Full Report for Listed Buildings
The list description is not intended to be a complete inventory of what is listed: it is principally intended to aid identification. By law, the definition of a listed building includes the entire building (i) and any structure or object that is fixed to the said building and ancillary to it and (ii) any other structure or object that forms part of the land and has done so since before 1 July 1948, and was within the curtilage of the building, and ancillary to it, on the date on which said building was first included in the list, or on 1 January 1969, whichever was later.
Summary Description
Reference Number
84118
Building Number
Grade
II
Status
Designated
Date of Designation
28/02/2005
Date of Amendment
28/02/2005
Name of Property
Dolau Siphon Inlet House
Address
Location
Unitary Authority
Powys
Community
Nantmel
Town
Locality
Dolau
Easting
301567
Northing
266924
Street Side
Location
To the S of Davarneithen Farm and on the W side of its approach road.
Description
Broad Class
Period
History
Part of the Birmingham Corporation scheme to supply water to the city from reservoirs in the Elan Valley. The project began in 1892 with the construction of the reservoirs and opened in 1904. Chief engineer was James Mansergh, joined and later succeeded as project engineers by his sons Ernest Lawson Mansergh and Walter Leahy Mansergh. The water was conveyed principally by means of a subterranean aqueduct, but where the river valleys caused the ground level fell below the hydraulic gradient one of the solutions was to direct the water into siphons that carried the water under the valley floors. Siphons consisted of cast-iron pipes of 42-inch (10.7cm) diameter, the relatively small dimensions of the pipe being offset by the high velocity of flow. Each siphon was designed for 6 pipes but only 2 were built in 1904, the remainder being reserved for an increase in future demand. A third pipe of 60-inch (15.2cm) diameter was completed in 1939 and a 4th pipe of the same diameter was constructed in the 1950s. Each siphon has an inlet and an outlet house where water is channelled to and from the main aqueduct. The water flows into a bell chamber beneath the railed forecourt, then into the pipes situated below the inlet/outlet houses, which house valve controls.
Exterior
A single-storey inlet house of brick with freestone dressings and rusticated quoins, on a battered rock-faced plinth. The roof is concealed behind a moulded cornice of reconstituted stone. The E side has central steel doors (beneath inscription bands now chiselled out) flanked by cross windows. The rear has 3 similar windows. The W front has forecourt railings on a rock-faced stone plinth, with diagonal sides to a central gate.
Interior
Reason for designation
Listed for its special architectural and historic interest as an integral component of one of the foremost civil engineering projects of the early C20 in Wales.
Cadw : Full Report for Listed Buildings [ Records 1 of 1 ]
Export