Rapid Coastal Zone Assessment Survey of Suffolk

 Changes taking place around the UK coastline have long been identified as having an impact on the archaeological resource. Coastal erosion, deposition and the movement of sediments around the coast have always influenced the survival of the archaeological resource within the inter-tidal zone and along the coastal littoral. Modern pressures (such as global warming, leading to an increase in mean sea level; the exploitation of coastal resources, through such activities as dredging; and new coastal defensive measures) have increased the pressures on the long-term survival of archaeological deposits, both along the coast and in the inter-tidal estuaries. Suffolk's intertidal zone is predominantly composed of relatively unconsolidated materials, laid down during the Pleistocene or Holocene periods. Whilst extensive deposition, in the form of mud-flats, salt mashes, sand dunes and shingle spits, does occur, there are lengthy stretches where erosion, along both coast and estuaries, predominates. Unsurprisingly therefore pressures on the modern coastline are many and varied, and a growing need to manage the changes that continue to take place has become imperative.

In order for archaeology to feed into strategic coastal planning policies it is, in the first instance, important to know what is there. The basic aims of the survey have therefore been to

To achieve these aims the project has taken two separate approaches; a desk-based programme involving:

• the plotting of archaeological features from major aerial photographic collections, in accordance with guidelines produced for English Heritage's National Mapping Programme, along with a study of all readily available map and documentary evidence, and
• a walkover field survey of the intertidal zone of the Suffolk coast and estuaries

The work has been funded by English Heritage and undertaken by the Suffolk County Council Archaeological Service.

 The desk-based work programme commenced in September 1999, and is not likely to reach completion until August 2004, due to the enormous amount of archaeological data recovered from aerial photographic sources. To date the survey has recorded 1140 new sites, the vast majority of which related to Suffolk's Second World War coastal defences as recorded from wartime RAF photography. These include extensive linear defences consisting of minefields, barbed wire, concrete anti-tank cubes and scaffolding, interspersed with pillboxes and gun batteries. The survey has also recorded specialist military sites such as the research stations at Bawdsey and Orford Ness. New sites have also been recorded in the inter-tidal zone including oyster pits, fish traps and various wrecks and jetties, the majority of which are likely to be of medieval or post medieval date. Interpretation of these types of features has been aided by the use of numerous historic maps and documentary references which have been collated by Ivan Ringwood from the University of East Anglia and will be aided further by the eventual integration of the aerial survey and field survey data.

The survey has also involved the mapping of a 1-2 km strip inland of the coast and estuaries, providing a context for the features recorded in the inter-tidal zone. This has lead to the accurate mapping and recording of extensive prehistoric and Roman cropmark landscapes for the first time and constitutes a significant enhancement of the county Sites and Monuments Record database. In addition the systematic survey has also lead to the discovery of a previously unrecorded small Roman villa site in the Deben estuary.

The desk-based survey has recorded features not found during the field survey and the field survey has discovered features not recorded during the desk-based survey, highlighting the complimentary nature of the two survey methods.

The field survey of the Suffolk intertidal zone was carried out between May and November 2002. This element of the project involved a rapid ground-based walkover survey of the intertidal zone along the rivers Blyth, Alde, Ore, Butley, Deben, Orwell and the north bank of the Stour to find and record features, structures and finds in mudflats, salt-marsh and eroded land surfaces. The coastal strip was also walked, although, as much of the Suffolk coastline is retreating due to coastal erosion, the discovery of new sites has been limited.

Access to and across the foreshore was negotiated with various national and regional conservation bodies, the Crown Estates as well as many individual landowners. Surveying was carried out according to low tides, beginning each survey two hours before the timetabled low tide and continuing until the particular survey area for that day had been completed or until the tide rose to a level which made further work impractical. Where the foreshore or mudflats were firm enough to walk over, they were subject to visual examination, to look for and identify finds scatters, man-made structures and exposed land surfaces. The vertical sections of eroded salt-marsh and land surfaces were also examined where accessibility of the foreshore made this possible. Where the mud was too soft to walk on safely or the salt-marsh too heavily dissected by creeks to traverse, surveying was done from the river bank or closest point of safety and binoculars used to search for sites on distant, inaccessible mudflats. Access onto the mud was generally poor with the exception of the Orwell and Stour where the majority of the foreshore was firm enough to survey as far out as the low water line. This was only possible in patches along the other rivers, the rest of the mud being too soft and thus presumably the result of continual deposition of river-borne silt and material eroding from the high tide line.

A total of 484 features were recorded within the Suffolk river estuaries over the course of the survey and included docks, jetties, red hills, tile kilns, fish traps, causeways and pottery scatters, as well as numerous military structures, hulks and unidentifiable post alignments. The majority of features remain undated but a quarter are present on first, second or third edition Ordnance Survey maps. Five red hill sites relating to Roman salt production were identified, four on the Alde around Snape and Iken, and one on the Blyth. Of these, two of the Alde examples were unknown prior to the survey. The aerial photographic survey has identified a number of other possible red hills on reclaimed marshland sites, one of which has so far been visited and confirmed as a Late Iron Age/Early Roman saltern. This information will improve our understanding of an industry which was previously little known in Suffolk.

 

Two fish traps were recorded on the Stour. These survived as rows of posts close to the low water mark with patches of wattle work alongside. Two further examples of wattle work visible in the mud of the Deben may also be related to fish traps. Although none of these structures are dated as yet, they are quite likely to be of Anglo Saxon or medieval date.

A number of finds scatters, jetties and docks appear to be associated with existing riverside farms and houses. In the past, rivers provided a vital and busy network for the transportation of goods associated with farming and industry, to the extent that probably all riverside dwellings had their own wharf or landing stage of some kind. In some instances, where jetties accessed the rivers below medieval manor sites, pottery scatters suggested that the site had seen long-term usage even if structural evidence for earlier periods was no longer evident.

 

In general, little of archaeological significance was discovered on foreshores where sea banks enclose reclaimed marshes, suggesting that deposits of any antiquity might be found in the reclaimed land behind these banks. Reclamation of this kind has occurred on a large scale in the Blythe, Alde, Ore and Deben estuaries, and as such, early sites have almost certainly been underrepresented by the survey.