Watercourse in Unknown Townland

Excavations carried out in 1996 by Linzi Simpson under licence no. 95E0045 for Margaret Gowen and Co. Ltd. on behalf of the National College of Art and Design (NCAD) uncovered a section of a medieval watercourse. The results of the excavation were summarised as follows; 'The site is located in the north-east corner of the National College of Art and Design, Thomas Street, which is currently under development. In medieval times it lay to the north of the hospital of St John the Baptist [DU018-020062-], which was founded outside the walled town of Dublin in the late twelfth century. At the time of the Dissolution, in the sixteenth century, the hospital was listed as owning three water-mills [DU018-020226-/0096-/982-] in the immediate area. As a medieval watercourse known as the ‘Glib water’ was thought to extend through the site under discussion, it was considered likely that one or more of the mills may originally have been located within the boundaries of the site. As a result an excavation was carried out in July/ August 1996. The site at NCAD straddles a steep slope, falling sharply from south to north (towards the Liffey), with extensive damage caused by deep Georgian cellars and a series of later concrete piles. At the southern end (the upper level) the archaeological deposits were almost completely removed by the cellars; however, the very truncated remains of a medieval watercourse were located, extending along the western boundary of the site and continuing down the slope towards the river. This U-shaped watercourse was cut into the natural boulder clay and, at the southern end, was 3m wide at the upper level, narrowing to 0.8m wide at the base. It had silted up over time and contained a large amount of Anglo-Norman medieval pottery. The watercourse may have turned to the north-east since the silt deposits were traced along the northern boundary of the site, orientated east-west (although this may represent an entirely independent watercourse). The truncated remains of a second watercourse were located along the eastern boundary of the site, also orientated north-south and feeding into the east-west watercourse. This was badly damaged and no measurements were obtained. The east-west section of watercourse 1 (following the line of Oliver Bond Street) was replaced c. 1600 by a stone-lined channel which followed the line of the earlier watercourse. It was built of limestone and was well faced, measuring 0.9m wide by 0.7m deep. The eastern watercourse was also replaced by a stone channel of similar dimensions; this was, however, slightly realigned. The channel, with its flagged base, was reused as a drain in the Georgian period and was partly sealed by a cobbled surface. It fed directly into the east-west stone channel. Both watercourses are presumed to have been related to the mills held by the hospital (marked ‘mills’ on Speed’s map of Dublin, dated 1610) which were still functioning at least until the seventeenth century. Watercourse 2 can probably be identified as ‘the Glib water' (Simpson 1997, 32; 1996:116 www.excavations.ie). This excavated section of the watercourse appears to be the same watercourse (DU018-020374-) depicted on John Speed's map of Dublin City from 1610. This map shows a watercourse or stream running E-W along St Thomas Street, at the E end of the watercourse there is a bridge (DU018-020228-) land immediately after the bridge the watercourse turns N possibly along the line of present day John's Lane West where it powers several watermills (DU018-020226-/0096-/982-) depicted on Speed's 1610 map where they are referred to as 'The mills' and shown standing opposite 'John's House' (DU018-020062-) labelled No. 54 on present day John Street. These watermills were located outside the city walls to the SW of Ormonds Gate (DU018-020029-) labelled 29 on Speed's 1610 Map. The watercourse possibly runs N along Mullinahack Lane enters the River Liffey to the N of the medieval mills in the vicinity of the modern Watergate House on Usher's Quay. On the 1610 this watercourse running along St Thomas Street labelled no. 51 on Speed's Map runs past the northern side of St. Catherine's Parish Church (DU018-020074-) labelled 57 on the map and then turns S running down past the W end of the church towards Thomas Court labelled 58 on Speed's map of the city. Cross-reference with DU018-020374- Simpson, L. 1995 Report on archaeological assessment at the National College of Art and Design, Phase III site at the old Power's Distillery, Oliver Bond St, Dublin, for Peter Doyle, Architects and the National College of Art and Design. Unpublished report 95E0045 submitted to the National Monuments Service. Simpson, L. 1995 Archaeological excavation at Oliver Bond Street/John St West/John's Lane, Dublin 8 (National College of Art and Design). Unpublished report 95E0045 submitted to the National Monuments Service. Compiled by: Caimin O'Brien Date of upload: 26 June 2023