Evaluation and Watching Brief at Winkburn Solar Farm Substation

Solar Farm Phase: The evaluation initially comprised the excavation of 34 trenches, all measuring 50m by 2m. An additional trench (Trench 35) measuring 65m by 2m was added to the scheme and trench 21 was extended by 7.5m based on the initial results. The locations of all trenches are detailed in Figure 2. All trenches were set out and the limits resurveyed using a Trimble VRS differential GPS accurate to +/-0.01m. The trenches were opened in a controlled manner using a 360 excavator using a flat-bladed ditching bucket under direct archaeological supervision. All topsoil deposits were removed in level spits (not more than 0.20m) with the topsoil and subsoil being separated to allow for re-instating in reverse order. Machining stopped at the first archaeological horizon or natural deposits, whichever was encountered first. All excavations of archaeological deposits were undertaken manually with the stripped surface being cleaned and investigated for archaeological remains. A soil sampling programme was undertaken consisting of bulk soil samples for the identification of plant macro-fossils, small animal bones and other small artefacts. All samples were taken from appropriate archaeological deposits, in accordance with the WSI and Historic England guidelines. All archaeological features were accurately recorded in plan at a scale of 1:20 or 1:50. Feature sections were drawn at a scale of 1:20. All plans and sections include spot heights that relate to Ordnance Datum in metres. All work was undertaken in accordance with the relevant standards (CIfA 2020; Historic England 2008) and in compliance with the WSI. A full written, drawn and photographic record was made of all archaeological work undertaken. Solar Farm Substation Phase: All investigations were undertaken in accordance with recognised professional standards (Historic England 2008, CIfA 2020a, 2020d) and ASWYAS methodologies (ASWYAS 2020). A full written, drawn and photographic record was made of all archaeological work undertaken. Trial Trenching- The evaluation involved the excavation of seven trenches, all measuring 30m by 2m. Trench were positioned to test features identified in the LiDAR data. The trial trenches were opened and the topsoil and recent overburden removed down to the first significant archaeological horizon in successive level spits of a maximum 0.2m thickness, by the use of an appropriate machine using a wide toothless ditching blade. Any machine work was carried out under direct archaeological supervision. Any archaeological features and overburden deposits were appropriately recorded. Watching Brief- The archaeological watching brief was conducted along the 3,245m long cable route from the substation to Roewood Farm. Depth of excavations were around 1m - 1.4m in accordance with cable route depth requirements. This was conducted using an appropriate machine, with a 0.7m wide toothless bucket. For trenching within Roewood Farm, a drill and handsaw were used to break the surface concrete. All ground reduction works were machine excavated with an archaeologist in attendance during any works within the watching brief area. Any archaeological features and overburden deposits were appropriately recorded. Solar Farm Phase: A scheme of trial trenching at Winkburn Solar Farm was successful in monitoring the removal of topsoil deposits to assess the resultant trenches for their archaeological potential. The trial trenching confirmed the presence of both Iron Age and Romano-British remains in the form of ditches and two pits. Evidence of post-medieval agricultural practices was demonstrated across the site, with plough furrows and field drains present, as well as drainage ditches in the eastern part of the site. It is recommended that any further archaeological work on the site is focused on the areas where Iron Age and Roman features have been identified.