Period: 2010
Status: Completed
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- English Heritage, more, co-ordinator
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| Abstract |
Historic assets on the coast are vulnerable both to the effects of natural coastal change and to the impacts of coastal management schemes. Besides this coasts are under pressure due to the expansion of new or existing industries (especially ports) and residential and recreational development.
Shoreline Management Plans (SMPs) are the strategic high-level plans that set the long-term policy for coastal management (McInnes 2003, 50-61). An SMP should provide the basis for policies for a length of coast and set the framework for managing risks along the coastline in the future” and “identify the best approach or approaches … over the next 100 years” (Defra 2006, 11). The SMP does not consider how these policies should be implemented: that is dealt with in subsequent stages of planning. Defra has defined four possible options for lengths of coast known as Policy Units:
‘Hold the existing defence line’ will involve maintaining or improving existing defences;
‘Advance the existing defence line’ will relate to situations where new land reclamation is appropriate;
‘Managed realignment’ calls for the identification of a new sustainable coastal defence line and construction of new defences landward of the existing defences; and
‘No active intervention’ allows natural processes to proceed in an unconstrained way, with no investment in defences.
The latter two options in particular have impacts on the historic environment. ‘Managed realignment’ involves breaching sea defences, (some of them of dating back to the early 1st millenium AD), and construction works for a new sea-wall and/or new drainage systems for the realigned area, which may cut through buried archaeological sites. The effects of re-wetting buried sites with saline water is hard to predict, but very likely will be deleterious. ‘No active intervention’ permits continued erosion, which may have impacts on historic buildings, sites and landscapes. The first two options may also have some effects: defence improvement frequently involves contractors’ excavations to obtain material for raising sea-walls, whilst land-claim results in burial and compaction of foreshore sites.
Selection of the preferred option arises from a process of stakeholder consultation by coastal Operating Authorities and depends on balancing a wide range of factors in a sustainable way. Participation by EH is essential to maintain a high profile for the historic environment, but it was already clear by the 1990s that our knowledge of the coastal historic environment was particularly poor. English Heritage initiated a programme of Rapid Coastal Zone Assessment Surveys, which have been developed and refined with increasing experience.
By the end of 2007 surveys had been completed or were under way along the entire east coast, from Berwick to the North Foreland in Kent, in north-west England between the Dee and Solway, and in the Severn estuary. Earlier studies of the Isles of Scilly, Dorset and the Isle of Wight (pre-dating the RCZAS) are requiring some additional work to bring them up to the standard needed to supply information for the SMPs, as are some of the earliest RCZAS themselves. At the time of writing specific Briefs to undertake survey of the remaining parts of South East and South West England are under development, in collaboration with Local Authority and other historic environment professionals in those areas.
The RCZAS have two main phases. Phase 1 (Desk-based Assessment) draws on data from aerial photographs, LiDAR, historic maps, the local authority Historic Environment Records, the National Monuments Record and other sources. Phase 2 (Field Assessment) comprises a rapid walk-over survey, designed to verify records from Phase 1, locate and characterise site types not visible from the air, assess significance and vulnerability. 2 The outputs will comprise enhanced local authority Historic Environment Records and the digital transfer to the National Monuments Record of data, together with a client report (or reports) for English Heritage. Aspects of the results will also be presented in talks, leaflets and other publications (e.g. Hegarty and Newsome 2007). In due course, it is intended that a synthesis of the new results and their significance will be published to replace Fulford et al. (1997).
The information gained will permit us to make a more informed input to SMP consultation and development and will help to ensure effective mitigation of the effects of coastal change through the 21st century. It will also provide a data-base which may be used for further research and in the development control process |
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