A concept applicable to all water bodies characterised by the movement of water in the direction of the slope. The water flow may be permanent or temporary (drying or freezing).

A watercourse is a generalised term for a body of water with a progressive movement of water in the direction of a slope in an elongated depression in the earth's surface (channel). Watercourses (rivers, streams, canals) are surface water bodies. Watercourses are divided into natural (rivers, streams) and artificial (canals for various purposes). Watercourses are also divided into permanent and temporary (drying up or freezing over). Permanent watercourses move water all or most of the year, while temporary watercourses move water only for a small part of the year. The totality of all watercourses in the territory is called the watercourse network, and the totality of all rivers and streams is called the river network.

Watercourses are important sources for maintaining and recharging aquifers and for filling mine workings with water. Artificial underground watercourses include drainage ditch streams, natural streams from karst caves and canals. Mining operations need to consider the possibility of sudden breakthrough of water flows into underground workings, particularly during floods.