River Colne, Hertfordshire

This article is about the River Colne in Hertfordshire. For other uses, see River Colne.

Colne
River
River Colne as it joins the Thames at Staines
Country	England
Counties	Hertfordshire, Greater London, Buckinghamshire, Surrey
Tributaries
- left	Mimmshall Brook, Tykes Water, River Pinn
- right	Ellen Brook, River Ver, River Gade, River Chess, River Misbourne
Towns	Watford, Uxbridge, West Drayton, Staines
Source
- location	North Mymms
Mouth	River Thames
- location	Staines
Discharge	for Denham
- average	4.05 m3/s (143 cu ft/s)
- max	18.4 m3/s (650 cu ft/s) 14 October 1993
- min	0.74 m3/s (26 cu ft/s) 26 August 1976
Discharge elsewhere (average)
- Berrygrove	0.79 m3/s (28 cu ft/s)

River Colne Hertfordshire

Legend River Colne (from source) River Gade Grand Union Canal River Colne Junction with canal River Chess Rickmansworth Batchworth Locks Weir A404 London Road Weir Feeder Navigable branch Weir Troy Cut Railway bridge Frays River Weir River Misbourne A40 road Shire Ditch A4077 Alder Bourne M25 Motorway Colne Brook M25 motorway Slough Arm River Pinn Grand Union Canal Reading - Paddington Railway M25 Motorway River Colne M4 Motorway Bigley Ditch A4 Colnbrook Bypass M25 Motorway Poyle Channel Culvert under Heathrow Airport Duke of Northumberland's River Longford River A3044 Stanwell Moor M25 Junction 14 slip road A3044 Stanwell Moor A3113 Airport Way M25 motorway Wraysbury River Bonehead Ditch Colne Brook Railway bridge A30 Staines Bypass River Ash Railway bridge Wraysbury River A308 Clarence St, Staines River Thames

The Colne is a river in England which is a tributary of the River Thames. It flows mainly through Hertfordshire and forms the boundary between the South Bucks district of Buckinghamshire and the London Borough of Hillingdon. It splits off into several separate branches, some of which rejoin it, and it flows into the River Thames on the reach above Penton Hook Lock at Staines.

Route

The Colne rises near North Mymms in Hertfordshire (although the now dry river bed can be followed further back for about 1.2 miles (1.9 km) to the Water End Swallow holes). It runs south west to Watford and then south to Uxbridge where it parallels the Grand Union Canal and its distributary the Frays River which is joined by the River Pinn. The Colne Brook splits off at Uxbridge and at West Drayton the Frays River rejoins and the Wraysbury River and Duke of Northumberland's River divide off.

The villages of Colney Heath near St Albans, Colney Street near Radlett, Colnbrook near Slough and London Colney in Hertfordshire all take their name from this river. The Colne is also one of the rivers referred to in the name of the Three Rivers district.

In its lower reaches, the river supplies water to Longford River, a 12-mile (19 km) artificial channel created in 1610 for King Charles I to supply water features in Bushy Park.

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 joined the river channel for part of its course. Construction began from Brentford, where it used the channel of the River Brent, and progressed northwards, with it reaching Uxbridge in November 1794. 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. The Slough Arm was built much later, in 1882, and required three aqueducts near its junction with the Grand Junction main line, to cross the Fray's River, the River Colne and the Colne Brook. There had been earlier proposals to link the river to London, including 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.

Between Croxley Green, where the River Gade joins the Colne, and West Drayton, below the Slough Arm, the river channels thread their way between many large lakes, some of which were once watercress beds, some chalk pits, and some of which were the result of brickmaking, an industry which developed over several miles of the valley after 1800, when the Grand Junction Canal company advertised the presence of good brick earth, discovered during the construction of the canal.

Structures

There are two London Coal Duty markers besides the river, which were positioned to mark the point at which coal duty became payable in the London area. The first is on the north side of the river at Colney Heath, and is a square-section cast iron pillar made by Henry Grissell at his Regents Canal ironworks and erected in 1861 or 1862. It is 5 feet (1.5 m) high and is painted white. The second is a stone obelisk, 13 feet (4.0 m) high, with a square base, which was erected at Colne Bridge in 1861. It was moved from its original position on the other side of the river in 1984, when it was repaired by Watford Borough Council. It is close to a five-arched railway viaduct, which was built in 1837 to carry the London to Birmingham Railway over the river. Each of the arches spans around 40 feet (12 m) and is 45 feet (14 m) high. The structure was designed by Robert Stephenson, and is grade II listed.

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 twentieth century, when parapets and railings were added.

There was a long-running dispute over water levels in the Batchford area, following 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, John Dickinson who was the miller at Batchworth Mill, and R. Williams of Moor Park, who was the landowner.

Tributaries and distributaries

These are listed from mouth (Thames) to source:

• Wraysbury River (branch West Drayton to Staines)
• River Ash (Staines to River Thames Sunbury on Thames)
• Colne Brook (Uxbridge Moor to River Thames Hythe End)
• Longford River (man made - Longford to River Thames Hampton Court)
• Duke of Northumberland River (man made West Drayton to River Thames Isleworth)
• Frays River (branch Watford to West Drayton)
  • River Pinn (Harrow Weald to West Drayton)
• River Misbourne (Amersham to Uxbridge)
• Alder Bourne (Fulmer to Colne)
• River Chess (Chesham to Rickmansworth)
• River Gade
  • River Bulbourne
• River Ver (Dolittle Mill to Colne)
• Tykes Water (Aldenham Reservoir to Colne)
• Ellen Brook (Hatfield to Colne)
• Mimmshall Brook (Elstree to Colne)
  • Catherine Bourne (Shenley to Mimmshall Brook)
  • Potters Bar Brook (Potters Bar to Mimmshall Brook)

See also

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

Bibliography

• Hadfield, Charles (1970). The Canals of the East Midlands. David and Charles. ISBN 0-7153-4871-X. 
• Nicholson (2006). Nicholson Guides Vol 1: Grand Union, Oxford and the South East. Harper Collins. ISBN 978-0-00-721109-8. 

References

Next confluence upstream	River Thames	Next confluence downstream
Colne Brook (north)	River Colne	Abbey River (south)