Reach (geography)

{{globalize|article|us|reason=only in the US would you define a reach between arbitrary features; normally they are set by the physics of sail|date=December 2019}}

A reach is a segment of a stream, river, or arm of the sea,{{citation needed|date=April 2020}} usually suggesting a straight, level, uninterrupted stretch.Macfarlane, Robert, "Landmarks", Hamish Hamilton Press, 2015Oxford English dictionary, reach, n., third meaning ("part of a river which can be looked upon at once between two bends")

They are traditionally defined by the capabilities of sailing boats, as a stretch of a watercourse which, because it is straightish, can be sailed in one "reach" (that is, without tacking).

Reaches are often named by those using the river, and a reach may be named for landmarks, natural features, and historical reasons (see, for instance, Gallions' Reach, named after the family that once owned its banks).

A reach may be an expanse, or widening, of a stream or river channel. This commonly occurs after the river or stream is dammed. A reach is similar to an arm, though an arm may bend and thus have multiple reaches. The term "reach" can also refer to a level stretch, as between river rapids or locks in a canal.{{citation needed|date=April 2020}} The word may also be used more generally to refer to any extended portion or stretch of land or water, or even metaphorically.

In fluvial hydrology, a reach is a convenient subdivision of study; it may be any length of river of fairly uniform characteristics, or the length between gauging stations, or simply the length of a watercourse between any two defined points.[http://water.usgs.gov/wsc/glossary.html#R Hydrologic Definitions], Science in Your Watershed, USGS{{cite web |title=Glossary: stream-related terms |archive-url=https://web.archive.org/web/20141207192549/https://www.streamnet.org/glossarystream.html|url=http://www.streamnet.org/glossarystream.html |website=Streamnet |date=7 December 2014|archive-date=2014-12-07}} These may be measured in terms of river miles.

As of 2015, the US Board on Geographic Names records 334 place names in the US with the characterization of a named "reach".[http://geonames.usgs.gov/apex/f?p=136:2:12938640691775:pg_R_49974142591090605124:NO&pg_min_row=91&pg_max_rows=15&pg_rows_fetched=15 USGS Survey GNIS Database]