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pipe installation in a storm drain project, Mexico.
Drainage is the natural or artificial removal of a surface's water and
from an area. The internal drainage of most
is good enough to prevent severe
(anaerobic conditions that harm root growth), but many soils need artificial drainage to improve production or to manage water supplies.
Remains of a drain at
circa 3000 BC
had advanced
and drainage systems. All houses in the major cities of
had access to water and drainage facilities. Waste water was directed to covered , which lined the major streets.
, a historical drain in the City of Sydney
The invention of hollow-pipe drainage is credited to Sir Hugh Dalrymple, who died in 1753.
A plastic (PVC) flexible drainage pipe, used to drain water from the roof of a residential house or building
New drainage systems incorporate
filters that retain and prevent fine
from passing into and clogging the drain. Geotextiles are synthetic textile fabrics specially manufactured for
applications. Geotextiles are designed to retain fine soil particles while allowing water to pass through. In a typical drainage system they would be laid along a trench which would then be filled with coarse : , , stone or . The geotextile is then folded over the top of the stone and the trench is then covered by soil.
seeps through the geotextile and flows through the stone to an outfell. In high
conditions a perforated plastic ( or ) pipe is laid along the base of the drain to increase the volume of water transported in the drain.
Alternatively, a prefabricated plastic drainage system made of
called , often incorporating geotextile,
can be considered. The use of these materials has become increasingly more common due to their ease of use which eliminates the need for transporting and laying stone drainage aggregate which is invariably more expensive than a synthetic drain and concrete liners.
Over the past 30 years geotextile and PVC filters have become the most commonly used soil filter media. They are cheap to produce and easy to lay, with factory controlled properties that ensure long term filtration performance even in fine silty soil conditions.
Seattle's Public Utilities created a pilot program called Street Edge Alternatives (SEA Streets) Project. The project focuses on designing a system "to provide drainage that more closely mimics the natural landscape prior to development than traditional piped systems". The streets are characterized by ditches along the side of the roadway, with plantings designed throughout the area. An emphasis on non curbed sidewalks allows water to flow more freely into the areas of permeable surface on the side of the streets. Because of the plantings the run off water from the urban area does not all directly go into the ground but can also be absorbed into the surrounding environment. According to the monitoring by Seattle Public Utilities, they report a 99 percent reduction of storm water leaving the drainage project
Drainage has undergone a large-scale environmental review in the recent past in the United Kingdom.
(SUDS) are designed to encourage contractors to install drainage system that more closely mimic the natural flow of water in nature. Since 2010 local and neighbourhood planning in the UK is required by law to factor SUDS into any development projects that they are responsible for.
Slot drainage has proved the most breakthrough product of the last twenty years as a drainage option. As a channel drainage system it is designed to eliminate the need for further pipework systems to be installed in parallel to the drainage, reducing the environmental impact of production as well as improving water collection. Both stainless steel and concrete channel slot drainage have become industry standards on construction projects.
Piping being placed for a sink
is responsible for drainage in construction projects. They set out from the plans all the , , drainage,
involved in
operations. During the construction process he/she will set out all the necessary levels for each of the previously mentioned factors.
Civil engineers and construction managers work alongside
and supervisors, planners, , the general workforce, as well as subcontractors. Typically, most jurisdictions have some body of
to govern to what degree a landowner can alter the drainage from his parcel.
Drainage options for the construction industry include:
Point drainage, which intercepts water at gullies (points). Gullies connect to drainage pipes beneath the ground surface and deep excavation is required to facilitate this system. Support for deep trenches is required in the shape of planking, strutting or shoring.
Channel drainage, which intercepts water along the entire run of the channel. Channel drainage is typically manufactured from concrete, steel, polymer or composites. The interception rate of channel drainage is greater than point drainage and the excavation required is usually much less deep.
The surface opening of channel drainage usually comes in the form of gratings (polymer, plastic, steel or iron) or a single slot (slot drain) that runs along the ground surface (typically manufactured from steel or iron).
Research evaluating drainage quantity and quality in urban mixed landscapes vegetation is limited. Insufficiencies and obstacles in understanding soil water conditions particularly in urban landscape environs undermine a sound judgement of urban soils. A research in South Australia investigates the relative impact of landscape variation on drainage and solute leaching in a public park containing heterogeneous urban-landscape vegetation that is irrigated with recycled wastewater. For this purpose, two pan lysimeters were designed and installed in two different land-scape zones.
An agricultural drainage channel outside ,
after a heavy rain. Note that protuberances create turbulent water, preventing sediment from settling in the channel.
Wetland soils may need drainage to be used for . In the northern United States and Europe,
created numerous small
which gradually filled with
to make . Some of these were drained using open
and trenches to make , which are primarily used for high value crops such as .
The largest project of this type in the world has been in process for centuries in the . The area between ,
times swampland and small lakes. Turf cutting ( ),
and shoreline
gradually caused the formation of one large lake, the , or lake of Haarlem. The invention of wind-powered
in the 15th century permitted drainage of some of the marginal land, but the final drainage of the lake had to await the design of large,
pumps and agreements between regional authorities. The elimination of the lake occurred between 1849 and 1852, creating thousands of km? of new land.
Coastal plains and river deltas may have seasonally or permanently high
and must have drainage improvements if they are to be used for agriculture. An example is the flatwoods -growing region of . After periods of high rainfall, drainage pumps are employed to prevent damage to the citrus groves from overly wet soils.
production requires complete control of water, as fields need to be flooded or drained at different stages of the crop cycle. The Netherlands has also led the way in this type of drainage, not only to drain lowland along the shore, but actually pushing back the sea until the original nation has been greatly enlarged.
In moist climates, soils may be adequate for cropping with the exception that they become
for brief periods each year, from
melt or from heavy . Soils that are predominantly
will pass water very slowly downward, meanwhile plant roots suffocate because the excessive water around the roots eliminates air movement through the soil.
Other soils may have an
layer of mineralized soil, called a
or relatively impervious rock layers may underlie shallow soils. Drainage is especially important in
production. Soils that are otherwise excellent may be waterlogged for a week of the year, which is sufficient to kill fruit trees and cost the productivity of the land until replacements can be established. In each of these cases appropriate drainage carries off temporary flushes of water to prevent damage to
Drier areas are often farmed by , and one would not consider drainage necessary. However, irrigation water always contains minerals and , which can be concentrated to toxic levels by . Irrigated land may need periodic flushes with excessive irrigation water and drainage to control .
A typical drain in
or watershed
or watershed
, who introduced land drainage to the .
by subsurface drainage
Arthur Coterell (1980). The Encyclopedia of Ancient Civilisations. Rainbird Publishers. pp. 176–178.  .
. National Library of Scotland 2015.
June 29, 2011, at the .
Variability of drainage and solute leaching in heterogeneous urban vegetation environs *
Wikimedia Commons has media related to .
in Wiktionary, the free dictionary.
Agricultural water management
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