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18-635: The Northern Outfall Sewer (NOS) is a major gravity sewer which runs from Wick Lane in Hackney to the Beckton Sewage Treatment Works in east London. Most of it was designed by Joseph Bazalgette , as a result of an outbreak of cholera in 1853 and the " Great Stink " of 1858. Prior to the work, drains in central London were built primarily to cope with rain water, but the growing use of flush toilets frequently meant that they became overloaded, causing sewage and industrial effluent to flow into

36-458: A trench and forming the upcast soil into a bank alongside it. This practice has meant that the name dïc was given to either the excavation or the bank, and evolved to both the words "dike"/"dyke" and "ditch". Thus Offa's Dyke is a combined structure and Car Dyke is a trench, though it once had raised banks as well. In the English Midlands and East Anglia , a dyke is what a ditch

54-657: A community to draw down local water tables when and where necessary without exacerbating drought problems at other times. Particularly in Colorado , the term ditch is also applied to open aqueducts that traverse hillsides as part of transbasin diversion projects. Examples include the Grand Ditch over La Poudre Pass , the Berthoud Pass Ditch, and the Boreas Pass Ditch. Herbicides may be used to maintain

72-407: A gravity sewer. Sewage treatment is most efficient at centralized locations; and pumping is often required to lift sewage from lower elevations to the sewage treatment plant headworks . Structures called regulators allow overflow into gravity outfall sewers when peak flow in combined sewers exceeds pumping capacity. Sanitary sewers are preferred for cost-effective pumping of sewage when treatment

90-401: A hazard to motorists and cyclists , whose vehicles may crash into them and get damaged, flipped over, or stuck and cause major injury, especially in poor weather conditions and rural areas. In Anglo-Saxon , the word dïc already existed and was pronounced [diːk] ("deek") in northern England and [diːtʃ] "deetch" in the south. The origins of the word lie in digging

108-453: A natural stream sinuosity and a multi-terraced channel cross section appear to be key to maintain both peak ditch drainage capacity, and minimum net pollution and nutrient transport. Flooding can be a major cause of recurring crop loss—particularly in heavy soils—and can severely disrupt urban economies as well. Subsurface drainage to ditches offers a way to remove excess water from agricultural fields, or vital urban spaces, without

126-582: A public footpath/cycleway called The Greenway , with access points along its length. 51°31′44″N 0°0′52″E  /  51.52889°N 0.01444°E  / 51.52889; 0.01444 Gravity sewer Gravity sewer systems typically resemble the regional runoff pattern with large trunk sewers in each valley receiving flow from smaller lateral sewers extending up hillsides. Sewer systems within comparatively level terrain require careful planning and construction to minimize energy losses in free falls, sharp bends, or turbulent junctions. Every reach of

144-480: Is a small to moderate trench 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 are commonly seen around farmland , especially in areas that have required drainage, such as The Fens in eastern England and much of the Netherlands . Roadside ditches may provide

162-741: Is in the south of England, a property-boundary marker or drainage channel. Where it carries a stream, it may be called a running dike as in Rippingale Running Dike , which leads water from the catchwater drain , Car Dyke, to the South Forty Foot Drain in Lincolnshire (TF1427). The Weir Dike is a soak dike in Bourne North Fen , near Twenty and alongside the River Glen . Drainage ditches play major roles in agriculture throughout

180-440: Is required. Gravity sewers are preferred where grades are favorable, but lift stations often move sewage to sewage treatment plants. Vacuum sewers have a permanent negative pressure; due to improvements in technology, they have become more comparable to gravity sewers in operation and maintenance costs, and are cheaper to install. The earliest sewers were ditches to remove standing water from muddy locations where dry ground

198-569: The River Thames . Bazalgette's London sewerage system project included the construction of intercepting sewers north and south of the Thames. The Southern Outfall Sewer network diverts flows away from the Thames south of the river. In total, five interceptor sewers were constructed north of the Thames. Three were built by Bazalgette, and two were added 30 years later: The flows from the two low-level sewers are raised by some 40 feet (12 m) into

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216-610: The world . Improper drainage systems accelerate water contamination , excessively desiccate soils during seasonal drought , and become a financial burden to maintain. Industrial earth-moving equipment facilitates maintenance of straight drainage trenches, but entrenchment results in increasing environmental and eventually profound economic costs over time. Sustainable channel design can result in ditches that are largely self-maintaining due to natural geomorphological equilibrium. Slowed net siltation and erosion result in net reduction in sediment transport . Encouraging development of

234-663: The Northern Outfall Sewer at Abbey Mills Pumping Station , to join the flows from the High and Middle Level sewers. The remaining sections of the NOS carry the sewage from Abbey Mills to the treatment plant at Beckton. The creation of the NOS was a massive undertaking, and involved the construction of huge embankments and several bridges. Today, the eastern end of the Northern Outfall Sewer, running some 4 + 1 ⁄ 2 miles (7 km) from Wick Lane to Beckton, has been landscaped to form

252-426: The erosion rates and pollution transport that results from direct surface runoff . However, excess drainage results in recurring drought induced crop yield losses and more severe urban heat island or desiccation issues. Controlled subsurface drainage from sensitive areas to vegetated drainage ditches makes possible a better balance between water drainage and water retention needs. The initial investment allows

270-923: The offensive liquids. Prosperous communities used masonry and brickwork to cover early sewers. Terracotta pipes were used for low volume sewers. The portion of a sewer discharging into a natural water feature is called an outfall . The Industrial Revolution increased population density in manufacturing districts, and produced pipes useful for drain-waste-vent systems from buildings to sewers. Gravity sewers have been assembled from cast iron pipe , vitrified clay pipe , precast concrete pipe, asbestos-cement pipe, and plastic pipe . While some older brickwork sewers remain in use, new sewers of diameters exceeding 1 metre (39 in) typically use reinforced concrete . Corrugated metal pipe may be used for storm drains or wastewaters with similarly low risk of corrosive conditions. Non-circular cross-sections may have advantages for large-diameter sewers. Ditch A ditch

288-465: The sewer outfall. Availability of reliable pumps allows lifting accumulations of water into gravity sewers from collection sumps in excavations like mines or building foundations, but the cost of pumping surface runoff discourages use of lift stations in storm drains or combined sewers. The capitalized cost of operation and maintenance of lift stations and emergency power supplies usually justifies considerable first cost for excavation or tunneling to build

306-609: The sewer should routinely experience the minimum velocity necessary to maintain solids in suspension and avoid blockage from solids deposition in low-velocity areas. Sewers in hilly areas, however, may require energy dissipation features to avoid sewer damage from high fluid velocities and the scouring effects of gritty solids in turbulent flow . Covered sewers are buried below the frost line to avoid freezing, and deep enough to receive gravity flow from anticipated wastewater sources. Long gravity sewers may require significant excavation depths or tunneling to maintain acceptable gradients near

324-411: Was preferable for human activity. Early sewers served a function similar to modern storm drains (sometimes called storm sewers.) Combined sewers evolved from the practice of using flow in early drainage ditches to remove other wastes including draft animal feces . Sewers became offensive as waste concentrations increased in communities with high population density. Culverts were installed to cover

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