Site Event/Activity record ECH6728 - Chester Northgate Redevelopment: Archaeological Evaluation Report (March 2018)

Four archaeological evaluation trenches were excavated during March 2018 as part of the Chester Northgate redevelopment scheme. This work forms part of an ongoing programme of archaeological research and monitoring which includes the following: the compilation of an initial desk-based assessment in 2016 (ECH 6205), supplemented by two additional desk-based assessments, also produced in 2016, for areas of 'off site' groundworks at New Crane Street (ECH6296) and a new drain linking the site to the River Dee (ECH6297), also evaluations undertaken in 2015 (ECH 6203), 2016 (ECH 6220), 2017 (ECH6726) and 2018 (ECH6727). The work undertaken in March 2018 comprised the excavation of four small trenches (Trenches 1, 2, 4, 5); two further trenches (Trenches 3, 6) had also been planned, but, in the event, these were not excavated during the current phase of works. The primary aim of the work was to recover empirical evidence for the presence/absence and scale of construction overcuts outwith the retaining walls of the Forum shopping centre and the Crowne Plaza Hotel, in order to provide information on the character and depth of these and their impact on significant below-ground archaeological remains. Similarly, the trenching sought to locate and characterise the deep drains or sewers that were known to exist beneath the carriageways of Princess Street, Hamilton Place and Trinity Street, in order to determine the extent to which these had also destroyed the significant archaeology beneath the roads. On the south side of Princess Street, the overcut for the north wall of the Forum/Market Hall was recorded in Trenches 1 and 2, whilst the overcut for the south wall was found in Trench 4, on the north side of Hamilton Place. This feature was found to have a battered upper edge, becoming near-vertical-sided at a greater depth, and was (except at the lip) quite narrow, from c 0.75-1.2m wide, as measured from the outer face of the retaining walls to the edge of the cut. Its maximum recorded depth below the modern surface was 2.61m (in Trench 1), but it could not be bottomed, either there or in the other two trenches. However, it seems highly probable that the overcut has completely destroyed all archaeological remains within 1m or so of the Forum’s retaining walls. The cuts for the main sewers beneath Princess Street and Hamilton Place were also located in Trenches 1, 2 and 4. These proved to be near-vertical-sided, c 1.45-2m wide and 2-2.5m deep (below the road surfaces), and had been dug to a sufficient depth to penetrate the natural bedrock, thereby destroying any archaeological remains at these locales. In Trench 5, on Trinity Street, no trace of the presumed overcut for the east wall of the hotel was found, nor was the sewer cut recorded. This was due to the fact that the western end of the trench, beneath the pavement, was found to overlie the eastern edge of the construction levels for the basement car park beneath the hotel, whilst the area beneath Trinity Street itself had been dug out to a depth of over 2m and backfilled with crushed sandstone at some point in the recent past, probably during the construction of the underpass linking the subterranean car parks beneath the hotel and the Forum. In addition to the disturbance resulting from the construction of the Forum and the insertion of sewers beneath the roads, much of the areas investigated within Trenches 1, 2 and 4 had suffered extensive damage from other modern activities. However, despite this, significant archaeological remains were found in situ in all three trenches, most notably in Trench 4, where an upstanding sandstone wall, almost certainly of Roman date, was recorded directly beneath modern overburden and service runs. In Trench 1, an extensive spread of charcoal rich soil lying above the natural geology was very probably an early Roman level. This overlay a linear feature, also presumably Roman, though the presence of post-medieval artefacts suggests that this had been disturbed. In Trench 2, significant archaeology was represented by a spread of sandstone rubble and ceramic building materials, presumably demolition debris derived from a Roman stone building within the legionary fortress, though, as this deposit was not excavated, its precise significance is unknown. (1)