Long before the present buildings stood beside St Saviour’s Bridge, the River Otter had been harnessed for milling. The valley had supported water‑powered sites since the Saxon period, and by the Middle Ages the river was already lined with leats, weirs, and small industrial works. The concentration of mills at Otterton downstream shows how intensively the river was used, and Ottery St Mary formed part of the same pattern: a place where water power could be controlled and directed to serve the cloth trade that shaped much of East Devon’s economy.
The mill at Ottery St Mary took on its recognisable form in the late eighteenth century, when a substantial woollen mill was built on the east bank of the river. Its position was chosen for practical reasons. The bend in the Otter allowed the construction of a reliable leat, and the circular tumbling weir — an unusual engineering feature even today — regulated the water level with enough precision to keep the wheel turning through most seasons. The long brick and stone ranges that survive were designed for carding, spinning, and fulling, and for a time the mill formed part of the determined but ultimately fragile attempt to keep Devon’s woollen industry competitive as mechanised production in the north began to dominate the market.
During the nineteenth century the mill followed the familiar Devon pattern of adaptation. Wool gave way to silk for a period, and the buildings were altered as new machinery was introduced. The river remained the constant: the leat, wheelpit, and sluices were maintained because they were the mill’s lifeblood, and the site remained one of the most prominent industrial structures in the town. Its tall elevations and chimney were visible from the bridge and from the rising ground to the east, marking Ottery as a place where manufacturing still had a foothold long after many rural mills had fallen silent.
The most striking transformation came in the twentieth century, when the textile phase ended and the buildings were taken over for electrical engineering. Under the name Ottermill Switchgear, and later as part of Drake and Gorham, Scull, Westinghouse, and Eaton, the old mill became a centre for the production of medium‑voltage switchgear. The shift from water‑powered cloth to modern electrical equipment was considerable, but the fabric of the mill proved adaptable, and for much of the century it remained a major employer in the town. The river still ran beneath it, but the power now came from motors rather than the wheel.
By the early twenty‑first century production had ceased and the buildings stood empty, their long fronts looking out over the quiet loop of the Otter. Yet the site remains one of the most instructive industrial survivals in East Devon. In one place it shows the continuity of water power from the medieval mills of the lower valley to the eighteenth‑century woollen industry, and then the shift to modern engineering without erasing the earlier phases. The tumbling weir still regulates the river as it did in the 1790s, and the mill buildings still dominate the bend in the river, a reminder that the Otter was once the working engine of the town rather than a picturesque backdrop.
