A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a

trench A trench is a type of excavation or in the ground that is generally deeper than it is wide (as opposed to a wider gully, or ditch), and narrow compared with its length (as opposed to a simple hole or pit). In geology, trenches result from ero ...

ditch A ditch is a small to moderate divot created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation. Ditches ar ...

. Flumes are not to be confused with aqueducts, which are built to transport water, rather than transporting materials using flowing water as a flume does. Flumes route

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

from a

diversion dam A diversion dam is a dam that diverts all or a portion of the flow of a river from its natural course. Diversion dams do not generally impound water in a reservoir; instead, the water is diverted into an artificial water course or canal, whic ...

weir A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...

to a desired

materiel Materiel (; ) refers to supplies, equipment, and weapons in military supply-chain management, and typically supplies and equipment in a commercial supply chain context. In a military context, the term ''materiel'' refers either to the spec ...

collection location. Flumes are usually made up of

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

metal A metal (from ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, e ...

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...

. Many flumes took the form of wooden troughs elevated on trestles, often following the natural contours of the land. Originating as a part of a

mill race A mill race, millrace or millrun, mill lade (Scotland) or mill leat (Southwest England) is the current of water that turns a water wheel, or the channel ( sluice) conducting water to or from a water wheel. Compared with the broad waters of a m ...

, they were later used in the transportation of logs in the

logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply cha ...

industry, known as a

log flume A log flume is a watertight flume constructed to transport lumber and logs down mountainous terrain using flowing water. Flumes replaced horse- or oxen-drawn carriages on dangerous mountain trails in the late 19th century. Logging operations pr ...

. They were also extensively used in

hydraulic mining Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...

and working

placer deposit In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish word ''placer'', meaning "alluvial sand". Placer mi ...

s for

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile ...

, tin and other heavy minerals.

Etymology

The term ''flume'' comes from the Old French word ''flum'', from the Latin ''flumen'', meaning a river. It was formerly used for a stream, and particularly for the tail of a

. It is used in America for a very narrow gorge running between precipitous rocks, with a stream at the bottom, but more frequently is applied to an artificial channel of wood or other material for the diversion of a stream of water from a river for purposes of irrigation, for running a sawmill, or for various processes in the hydraulic method of gold-mining.

Types of flumes

Millrace

A diversionary flume is used to transfer water from one body to another, such as between two reservoirs.

Log flume

Log flumes use the flow of water to carry cut logs and timber downhill, sometimes many miles, to either a sawmill or location for further transport.

Flow measurement flume

Some varieties of flumes are used in measuring water flow of a larger channel. When used to measure the flow of water in open channels, a flume is defined as a specially shaped, fixed hydraulic structure that under free-flow conditions forces flow to accelerate in such a manner that the flow rate through the flume can be characterized by a level-to-flow relationship as applied to a single head (level) measurement within the flume. Acceleration is accomplished through a convergence of the sidewalls, a change in floor elevation, or a combination of the two.Flumes
Openchannelflow.com Flow measurement flumes typically consist of a converging section, a throat section, and a diverging section. Not all sections, however, need to be present. In the case of the Cutthroat flume, the converging section directly joins the diverging section, resulting in a throat section of no length (hence the term "Cutthroat"). Other flumes omit the diverging section (Montana, USGS Portable Parshall, and HS / H / HL flumes).Sections of a Flume - Their Location and Function
Openchannelflow.com Flumes offer distinct advantages over sharp-crested weirs: *For the same control width, the head loss for a flume is about one-fourth of that needed to operate a sharp-crested weir *The velocity of approach is part of the calibration equations for flumes *Unauthorized altering of the dimensions of constructed flumes is difficult (and therefore unlikely) *Most flume styles readily allow for the passage of sedimentation and floating debris – reducing the time and effort associated with maintaining a flume installation Styles of flow measurement flumes include: Cutthroat, HS / H / HL-type, Khafagi,

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...

, RBC, Parshall, Palmer-Bowlus, Trapezoidal, and Venturi Flume. Flow measurement flumes can be installed in earthen channels, concrete canals, below ground chambers, or factory integrated into Packaged Metering Manholes.

Navigable canal flume

200px, A bypass flume on the Chesapeake and Ohio Canal In some nineteenth-century canals, a bypass flume diverted water around a

lift lock A boat lift, ship lift, or lift lock is a machine for transporting boats between water at two different elevations, and is an alternative to the canal lock. It may be vertically moving, like the Anderton boat lift in England, rotational, like ...

from the level (or pound) above to the level below the lock, so that the level below would have sufficient water. p. 270

Recreational flumes

In competitive

swimming Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...

, specialized flumes with transparent sides are often employed by coaches to analyze a swimmer's technique. The speed of the flow is variable to accommodate the full spectrum of swimming styles and ability.

Gallery

Flume, Hafren Forest - geograph.org.uk - 228904.jpg, Measuring flume in the UK Gold Creek, AK, with pipe.jpg, Flume outflow Creek diversion above the southern portal of Woy Woy tunnel.jpg, A temporary flume in New South Wales

References

External links

{{Rivers, streams and springs Aqueducts