Cwm Du Outfall and overflow sluice on Swansea Canal is a Grade II listed building in the Neath Port Talbot local planning authority area, Wales. First listed on 26 October 1979. Gate lodge.
Cwm Du Outfall and overflow sluice on Swansea Canal
- WRENN ID
- low-brass-lark
- Grade
- II
- Local Planning Authority
- Neath Port Talbot
- Constituency
- Brecon, Radnor and Cwm Tawe MP: David Chadwick (LD)
- Country
- Wales
- Date first listed
- 26 October 1979
- Type
- Gate lodge
- Address
- Cwm Du Outfall and overflow sluice on Swansea Canal, Ynysmeudwy, Ystalyfera
- OS grid reference
- SN 741 058
- Coordinates
- 51.73679, -3.82396
- Source
- Cadw listing
Description
The Cwm Du Outfall and overflow sluice on the Swansea Canal is a structure that consists of two chambers. The first chamber, as described in the 1979 listing, is a stone-lined overflow chamber featuring a dividing wall with four stop planks and a paddle apparatus on the canal side. This chamber is currently covered with metal plates and has a black painted metal control box on top. The second chamber, located on the southeast side of the dividing wall, is visible but covered with a metal grid. This chamber is faced with stone and has a bow-shaped end wall with a small arched outlet.
Local climate
Cwm Du Outfall and overflow sluice on Swansea Canal sits in one of the wettest parts of the UK, with an average of 1,380 mm of rain a year. This makes it wetter than 97% of listed buildings in the UK. Its exposure to wind-driven rain is greater than that of 96% of listed buildings.
It experiences an average of 28 freeze-thaw cycles a year, fewer than 69% of listed buildings. Of these, 12 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
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- 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.
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