Editing River Ancholme (section)

==Water supply==
[[File:The New River Ancholme - geograph.org.uk - 310291.jpg|thumb|left|The Anglian Water intake at Cadney can abstract up to 31,000 Ml per year from the river.]]
During the late 1960s, there was increasing demand for water, particularly within the South Humber bank industrial area. Extractions from the underlying [[chalk]] [[aquifer]] could not be increased, and so the demand was met by building the Trent Witham Ancholme Transfer Scheme (TWA), which was commissioned in 1974. A pumping station at [[Short Ferry]] on [[Barlings Eau]], near its junction with the [[River Witham]], pumps water through {{convert|17|km|mi|1|order=flip}} of pipeline to a reservoir at [[Toft Newton]], which covers an area of {{convert|16.5|ha|acre|order=flip}}. During the summer months and other dry periods, water is released from the reservoir into the Ancholme to augment its flow and maintain its level. In the event of failure of the pumps at Short Ferry, the reservoir has enough capacity to maintain flows in the Ancholme for up to seven days. There is another pumping station at [[Torksey]], on the River Trent, and in the event of low flows on the Witham, water is pumped from the Trent into the [[Foss Dyke]], from where it flows eastwards to [[Lincoln, England|Lincoln]] and the River Witham system.{{sfn|Itinerary |1996 |p=6}}

In 1996, removal of some {{convert|37698|Ml|e6impgal}} per year from the river was covered by abstraction licences.{{sfn|Itinerary |1996 |p=6}} Major holders of licences included [[British Steel plc]], [[Centrica]] and [[Anglian Water]]. British Steel take water for the [[Scunthorpe Steelworks]] from a pumping station immediately to the north of Worlaby railway bridge. Centrica run the [[Glanford Brigg Power Station]], located on the west bank of the river near Brigg.{{sfn |Itinerary |1996 |p=7}} It is a gas-fired generating station, capable of producing 240 MW from six turbines. Water is taken from the river to supplement cooling water lost by evaporation, and some of the cooling water is discharged to the river to prevent a build up of suspended and dissolved solids. Water is also processed by a treatment plant, where it is filtered and ion-exchanged, to provide a clean supply for the boilers, which will not cause scaling or corrosion. Like the cooling water, the boiler feed water is also purged regularly, to prevent dissolved solids building up.{{sfn |Itinerary |1996 |p=22}}

The largest abstractor is Anglian Water, who maintain a pumping station on the east bank of the river by Cadney bridge.{{sfn |Itinerary |1996 |p=7}} They were licensed to remove {{convert|31000|Ml|e6impgal}} per year in 1996, which is about 82 per cent of the total abstraction. After initial grit removal and chlorination, water is pumped for {{convert|1.2|mi|km}} through twin {{convert|5.9|ft|m|adj=on}} diameter concrete pipelines to Cadney reservoir, which can hold {{convert|900|Ml|e6impgal}}, covers {{convert|14|ha|acre|order=flip}}, and has a maximum depth of {{convert|36|ft|m}}. After further chlorination, the water is pumped for another {{convert|6.2|mi|km|0}} through a {{convert|1.22|m|ft|adj=on|order=flip}} diameter steel pipeline to [[Elsham, Lincolnshire|Elsham]] Water Treatment Works, which produces up to {{convert|30|Ml|e6impgal}} per day of potable water for public water supply.{{sfn|Itinerary |1996 |p=16}}

In addition to supporting these abstractions, the use of water from the TWA scheme has other benefits. Because the flow is maintained even in dry weather, [[eutrophication]], which is caused by a build up of nutrients in the water, is reduced, and the flow through Ferriby sluice also helps to prevent the ingress of salt water from the Humber into the river. The volume of water transferred via the TWA scheme depends on the weather conditions. In 1987 it was {{convert|2425|Ml|e6impgal}}, while in 1979 it was {{convert|17425|Ml|e6impgal}}.{{sfn|Itinerary |1996 |pp=6–7}}