Scheduled Monument: CALVER WEIR AND WATER MANAGEMENT SYSTEM 200M NORTH EAST OF STOCKING FARM (1021447)

REASONS FOR DESIGNATION A watermill uses the gravitational force of water to turn a paddled or bucket wheel, the energy thus generated in the axle of the wheel enabling the operation of varying kinds of machinery. The waterwheel can be set directly into a stream, with a simple 'shut' to control water flow, or may be spring fed or use tidal waters. More usually, however, an artificial channel, goit or leat, is diverted from the main watercourse and its flow to the wheel regulated by sluices. The spent water returns to the main stream via a tailrace which may be straightened to increase efficiency. Where the natural flow of water is inadequate, a millpond may be constructed to increase the body of water (and thus the flow) behind the wheel. During the medieval period, mills, usually used for corn grinding, were a sign of status, and an important source of income to the lord of the manor who usually leased the mill and its land to the miller. With technological improvements, an increasing range of equipment including fulling stocks, tilt hammers, bellows, and textile machinery could be powered by watermills, and they became increasingly important to urban and rural life and industry. With the advent of steam power and the introduction of iron gears in the 18th century, waterpower eventually became obsolete for major industry, although many smaller rural mills continued in use until well into the C20. As a common feature of the rural and urban landscape, watermills played an important role in the development of technology and economy. Many of those retaining significant original features or of particularly early date will merit protection. The weir and water management system of Calver Weir are a well preserved group of features representing several phases of the mill's development. They represent a major historic engineering enterprise, necessary to harness the power of one of the region's largest rivers, much of the course of which is included in a World Heritage Site which takes its name from the River Derwent. Features relating to early phases of the mill such as redundant sluice gates and a weir provide evidence of the changing technological developments necessary in the cotton industry as a whole and specifically at Calver. Buried archaeological deposits both within and below the earthwork banks running parallel to the goit will provide important details relating to the construction of the goit as well as palaeoenvironmental evidence relating to the natural landscape at the time the mill was built. The combination of structural evidence, archaeological deposits, documentary and map evidence provides this monument with a rare opportunity to enhance our understanding of the social and economic place the mill held in the wider landscape. DETAILS The monument includes the remains of Calver weir, goit and the water management system associated with Calver Mill. The mill itself is a Grade II listed building (LB 81617) and not included in the scheduling. The existing mill building represents the latest phase of the cotton mill but earlier mill buildings on the site are documented and mapped from at least 1752. The weir is situated in the River Derwent approximately three quarters of a kilometre downstream from the mill. The goit (water channel) runs almost parallel to the Derwent from New Bridge in the north, to the wheel house in the south. The weir was built in the first half of the 19th century by the family of Sir William Heygate, to serve Calver cotton mill. It is built of large squared grit stone blocks and forms an elongated reversed S, a shape designed to minimise the impact of flood waters. This weir replaced an earlier one close to the current site. A retaining wall, also of gritstone blocks, survives along the western bank of the river and would have served to prevent the erosion of the bank from the water as it flowed, at an angle, from the weir. A small quarry evident in the hill side to the west of the Shuttle House may have provided at least some of the stone used in the project. The goit provided a managed flow of water that enabled the amount of water which reached the mill wheel to be controlled, reducing the impact of flooding on the operation of the mill. The original goit appears to have been cut sometime between 1799 and 1804. In the 1830s or early 1840s, the southern stretch of the goit was diverted around the main mill building to a new wheel house to its south. The wheel house is a Grade II Listed Building (LB 81618) and is not included in the scheduling. Map evidence shows clearly the changes in the water management system over time. Such changes would have been essential to the running of the developing mill technology. The goit survives as a clay lined channel with linear banks following its contours on the eastern bank of the goit. Banks on the western side are also visible just north east of Stocking Farm and continue to immediately north west of the mill building. The banks survive up to 0.75m in height and approximately 2m wide. At its most northern point the goit flows through a tunnel under the garden of the Shuttle House, and emerges through a low grit stone arch about 80m south of the house. Originally the flow was regulated by gates beneath the Shuttle House but it is understood that the gates no longer survive. The tunnel and arch are included in the scheduling although the ground above these structures as well as Shuttle House are excluded from the scheduling. The remains of a sluice gate survive approximately 10m south of the edge of the Shuttle House garden. As the goit continues south it is crossed by two low arched bridges, which would have originally given private access to the riverside. Further south another bridge gives access to the mill complex but this is excluded from the scheduling, although the ground beneath it is included. East of Stocking Farm on the east side of the goit the scheduling extends slightly to include the visible and buried remains of an earlier weir and sluice. This is the point at which the original goit flowed into the northern side of the mill complex to turn wheels within the mill building. When the goit was rerouted is unclear but Ordnance Survey maps show the new line of the goit in place by 1840/41. As well as the built structures mentioned earlier all modern paths, fences and gates are excluded from the scheduling, although the ground beneath all these features is included. SELECTED SOURCES Other Reference - Author: Calver Weir Restoration Project - Title: Archaeological and Historical Gazetteer and Historic Map sequence - Type: DESC TEXT