|Districts / Boroughs||Chichester (district), East Hampshire (district), Waverley, Guildford, Woking, Elmbridge, Runnymede|
|Towns||Alton, Haslemere, Farnham, Godalming, Guildford, Weybridge|
|• location||Alton, East Hampshire, Hampshire|
|• elevation||109 metres (358 ft)|
|• location||Black Down, West Sussex, Chichester, West Sussex|
|• elevation||199 metres (653 ft)|
|• location||Tilford, Waverley, Surrey|
|• elevation||51 metres (167 ft)|
|Weybridge, Elmbridge, Surrey|
|12 metres (39 ft)|
|Length||140 km (87 mi)|
|Basin size||904 km2 (349 sq mi)|
|• location||Weybridge (mouths)|
|• average||6.76 m3/s (239 cu ft/s)|
|• minimum||1.30 m3/s (46 cu ft/s) 12 August 1990|
|• maximum||74.8 m3/s (2,640 cu ft/s) 29 December 1979|
|• location||Farnham (north/western branch)|
|• average||0.73 m3/s (26 cu ft/s)|
|• location||Tilford (confluence of both branches)|
|• average||3.25 m3/s (115 cu ft/s)|
|• average||5.17 m3/s (183 cu ft/s)|
|Progression||Wey (north branch), Wey, Thames|
Wey (south branch), Wey, Thames
|River system||Thames Basin|
|• left||Nadder Stream, Bentworth Stream, Oakhanger Stream, Kingsley Stream, Oxney Stream, Hell Ditch, Hoe Stream, Hollywater, Deadwater, River Slea|
|• right||River Tillingbourne, Cranleigh Waters, River Ock, East Clandon Stream, Guileshill Brook, Royal Brook, Stratford Brook, Truxford Brook|
The River Wey is a main tributary of the River Thames in south east England. Its two branches, one of which rises near Alton in Hampshire and the other in West Sussex to the south of Haslemere,[n 1] join at Tilford in Surrey. Once combined the flow is eastwards then northwards via Godalming and Guildford to meet the Thames at Weybridge. Downstream the river forms the backdrop to Newark Priory and Brooklands. The Wey and Godalming Navigations were built in the 17th and 18th centuries, to create a navigable route from Godalming to the Thames.
The Wey drains much of south west Surrey (as well as parts of east Hampshire and the north of West Sussex) and has a total catchment area of 904 square kilometres (350 sq mi). Although it is the longest tributary of the Thames (if the Medway is excluded), its total average discharge is lower than that of the Kennet and Cherwell. The river morphology and biodiversity of the Wey are well studied, with many places to take samples and record data. The main tributary is the Tillingbourne, which rises on the western slopes of Leith Hill and flows westwards to join the Wey to the south of Guildford, between Shalford and Peasmarsh.
The name Wey is of unknown origin and meaning.
The Wey north branch, sometimes referred to as the Alton Wey, has its official nomenclature source in Alton in Hampshire; however is exceeded by length and, in wet weather, in flow by the nearby Caker Stream rising in dendritic drainage spanning fields of Upper Farringdon and Hartley Mauditt, passing Chawton between these places. After the union in Alton the brook runs quite straight, east north-east through Upper Froyle and Bentley, turning southeast after Farnham's centre to Tilford.
The steep-sided valley accentuates entering Surrey, between vast masses termed the Lower Greensand Group (south), then down the more easterly valley on both sides (east and west). Reflecting the crumbly nature of this material which has readily eroded, the valley falls from about 230 feet (70 m) entering Surrey 1.5 miles (2.4 km) west of Farnham to 60 feet lower at Tilford 4 miles (6.4 km) south-east of Farnham and changes from almost v-shaped to a more u-shaped alluvial plain.
The upper parts of the branch were the start of the upper River Blackwater's catchment. The Wey captured this following cumulative flooding and deposition right up to around Aldershot. A vestige of this is that the upper Blackwater valley proper, north of today's wind gap, is not lower than 226 feet (69 m) (Tongham Pool) and of very low gradient. This transported distinctive gravels containing chert, to deposit them north of the gap in the chalky ridge at Farnham. The source rocks of the gravels prove the former extent of the river. Great erosion has occurred in the Wey down to Tilford, along the sinuous, multiple-anabranch Waverley Abbey stretch, through, what Blyth notes as, the "soft strata", of that landscape.
The Wey South branch stems from two main westward brooks, one now followed by the Portsmouth Direct Line,[n 2] the other – with longer source brooks – following the Surrey/Sussex boundary,[n 3] which combine at a point, heading west, where the line first comes as close as 97 metres to the boundary – in the east end of a park, next to one of its three river footbridges. These brooks are fed by six main streams. The farthest are the southern streams. These drain parallel, north, narrow vales between the northerly "fingers" or "ribs" of:
- Blackdown, the third-highest hill in Southeastern England
- Ridge Hill
- Fridays Hill
- Marley Heights (formerly Moseshill), called Marley Common
The northern streams drain fingers of a single east–west ridge of Greensand, their common names, again from east to west, are:
- Wey Down (High Lane Estate)
- Stoatley Rise
Of varying size, these are long, sandy hills south-east of the upper tip of the Devil's Punch Bowl: Gibbet Hill, Hindhead. One of the northern streams adjoins strips of woodland named Weydown Common and Weycombe.
The south sources are specifically: a wood-surrounded neighbourhood, Kingsley Green (formerly Marsh) in Fernhurst; Chase Farm marking the furthest point south in Surrey; and upper fishponds at Wades Marsh marking the Fernhurst/Lurgashall boundary (both in West Sussex), next to the summit of Ridge Hill (which is the furthest source).
The Wey drains and passes Haslemere's western suburbs then Liphook, Bramshott (including Passfield), Standford and Lindford, and the large parish of Frensham. It combines with the north branch at Tilford, in which parish all three flows have large meanders.
From Tilford the river runs through Elstead, Eashing, Godalming, Peasmarsh/Shalford, Guildford, Send, Old Woking, Pyrford, Byfleet, New Haw and forms the historically much more meandering border between Addlestone/Weybridge, today doing so most accurately between Hamm Court and Whittet's Ait respectively. From Godalming the river is intertwined with the Wey and Godalming Navigations. The 20 miles (32 km) of the navigations' towpath is open to pedestrians. The river joins the Thames at a cascading channel off its Navigation Canal (above Thames Lock) between Hamm Court and Whittet's Ait and a weir-fed navigation east of the ait facing the main weir stream of Shepperton Lock.
The river has long been used as a source of power for mills, and many are recorded in the Domesday Book. Between the 17th and 19th centuries there were over 40 mills on the river and more on its tributaries. At various times they have been used for grinding grain, fulling wool, rolling oats, crushing cattle cake, leather dressing, paper production and gunpowder manufacture. Willey Mill, at Farnham, was still in use in 1953. Headley Mill is still in commercial operation.  Guildford Town Mill, though no longer used for milling, still harnesses the power of the river to generate electricity.
During the seventeenth century, the river was made navigable to Guildford and extended in the eighteenth century to Godalming. The Basingstoke Canal and Wey and Arun Junction Canal were later connected to the river. The navigable sections are now owned by the National Trust.
Much of the upper reaches of the river are within the Surrey Hills Area of Outstanding Natural Beauty. The river passes through a variety of habitats including heathland, woodland and watermeadow, resulting in a diversity of wildlife. There are Sites of Special Scientific Interest (SSSI) and Nature Reserves along the river.
A broad basin of aquifers drain steeply to the river so, as with the Mole, in its natural state, much of the flood plains were prone to regular flooding. This has been greatly reduced by flood alleviation measures, upstream lakes such as Frensham Great Pond and, inadvertently, the Wey navigations. The lowest urban areas of Godalming, Byfleet and Weybridge saw extensive flooding in the exceptional winter storms of 2013–14.
The Environment Agency measure water quality of the river systems in England. Each is given an overall ecological status, which may be one of five levels: high, good, moderate, poor and bad. There are several components that are used to determine this, including biological status, which looks at the quantity and varieties of invertebrates, angiosperms and fish. Chemical status, which compares the concentrations of various chemicals against known safe concentrations, is rated good or fail.
Water quality of the River Wey in 2019:
|North Wey at Alton||Moderate||Fail||Moderate||2.802 km (1.741 mi)||54.231 km2 (20.939 sq mi)||Heavily modified|
|North Wey (Alton to Tilford)||Poor||Fail||Poor||31.242 km (19.413 mi)||82.531 km2 (31.865 sq mi)|
|South Wey (Haslemere to Bordon)||Poor||Fail||Poor||17.234 km (10.709 mi)||40.382 km2 (15.592 sq mi)|
|South Wey (Bordon to River Slea confluence)||Moderate||Fail||Moderate||5.823 km (3.618 mi)||11.342 km2 (4.379 sq mi)|
|South Wey (River Slea confluence to Tilford)||Moderate||Fail||Moderate||11.633 km (7.228 mi)||38.999 km2 (15.058 sq mi)|
|Wey (Tilford to Shalford)||Poor||Fail||Poor||23.332 km (14.498 mi)||63.274 km2 (24.430 sq mi)|
|Wey (Shalford to River Thames confluence at Weybridge)||Moderate||Fail||Moderate||46.346 km (28.798 mi)||75.772 km2 (29.256 sq mi)||Heavily modified|
- Inland Waterways Association (South-East Region) The River Wey and Godalming Navigation: Weybridge to Godalming Inland Waterways Association 1976
- Tributaries of the River Thames
- Canals of the United Kingdom
- List of rivers of England
- Perseverance IV, last floating River Wey barge.
- Mills on the River Wey and its tributaries
Notes and references
- "About the Wey Catchment Abstraction Management Strategy". The Environment Agency website. Archived from the original on 9 February 2008. Retrieved 23 October 2007.
- Mills, A.D. Dictionary of English Place-Names. Oxford: Oxford University Press, 1991. Print. (ISBN 0-19-869156-4)
- Linton DL (1930). "The development of the Wey drainage system". Proc. Geol. Assoc. 41 (2): 160–174. doi:10.1016/S0016-7878(30)80030-0.
- "The River Wey and Wey Navigations Community Site". Archived from the original on 25 June 2008. Retrieved 27 June 2008.
- Geology for Engineers, F.G.H. Blyth, published by Arnold, third edition, 1952. cited with approval by http://weyriver.co.uk/theriver/wey_north_B.htm Archived 19 February 2020 at the Wayback Machine and Surrey Nature Partnership in its 2018 Wey Catchment Plan
- "Elevation Finder". Archived from the original on 20 April 2020. Retrieved 30 August 2020.
- Ordnance Survey: Surrey: Sheet: XLV.NW, Revised: 1895 to 1896, Published: 1898 https://maps.nls.uk/geo/explore/#zoom=15&lat=51.11727&lon=-0.70149&layers=6&b=7 Archived 6 October 2020 at the Wayback Machine
- Ordnance Survey: Surrey: Sheet: XLIV.SE, Revised: 1895 to 1896, Published: 1898 https://maps.nls.uk/geo/explore/#zoom=16&lat=51.07178&lon=-0.72304&layers=6&b=7 Archived 6 October 2020 at the Wayback Machine
- Ordnance Survey: Surrey: Sheet: XLV.SW, Revised: 1895 to 1896, Published: 1898
- Ordnance Survey: Surrey: Sheet: XL.S, Revised: 1895 to 1896, Published: 1898
- Church of England Archived 23 January 2021 at the Wayback Machine current ecclesiastical parish boundaries
- old parish boundary approximate maps Archived 23 January 2021 at the Wayback Machine Vision of Britain: History of Parliament Trust; University of Portsmouth and Others.
- "Council to Take over Land | Richmond and Twickenham Times". Archived from the original on 24 June 2020. Retrieved 23 June 2020.
- "All About Watermills & Their Millers". The River Wey & Navigations website. Archived from the original on 6 August 2018. Retrieved 23 October 2007.
- "Headley Mill". Hampshire Mills Group. Archived from the original on 19 January 2019. Retrieved 2 August 2019.
- Recap: Flood-hit communities prepare for further rainfall Archived 18 April 2014 at the Wayback Machine Surrey Advertiser Group. 12 February 2014. Retrieved 18 April 2014
- "Glossary (see Biological quality element; Chemical status; and Ecological status)". Catchment Data Explorer. Environment Agency. 17 February 2016. Archived from the original on 2 October 2020. Retrieved 25 July 2020. Text was copied from this source, which is available under an Open Government Licence v3.0. © Crown copyright.
- "North Wey at Alton". Catchment Data Explorer. Environment Agency.
- "North Wey (Alton to Tilford)". Catchment Data Explorer. Environment Agency.
- "South Wey (Haslemere to Bordon)". Catchment Data Explorer. Environment Agency.
- "South Wey (Bordon to River Slea confluence)". Catchment Data Explorer. Environment Agency.
- "South Wey (River Slea confluence to Tilford)". Catchment Data Explorer. Environment Agency.
- "Wey (Tilford to Shalford)". Catchment Data Explorer. Environment Agency.
- "Wey (Shalford to River Thames confluence at Weybridge)". Catchment Data Explorer. Environment Agency.
- The River Wey Trust
- River Wey and Godalming Navigations and Dapdune Wharf
- River Wey Catchment Flood Warnings