In engineering

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

, a gate is a rotating or sliding structure, supported by hinges or by a rotating horizontal or vertical axis, that can be located at an extreme of a large pipe or canal in order to control the flow of water or any fluid from one side to the other. It is usually placed at the mouth of irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 channels to avoid water loss or at the end of drainage

Drainage

Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...

channels to elude water entrance.