A FLUME is a man-made water channel that is typically used to transport logs or other materials. An AQUEDUCT is a large water channel that is used to transport water from one place to another. A GUTTER is a shallow water channel that is usually found along the edge of a roof or street. A SLUICE is a water channel with a gate or valve that is used to control the flow of water. A GULLY is a small water channel that is usually found in a ravine or valley. A riverbed is the bottom of a river, which is usually composed of rocks and sediment. A CANAL is an artificial water channel that is used for transportation or irrigation. A DRAIN is a pipe or channel that is used to remove excess water from an area. A CULVERT is a tunnel or pipe that is used to allow water to pass under a road or railway. A STRAIT is a narrow water channel that connects two larger bodies of water. Guttering is the process of collecting and directing rainwater away from a building. A GAT is a small water channel that is used to divert water away from a low-lying area. A RACE is a water channel that is used to power a mill or other machinery. A millrace is a water channel that is used to power a mill.