I read it as only being a plan rather than having been dug.
There's another one linked from there too:
https://discovery.nationalarchives.gov.uk/browse/r/h/5cf9dab8-41fc-40da-8852-53eca81d2cd3
CANAL FROM NEWCASTLE TO HAYDON BRIDGE
Course of Canal from Newcastle to Haydon Bridge passing through the Northumberland Townships of Newcastle (Town Moor Elswick, Benwell, East Denton, West Denton, Newburn Hall, Walbottle, Newburn, Throckley, Heddon-on-the-wall, Houghton and Close House, Wylam, Horsley, Ovingham, Ovington, Bearl, Bywell St. Peter, East Acomb, Newton Hall, Styford, Thornbrough, Corbridge, Anick, Sandhoe, Anick Grange, West Acomb, Barden, Newbrough and Haydon (near Haydon Bridge).