Clewer Mill Stream is a narrow twisting backwater of 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,...

 near Windsor, Berkshire

Windsor, Berkshire

Windsor is an affluent suburban town and unparished area in the Royal Borough of Windsor and Maidenhead in Berkshire, England. It is widely known as the site of Windsor Castle, one of the official residences of the British Royal Family....

 which leaves the river at Bush Ait

Bush Ait

Bush Ait is an island in the River Thames on the reach above Boveney Lock at the mouth of the Clewer Mill Stream which leads to Windsor Racecourse Marina. The island is unpopulated and wooded.-See also:*Islands in the River Thames*Ait...

 and rejoins just above Queen Elizabeth Bridge

Queen Elizabeth Bridge, Windsor

The Queen Elizabeth Bridge is a road bridge just to the west of the town of Windsor, Berkshire, England.The Elizabeth bridge carries the A332 Windsor By-pass across the River Thames, on the reach between Romney Lock and Boveney Lock...

. Clewer Mill Stream is named after the watermill

Watermill

A watermill is a structure that uses a water wheel or turbine to drive a mechanical process such as flour, lumber or textile production, or metal shaping .- History :...

 that it once provided power for.

Clewer Mill Stream has provided a source of food

Food

Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

, power and freshwater

Freshwater

Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

, safe harbour and navigable access to the Thames for the small settlement of Clewer

Clewer

Clewer is an ecclesiastical parish and region of Windsor making up three wards of the Royal Borough of Windsor and Maidenhead in the English county of Berkshire.-History:...

 since the 10th century. In 1198 the Knights Templar

Knights Templar

The Poor Fellow-Soldiers of Christ and of the Temple of Solomon , commonly known as the Knights Templar, the Order of the Temple or simply as Templars, were among the most famous of the Western Christian military orders...

s of Bisham

Bisham

Bisham is a village and civil parish in the Windsor and Maidenhead district of Berkshire, England. According to the 2001 census it had a population of 1,149. The village is on the River Thames, north of which is Marlow in Buckinghamshire...

 granted a fishery

Fishery

Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

 at Clewer to Richard de Sifrewast. The corn mill

Gristmill

The terms gristmill or grist mill can refer either to a building in which grain is ground into flour, or to the grinding mechanism itself.- Early history :...

 at Clewer was first mentioned in the Domesday Book

Domesday Book

Domesday Book , now held at The National Archives, Kew, Richmond upon Thames in South West London, is the record of the great survey of much of England and parts of Wales completed in 1086...

 with a value of 10 shilling

Shilling

The shilling is a unit of currency used in some current and former British Commonwealth countries. The word shilling comes from scilling, an accounting term that dates back to Anglo-Saxon times where it was deemed to be the value of a cow in Kent or a sheep elsewhere. The word is thought to derive...

s and there has been a building on the site ever since. In 1781 the mill burnt down and its machinery, which had been visited by George III

George III of the United Kingdom

George III was King of Great Britain and King of Ireland from 25 October 1760 until the union of these two countries on 1 January 1801, after which he was King of the United Kingdom of Great Britain and Ireland until his death...

 as it was so "singular and curious", was destroyed. The mill was rebuilt after the fire and although the water levels were affected following the building of the weir

Weir

A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...

s at Romney

Romney Lock

Romney Lock is a lock on the River Thames in England near Windsor and Eton. It is on the Windsor side of the river next to a boatyard and adjoins Romney Island, a long strip of land in the middle of the river. The first lock was built by the Thames Navigation Commission in 1798.The weir is some...

 and Boveney Lock

Boveney Lock

Boveney Lock is a lock on the River Thames situated on the Buckinghamshire bank opposite the Windsor Racecourse and close to Eton Wick. Boveney is a village a little way upstream on the same side. The lock was first built in 1838 by the Thames Navigation Commission...

s, Clewer Mill was operational until the late 19th century. In the 1920s Clewer Mill House was the home of a Mrs Moscockle who used to dress like Queen Mary

Mary of Teck

Mary of Teck was the queen consort of the United Kingdom and the British Dominions, and Empress of India, as the wife of King-Emperor George V....

 and wave regally to pedestrians from her Rolls-Royce

Rolls-Royce (car)

This a list of Rolls-Royce motor cars and includes vehicles produced by:*Rolls-Royce Limited *Rolls-Royce Motors , which was owned by Vickers between 1980 and 1998, and after that by Volkswagen...

 as she was driven around Windsor.

Clewer Mill Stream was a popular haunt of schoolboys

Student

A student is a learner, or someone who attends an educational institution. In some nations, the English term is reserved for those who attend university, while a schoolchild under the age of eighteen is called a pupil in English...

 from nearby Eton College

Eton College

Eton College, often referred to simply as Eton, is a British independent school for boys aged 13 to 18. It was founded in 1440 by King Henry VI as "The King's College of Our Lady of Eton besides Wyndsor"....

 although it was, along with the Thames itself, officially out-of-bounds and a punishment of 100 lines could be given by a sixth form

Sixth form

In the education systems of England, Wales, and Northern Ireland, and of Commonwealth West Indian countries such as Barbados, Trinidad and Tobago, Belize, Jamaica and Malta, the sixth form is the final two years of secondary education, where students, usually sixteen to eighteen years of age,...

er to any lower boy caught "shooting [water birds] in the Clewer Stream".
An account from the 1840s of life at Eton describes the thrill of sculling

Skiffing

Skiffing refers to the sporting and leisure activity of rowing a Thames skiff. A Thames skiff is a traditional hand built clinker-built wooden craft of a design which has been seen on the River Thames and other waterways in England and other countries for nearly 200 years...

 up the backwater to the mill, waiting until the "miller was at dinner" to carry one's skiff

Thames skiff

A Thames skiff is a traditional River Thames wooden rowing boat used for the activity of Skiffing. These boats evolved from Thames wherries in the Victorian era to meet a passion for river exploration and leisure outings on the water.-Construction of a skiff:...

 around the mill wheel

Water wheel

A water wheel is a machine for converting the energy of free-flowing or falling water into useful forms of power. A water wheel consists of a large wooden or metal wheel, with a number of blades or buckets arranged on the outside rim forming the driving surface...

 and launch it in to the "mill-stream where it was really dangerous, above the wheel".

The 165 acre (0.6677319 km²) tract of land between Clewer Mill Stream and the main channel of the Thames is a meadow called The Rays which has been used for horse racing

Horse racing

Horse racing is an equestrian sport that has a long history. Archaeological records indicate that horse racing occurred in ancient Babylon, Syria, and Egypt. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC...

 meetings since 1866. It is now the site of Royal Windsor Racecourse

Windsor Racecourse

Windsor Racecourse, also known as Royal Windsor Racecourse is a thoroughbred horse racing venue located in Windsor, Berkshire, England. It is one of only two figure-of-eight courses in the United Kingdom, the other being at Fontwell Park. It abandoned National Hunt jump racing in December 1998,...

.

The upstream part of Clewer Mill Stream from Bush Ait forms the entrance channel to Windsor Racecourse Marina, providing a maximum of an 11 feet (3.4 m) draft

Draft (hull)

The draft of a ship's hull is the vertical distance between the waterline and the bottom of the hull , with the thickness of the hull included; in the case of not being included the draft outline would be obtained...

 although this is significantly reduced during drought

Drought

A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...

years. The downstream section, below the marina is unnavigable by powered craft except for a short reach from the mouth of the stream upstream to Clewer Boatyard.