Backwater (river)

A backwater is a relatively stagnant part of a river in which there is little or no current. It can refer to a small anabranch of a main river, which diverges from and meanders alongside the main stem before rejoining it downstreams, and thus carrying a significantly weaker flow; or an ectopic stream pool extend from the side of a watercourse backed up by reverse flow from tides (as in the case of tidal rivers) or due to increased flow resistance caused by obstacles such as a weir, dam or levee. Temporary natural obstructions such as ice jams, vegetation blockages, rockslides, debris flow, beaver damming or "backlogging" due to downstream flooding (e.g. due to a storm surge) can also create backwaters.