The stream flowing out of the ridgeway just above Sutton Poyntz has always been a stable source of running water, and was almost certainly the reason for the location of the village. It once powered three separate mills for the grinding of corn. At the top end of Sutton Poyntz was the Upper Mill, later extended as a water pumping station for the supply of Weymouth (see below). The Mill House, now used as Waterworks offices, is an attractive 18th Century building, and may have been used as the model for the frontispiece illustration in the First Edition of Hardy's Trumpet Major. Signs of the header pond and watercourse for this mill are still just visible.

In the centre of Sutton Poyntz still stands Sutton Mill and the associated Mill House; the first an imposing 3-storey brick building dating from around 1815 and the latter an attractive stone house, built just a little later. The village duck-pond was the header pond for this mill; the mill continued to operate until after the 2nd World War, and most of the machinery is still in situ.

One other mill operated further downstream, near the Bridge Inn in Preston. This mill closed down in the 1890's, but the Mill house still exists, just behind The Bridge.

From the documents we have found, it appears that one of the mills is ancient, but it is not obvious which. The earliest clear reference that we have found to a mill is dated 1273; slightly later in 1435, at the death of Alice de Bures (see above), the manor of Sutton Poyntz is stated to have a watermill for grain (the description says it had a house and 10 acres, which could fit the Upper Mill or Preston Mill), and an out-of-use fulling mill. Several 18th Century Harvey family documents refer to mills in Sutton Poyntz; the first, dated 1750 states that the manor has one watermill, but a later one dated 1780 gives it 3 mills.The Harvey estate survey of 1788 refers to both Sutton Poyntz mills, but Preston Mill is not referred to explicitly until the Weld family commissioned a survey about 10 years later. From these sources, we tentatively conclude that Upper Mill in Sutton Poyntz dates back to at least the 13th Century, at least one other medieval mill was used from time to time, but that Sutton Mill and Preston Mill only existed continuously from the mid-18th Century.

The last operational mill, Sutton Mill, closed down in about 1960.

Water extraction

In 1855, the Upper Mill in Sutton Poyntz was sold to the Weymouth Waterworks Company, who installed pumping equipment to supply water to the town of Weymouth. Water had already been supplied to Weymouth from within the parish, from a spot known as Boiling Rock, but this new installation gave a larger and more secure supply. Among the equipment installed at that time was a funnel from SS Great Eastern (one of Brunel's ships), which was (until very recently) used for filtration.

Guarantees were given by Weymouth Waterworks for the continued volume of water in the stream flowing through the village. As a result, the site has one of the longest continuous records in existence of water flow.