Flash Lane Aqueduct, 290m north-east of the lodge.
Reasons for Designation
The provision of clean water has been seen as a public responsibility since early times. The earliest water-supply systems in Britain were built during the Roman period. Aqueducts supplied civil and military centres from wells, springs and impounded sources. Medieval water systems were constructed for monasteries as early as the twelfth century, and similar conduit systems were built for some medieval towns. Early supplies depended on gravitational flow from a spring to a conduit head. Conduits were pipes or channels used to convey and transport the water. Some conduits, such as that at Exeter in the 14th and 15th centuries, were laid underground, whilst others, such as Wells, ran in the street. In the 17th century, the construction of New River, an artificial watercourse supplying the City of London, was a major development. It was an exceptional example of a long-distance water-supply system, spanning as it did nearly 65km. Despite its technical and financial success, nothing of comparable scale was built until the impounding schemes of the late Georgian period. In the 19th century, the idea of universal access to water became prevalent. Developments in pumping stations, reservoirs and filtration plants were the forerunners of the modern supply system.
Despite later repairs and alterations, Flash Lane Aqueduct survives well. It is a major survival of part of the New River watercourse, one of the most significant and ambitious developments in water supply in England. As part of improvements to New River, it is testament to 19th century developments in construction technique, engineering and ever increasing sophistication of water provision; forming a forerunner to the modern supply system.
This record was the subject of a minor enhancement on 19 June 2014. The 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 includes a 19th century multi-span bridge and cast iron aqueduct, which once carried the New River over Cuffley Brook. It is situated at the foot of a river valley on the southern edge of Whitewebbs Wood.
The New River was a 17th century artificial watercourse designed to improve the water supply of the City of London. The aqueduct formed an integral part of 19th century improvements to the watercourse. It is a cast-iron trough, which rests on the central pier of a two-arch brick bridge with stone dressings. The trough is cast in four ‘E’-shaped sections, sealed with lead, bolted together and bolted onto deep side plates, 2.5cm thick. Brickwork has been added to the top of the side plates and it is cantilevered out at either end of the bridge to prevent water loss to the New River. Originally the base of the aqueduct was filled with clay to make it watertight.
The ‘New River’ was constructed by Sir Hugh Myddleton between 1609 and 1613 to carry fresh water to the City of London. The channel followed natural contours for a distance of nearly 65km from springs in Hertfordshire to reservoirs at Clerkenwell and from thence was piped in wooden pipes to the City of London. This system was improved in the 19th century by use of new reservoirs and pumping stations and some of the tortuous loops in the water course were 'straightened' out. In 1820, this resulted in the construction of the Flash Lane aqueduct. It was cast by Hunter and English of Bow and cost £252 2s. The brickwork was carried out by Henry Rogers at a cost of £265 11s. However by the 1850s the aqueduct was superseded by the installation of the pumping stations of the ‘New River Company’ (formed 1619). These enabled the Whitewebbs loop at Flash Lane to be bypassed completely, instead using the Docwra Aqueduct and embankment built in 1855. The dry channel gradually filled up with soil and was lost, until its course was traced and the aqueduct was excavated by the Enfield Archaeological Society in 1968-9. The rest of the channel of the ‘Old loop’ survives in places as a linear earthwork denoted by a wide ditch. Flash Lane aqueduct was repaired and restored in 1998.