The find was noted and then, more or less, forgotten. It was not until 1994 that archaeologists excavated what remained, by which point the drainage work itself had destroyed most of the site's stratigraphy and probably much of the original structure.

What survived was enough to reconstruct the essentials of a horizontal-wheeled water mill dating to around AD 800. A horizontal mill, sometimes called a Norse mill, works differently from the more familiar vertical wheel: water is directed through a narrow chute, called a flume, to strike a wheel mounted horizontally on a vertical shaft, which in turn drives the millstone directly above without the need for gearing. At Crushyriree, the flume had been carved from a single block of oak, with a rectangular channel roughly 0.3 metres wide and 0.34 metres deep that narrowed towards its lower end, deliberately designed to concentrate the force of the water jet. A rebate along one upper edge showed that the channel had originally been closed with a wooden lid. Beneath the flume, a substantial oak beam served as its support, fixed to the southern soleplate, the horizontal timber forming the base of the wheelhouse wall, by means of a lap joint. The undercroft, the low chamber housing the wheel mechanism, measured roughly 2.14 metres east to west and 2 metres north to south. Its northern stone wall had slumped inwards over the centuries, and the northern ends of the oak floorboards had completely decayed, but the southern soleplate survived intact, its mortices still clearly cut to receive the uprights of the wheelhouse walls. Among the structural timbers, all of oak, excavators also recovered a single small peg made of holly lying on the floorboards, a quiet detail that survives from a working mill on the banks of a Cork stream twelve centuries ago.