In
physical geography, a 'channel' is the physical confine of a
river,
slough or ocean
strait consisting of a 'bed' and 'banks'. See
Stream bed.
A 'channel' is also the natural ''or man-made'' deeper course through a
reef,
bar,
bay, or ''any shallow body of water''. It is especially used as a
Nautical term to mean the dredged and marked (See:
Buoy) lane of safe travel which a cognizant governmental entity ''guarantees'' to have a minimum depth across its specified minimum width to all
vessels transiting a body of water. The term not only includes the
deep-dredged ship-navigable parts of an
estuary or river leading to
port facilities, but also to lesser channels accessing
boat port-facilities such as
marinas. When dredged channels traverse
bay mud or sandy bottoms, repeated dredging is often necessary because of the unstable subsequent movement of benthic soils.
[1]
Responsibility for monitoring navigability conditions of ''navigation channels'' to various port facilities varies, and the actual maintenance work is frequently performed by a third party. Storms, sea-states, flooding, and seasonal sedimentation adversely affect navigability. In the
United States, navigation channels are monitored and maintained by the
United States Army Corps of Engineers (USACE), although dredging operations are often carried out by private contractors (under USACE supervision). USACE also monitors water quality and some remediation. This was first established under the
Rivers and Harbors Act of 1899 and modified under acts of 1913, 1935, and 1938, which are contained in chapter 33 of the US Code, "Navigation and Navigable Waters." For example, the USACE developed the
Intracoastal Waterway, and has the
Mississippi Valley Division responsible for the
Mississippi River from the Gulf to
Cairo, Illinois, the
North Atlantic Division for
New York Harbor and
Port of Boston, and the
South Pacific Division for
Port of Los Angeles and
Port of Long Beach. Waterways policing as well as some emergency spill response falls under
United States Coast Guard jurisdiction, including inland channels serving
ports like
Saint Louis hundreds of miles from any coast. The various state or local governments maintain lesser channels, for example former
Erie Canal.
In a larger nautical context, as a geographical place name, the term 'channel' is another word for
strait, which is defined as a relatively narrow body of water that connects two larger bodies of water. In this
nautical context, the terms ''strait'', ''channel'', ''sound'', and ''passage'' are synonymous and usually interchangeable. For example, in an
archipelago, the water between
islands is typically called a ''channel'' or ''passage''. The
English Channel is the strait between
England and
France.
Notes
1. ''History of the Waterways of the Atlantic Coast of the United States'', USACE, January 1983
See also
★
Hydrology transport model
★
Ship canal
★
Rivers and Harbors Act of 1899
★
Surge channel