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
16202
Building Number
Grade
II*
Status
Designated
Date of Designation
31/07/1995
Date of Amendment
31/07/1995
Name of Property
Caban Coch Dam (partly in Llanwrthwl community)
Address
Location
Unitary Authority
Powys
Community
Rhayader
Town
Locality
Elan Valley
Easting
292451
Northing
264489
Street Side
N
Location
About 6km SW of Rhayader centre.
Description
Broad Class
Water Supply and Drainage
Period
History
One of series of dams in Elan Valley built by City of Birmingham 1893 to 1904. Engineer James Mansergh. The scheme was amongst the greatest civic achievements of the late C19. The Corporation of Birmingham employed direct labour for the scheme which involved the construction of 53 km of railway to transport materials from the Wye Valley line at Rhayader, 4 dams, an aqueduct 126 km long, and a village for construction workers. The height of the reservoirs enabled water to reach the outskirts of Birmingham by gravity alone, without the expense of pumping. Provision was made for future expansion in the Claerwen Valley where the scheme was brought to its current state by the Claerwen dam in 1952.
Bronze plaque from dam (removed to visitor centre) says
" Caban Coch Reservoir
Total Capacity 8,000,000,000 gallons
Top Water Area 500 Acres
Top Water Level 822 feet above Ordnance Datum
Height of Dam above River Bed 122 ft
Depth of Foundations below River Bed 25 ft
Length of Weir 566 ft
Thickness of Dam at Base 122 ft 6 in
Estimated quantity of masonry 144,800 cubic yards"
Exterior
Masonry dam with massive heavily rock-faced blocks. To ends, spillways with parapet walls, spillways broaden as they drop, walls turning to become parallel with stream. Two rows of protruding blocks (used to support scaffolding during construction). At bottom of dam, two massive circular outlets with keyblock set in surrounds with piers to ends and pyramidal pediment with tumbled blocks. To each end of dam, platform with gigantic capstones worked to resemble natural rock; steps down to top of dam, arches to reservoir side, 3 windows towards dam, square outlet to spillway.
Interior
Reason for designation
Graded II* as part of one of the greatest civil engineering projects of C19.
Cadw : Full Report for Listed Buildings [ Records 1 of 1 ]
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