Windsor Sewage Treatment Works, Old Windsor

An archaeological assessment of the site was undertaken by Oxford Archaeological Unit on behalf of Thames Water Authority for a proposed planning application at Windsor Sewage Treatment Works.

About 300m of trenching on this site suggested that it includes a low gravel terrace forming the core of the Ham Field promontory, and that this had a single phase field system, as yet undated. The field system extended onto the flood plain, where in one hollow the field ditch became filled with alluvial silt soon after it was dug, apparently coinciding with a rise in the permanent water table. The date of this event might be in the 2nd millennium BC, as suggested by Mark Robinson for Runnymede, (pers. comm.), or it could be much later, even related to mill construction on the nearby high status settlement of Old Windsor. Despite the archaeological gravel surface having been truncated by ploughing and lagoon construction related to the sewage works, the site has nevertheless produced prime evidence for a major hydrological event in this part of the Thames Valley.

Archaeological works in excavation showed part of an enclosure system in use in the Roman period in an area of Neolithic and Bronze Age activity.