Part of the Dorchester Roman Aqueduct.
Reasons for Designation
An aqueduct is an artificial channel used to carry water. All known Roman aqueducts functioned on a gravity flow principle, whereby a water source was impounded at a higher level than the place to be supplied, and was then made to flow to it under the influence of gravity. Water was needed for domestic purposes including bathing and drainage, and also for some industrial processes. Three main types were built; pipeline aqueducts carried water through enclosed pipe work which was normally ceramic, lead or wooden. Channel aqueducts carried water in U-shaped channels, normally a wooden or stone duct, which was either open or covered by stone flags. Leats were the simplest form of aqueduct, and carried water in an open channel dug into the ground and generally lined with clay. They often extended for several kilometres following contour levels. Bridges or other forms of support were used to carry the aqueduct over ravines and uneven terrain such as streams or rivers. The earliest aqueducts date from the period immediately following the Roman Conquest of Britain. These early examples are associated almost exclusively with military activity and provided water to forts. By the end of the 2nd Century, most forts and also public towns had been provided with aqueducts, the need for water being driven particularly by the construction of elaborate bath houses, and the developing fashion of bathing as a social activity amongst both the military and civilian populations. Aqueducts were used throughout the Roman period, and some were still functioning into the 5th century AD. They were found throughout Roman Britain with particular concentrations along Hadrian's Wall. Only 60 have now been identified to survive. Roman aqueducts are a rare monument type which provides an important insight into Roman engineering skills and both military and civilian life, all surviving examples are important.
This part of the Dorchester Roman Aqueduct survives well and will contain further archaeological and environmental evidence relating to its construction, longevity, social, political and economic significance, technical achievements and overall landscape context.
This record was the subject of a minor enhancement on 17 December 2015. This record has been generated from an "old county number" (OCN) scheduling record. These are monuments that were not reviewed under the Monuments Protection Programme and are some of our oldest designation records.
The monument, which falls into six separate areas of protection, includes part of a Roman aqueduct which carried water from the River Frome to Dorchester and sinuously follows the contours on the western side of the Frome valley. Originally measuring approximately 19km long and with a total drop of 7.6m, it survives differentially along its length as earthworks including scarp slopes of up to 2.5m high or as entirely buried features visible on aerial photographs. Between 1855 and 1956 excavations have been carried out at 14 different points along its length. These revealed it was constructed as a flat bottomed channel cut into the chalk ranging from 1.8m up to 3.1m wide and from 1.8m up to 2.1m deep with steep sides and the originally excavated material was used to produce an outer bank or form a terrace depending on the terrain. It was apparently not covered or lined except for the section known as ‘Poundbury Ditch’ where clay may have been puddled into the channel to prevent leakage. Some Samian pottery of 1st or 2nd century AD date was recovered and the aqueduct was abandoned during the 5th-6th centuries.