With the numerous streams on the island, it's understandable that there were a large number of watermills - there were 24 recorded in the Doomesday Book.
Watermills tended to have advantages over other types of mill; they were not dependant upon the wind (as were windmills) nor limited by the tide times (as were tide mills).
The peak number of watermills was in the early part of the 19th century when the increase in military personnel and the local population combined to increase the demand for flour.
From the mid 19th century, reductions in the military population and changes in technology led to a reduction in the number of watermills however some buildings continued to be used as mills but powered by other energy sources.
Most watermills on the island were used to grind corn to produce flour for human consumption, however others were used for papering making, fulling or grinding animal feed.
Today, (2016), The one remaining operating watermill is at Calbourne, one of the mills mentioned in the Doomsday Book, where it grinds a small amount of flour as part of a tourist attraction. Other watermill structures still exist with the wheel in place, though not operating; such as Yafford and Gatcombe. While other mill buildings exist but without any visible evidence of their original function and at other mill sites, no evidence of the mill buildings remains.