The canalisation of the Afon Cletwr was undertaken as part of the 19th century drainage works for the Cors Fochno. The waterway was originally envisaged as being navigeable as far as the limekilns at Newydd. The map of Cors Fochno compiled by T Lewis in 1790 includes the annotation 'Line of navigeable canal marked out fully in 1788'. The embankments may comprise some of the earlier reclaimation work undertaken after an Enclosure Act for Cors Fochno was given Royal assent in June 1813. It appears that work on the Dyfi embankments had been completed by the end of 1818, as surviving documentation reveals contractors beginning to press the Enclosure Commisssioners for the outstanding balance of payment (£2500) in January 1819. The eastern embankment continues northwards and is cut by the railway line.

Sources include:
Lewis, T, 1790, Map of Cors Fochno, National Library of Wales
Colyer, R J, The enclosure and drainage of Cors Fochno (Borth Bog) 1813-47 in Ceredigion, Vol. 8, no. 2 (1977), p. 181-192

Maritime Officer, RCAHMW, January 2010