A reach is a segment of a stream, river, or arm of the sea, usually suggesting a straight, level, uninterrupted stretch.[1] [2] 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. 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.[3] [4] 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".[5]