Site Event/Activity record ECH6726 - Chester Northgate Redevelopment: Archaeological Evaluation

A programme of archaeological evaluation trenching and borehole monitoring was undertaken during November and December 2017 as part of the Chester Northgate redevelopment scheme. This work follows on from compilation of a desk-based assessment in 2016 (ECH 6205), also evaluations undertaken in 2015 (ECH 6203) and 2016 (ECH 6220). Six archaeological test pits (TPs 1-6) were excavated and ten geotechnical boreholes (BHs 5, 6, 8, 11, 12, 13, 16, 20, 101,103) monitored. A seventh trench, representing an extension to the start hole for BH 101, was also investigated. The work was undertaken to inform the design process of the proposed redevelopment, by identifying the presence/absence and representative depth (according to Ordnance Datum) of significant archaeological deposits at key locales within the development site. The test-pitting demonstrated the existence of in-situ stratigraphy, including deposits of probable Roman date, at the south end of Trinity Street, adjacent to 68 Watergate Street (TP 4), where the top of significant archaeology seemingly lay only 0.5m or so below the modern surface. No archaeological deposits were recorded in the other five test pits, or in the borehole extension trench, though this may have been because these could not be excavated to a significant depth. Consequently, the possibility that intact archaeology survived beneath the excavated levels at some or all of these locations could not be ruled out. Of the ten boreholes investigated, what was probably the top of significant archaeological deposits was recorded in all three of those on Northgate Street (BHs 12, 13, 20), and in two of the three located within the former bus exchange north of Princess Street (BHs 5, 6). The presence of a seemingly undisturbed, post-medieval soil layer in BH 103, on Hamilton Place, also hinted at the likely survival of archaeological deposits beneath, though this remains uncertain. In BHs 8, 11, 16 and 101, only modern deposits were encountered in the start holes, though it is conceivable that intact archaeological remains survived at these locales at greater depths. Indeed, the possible existence of archaeological strata extending to a considerable depth was suggested by the borehole logs compiled for all but two of the boreholes (the exceptions being BHs 16 and 103, which were not drilled), which recorded zones of ‘made ground’ at depths of c 2-4m below the surface. Whilst the precise significance of this could not be determined, the recovery, from most of the boreholes, of small brick/tile fragments from these deep levels suggested that the ‘made ground’ may represent intact archaeological strata of considerable thickness. Although no archaeological remains were found in BH 16, the investigation was of value in suggesting the possible existence of a sand-filled overcut outside the south-west corner of the Crowne Plaza Hotel complex, though the exposure was too restricted for this interpretation to be entirely secure. Deposits of earth and rubble recorded in BHs 8 and 11 may also have been associated with the construction of the Forum shopping centre, but there too the work was too limited for there to be any certainty. (1)