequipment used) should be designed to ensurethe adequate detection of archaeologicalmaterial

8.4.5 In addition to incorporating archaeologicaladvice into the detailed specification of thegeophysical survey, it may be helpful for thedeveloper’s archaeological contractor to bepresent on board in the course of the survey, toenable their advice to be accommodated withinthe survey whilst it is still under way. This will beespecially helpful where anomalies or materialare detected during the survey that can befurther investigated by quickly modifying thesurvey plan, by acquiring more lines of data orby revising the position of cores or grabs, forinstance.

8.4.6 Surveys should be carried out to a singledatum and co-ordinate system, preferablyWGS84 UTM. All survey data – including

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navigation (position, heading and velocity) –should be acquired digitally in industry-standardformats. Care should be taken to maintain theorientation and attitude of sensors on line.Trackplots should be corrected for layback(including catenary effects) and made availablein digital (GIS) form.

8.4.7 Once the surveys have been processed tomeet their primary objectives, the survey data –together with factual reports – should be madeavailable in digital formats to the developer’sarchaeological contractor for archaeologicalanalysis and interpretation.

8.4.8 Sidescan sonar survey should be carriedout at frequency, range and gain settingscapable of resolving all objects that are 0.5mand above throughout the survey area.Preferably, line spacing should be equal to orless than the effective range, and no more than1.75x the effective range. Anomalies ofapparent archaeological potential should be‘boxed’ by at least two and preferably four linesalong and across the principal axis of theanomaly. These lines should be offset so thatthe anomaly does not lie immediately beneaththe fish, and run at optimal frequency and rangesettings for imaging the anomaly. Forarchaeological purposes, true sidescan ispreferable to multibeam pseudo-sidescan.Sidescan sonar data should be made availablein the form of raw, un-mosaiced files in asuitable proprietary format.

8.4.9 Sub-bottom survey should be carried outusing a source capable of resolving internalstructures to the full depth of anticipatedscheme impacts within Quaternary deposits.Line and cross-line spacings and orientationsshould be sufficient to resolve the extents andcharacteristics of the principal Quaternarydeposits. A single beam echosounder should berun in conjunction with the sub-bottom survey;the first reflector (seabed) should be levelledwith reference to a tide gauge. Sub-bottom datashould be made available in a suitableproprietary format.

8.4.10 Magnetometer survey should be carriedout using a caesium gas or equivalent systemcapable of resolving anomalies of fivenanoTeslas and above. Lines can be run in

conjunction with other sensors (i.e. on the sameline spacings and orientations) but provisionshould be made to run additional lines andcross-lines in areas of apparent archaeologicalpotential as indicated by the desk-basedinformation or any of the other sensors.Magnetometer data should be made availableas cleaned, de-spiked text (x,y,z) files for eachline, including layback.

8.4.11 Multibeam survey should be carried outusing a system capable of achieving aneffective cell/bin size better than 1m. Use of abeam-forming system is preferred. The entiresurvey area should be ensonified. Where ananomaly of apparent archaeological potential isidentified, an additional single slow pass shouldbe carried out at the highest possible ping rate.Single beam and multibeam data should bemade available as de-spiked and tidally-corrected text (x,y,z) files for each line, inaddition to any gridded/rendered surfaces.

8.4.12 Archaeological interest in boreholes andvibrocores will be confined to Quaternarydeposits, especially fine-grained materialindicative of low energy deposition, and peatyhorizons indicative of vegetated land surfaces.Engineering logs are unlikely to record sufficientdetail for archaeological purposes, but they canbe used to target further studies. It is essentialthat cores are logged relative to a knownvertical datum, together with their position.Where possible, opportunities should be takento target planned cores on deposits identifiedfrom desk-based studies or sub-bottomgeophysical surveys. If fine grained or peatyhorizons are anticipated, provision should bemade to obtain undisturbed cores that can becut or extruded under archaeologicalsupervision, to enable archaeological loggingand sub-sampling. Material from disturbedcores can also be sub-sampledarchaeologically, but the important stratigraphicrelationships within the core will have been lost.Subject to the results of archaeological logging,sub-samples may be assessed for the presenceof usable quantities of microscopic palaeo-environmental remains, such as pollen, diatomsand foraminifera. If the assessment isfavourable, analysis and scientific dating maybe warranted to provide detailed informationabout the previously inhabitable land, and about

Acquiring, Processing and Interpreting Marine Geophysical and Geotechnical Data

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how that environment changed in the course ofsea-level rise. This information will, in turn,facilitate assessment of the potential forprehistoric artefacts and sites to be found inthe vicinity.

8.4.13 The stages of acquiring, logging,assessing, analysing, dating and interpretingcores can be prolonged, especially asassessment, analysis and dating can takeseveral months. Depending on the anticipatedconsequences of the results for the scheme, thelater stages of this process may be deferred asthey may be considered to amount to mitigationrather than evaluation. The views of curators onthe timing of geoarchaeological investigationsrelative to the development process should besought in advance.

8.4.14 As noted above, grab sampling may beused to gather data on the presence or absenceof prehistoric artefacts on or close to theseabed. Provision can be made either toprocess archaeologically the mineral residues of

samples obtained for assessing benthic ecology,or to carry out grab sampling specifically forarchaeological purposes. Grabbing for benthicecology will generally be carried out on a lessdense survey pattern than archaeologicalgrabbing. In either case, the position of eachsample needs to be recorded on site. Samplescan be processed in whole or in part while onboard, or returned for processing ashore.Standard artefact-sieving procedures canusually be carried out, and any artefactsquantified, assessed and mapped relative to thetopographies identified by geophysical survey. Ifpeaty deposits are recovered in grabs, theyshould not be sieved; they are best retained asentire samples and processed as waterloggedremains in the laboratory.

8.4.15 Developers need to be aware thatintrusive activities that disturb the seabed, suchas coring and grab sampling may requireagreement from The Crown Estate and consentunder the Coast Protection Act 1949.


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9.1 As noted above, ‘impact’ is taken here tomean the physical coincidence of adevelopment activity and an element of thehistoric environment, whether it occurs throughmechanical, chemical or biological processes.‘Effect’ is taken to mean the consequence of theimpact for the historic environment, takingaccount of the change in the public value of thehistoric environment that results from theimpact, as well as the physical change.

9.2 The coincidence of development activitiesand the known and potential archaeologicalheritage can be established by mapping thefootprint of the scheme onto the results of thebaseline study. Care must be taken to ensurethat all impacts have been identified, includingindirect and secondary impacts, with referenceto the assessments carried out for other topics.Care must also be taken to understand thedetail of how development activities will becarried out, partly as a basis for subsequentlyassessing the effect, and partly to identifyopportunities for mitigation and monitoring.

9.3 For the coastal and marine historicenvironment, knowing the vertical extent of animpact can be as important as knowing thehorizontal footprint. For example, proposedcable laying may coincide horizontally withknown deposits of prehistoric interest on theseabed and in the inter-tidal area. However, ifthe cable is to be laid wholly within marinesediments that have been deposited or re-

worked on top of the prehistoric deposits, thenthe impact will be avoided. Equally, piles driventhrough a sandbank may have no archaeologicalimpact throughout much of their length, exceptfor where they puncture the veneer of prehistoricland surface immediately overlying the Tertiarydeposit into which the pile is to be driven.

9.4 Offshore renewable energy schemes oftenallow a fair amount of flexibility in the details oftheir layout relative to other forms of marinedevelopment. Consequently, the process ofidentifying impacts on the historic environmentcan be a productive opportunity for seekingminor design changes to avoid impacts,especially in respect of foundation structuresand cable routes, both offshore and on land.The impact identification stage can also be usedto flag specific constraints if avoidance is notpossible, such as the need to obtain licences forany works – including site investigations – thatfall within statutorily heritage designations.

9.5 Where unavoidable impacts are identified, itmay be helpful to classify them by the stage atwhich they will occur, their duration, and theirmagnitude.

9.6 The assessment of significant effects willusually be carried out by correlating impactsupon receptors with the importance of thereceptor, as ascribed in the baseline study. Ifboth magnitude of impact and importance ofreceptor have been classified, then a simple

9 Identifying Impacts and Assessing Effects

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matrix may be used to determine thesignificance of effects. Classifications ofimportance, impact and the significance ofeffect, combined within a matrix, have theadvantage of offering a transparentmethodology, and may also enable cross-correlation with effects arising from otherenvironmental topics. However, many suchschemes have been designed for dealing withsuch other environmental topics, and theirapplication to the historic environment may beinappropriate. More qualitative, textualdescriptions of effects may be moresympathetic to the characteristics of the historicenvironment and to the current state ofknowledge and understanding resulting in anassessment that is more adequate overall.

9.7 Where effects are assessed, it should bemade clear whether the assessment is withoutmitigation, or whether it assumes theimplementation of the mitigation proposed inthe ES. The effect ‘with mitigation’ is sometimesreferred to as the ‘residual effect’. It might beappropriate to record only residual effectswhere mitigation is to take the form of

avoidance by a modification to the schemedesign that has already been implemented.However, effects without mitigation should berecorded where the implementation of thatmitigation is not yet assured, either because thenecessary investigations have not beencommissioned, or because the measures will besubject to a condition or agreement that has notyet been concluded.

9.8 As indicated previously, EIA should identifybeneficial effects as well as adverse effects. Forthe historic environment, beneficial effects suchas improved access or the contribution to newknowledge that arises from investigation arelikely to depend on the implementation ofmitigation measures. As above, beneficialeffects that have been designed-in to thescheme can be highlighted, but beneficialeffects that are subject to unconfirmedmeasures should be dealt with more cautiously.

9.9 Gaps in data or methodology should behighlighted where uncertainty remains aboutknown or potential sites, about importance,about impacts, or about effects.


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10.1 Overview

10.1.1 The elimination of adverse environmentaleffects or their reduction to an acceptable levelis the essence of EIA. Mitigation measures arethose design and operational modifications orother measures implemented to avoid, minimiseor offset the adverse effects and enhance thepositive effects of a development during eachstage of its life.

10.1.2 Mitigation can take place at variousstages during the project life and for eachscheme will be based primarily on the measuresproposed in the EIA. Some mitigation may beimplemented pre-submission or pre-consent.There may be a requirement to implementmitigation measures, such as exclusion zonesaround archaeological sites and features, duringthe project design stage. Other measures maybe required during the construction, operationand decommissioning of a scheme.

10.1.3 Mitigation measures applicable toarchaeological sites generally take three forms:• Prevention or avoidance.• Reduction.• Remedying or offsetting.

10.2 Prevention or avoidance

10.2.1 Government policy and internationalbest practice favour the preservation in situ ofnationally important archaeological remains. Inaddition, the finite and non-renewable nature of

archaeological sites and material means that theprevention of significant effects by re-designingschemes to avoid sites should be viewed as thepreferred means of mitigation.

10.2.2 Preservation in situ has a practicaladvantage to offshore renewable energydevelopments. The nature of the offshoreworking environment means that marinearchaeological site investigation and excavationis expensive and time consuming. Theavoidance of identified sites and therebyreducing the possibility of direct or indirectimpacts helps to alleviate the risk to developerof having to support site excavation andremoval, and the subsequent stages ofinvestigation (e.g. post-fieldwork assessmentand publications) as set out in 3.1.3 above.

10.2.3 Avoidance of known sites can beobtained through the implementation ofarchaeological exclusion zones around eitherdiscrete sites or more extensive areas identifiedin the EIA. Exclusion zones precludedevelopment-related activities within theirextents. If exclusion zones will not impedescheme activities, they are a low cost solutionand can be used widely and in a precautionarymanner even if the actual character of the site isnot known. In this respect they are useful meansof dealing with unidentified anomalies or areasof potential. However, if the implementation ofan exclusion zone is likely to have an impact ondevelopment activities, the additional costsarising from the constraint might warrantarchaeological field evaluation to establish theactual presence and character of the feature,enabling the exclusion zone to be refined orremoved entirely.

10.2.4 The position, extent and design ofexclusion zones should be based on the bestavailable data for each site, taking into accountlocal geology, hydrology and sediment transportto ensure the continued stability of the sitesthroughout the period that the zone isoperational. Exclusion zones should beconsidered at a very early stage of projectplanning so that they can inform the layout andcabling of proposed schemes. As with allaspects of mitigation, early discussion witharchaeological curators about the position anddesign of exclusion zones is advisable.

10 Forms of Mitigation

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10.3 Reduction

10.3.1 Notwithstanding precautions to avoidarchaeological material, it is possible thatpreviously unknown archaeological sites ormaterial will be encountered only in the courseof the construction, operation ordecommissioning of a scheme. The effectsupon unexpected material can be reduced byputting in place measures to ensure that suchmaterial receives rapid archaeological attention.

10.3.2 In the case of inter-tidal and terrestrialareas, an archaeological watching brief can bean effective mechanism for monitoringdevelopment activities for archaeologicaldeposits, the presence and character of whichcould not be established (or established withsufficient certainty) in advance of developmentactivities. The purpose of a watching brief is torecord such deposits and recover any findswhen they are encountered. A watching briefcan also be used to trigger a more intensivearchaeological intervention if warranted by thediscovery.

10.3.3 Where there is continuing potential forarchaeological material to be present offshore,and the specific construction methods areamenable to archaeological monitoring, then anoffshore watching brief might be a viable option.However, the offshore marine environment andthe construction methods often associated withoffshore renewable energy schemes may besuch that an offshore watching brief is not apractical or effective option.

10.3.4 Where the potential for previouslyunknown archaeological material to beencountered or recovered during offshorescheme works is more general, appropriatemeasures will need to be in place to ensure thatany finds are promptly reported, archaeologicaladvice is obtained, and any recovered materialis stabilised, recorded and conserved. Thesemeasures can be set out in a formal protocol, asdiscussed below.

10.4 Remedying or offsetting

10.4.1 In some cases, it may not be possible toavoid a known site by design or theimplementation of an exclusion zone. In thesecircumstances, the effects of the scheme can beremedied by carrying out excavation andrecording prior to the impact occurring. Althoughthe site will be destroyed, the informationembedded within it will be ‘preserved by record’.

10.4.2 Intrusive investigation can becomplicated and time consuming, and in marineand coastal environments it is likely to result inthe recovery of finds and structural material thatwill be unstable unless conserved.Consequently, the developer will be responsiblefor any intrusive investigation and all associatedpost-excavation stages of evaluation through todissemination and deposition of the archive.Careful planning by the developer is thereforeessential to ensure sufficient resources areallocated to support such work to establishedarchaeological practice (see 3.1.3).

10.4.3 Intrusive investigation requires carefulplanning and it may be advisable to carry outone or more incremental evaluations prior tocommencing open excavation. Evaluation islikely to require a physical inspection by diver orRemote Operated Vehicle (ROV), possiblyfollowed by the excavation of small trenches, toobtain results that can inform the overallprogramme for site excavation and recording.Such work should take place well in advance ofthe anticipated impact. Where this is notpossible, sufficient time and funding must beprovided within the construction programmefor the work to be undertaken. Adequateprovision will also be required for post-fieldworkactivities through to dissemination anddeposition of the archive.

10.4.4 Other forms of remedy might include re-stabilising sites that have been destabilised (butnot destroyed) by development, or offsettingdamage to a site by detailed analysis andsafeguarding of otherwise comparable siteselsewhere.


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11.1 Conditions on consent

11.1.1 Consent for an offshore renewableenergy scheme is likely to be subject toconditions. Many of these conditions will giveeffect to mitigation proposed within the ES, andwill aim to ensure that the measures identified inthe ES are implemented. Where the ES hasidentified significant effects on the historicenvironment, developers should expect consentconditions that require the implementation ofarchaeological mitigation.

11.1.2 Although the details of mitigationmeasures will differ from scheme to scheme,two general measures are likely to beencountered among consent conditions, namelythe preparation and acceptance by the relevantcurators of:• An overall framework for archaeological

mitigation and/or monitoring during theconstruction, operation anddecommissioning of the scheme, usuallyreferred to as a Written Scheme ofInvestigation (WSI); and

• A formal mechanism for intercepting andreporting accidental discoveries ofarchaeological material in the course ofconstruction, operation anddecommissioning, referred to as a Protocolfor Unexpected Discoveries or similar.

11.2 Written Schemes ofInvestigation

11.2.1 The design and implementation ofmitigation measures should be informed by bestarchaeological practice and is likely to take theform of a Written Scheme of Investigation,which is a document that can be used to explainwhen, how and why mitigation measuresrecommended in the ES are to be implementedfor any given scheme. In designing mitigationmeasures, reference should be made to theopinions provided by curators during scoping. Itis advisable to discuss the content of a WSI withthe relevant curators in the course of itspreparation.

11.2.2 The objectives of a WSI are to:• Set out the respective responsibilities of the

developer, main contractors, and

11 Frameworks for Mitigation

archaeological contractors/consultants, toinclude contact details and formal lines ofcommunication between the parties and witharchaeological curators;

• Ensure that any further geophysical andgeotechnical investigations associated withthe project are subject to archaeologicalinput, review, recording and sampling;

• Provide for archaeological involvement inany diver and/or ROV obstruction surveysconducted for the scheme;

• Establish the exact position and extent ofarchaeological exclusion zones, andmethodologies for their monitoring,modification and/or removal;

• Propose measures for mitigating effectsupon any archaeological materialencountered during the operation anddecommissioning of the scheme; and

• Establish the reporting, publication,conservation and archiving requirements forthe archaeological works undertaken in thecourse of the scheme.

11.3 Protocols for UnexpectedDiscoveries

11.3.1 Unexpected archaeological material orsites may be encountered during worksassociated with construction, operation ordecommissioning. In anticipation of suchinstances, offshore renewable energy

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developments can be accompanied by formalprotocols for reporting discoveries, which willestablish the procedure for reporting such finds.Such protocols may form part of the WSI. Onceagreed by the developer and the relevantcurators they can be reproduced in formssuitable for use by project staff.

11.3.2 The aim of protocols for unexpecteddiscoveries is to reduce any adverse effects ofthe development upon the marine historicenvironment by enabling people working on theproject to report their discoveries or recoveredmaterial rapidly in a manner that is convenientand effective. The protocol will set out therespective responsibilities of the developer,main contractors, and archaeologicalcontractors/consultants, to include contact

details and formal lines of communicationbetween the parties and with archaeologicalcurators. The protocol therefore provides amechanism to aid compliance with theMerchant Shipping Act 1995 in respect torecovery of ‘wreck’, as defined by the Act andreporting of military vessel and aircraft wrecksto the Ministry of Defence.

11.3.3 The response to reported finds will beimplemented through measures set out in theprotocol, which may include the provision ofprompt archaeological advice, archaeologicalinspection of significant features prior to furtherconstruction in the vicinity, and theestablishment of archaeological exclusion zonesif appropriate.


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12 Monitoring

12.1 The provision made by a developer forimplementing mitigation measures will need toinclude measures to ensure that theimplementation is effective. The developer’smonitoring methods can be set out in the WSI,and may include periodic reporting onadherence to exclusion zones and the results ofwatching briefs.

12.2 Protocols can be monitored by means ofperiodic visits to construction vessels. Provisionshould be made for periodic reporting on theimplementation of the protocol. A requirementto report periodically on implementation of theprotocol even if no reports have been made(e.g. by a weekly note that ‘nothing has beenreported’) will help to ensure continuingawareness of the protocol.

12.3 Copies of monitoring reports should besubmitted to the relevant curators, who mayalso wish to set up arrangements for their ownmonitoring of mitigation measures, especiallywhere these are subject to conditions onconsent. Curators are likely to undertake aprogramme of visits to observe the

implementation of mitigation measures, as wellas requiring a formal structure for reporting andsigning off the implementation of the WSI,including post-fieldwork provisions, during thelife of the project. The scope of curatorialmonitoring may need to be agreed as part of theWSI itself.

12.4 At a broader level, provision should bemade for monitoring the accuracy of the EIAprocess in respect of the historic environment.In particular, measures should be put in place toestablish whether indirect impacts andsecondary impacts occur – and are mitigated –as predicted. Monitoring can also addressanticipated cumulative effects, with a relevancethat extends to other schemes in the region.

12.5 For monitoring to have any value inmitigating significant effects it will have to beaccompanied by a scheme of adaptivemanagement. Mechanisms must be in place toallow the results of monitoring programmes toinform subsequent development activitiesthroughout the construction, operation anddecommissioning of the scheme.

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Further Reading

BMAPA and English Heritage, 2003, MarineAggregate Dredging and the HistoricEnvironment: guidance note. BMAPA andEnglish Heritage: London http://www.bmapa.org/media.htm#news

BMT Cordah Limited, 2003, Offshore WindEnergy Generation: Phase 1 Proposals andEnvironmental Report. BMT Cordah:Penicuik. http://www.og.dti.gov.uk/offshore-wind-sea/process/phase1_env_report.pdf

Cadw: Welsh Historic Monuments, 1998,Register of Landscapes of OutstandingHistoric Interest in Wales.

Cadw: Welsh Historic Monuments, 2001,Register of Landscapes of Special HistoricInterest in Wales.

Cadw: Welsh Historic Monuments, 2006, Guideto Good Practice on Using the Register ofLandscapes of Historic Interest in Wales inthe Planning and Development Process (2ndrevised ed.).

Centre for Environment, Fisheries andAquaculture Science (CEFAS), June 2004,Offshore Wind Farms: Guidance note forEnvironmental Impact Assessment in respectof FEPA and CPA Requirements. Version 2.Centre for Environment, Fisheries andAquaculture Science: Lowestoft. http://www.cefas.co.uk/publications/files/windfarm-guidance.pdf

Clark, J., Darlington, J. and Fairclough, G.,2004, Using Historic LandscapeCharacterisation: English heritage’s review ofHLC Applications 2002–03. English Heritageand Lancashire County Council.

Defra, March 2006, A Marine Bill: a consultationdocument of the Department forEnvironment, Food and Rural Affairs,London.

Department for Communities and LocalGovernment, June 2006, Amended Circularon Environmental Impact Assessment.A consultation paper. Department forCommunities and Local Government:London.

Department for Communities and LocalGovernment, June 2006, Consultation Paperon Draft Marine Minerals DredgingRegulations and Procedural Guidance.Department for Communities and LocalGovernment: London.

Department for Communities and LocalGovernment, June 2006, EnvironmentalImpact Assessment: A guide to goodpractice and procedures. A consultationpaper. Department for Communities andLocal Government: London.

Department of the Environment, 1995,Preparation of Environmental Statements forPlanning Projects. The Stationery Office.

Department of Trade and Industry, March 2004,Guidance Notes: Offshore Wind FarmConsents Process. Department of Trade andIndustry: London. http://www.dti.gov.uk/energy/leg and reg/consents/guidance.pdf

Department of Trade and Industry, November2005, Guidance on the Assessment of theImpact of Offshore Wind Farms: Seascapeand Visual Impact Report. Department ofTrade and Industry: London. http://reporting.dti.gov.uk/cgi-bin/rr.cgi/http://www.dti.gov.uk/files/file22852.pdf

Department of the Environment NorthernIreland, 1999. Planning Policy Statement 6.Department of Environment, NorthernIreland.

English Heritage, 1996, England’s CoastalHeritage: A statement on the management ofcoastal archaeology. English Heritage andthe Royal Commission on the HistoricalMonuments of England.

English Heritage, 2002, Military Aircraft CrashSites: Archaeological guidance on theirsignificance and future management. EnglishHeritage: London. http://www.english-heritage.org.uk/upload/pdf/Mil_Air_C_Sites.pdf

English Heritage, 2002, Taking to the Water:English Heritage’s Initial Policy for theManagement of Maritime Archaeology in

www.bmapa.org/media.htm#news

www.og.dti.gov.uk/offshore-wind-sea/process/phase1_env_report.pdf

www.cefas.co.uk/publications/files/windfarm-guidance.pdf

www.cefas.co.uk/publications/files/windfarm-guidance.pdf

http://www.dti.gov.uk/energy/leg and reg/consents/guidance.pdf

reporting.dti.gov.uk/cgi-bin/rr.cgi/http://www.dti.gov.uk/files/file22852.pdf

http://www.english-heritage.org.uk/upload/pdf/Mil_Air_C_Sites.pdf

http://www.english-heritage.org.uk/upload/pdf/Mil_Air_C_Sites.pdf

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England. English Heritage: London. http://www.english-heritage.org.uk/upload/pdf/maritime_arch_policy.pdf

English Heritage, 2005 Wind Energy and theHistoric Environment. English Heritage:London. www.helm.org.uk

European Commission, 1985, Council Directiveof 27 June 1985 on the assessment of theeffects of certain public and private projectson the environment, (85/337/EEC). http://ec.europa.eu/environment/eia/full-legal-text/85337.htm

European Commission, 1997, Council Directive97/11/EC of 3 March 1997 amendingDirective 85/337/EEC on the assessment ofthe effects of certain public and privateprojects on the environment. http://ec.europa.eu/environment/eia/full-legal-text/9711.htm

Flemming, N.C., 2002, The scope of StrategicEnvironmental Assessment of North Seaareas SEA3 and SEA2 in regard to theprehistoric archaeological remains,Department of Trade and Industry ReportNo. TR_014.

Hill, M., Briggs, J., Minto, P., Bagnall, D., Foley,K. and Williams, A., March 2001, Guide toBest Practice in Seascape Assessment. TheMarine Institute: Dublin. http://www.ccw.gov.uk/Images_Client/Reports/ACF1676.pdf

Historic Scotland, 1999, Conserving theUnderwater Heritage: Historic ScotlandOperational Policy Paper, HP 6. Edinburgh:Historic Scotland.

Howard, T., Archaeology in the EnvironmentalImpact Assessment Process: AnAssessment of Current and Best Practice,Unpublished research paper.

Institute of Field Archaeologists, 2002, Code ofConduct. http://www.archaeologists.net/modules/icontent/index.php?page=15

Joint Nautical Archaeology Policy Committee,(2006), Code of Practice for Seabed

Development. JNAPC, c/o CBA: York. http://www.thecrownestate.co.uk/jnapc_code_of_practice

Jones, C. and Slinn, P., February 2006, CulturalHeritage and Environmental ImpactAssessment in the Planarch Area of NorthWest Europe. Planarch: Maidstone.

Lambrick, G. and Hind, J., May 2005, Planarch 2:A review of cultural heritage coverage inEnvironmental Impact Assessments in England– Final Report. Oxford Archaeology: Oxford.

Masser, P., February 2006, EnvironmentalImpact Assessment of Windfarms: culturalheritage and the problem of ’setting’.Headland Archaeology: Edinburgh. http://www.headlandarchaeology.com/Projects/Windfarms_EIA/Website_discussion_paper.pdf

Planning Guidance (Wales): Planning Policy 1996.

Planning Order (Northern Ireland) 1991. http://www.opsi.gov.uk/si/si1991/Uksi_19911220_en_1.htm

Royal Haskoning, 2004, Marine AggregateExtraction: approaching good practice inenvironmental impact assessment. RoyalHaskoning: Peterborough. http://www.dclgaggregatefund.co.uk/themea.htm

Scottish Office, 1994a. National Planning PolicyGuideline: NPPG5 – Archaeology andPlanning. Environment Department of theScottish Office.

Scottish Office, 1994b. Planning Advice Note:PAN 42. Archaeology – the Planning Processand Scheduled Monument Procedures.Environment Department of the Scottish Office.

Scott, K.E., Anderson, C., Dunsford, H., Benson,J.F. and MacFarlane, R. (2005). Anassessment of the sensitivity and capacity ofthe Scottish seascape in relation to offshorewindfarms. Scottish Natural HeritageCommissioned Report No.103 (ROAME No.F03AA06). http://www.snh.org.uk/pdfs/publications/commissioned_reports/F03AA06.pdf

http://www.english-heritage.org.uk/upload/pdf/maritime_arch_policy.pdf

http://www.english-heritage.org.uk/upload/pdf/maritime_arch_policy.pdf

www.helm.org.uk

http://ec.europa.eu/environment/eia/full-legal-text/85337.htm




www.ccw.gov.uk/Images_Client/Reports/ACF1676.pdf

www.ccw.gov.uk/Images_Client/Reports/ACF1676.pdf

www.archaeologists.net/modules/icontent/index.php?page=15

www.thecrownestate.co.uk/jnapc_code_of_practice

www.headlandarchaeology.com/Projects/Windfarms_EIA/Website_discussion_paper.pdf

www.headlandarchaeology.com/Projects/Windfarms_EIA/Website_discussion_paper.pdf

www.opsi.gov.uk/si/si1991/Uksi_19911220_en_1.htm

www.opsi.gov.uk/si/si1991/Uksi_19911220_en_1.htm

www.dclgaggregatefund.co.uk/themea.htm

http://www.snh.org.uk/pdfs/publications/commissioned_reports/F03AA06.pdf



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Securing the Future – UK Governmentsustainable development strategy, 2005.http://www.sustainable-development.gov.uk/publications/uk-strategy/index.htm

Welsh Office Circular 60/96: Planning and theHistoric Environment: Archaeology.

Wessex Archaeology, 2005, On the Importanceof Shipwrecks, Aggregate Levy SustainabilityFund: Marine Aggregates and the HistoricEnvironment.


www.sustainable-development.gov.uk/publications/uk-strategy/index.htm

www.sustainable-development.gov.uk/publications/uk-strategy/index.htm

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Glossary

Archaeology The study of the development ofthe human species and its environmentthrough their material remains.

Archive All parts of the archaeological record,including finds and digital records as well aswritten, drawn and photographicdocumentation.

Artefact Any object or part of an object whichhas been made, used or modified in someway by human beings. Common examplesinclude tools, utensils, art, food remains, andother products of human activity.

Bronze Age The period in history after theStone Age characterised by the developmentof bronze and its use, especially for weaponsand tools. In the UK the Bronze Age dates to2,400–700 BC and is divided into threephases – Early (2,400–1,500 BC), Middle(1,500–1,100 BC) and Late (1,100–700 BC).

Coastal margin Shallow coastal waters,beaches, dunelands, lowland rivers,estuaries, salt marsh and all adjacent landareas that are affected by potential andactual impacts caused by the dynamicmarine environment.

Contractor A person or organisationcommissioned to undertake archaeologicalresearch and fieldwork usually to a brief setby a curator.

COWRIE Collaborative Offshore Wind ResearchInto the Environment.

Curator A person or organisation responsiblefor the conservation and management ofarchaeological evidence by virtue of officialor statutory duty, including for exampleCounty, District or Council archaeologicalofficers, and the national bodies, EnglishHeritage, Historic Scotland, Cadw (Wales),and Department of Environment, NorthernIreland.

Defra Department for Environment, Food andRural Affairs.

Deposit Any accumulation laid down by humanoccupational activities.

DTI Department of Trade and Industry.

Feature Evidence of human activities visible asdisturbances in the soil. Such disturbancesare produced by digging pits for storage,setting posts for houses, or by constructinga hearth for cooking. These disturbances areoften distinguished by soil discolorations ornon-natural formations of stone, shell, bone,soil, coals, wood, etc.

Foreshore The area of a shore that liesbetween the average high tide mark and theaverage low tide mark.

GIS Geographic Information System.

Hard A firm or paved beach or slope convenientfor hauling vessels out of the water.

ICOMOS The International Council onMonuments and Sites (see http://www.international.icomos.org/about.htm)

In situ preservation The retention ofarchaeological items in the location wherethey were last deposited.

Inter-tidal zone see ‘Foreshore’.

Iron Age A cultural stage characterised by thefirst use of iron as the main metal. In the UKthe Iron Age dates to the period betweenc. 700 BC and 43 AD.

Medieval The period between the Dark Ages andthe Renaissance (11th–14th centuries AD).

Mesolithic A transitional period of the StoneAge intermediate between the Palaeolithicand the Neolithic periods, characterised byadaptation to a hunting, collecting, andfishing economy based on the use of forest,lakeside, and seashore environments.

Middle Bronze Age see ‘Bronze Age’.

Mitigation The process of avoiding, reducing orremedying adverse effects On theenvironment.

National curator see ‘Curator’.

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Palaeoenvironmental Relating to pastenvironmental/climatic conditions.

Palaeolithic The earliest of three subdivisions ofthe Stone Age, preceding the Mesolithic andNeolithic. It lasted several million years, fromthe first appearance of stone tools to theMesolithic microlith-using hunter-gatherersof the most recent postglacial period(± 8,500 years BC), and is normally dividedinto Lower, Middle and Upper phases.

Post-medieval The term used to describe theperiod covering the last 500 years, or sincethe end of the 14th century. In other areas itmay be known as Historical Archaeology.

Prehistoric The period prior to written recordsfor any given area which is revealed byarchaeological methods and interpreted withthe help of anthropological and historicalanalogies.

Receptor Means any sites or objects which are,or may be expected to be affected byactivities related to, in this case, offshorerenewable energy development.

Roman Refers to the period between AD 43 andAD 410 when parts of the UK were underRoman control.

SEA Strategic Environmental Assessment.

Site A location where human activities oncetook place and left some form of materialevidence.

UNESCO United Nations Educational, Scientificand Cultural Organisation (see http://portal.unesco.org)


http://portal.unesco.org

Historic EnvironmentGuidance

for theOffshore Renewable

Energy Sector

Prepared by Wessex Archaeology Ltd for COWRIEJanuary 2007

www.offshorewind.co.uk

This report was commissioned by COWRIE (Collaborative Offshore Wind Research Into theEnvironment). COWRIE is a registered Charity set up to raise awareness and understanding ofthe potential environmental impacts of the UK offshore windfarm programme. It was createdfollowing the completion of the second licensing round for UK offshore windfarms, and isfunded by developers’ non-refundable option fees. The Charity carries out three inter-relatedstrands of work: Data Management, Education and Communication, and GenericEnvironmental Research.

This report provides generic guidance in relation to the survey, appraisal and monitoring of thehistoric environment during the development of offshore renewable energy projects in theUnited Kingdom. It covers both the marine and coastal environments and those areas furtherinland likely to be affected by such developments.

The guidance is intended to promote the development of best practice in relation to the marinehistoric environment for the offshore renewable energy sector. It is also intended to promotean understanding of the conservation issues arising from the impacts of offshore renewableenergy projects on the historic environment, and in this way develop capacity amongstdevelopers, consultants and contractors.

ISBN-13: 978-0-9554279-1-6

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