The River Wandle is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in south-east England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. The names of the river and of Wandsworth are thought to have derived from the Old English

Old English language

Old English or Anglo-Saxon is an early form of the English language that was spoken and written by the Anglo-Saxons and their descendants in parts of what are now England and southeastern Scotland between at least the mid-5th century and the mid-12th century...

 "Wendlesworth" meaning "Wendle's Settlement". The river runs through southwest London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 and is about 9 miles (14.5 km) long. It passes through the London Boroughs of Croydon

London Borough of Croydon

The London Borough of Croydon is a London borough in South London, England and is part of Outer London. It covers an area of and is the largest London borough by population. It is the southernmost borough of London. At its centre is the historic town of Croydon from which the borough takes its name...

, Sutton

London Borough of Sutton

The London Borough of Sutton is a London borough in South London, England and forms part of Outer London. It covers an area of and is the 80th largest local authority in England by population. It is one of the southernmost boroughs of London...

, Merton

London Borough of Merton

The London Borough of Merton is a borough in southwest London, England.The borough was formed under the London Government Act in 1965 by the merger of the Municipal Borough of Mitcham, the Municipal Borough of Wimbledon and the Merton and Morden Urban District, all formerly within Surrey...

, and Wandsworth

London Borough of Wandsworth

The London Borough of Wandsworth is a London borough in southwest London, England, and forms part of Inner London.-History:The borough was formed in 1965 from the former area of the Metropolitan Borough of Battersea and much of the former area of the Metropolitan Borough of Wandsworth, but...

 to join the River Thames

River Thames

The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...

 on the Tideway

Tideway

The Tideway is a name given to the part of the River Thames in England that is subject to tides. This stretch of water is downstream from Teddington Lock and is just under long...

 at Wandsworth

Wandsworth

Wandsworth is a district of south London, England, in the London Borough of Wandsworth. It is situated southwest of Charing Cross. The area is identified in the London Plan as one of 35 major centres in Greater London.-Toponymy:...

.

Rain falls on the North Downs

North Downs

The North Downs are a ridge of chalk hills in south east England that stretch from Farnham in Surrey to the White Cliffs of Dover in Kent. The North Downs lie within two Areas of Outstanding Natural Beauty , the Surrey Hills and the Kent Downs...

, filters through the chalk and emerges on the spring line at the Wandle's two main sources, both at about 115 ft (38 yd, 35 m) above sea level.