The London Thames: a decade of research into the river and its floodplain

The 1991 Alluvial Archaeology conference ( Needham & Macklin 1992 ) coincided with the initial implementation of Planning Policy Guidance Note 16 (PPG 16) ( Department of the Environment 1990 ) which radically re-shaped how planning and developer-funded archaeology is undertaken in England. It has led to a far greater examination of the less archaeologically “visible” parts of the country, which in turn has led to more detailed examination of prehistoric sites and also palaeoenvironmental sequences. Nick Merriman’s paper at the 1991 conference ( Merriman 1992 ) indicated that in London, examination of the floodplain beneath the alluvium was beginning to lead to the discovery of important, hitherto unexpected, prehistoric sites. He argued for the importance of formulating a strategy for further examination of the floodplain. However, such targeting is not easily achievable through the modern planning process. Nevertheless a great deal of prehistory and palaeoecology has been examined over the last decade, but rarely with the coherent targeting suggested in 1991. This current paper will examine the constraints on archaeology in London and the achievements in the last ten years through both individual discoveries and synthetic geoarchaeological analysis. The examples will be based solely on commercially funded work, in order to make valid judgements of the effectiveness of PPG 16 within this sphere. Examples will include the Neolithic-Bronze Age discoveries within the north-east London wetlands ( Meddens 1996 ) and the prehistory and geoarchaeology associated with the construction of the Jubilee Line Extension (Neolithic to post-medieval) ( Sidell et al. 2000 ; Thomas et al. forthcoming).