County: Donegal Site name: Tributary of Lough Foyle, St Johnstown
Sites and Monuments Record No.: N/A Licence number: 07D002; 07R007
Author: Rex Bangerter, The Archaeological Diving Co. Ltd, Brehon House, Castlecomer, Co. Kilkenny.
Site type: Riverine; tidal watercourse
Period/Dating: —
ITM: E 634941m, N 909760m
Latitude, Longitude (decimal degrees): 54.934327, -7.454781
Visual inspection and magnetometer survey by hand-held underwater metal detection was employed as part of the proposed St Johnstown sewage scheme, to assess the archaeological potential of a 150m section of riverbed and attendant bank structures. In-water impacts associated with the project included the proposed insertion of a 400mm-diameter (gravity-fed) sewer pipe under the riverbed, downstream of a disused railway bridge and running north–south across the watercourse. In addition, two outfall pipes will be constructed to carry the treated effluent discharge, located along the southern bank at NGR 234997 409772 and 234935 409774.
The survey area is located within the environs of St Johnstown, adjacent to the zone of archaeological potential identified for the village, DG055–028. The survey was undertaken at low water and a water depth of 0.25m was recorded for much of the survey area, a maximum water depth of 0.5m being recorded for the eastern limit of the survey. The shallow depths present negated the need for a dive survey, and the survey area was extensively and systematically waded/snorkelled. The assessment was comprehensive and extended beyond the boundaries of the proposed impact area. No archaeologically significant material, structures or deposits were encountered.
