Carreg Ddu Viaduct and Submerged Dam is a Grade II* listed building in the Powys local planning authority area, Wales. First listed on 31 July 1995. Terrace house.
Carreg Ddu Viaduct and Submerged Dam
- WRENN ID
- silver-lancet-fen
- Grade
- II*
- Local Planning Authority
- Powys
- Constituency
- Brecon, Radnor and Cwm Tawe MP: David Chadwick (LD)
- Country
- Wales
- Date first listed
- 31 July 1995
- Type
- Terrace house
- Address
- Carreg Ddu Viaduct and Submerged Dam, Elan Valley, Rhayader
- OS grid reference
- SN 910 639
- Coordinates
- 52.26294, -3.59799
- Source
- Cadw listing
Description
Carreg Ddu Viaduct and Submerged Dam is a significant structure built in 1900. It features a rock-faced brown stone viaduct that rests on a submerged dam. The viaduct has five narrow arches on the northeast side and seven broader elliptical arches at the center. It is topped with a parapet and has massive rock-hewn capstones at both ends. A stone plaque at the southeast end commemorates the laying of the stone by Alderman Charles Gabriel Beale, the Lord Mayor of Birmingham, in the presence of the City Council on June 19, 1900.
Local climate
Carreg Ddu Viaduct and Submerged Dam sits in one of the wettest parts of the UK, with an average of 1,200 mm of rain a year. This makes it wetter than 91% of listed buildings in the UK. Its exposure to wind-driven rain is greater than that of 84% of listed buildings.
It experiences an average of 54 freeze-thaw cycles a year, more than 95% of listed buildings. Of these, 33 follow at least 1 mm of rain in the preceding 48 hours. Average temperatures at this location have risen by 0.3°C per decade since 1991.
Averages for 1991–2020; temperature trend 1991–2025. Figures describe the wider area (a grid cell of roughly 10 km), not the individual site. Contains modified Copernicus Climate Change Service information 2026.
More on this building
Sign in or create a free account to unlock:
- No EPC on record for this property
- No sale records on file
- No related consent applications matched
- Detailed attributes — period, style, materials, features
- Flood risk assessment
- Radon risk assessment
- Weather exposure and heating demand — rain and frost month by month and year by year, wind direction, solar and humidity
Matched applications, energy data and sale records are assembled automatically and may contain errors. Flag incorrect data.
Similar buildings
The closest matches to this building from all 493,000 UK listed buildings, by architecture, period and materials.
this building 1 similar nearby listed buildings
Nearby listed buildings
- Foel Valve Tower
- Caban Coch Dam (partly in Llanwrthwl community)
- Caban Coch dam (partly in Rhayader community)
- Footbridge at hydro-electric station (partly in Llanwrthwl community)
- Footbridge at hydro-electric station (partly in Rhayader community)
- Hydro-electric Station below Caban Coch Dam (north power house)
- Hydro-electric Station below Caban Coch Dam (south power house)
- Cadan View
- Estate Office including House to rear
- Shelter and Fountain