The history of water milling in Gwalchmai is characterized by a long tradition of hydraulic exploitation that predates the more visible 19th-century windmill. The primary water mill in the parish was located near St. Morhaiarn’s Church, suggesting it served a centralized communal function for the village.
The earliest detailed records of the mill come from the mid-19th century. The 1841 census identifies William Williams as the occupant of both the water mill near the church and the land where the Gwalchmai windmill was later established. Following his death in late 1841, his son, also named William, took over the milling operations.
The technical expertise required to run these mills was often a closely guarded family asset. Records from 1833 also list Thomas Grey as a miller in Gwalchmai, indicating he may have worked at either the water mill or the windmill during that period.
Technical Specifications and Decline
Surveys conducted in the 1970s revealed the physical remains of the infrastructure:
- Structure: The mill near the church survived as an unroofed stone building measuring 8.2m by 4.9m.
- Machinery: It featured a wheel pit on the north side that once accommodated an overshot wheel approximately 0.9m wide.
- Water Source: The local stream course feeding the mill had been deepened through the former mill pond by the time of modern surveys.
A second site, Melin Ddrydwy, also existed within Gwalchmai. By the mid-20th century, its rubblestone shell had been converted into a cowshed. Inside the structure, a wooden beam was found bearing the carved initials “WTM”.
Water mills in Gwalchmai faced significant operational challenges due to Anglesey’s geography. While the island’s landscape provided many small streams, the water flow was often restricted to seasonal periods, and the drainage basins were subject to frequent dry spells. This unreliability necessitated a dual infrastructure where water mills and windmills—like the prominent Melin Gwalchmai—operated in a complementary fashion to ensure consistent grain production