Cyfyng overflow and outlet sluice, Swansea Canal at Ystalyfera OUTLET 14 OVERFLOW 18

Five openings of between 0.80m to 1m wide allowed surplus water to escape from the canal before it reached and damaged the Godre'r-Graig flight of locks (16 to 22) and their maintenance complex. Presumably, after sudden rain, the swollen Afon Twrch would have channelled substantial amounts of water into the canal by way of feeders 10, 11 and 12. The depth of water in the canal was regulated by stop-planks positioned on a timber sill. The canal could be drained for periodic cleaning by way of the accompanying outlet. The final remains disappeared in 1976.

Overflow & outlet SN 76286 08086

Stephen R. Hughes, 19.08.2007