The Civil Survey of 1654 to 1656, a remarkable inventory of Irish land and resources compiled in the aftermath of the Cromwellian wars, noted 'fower Eele fishings' in the vicinity of Holycross Abbey, the Cistercian foundation on the Suir whose fame rested partly on its relic of the True Cross. Eels were a significant economic resource in medieval and early modern Ireland, and weirs built to trap them, typically low stone structures that funnel fish into a narrow channel or basket, were worth recording as property alongside land and buildings.

The first edition of the Ordnance Survey six-inch map, surveyed in 1840 to 1841, shows a curving weir crossing the river at this location. By the time the revised edition was published in 1952 to 1953, the same crossing appears as a shorter, straighter structure. Whether the change reflects rebuilding, partial demolition, or simply a difference in how the surveyors recorded it is not clear, but the weir's presence across more than a century of mapping, in roughly the same position each time, suggests a structure with considerable longevity. It may well incorporate stonework that was already old when the Civil Survey commissioners rode through Tipperary and counted the eel fishings of Holycross.