The river turns to the north-west, and is joined by the River Whitewater, flowing northwards from Greywell, near Greywell Tunnel, the present end of the Basingstoke Canal. As it approaches Swallowfield, the channel splits and there are weirs on both branches. They enter Swallowfield Park, a grade II listed park and gardens. The park was enclosed by King Edward III in 1354, and remained the property of the monarch until the late 16th century, after which it was privately owned until 1965. The large country house was built in the late 17th century, was altered in 1820, and restored in the 1970s. The house and adjoining stable block are grade II* listed. The main drive to the house crosses the river on a five-arched brick bridge, dating from the late 18th century. The river continues through the park until it reaches the River Loddon. Milling There is clear evidence for one watermill on the Blackwater, but when the Domesday Book was compiled in 1086 there were four mills in the locality. The manors of Little Bramshill and Great Bramshill had one each, while there were two in the manor of Eversley. By 1237, the manor of Eversley was owned by William de Wauton, who mentioned a mill pond in an agreement he made with a tenant called William Banastre. When a dower was assigned to Ella de Bradeston in 1374, to provide for her should she become widowed, there was only one mill, which was ruined by 1435. There is no subsequent mention of a mill in the records of the manor. New Mill at Eversley dates in part from the 15th century, with 17th, 19th and 20th century alterations and additions. It is powered by an undershot water wheel, in the mill building. In 1948 it was bought by Squadron Leader Royston Albrecht, who restored it almost single-handedly between 1949 and 1976. He was a member of the Society for the Protection of Ancient Buildings, who used the restored mill to produce provender. Some of the machinery is believed to date from 1746, and the wheel drives two pairs of stones. The building was sold in 1995 to become a restaurant, and as part of the conversion process, a refurbished waterwheel was fitted while the machinery was shielded by a glass screen so that it could be seen from the restaurant area. The restaurant became insolvent in 2012 and