In hydrology, a current in a

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

or other water body is the flow of water influenced by gravity as the water moves downhill to reduce its

potential energy In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors. Common types of potential energy include the gravitational potentia ...

. The current varies spatially as well as temporally within the stream, dependent upon the flow volume of water, stream gradient, and

channel Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Austral ...

geometry. In tidal zones, the current and streams may reverse on the flood tide before resuming on the ebb tide. The term ''upstream'' (or ''upriver'') refers to the direction towards the source of the stream (or river), i.e. against the direction of flow. Likewise, the term ''downstream'' or ''downriver'' describes the direction towards the mouth of the stream or river, in which the current flows. The term " left bank" and " right bank" refers to banks as seen from the direction of flow.

See also