2023:810 - Annacotty Weir, River Mulkear, Annacotty, Limerick

Underwater Archaeological Impact Assessment (UAIA) took place of the River Mulkear as part of the proposed Annacotty Fish Passage Project. The UAIA was commissioned as part of the pre-design scoping phase for an appropriate method of providing safe passage for fish at the weir site in which seven potential solutions to the safe passage of fish upstream of weir structure were being explored.

The UAIA comprised systematic visual inspection of Annacotty Weir and the wider river area, extending 100m upstream and 230m downstream of the weir structure; ITM 564302E, 657484N – ITM 564199E, 657791N. The assessment sought to provide a detailed account of the existing river environment, recording riverbed topography, assessing the potential of the riverbed deposits to retain archaeological material, and identifying any additional features/structures of archaeological or historic significance that may be present. In addition, targeted metal detection was employed to help assess the riverbed and highlight any metallic concentrations present.

Three features of interest were observed as part of the survey, these include Annacotty Weir itself, its attendant millrace, and a downstream road-bridge: Features F01-F03 respectively.

Annacotty Weir (Feature F01, ITM 564291E, 657579N), comprising a v-shaped, structure that includes a Denil (baffle-type) fish pass to its apex, is associated with a late eighteenth-century corn mill (NIAH 21900605) located adjacent on the west bank of the River Mulkear. The former mill complex is built on the site of a probable paper mill, built in the mid-1700s. The existing weir structure differs from that of the original, as depicted on the OS historic map editions, and is likely to have been modified in the late 1800s, as part of the arterial drainage works associated with the Mulkear Drainage District works (1874) and later re-configured as part of an OPW drainage scheme in 1945.

A millrace (Feature F02, ITM 564272E, 657589 N – ITM 564254E, 657620N) is located on the west side of the weir structure and comprises a short headrace, sluice, by-pass gate, and tailrace that once powered an undershot mill-wheel no longer in situ.

A road-bridge, carrying Woodstown Road, is located 84m downstream of the weir. This structure comprises a masonry bridge (Feature F03, 564254E, 657656N), of probable early nineteenth-century date, which has been extended (using poured mass concrete) on both its upstream and downstream side. A second bridge is located a short distance further downstream (c. 20m), built in 1980s to carry an upgrade to the N7 and by-pass Annacotty.

The above features were recorded in detail within UAIA report.

No finds of archaeological/historic interest were recovered as part of the metal-detection survey. Despite this, a relatively good archaeological holding-content for the riverbed deposits is present. This observation, coupled with a concentration of industrial period activity surrounding the watercourse, lends increased potential to the stretch of river under assessment.

The on-site work was completed on 30 August 2023.