The Bybrook, also known as the By Brook, is a small river in England. It is a tributary of the Bristol Avon and is some long. Its sources are the Burton Brook and the Broadmead Brook, which rise in South Gloucestershire at Tormarton and Cold Ashton respectively, and join just north of Castle Combe in Wiltshire. The river has a mean flow rate of as recorded at Middlehill near Box. A variety of flora and fauna is supported by the river including the endangered white-clawed crayfish. Twenty watermill sites have been identified on the river but none now remain in use.
Course
The Burton Brook rises near Lower Lapdown Farm at Tormarton and runs in an easterly direction towards the village of Burton on the Gloucestershire-Wiltshire border. The Broadmead Brook rises at Folly Farm at Cold Ashton and runs eastwards south of the Burton Brook; the two join below Gatcombe Hill, just north of the Wiltshire village of Castle Combe, at the beginning of a steep valley.
The Bybrook now flows southwards towards the village of Ford. Just before the village, the Danscombe Brook and another unnamed tributary join on the right bank from North Wraxall and Colerne Airfield. On through Slaughterford and turning southwards, the Bybrook is joined on the right bank by the Lid Brook at Drewett's Mill, north of Box; locally, the Bybrook is more commonly referred to as the Weavern downstream of Weavern Farm. The stream now runs in a southwesterly direction through a shallower valley, past Shockerwick House, before joining the Bristol Avon at Bathford, at a point adjacent to the main railway line from London and the A4 road.
Mills
There is evidence of at least 20 mill sites along the Bybrook; many were seasonal and only operated when there was sufficient water. In Roman times, the mills were exclusively used for grinding corn, but by the end of the 12th century, this part of Wiltshire became an important centre for the wool trade. Mills were converted to the cleansing and thickening of wool, a process known as fulling.
Fulling mills were established by Sir John Fastolf in Castle Combe, along the Bybrook, in the thirteenth and fourteenth centuries, supporting a thriving woollen industry. With the decline of the woollen industry in the 17th century, accelerated by the Civil War and plague, many mills returned to grain, and fulling finally ceased when steam power shifted cloth-making to the north in the Industrial Revolution. The rise in demand for paper for packaging from nearby Bristol led to many mills converting to papermaking in the 18th and 19th centuries. Among them was Bathford Mill, just upstream of the confluence with the Avon, where papermaking began in 1809; paper for banknotes and passports is still made there by Portals.
Chapps Mill paper mill, which is associated with Slaughterford although it is in Colerne parish, continued in production until the 1990s.
Named mills
Goulters Mill, also known as Littleton Mill (1773) was a corn mill mentioned in the Domesday Book.
Gatcombe Mill, also known as Gadcombe Mill, was of greater significance than Goulters Mill. It was known to be a corn mill in 1887 and continued in use until the 1920s. There is no evidence of use other than to grind corn, but the proximity to Castle Combe raises the possibility of earlier cloth industry unless water was insufficient.
Tanners Mill, also known as Old Mill (1887), which dates back to at least 1773, is now incorporated in the buildings of Lower Shirehill Farm. Due to inadequacy of water supply, this must have been a seasonal corn mill.
West Kington Mill. Its size and age seem to be similar to Gatcombe Mill. In 1887 it was a corn mill that also housed a shoemaker and a butcher's shop.
Wick Mill, also known as Longs or Langs Mill and Hennars Mill. This was derelict by 1887. In 1704, three mills in the parish of North Wraxall paid tithes: Doncombe Mill 4s, Ford Mill 3s 4d and Hennars Mill 4s. A cloth mill in 1802, by 1829 it became a grist mill.
Nettleton Mill is part of the Castle Combe estate. The buildings date from the 18th century. A grist mill, its undershot wheel was replaced by a turbine during the 19th century. In the 1950s and 60s, the turbine power was utilised at some time, probably when the stream flow became inadequate.
Castle Combe Mill. The stepping stone weir and sluice are all that remain, in the gardens of the Manor House Hotel.
Upper Colham Mill. A barn on the old mill site is reported to have been a weaving shed. A turbine was in use in the 20th century for a sawmill on the opposite bank from the mill.