River Colne, Hertfordshire

Colne
River Colne as it joins the Thames at Staines-upon-Thames
Location
Country	England
Counties	Hertfordshire, Greater London, Buckinghamshire, Surrey, Berkshire
Towns	Watford, Rickmansworth, Uxbridge, West Drayton, Staines-upon-Thames
Physical characteristics
Source	Unnamed brook
• location	east of Bell Bar, Brookmans Park
• coordinates	51°43′50″N 0°10′47″W / 51.7306°N 0.1798°W / 51.7306; -0.1798
• elevation	410 feet (120 m)
2nd source	"Water End" brook
• location	east side of North Mymms Park (coalesence of two streams, liable-to-flood meadow)
Mouth	River Thames
• location	Staines-upon-Thames town centre
• coordinates	51°25′58″N 0°30′55″W / 51.4329°N 0.5152°W / 51.4329; -0.5152
• elevation	48 feet (15 m)
Length	58 kilometres (36 mi)
Discharge
• location	Denham, Buckinghamshire (rate at lower coalescence)
• average	4.05 m3/s (143 cu ft/s)
• minimum	0.74 m3/s (26 cu ft/s)26  August 1976
• maximum	18.4 m3/s (650 cu ft/s)14  October 1993
Discharge
• location	Berrygrove, Berry Grove Lane, Watford (rate at mid-to-upper coalescence)
• average	0.79 m3/s (28 cu ft/s)
Basin features
Thames Basin
Tributaries
• left	Mimmshall Brook, Potters Bar Brook, Tyttenhanger Stream, Tykes Water (The Brook (Radlett)), Hillfield Brook, River Pinn
• right	Ellen Brook and river: Ver, Gade, Chess, Misbourne
Number of distributaries including namesake:	6

v t e River Colne (Hertfordshire)
Legend
Source: two subterranean streams in east of North Mymms Park Colney Heath River Ver Weir Weir Watford — on opposite bank: Oxhey Weir Weir River Gade Grand Union Canal side weir River Chess Rickmansworth (east of)} Batchworth Locks Town Ditch, Rickmansworth  A404  Riverside Drive/Church Street Short navigable branch of river Troy Cut of the Grand Union Canal Railway bridge — Chiltern Main Line Frays River River Misbourne  A40   A4020  Shire Ditch, Uxbridge Park, Denham Uxbridge  A4007  Alder Bourne from Fulmer  M25  Colne Brook  M25  Slough Arm River Pinn Grand Union Canal towards London Great Western Main Line  M25  River Colne  M4  Bigley Ditch  A4  Colnbrook Bypass  M25  Poyle Channel Duke of Northumberland's River Hampton Court  A3044  Stanwell Moor  M25  Jn 14 Heathrow Terminal 5 Slip Road  A3044  Stanwell Moor  A3113  Airport Way  M25  Wraysbury River (Staines Moor) Bonehead Ditch Colne Brook Railway bridges — via Staines upon Thames  A30  Staines Bypass River Ash to Sunbury-on-Thames Railway bridge Church Street, Staines-upon-Thames  A308  Clarence Street River Thames

The Colne is a river and a tributary of the River Thames in England. Just over half its course is in south Hertfordshire. Downstream, it forms the boundary between Buckinghamshire and the London Borough of Hillingdon. The confluence with the River Thames is on the Staines reach (above Penton Hook Lock) at Staines-upon-Thames.

Two of its distributaries, constructed in the 1600 – 1750 period largely for aesthetic reasons for Hampton Court and for Syon Park, have been maintained. Their main purpose was not drinking water but these can be likened to the New River in scale and in date. Crossing its route, many viaducts and a canal, the intersecting Grand Union Canal, have been recognised for pioneering engineering during the Industrial Revolution.

Digging for gravel and clay along its lower course near

Route

The Colne becomes universally so-named after two close subterranean streams converge at a spring, or in very wet weather in the meadows above, all along the east side (Tollgate Road) of North Mymms Park in Hertfordshire. The source streams are long, multi-source, in final, northern stages, partly underground tributaries: a north-eastern, which can be considered the upper Colne; and the Mimmshall Brook. Their main sources are 2.5 to 4 mi (4.0 to 6.4 km): in western Northaw, Brookmans Park, Hadley, London and Borehamwood, draining much of those places.^[1] A seasonal, intra-parochial stream runs under the seven-building village of North Mymms draining most of the park, which, with adjoining woods is a small square plateau, sloping down to its corners except the south-west.^{[2] [3]}

Shallow

Soon after, at Longford, the intake is given to the Longford River, a 12-mile (19 km) artificial channel created in 1610 for King Charles I to supply the water features in Bushy Park and the rectangular lakes in Hampton Court Park.^[4]

The Colne's drainage basin extends almost as far north again as its northern limit – the inflowing Gade, Ver and Misbourne extend well into the Chilterns. Opposite, the other 2⁄3 of outer west and north-west London is drained by the Pymmes Brook, Brent, or Crane sub-basins of the Thames. In the north-west, centred on Tring's northern boundary the Chiltern ridge is most noticeable, a watershed of this basin and that of the River Great Ouse, north and east towards the Wash.

Eponymous settlements and indirect reference within a district name

The villages of Colney Heath east of St Albans, London Colney south of St Albans, Colney Street (almost wholly a large business park) north of Radlett and Colnbrook between Slough and Heathrow take their name from the river. Three Rivers District Council covers part of Hertfordshire and is named after the River Colne and its two tributaries, the River Chess and the River Gade.

Use of valley and river for navigation

Among early proposals to link the river to London was one in 1641 by Sir Edward Forde for a navigable canal, the main purpose of which seems to have been the supply of clean water, and two in 1766, for canals from Marylebone to the river at Uxbridge and another from Marylebone to West Drayton.^[5]

The river underwent considerable change in the 1790s, when the Grand Junction Canal (which became part of the Grand Union Canal in 1929) was routed along the valley and still takes the river channel for part of its course. Construction began from Brentford, where it used for 3 miles (4.8 km) the channel of the River Brent, and progressed westwards then northwards, with it reaching Uxbridge in November 1794. To reach the Midlands it continued along the river channel until its junction with the River Gade, which it ran parallel to, but did not take over the channel.^[6] The Slough Arm was built in 1882 which required three aqueducts to carry it close to its junction with the Grand Junction, to cross the Fray's River, the River Colne and the Colne Brook.^[7]

Between

At London Colney, there is a seven-arched brick bridge which carries Barnet Road over the river. It dates from 1774 and is called Telford's Bridge, although it is not thought to have been designed by Thomas Telford. It was modified in the 20th century when parapets and railings were added.^[12]

There was a long-running dispute over water levels in the Batchford area, following the construction of the Grand Junction Canal, which were resolved in 1825, when an 8.2-foot (2.5 m) obelisk was erected in a pond, to act as a water gauge. The obelisk records the agreement made between the canal company,

• Sweeps Ditch (distributary in Staines-upon-Thames)
• Wraysbury River (anabranch West Drayton to Staines)
• Sunbury on Thames
  /Shepperton border)
• Hythe End, Wraysbury
  )
  • the Alder Bourne (Fulmer to Uxbridge Moor)
• Hampton Court
  )
• Duke of Northumberland River (man-made distributary from West Drayton to Isleworth
  )
• Frays River (anabranch Watford to West Drayton)
  • the Pinn (Harrow Weald to West Drayton)
• the Misbourne (Amersham to Uxbridge)
• the Chess (Chesham to Rickmansworth)
• the Gade
  • the Bulbourne
• Hillfield Brook
• the Ver (from Dolittle Mill)
• Tykes Water (or The Brook, Radlett) (from Aldenham Reservoir)
• Ellen Brook (from Hatfield)
  • Butterwick Brook (from eastern St Albans)
• Water End (north, broad end of the Mimmshall Brook having drained brook from north Brookmans Park via Welham Green, identifiable as the source and others below)
• Mimmshall Brook (Elstree to Water End (broad meandering end and sinks))
  • Catherine Bourne (Shenley to Mimmshall Brook)
  • Ray Brook (Brookmans Park to Water End (see above))
  • Potters Bar Brook (Potters Bar to Water End (see above))

See also

• Tributaries of the River Thames
• List of rivers in England
• Mid Colne Valley

Bibliography

51°25′59″N 0°30′55″W / 51.43306°N 0.51528°W / 51.43306; -0.51528