2022:085 - Keshcarrigan to Castlefore Water Mains Scheme in Co. Leitrim, Leitrim

Archaeological monitoring of groundworks (consisting of twelve trenches) was undertaken along the western and eastern end of the R209 road. The scheme was located along the R209 to the north-east of Keshcarrigan village and comprised the installation of 2,074m of new/replacement water mains along the existing road network. The scheme forms part of an Irish Water nationwide programme to upgrade the existing water network.
The monitoring followed a preliminary archaeological screening assessment, undertaken for the scheme in August 2021 by AMS (Smith 2021). The assessment identified that the proposed scheme route impacted the Zone of Notification (ZoN) of one recorded archaeological site listed in the SMR (LE024 051:) and identified two areas of archaeological potential – one comprising the westernmost 850m of the scheme (incorporating the aforementioned recorded archaeological site and located close to the find location of the Keshcarrigan Bowl), and the other comprising the easternmost 920m of the scheme along the shoreline of Castlefore Lough, where at least one crannog is known, LE024-054.
The methodology for pipe installation within the ZoN for the burial (LE024 - 051) was originally planned to have been carried out using open-cut trenching to identify any subsurface archaeological remains or objects that may potentially survive. However, AMS were informed by the site engineer that this section of the road was not suitable for open-cut trenching due to underlying unstable ground conditions which would result in a road collapse. Therefore, a site inspection and assessment of site investigation results (previously undertaken close to the ZoN) was carried out, to supplement the desk-based screening assessment and determine the potential archaeological risk of directional drilling within the road carriageway in this area.
The engineer informed the archaeologist that the road was 1.5m higher than the surrounding flood plain on either side and site investigations indicate that the road had been built up and raised with imported material during its construction. The proposed depth of the directional drilling was limited to 1.2m and therefore the works had minimal impact on the original ground surface. The archaeological risk was thus considered to be low. Nevertheless, it was considered prudent to monitor associated proposed ground excavation works within/near the ZoN. These associated works were carried out with a toothless bucket and comprised a series of access pits for the directional drilling (five pits measuring generally 2.8m by 1m and 1.2m deep within the ZoN).
In line with the screening assessment recommendations, it was proposed to monitor the excavation of these launch and receive pits to identify any subsurface archaeological remains or objects that may potentially survive. If remains were discovered, an appropriate mitigation strategy (i.e., preservation in situ and/or preservation by record) was to be implemented in consultation with the National Monuments Service.
In line with the monitoring recommendation, all five launch and receive/access pits excavated within the ZoN for the burial (LE024-051) were carried out under the direct and continuous supervision of an archaeologist in order to identify any subsurface archaeological remains that may have survived.
No potential archaeological finds, features, or deposits were noted during the archaeological monitoring.
No additional ground disturbance works are required for this scheme and as such no further archaeological mitigation is proposed for this development.

Reference
Smith, F. C. 2021. Archaeological and Architectural Heritage Screening Report for Keshcarrigan to Castlefore Water Mains Scheme in Co. Leitrim. Unpublished report prepared by AMS for Jacobs on behalf of Irish Water.

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