The structure was not discovered through deliberate archaeological investigation but through necessity: it came to light during drainage works, when contractors cutting new pipework through the riverbed exposed foundations that had been quietly sitting there, unrecorded, for several centuries.

The weir was identified by archaeologist Ed O'Donovan, excavating on behalf of Margaret Gowen & Co. Ltd under licence No. 98E0581, as part of the wider Limerick Main Drainage Scheme. The work extended across a considerable stretch of the Abbey River, from Matthew Bridge down to Curragour Point where the Abbey meets the Shannon, and then along to Sarsfield Lock. Dating to the sixteenth or seventeenth century, the weir foundations pre-date both Charlotte's Quay and Bank Place, two of the quayside features that now define that part of the city. Archaeologists believe the structure functioned as a head-race, meaning it was built to channel and direct water flow to power mills on either side of the river: one positioned beneath what is now Bank Place, the other at the junction of Creagh Lane and George's Quay. Both mills may be connected to Nicholas Arthur's Mill, which appears on Hardiman's map of the city dated to around 1590, now held at Trinity College Dublin. The same excavation season uncovered further sections of Limerick's medieval town wall along George's Quay, and organic deposits from a sixteenth-century context contained the grain weevil Sitophilus granarius, a pest entirely dependent on human activity for its spread, suggesting grain storage in the vicinity of the mill.

There is nothing to see at river level today; the weir foundations are submerged and were reburied following excavation. But the area repays a slow walk along George's Quay and Bank Place, where the relationship between the medieval street plan, the later quay frontages, and the invisible river infrastructure below begins to make a certain sense. The Hardiman and Speed maps of the city, both reproduced in various local history collections, are worth consulting beforehand to see how this stretch of the Abbey River looked when the weir was still in use.