Part of an extensive system of conduits fed from a leat from the river Cober.
Reasons for Designation
The system of conduits in Helston is designated at Grade II for the following principal reasons:
* Early date: an early example of a sanitation system laid out in the first part of the C19;
* Design interest: substantial sections have good quality detailing and construction of dressed granite;
* Intactness: though much renewed and replaced, the system retains its overall character and form;
* Group value and setting: the conduits are an integral part of the streetscape of Helston contributing significantly to the character of the town, together with the numerous listed buildings which line the streets.
The system of conduits at Helston is likely to date from the early C19, at a time when the town was still enjoying the prosperity brought by its position as a stannary town and an important centre for the local tin mining industry. The population of Helston rose from 2250 in 1801 to 3500 in 1841, but there was little expansion in the overall extent of the town, with the greater numbers being accommodated by small-scale infill housing. One result of the population boom was a major investment in public sanitation. There is a lack of documentary evidence regarding the inception of the conduits, but it is thought that these channels, known locally as 'kennels', were installed at this time, and may have replaced an earlier, less sophisticated system.
The conduits have undergone much repair over the years, involving the replacement and rearrangement of significant portions of their fabric, and the resurfacing of some elements. Repairs generally have used appropriate materials and stylistic finishes. Additionally, parts of the system have been covered over to provide wider roads, notably in Meneage Street. However, the channels remain extant beneath the road covering and continue to carry water.
Coinagehall Street is the town's principal thoroughfare, with civic buildings at the east end and the former Coinage Hall to the west, on the far side of Almshouse Hill; this, like the majority of the buildings which front Coinagehall Street, is listed. The status of the street is reflected in the quality and layout of the conduits.
MATERIALS: granite revetments, some dressed with linear and dimpled finishes to provide grip, some plain. Cut granite, shale or cobbled channel base. Iron grates.
PLAN & FORM: the topography of the town is key to the arrangement of the extensive system, which is fed from the diverted River Cober approximately 2km to the north, and feeds back into it to the south of the town. The majority of the system is below ground; only on the main roads through the centre are the channels exposed.
There is a conduit on either side of Coinagehall Street, between pavement and road, with several pedestrian granite bridges and C20 inserted concrete bridges. The upper(eastern) section, on the south side of the street, has a wider carriageway curb of cut granite, and the base of the channel is also of cut granite; this higher level of finish may reflect the proximity of the Town Hall. The water flows downhill to the west and the northern channel passes beneath a raised pavement and continues north down the eastern side of Almshouse Hill. The conduit in Almshouse Hill, which is crossed by a number of pedestrian and vehicular bridges, lacks the detailing which characterises the kennels of Coinagehall Street.