Canal - Types of Artificial Waterways

Types of Artificial Waterways

Canals are created in one of three ways, or a combination of the three, depending on available water and available path:

• A canal can be created where no stream presently exists. Either the body of the canal is dug or the sides of the canal are created by piling dirt, stone, concrete, or other building materials. The water for the canal must be provided from an external source like other streams or reservoirs. Examples include canals that connect valleys over a higher body of land, like Canal du Midi and Canal de Briare.
• A stream can be canalized to make its navigable path more predictable and easier to maneuver. Canalization modifies the stream to more safely carry traffic by controlling the flow of the stream with dredging, damming, and modifying its path. Examples include Basse Saône, Canal de Mines de Fer de la Moselle, and Aisne River. Riparian zone restoration may be required.
• When a stream is too difficult to modify with canalization, a second stream can be created next to the existing stream. This is called a lateral canal. The existing stream usually acts as the water source and its banks provide a path for the new body. Examples include the Chesapeake and Ohio Canal, Canal latéral à la Loire, Garonne Lateral Canal, and Canal latéral à l'Aisne.

Smaller transportation canals can carry barges or narrowboats, while ship canals allow seagoing ships to travel to an inland port (e.g., Manchester Ship Canal), or from one sea or ocean to another (e.g., Caledonian Canal, Panama Canal).