Editing Canal (section)

==Structures used in artificial waterways==

Both navigations and canals use [[civil engineering|engineered]] structures to improve navigation:
* [[weir]]s and [[dam]]s to raise river water levels to usable depths;
* looping descents to create a longer and gentler channel around a stretch of rapids or falls;
* [[lock (water transport)|locks]] to allow ships and barges to ascend/descend.

Since they cut across drainage divides, canals are more difficult to construct and often need additional improvements, like [[viaduct]]s and [[Aqueduct (bridge)|aqueducts]] to bridge waters over streams and roads, and ways to keep water in the channel.