View source for Abbey River

{{Short description|River in Surrey, England}}
{{ for|the river in Ireland|Abbey River, Limerick}}
{{Use dmy dates|date=January 2018}}
{{Use British English|date=January 2018}}

{{Chertsey Lock map}}
The '''Abbey River''' is a [[bank (geography)|right-bank]] backwater of the [[River Thames]] in England, in [[Chertsey]], [[Surrey]] &mdash; in the town's northern [[buffer zone|green and blue buffers]]. The L-shaped conduit adjoins mixed-use [[flood plain]]: [[water-meadows]] landscaped for a golf course, a motorway and a fresh water treatment works on the island it creates, [[Laleham Burway]] to its east and north in turn. Its offtake from the [[River Thames|Thames]] is at the [[inflection point|apex]] of [[Penton Hook Island|Penton Hook]], [[Staines upon Thames]] below its lower weir close to the Chertsey-[[Thorpe, Surrey|Thorpe]] boundary in the Borough of [[Runnymede (borough)|Runnymede]]. Its outfall is the weir pool of [[Chertsey Lock]] back into the Thames, visible from [[Chertsey Bridge]]. 

Under the "River Thames Scheme", proposed by the [[Environment Agency]], a [[fish ladder|fish pass]] will be installed on the Abbey River and the riverbed will be lined with gravel to provide additional habitats for [[spawn (biology)|spawning]]. A new flood relief channel, intersecting the river, will be constructed to improve the drainage of floodwater from the Abbey Meads to the Thames.<ref>{{cite web |title= River Thames Scheme |date= October 2022 |publisher= Environment Agency and Surrey County Council |url= https://infrastructure.planninginspectorate.gov.uk/wp-content/ipc/uploads/projects/WA020001/WA020001-000013-WA020001%20Scoping%20Report%20main%20report.pdf |access-date= 30 March 2023 }}</ref>

==History and status==
{{See also|Laleham Burway}}
The {{cvt|3.2|km}} long river, which was also known as Oxley, Oxlake or Oaklake Mill River or Stream was a [[leat]] [[cutting (transportation)|cut]] by order of the Abbot of [[Chertsey Abbey]] in the eleventh century to supply power to the mill closest to their monastery/abbey and water their numerous fish ponds.<ref name=malden/>
[[File:Abbey River Chertsey.jpg|thumb|Abbey River north of the Abbey site. No longer a mill race, in summer time the channel is near-stagnant.]]

The Abbey River with the Thames encircles [[Laleham Burway|Laleham Burway also known as the Abbey Mead]], which belonged to Chertsey Abbey founded in the 7th century AD of [[Anglo Saxon England]]. It forms a better-drained flood meadow beside the Thames and provides a mill race ([[leat]]). The bulk of its large island thereby formed passed to Laleham manor which for about seven centuries [[Agricultural Tenancies Act 1995|let]] it to farmers breeding and selling horses and cattle. In the 18th and 19th centuries the stream became ancillary to [[pasture]], used for seasonal drainage and ornamental value of houses and a farm, Abbey Chase, adjoining its southern meander close to the centre of Chertsey, rather than corn, wheat and barley milling. It today contains Laleham Golf Course, park homes built of light materials on decking, a line of riverside homes and a groundwater fresh water waterworks with emergency/dry period storage reservoir, producing {{cvt|60|Ml|Impgal}} of drinking water per day.<ref>{{Cite web|url=http://mackley.co.uk/capabilities/waste-water/chertsey-water-treatment-works/|title = Chertsey WTW – Mackley Civil Engineering}}</ref> Laleham Burway re-incorporates in its modern definition Abbey Mead for many years considered its southern tract (and the parent of Laleham Burway in terms of naming). For more than a millennium the tract formed the largest [[Islands in the River Thames|Island in the non-tidal River Thames]]; namely the largest upstream of its tidal section known as the [[Tideway]] where there are two larger islands. It is much smaller than [[Canvey Island]] and the [[Isle of Sheppey]] and narrowly ahead of [[Andersey Island]] facing [[Abingdon-on-Thames]], another market town with an abbey which had multiple medieval mills, another of note being [[Westminster Abbey]], the island of which [[Thorney Island (London)|Thorney Island]] no longer exists. The outfall of the Abbey River is {{cvt|400|m}} above [[Chertsey Bridge]], into the weir pool of Chertsey Weir. The manmade strictly-considered "island" the bypass channel forms is outranked in size since the 2002 completion of the [[Jubilee River]] by the example containing [[Dorney]] and [[Eton, Berkshire]].

==Flow and habitats==
{{See also|Jubilee River|Locks and weirs on the River Thames}}
The flow is artificially constrained by less depth than medieval times and by numerous built-up weirs. These have the effect of tending to keep any flooding towards its upper reach when most prolonged-rain-event flooding occurs, sparing built-up parts of [[Chertsey]] in normal floods which occur every few years; for < 1-in-50-years (most severe) events the [[River Thames]] such as during the [[2013–14 United Kingdom winter floods#Thames Valley|2013-2014 Winter]] floods up to the arches of [[Chertsey Bridge]] &mdash; the statutory authority mainly tasked with reduction of flood risk has noted the Abbey River watercourse no longer provides a sufficient [[corollary]] and in its official view merits replacement,<ref name=sea/> its flow being far less than in medieval times when it was a powerful [[leat|mill race]], having the by-product of draining flood waters upstream. The contemporary decades of reduced capacity (see [[deposition (geology)|deposition]]) and multiple-barraged flow has led to the [[Environment Agency]] to propose negligible use of its route in the creation of two seasonal drainage channels &mdash; partly due to better biodiversity in shallow rivers it is proposed to intersect its course possibly thereby slightly adding to its final flow, but with a main outflow channel across its existing island. Relevant officially planned channels:
*Channel 2 (specifically the red route, taken forward to strategy stage) across land and large lakes more inland on the [[Bank (geography)|right]] bank of the Thames
*Channel 3 (specifically the orange route, taken forward to strategy stage) across [[Dumsey Meadow]] and the bend below on the left bank of the Thames.<ref>SEA 2009, p. 101</ref>

The Abbey River is a subchannel of the Thames, so is believed to have similar water quality and species to the main river.<ref name=sea>SEA 2009, p. 133</ref>

=== Abbey Mill===
{{Main|Chertsey Abbey}}

This mill was one of several the institution owned in its vast Surrey estates &mdash; remaining substantial after some [[Manorialism|manor]]s and small parcels were sold or gifted to wealthy local nobles and institutions, including Oxford and Cambridge Colleges. The land was added to the foremost Royal park, paying compensation to the abbot for his retirement, to expand [[Henry VIII]]'s [[Windsor Great Park]] thereby covering much of the land from [[Wokingham]] and [[Sandhurst, Berkshire]] in the west to the [[River Wey]] east of Chertsey. Underlining these centuries of agricultural-based abbey wealth were useful "abbey mills" enjoying a local [[monopoly]] for grain &mdash; the [[Valor Ecclesiasticus]] of 1535 gives the clear annual value (surplus) of the abbey as £659 15s. 8¾d.<ref>{{cite web |url = http://www.british-history.ac.uk/report.aspx?compid=37813 |title = House of Benedictine monks: Abbey of Chertsey |editor-first = H.E. |editor-last = Malden |publisher=Institute of Historical Research |year = 1967 |work = A History of the County of Surrey: Volume 2 |access-date = 21 October 2013 }}</ref>{{NoteTag|{{inflation|UK|660|1535|fmt=eq|cursign=£}}}} In 1608 two [[watermill]]s on the river are recorded as the Oaklake Mylles.

===19th century proposal as a navigation channel===
In 1809 the millers, in concert with [[City of London Corporation]], offered the stream as the Thames navigation channel by building a weir to protect Chertsey, Shepperton, and other areas downstream from floods, as well as keeping water levels sufficiently deep, but the latter decided to pursue its own shorter route plans, so built [[Chertsey Lock|Chertsey Weir and Lock]].<ref>Fred. S. Thacker ''The Thames Highway: Volume II Locks and Weirs'' 1920 - republished 1968 David & Charles</ref> Much of the channel is lightly surrounded by trees and it is, at most, {{cvt|980|m}} from the River Thames.<ref>[http://gridreferencefinder.com/ Grid Reference Finder] distance tools</ref>

The site of the abbey was bought in 1861 by Mr Bartrop, the secretary to the Surrey Archaeological Society, a combination of earlier collections and other archaeologists centred at [[Guildford Museum]]. Among the "appurtenances" (land holdings and interests) of the site of the abbey were the "watermills known as the Oxlake or Okelake mills" and "a small river or brook known as the Abbey River or the Bargewater".<ref name=malden>{{cite web |url=http://www.british-history.ac.uk/report.aspx?compid=42997 |title=Parishes: Chertsey |editor-first=H.E. |editor-last=Malden |publisher=Institute of Historical Research |date=1911 |work=A History of the County of Surrey: Volume 3 |accessdate=21 October 2013 }}</ref>

== Notes ==
{{NoteFoot}}

== References==
=== Citations ===
{{Reflist}}

=== Sources ===
{{refbegin}}
*[http://www.jubileeriver.co.uk/Complete_SEA_Environmental_Report.pdf Lower Thames Strategy Study: Strategic Environmental Assessment environmental report], Environment Agency, 2009. Accessed 31-12-2017 &mdash; cited as "''SEA 2009''"
{{refend}}

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{{River confluence start|River=[[River Thames]]}}
{{River item line|upstream=[[River Colne, Hertfordshire|River Colne]] (north)
|downstream=[[River Bourne, Chertsey]] <br> [[River Bourne, Addlestone]] (south)}}
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{{Hydrology of Surrey}}

[[Category:Rivers of Surrey|0A]]
[[Category:Thames drainage basin|0Abbey]]