York Historic Environment Record

This fifth version of YAT report 2019/111 has been updated to include the results of 6 months water monitoring undertaken between August 2019 and February 2020 (Appendix 3). The water monitoring shows that the hydrology of the site is connected more to fluctuations in levels of the River Foss than to rainfall, which has lesser impact on the localised groundwater levels than fluctuations in river levels. The readings also suggest that changes in the river levels are relatively slow to affect the hydrology of the site and that any organic remains that may survive in the vicinity are therefore unlikely to be adversely effected by short-term fluctuations in river levels as long as this hydrological connectivity is maintained. Two dipwells (designated BH 5 and BH 11) were installed during the site evaluation conducted in August 2019. Due to the absence of organic-rich deposits a limited programme of fortnightly measurement of groundwater levels using an audible dipmeter was agreed by CYC and the HE archaeological science advisor, and carried out by YAT field team staff between August 2019 and February 2020.