A sluice is a water channel that is controlled at its head by a gate (from the Dutch word 'sluis'). For example, a millrace is a sluice that channels water toward a water mill. The terms "sluice gate", "knife gate", and "slide gate" are used interchangeably in the water/wastewater control industry.

A sluice gate is traditionally a wooden or metal plate that slides in grooves in the sides of the channel. Sluice gates are commonly used to control water levels and flow rates in river
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s and canal
Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...

s. They are also used in wastewater treatment plants and to recover minerals in mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

 operations, and in watermills.


The term sluice gate refers to any gate that operates by allowing water to flow under it. When a sluice gate is fully lowered, water sometimes spills over the top, in which case the gate operates as a weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...


Usually, a mechanism drives the sluice gate up or down. This may be a simple, hand-operated, worm drive or rack-and-pinion drive
Rack and pinion
A rack and pinion is a type of linear actuator that comprises a pair of gears which convert rotational motion into linear motion. A circular gear called "the pinion" engages teeth on a linear "gear" bar called "the rack"; rotational motion applied to the pinion causes the rack to move, thereby...

, or it may be electrically or hydraulically
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...


Types of sluice gates

Flap sluice gate: A fully automatic type, which is controlled by the pressure head across it; operation is similar to that of a check valve
Check valve
A check valve, clack valve, non-return valve or one-way valve is a mechanical device, a valve, which normally allows fluid to flow through it in only one direction....

. It is a gate hinged at the top. When pressure is from one side, the gate is kept closed; a pressure from the other side opens the sluice when a threshold pressure is surpassed.
Vertical rising sluice gate: A plate sliding in the vertical direction, controlled by machinery.
Radial sluice gate: A structure, where a small part of a cylindrical surface serves as the gate, supported by radial constructions going through the cylinder's radius. On occasion, a counterweight is provided.
Rising sector sluice gate: Also a part of a cylindrical surface, which rests at the bottom of the channel and rises by rotating around its centre.
Needle sluice: A sluice formed by a number of thin needles held against a solid frame through water pressure as in a needle dam
Needle dam
A needle dam is a weir designed to maintain the level or flow of a river through the use of thin "needles" of wood. The needles are leaned against a solid frame and are not intended to be water-tight...

The gates of a Guillotine lock
Guillotine lock
A guillotine lock is a type of canal lock. The lock itself operates on the same principle as any normal pound lock, but is unusual in that each gate is a single piece, usually of steel, that slides vertically upwards when opened to allow a boat to traverse underneath...

 work in a way similar to a sluice gate, but most canal lock
Lock (water transport)
A lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...

 gates are hinged to swing like doors.

Regional names for sluice gates

In the Somerset Levels
Somerset Levels
The Somerset Levels, or the Somerset Levels and Moors as they are less commonly but more correctly known, is a sparsely populated coastal plain and wetland area of central Somerset, South West England, between the Quantock and Mendip Hills...

, sluice gates are known as clyse or clyce.
Most of the inhabitants of Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

 refer to sluices as kokers.

Logging sluices

In the mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...

s of New England
New England
New England is a region in the northeastern corner of the United States consisting of the six states of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut...

, sluices were used to transport logs from steep hillsides to downslope sawmill
A sawmill is a facility where logs are cut into boards.-Sawmill process:A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end....

A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens, water features and koi ponds; all designed for aesthetic ornamentation as landscape or architectural...

s or yarding areas. Nineteenth-century logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...

 was traditionally a winter activity for men who spent summers working on farm
A farm is an area of land, or, for aquaculture, lake, river or sea, including various structures, devoted primarily to the practice of producing and managing food , fibres and, increasingly, fuel. It is the basic production facility in food production. Farms may be owned and operated by a single...

s. Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 was applied to logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...

 sluices every night
Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day...

 so a fresh coating of slippery ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

 would reduce friction of logs placed in the sluice the following morning
The word morning originally referred to the sunrise. Morning precedes midday, afternoon, and night in the sequence of a day.Morning is the part of the day usually reckoned from dawn to noon...


Placer mining applications

Sluice boxes are often used in the recovery of black sand
Black sand
Black sand is sand that is black in color. One type of black sand is a heavy, glossy, partly magnetic mixture of usually fine sands, found as part of a placer deposit. Another type of black sand, found on beaches near a volcano, consists of tiny fragments of lava.While some beaches are...

s, gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, and other minerals from placer deposit
Placer deposit
In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation during sedimentary processes. The name is from the Spanish word placer, meaning "alluvial sand". Placer mining is an important source of gold, and was the main technique used in the early...

s during placer mining
Placer mining
Placer mining is the mining of alluvial deposits for minerals. This may be done by open-pit or by various surface excavating equipment or tunneling equipment....

 operations. They may be small-scale, as used in prospecting
Prospecting is the physical search for minerals, fossils, precious metals or mineral specimens, and is also known as fossicking.Prospecting is a small-scale form of mineral exploration which is an organised, large scale effort undertaken by mineral resource companies to find commercially viable ore...

, or much larger, as in commercial operations, where the material is first screened using a trommel
A trommel is a screened cylinder used to separate materials by size - for example, separating the biodegradable fraction of mixed municipal waste or separating different sizes of crushed stone....

 or screening plant. Typical sluices have transverse riffles over a carpet, which trap the heavy minerals, gemstone
A gemstone or gem is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments...

s, and other valuable minerals. The result is a concentrate.

See also

  • Floodgate
    Floodgates are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or...

  • Gatehouse (waterworks)
    Gatehouse (waterworks)
    A gatehouse, gate house, or valve house for a dam is a structure housing sluice gates, valves, or pumps . Many gatehouses are strictly utilitarian, but especially in the nineteenth century, some were very elaborate....

     – An (elaborate) structure to house a sluice gate
  • Lock
    Lock (water transport)
    A lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...

  • Slussen
    Slussen is an area of central Stockholm, connecting Södermalm and Gamla stan. The area is named after the locks between Lake Mälaren and the Baltic Sea. The locks themselves allow passage between these two bodies of water...

  • Zylstra
    Zylstra is a common surname in rural regions of the Netherlands.-Etymology:The name Zylstra is a Dutch name for a family or group of people who lived by a body of water, or a sluice...

     – A Dutch name
    Family name
    A family name is a type of surname and part of a person's name indicating the family to which the person belongs. The use of family names is widespread in cultures around the world...

    referring to one who lives near a sluice

External links

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