Contour canal
A contour canal is an artificially-dug navigable canal which closely follows the contour line of the land it traverses, in order to avoid costly engineering works such as:
- Digging a cutting or tunnel through higher ground;
- Building an embankment or aqueduct over lower ground, or;
- Constructing a canal lock to change the level of the canal.
In the United Kingdom, many of the canals built in the period from 1770 to 1800 were contour canals - for example, the Thames & Severn Canal completed in 1789, and the Oxford Canal completed in 1790. Later canals tended to be much straighter and more direct - a good example is the Shropshire Union Canal engineered by Thomas Telford.