sedimentary clay

River Brent

The Brent is a river within Greater London which is a tributary of the River Thames. It is 17.9 miles (29km) long, running north-east to south-west, and it joins the Thames on the Tideway at Brentford.

The name has very ancient origins in the linguistic root of the Celtic tutelary goddess Brigant. A letter from the Bishop of London in AD 705 suggesting a meeting at Breguntford now Brentford, is the earliest record of this place and probably therefore that of the river.


The river Brent and its valley's formation is the result of glacial action during the ice age which had started some 500,000 years ago. Back then, the major drainage channel for this part of England (or early proto-Thames) was several miles to the north and travelled east, past present day Ipswich in East Anglia. Progressively, the channel was pushed south to form the St Albans depression by the repeated advances of the ice sheet. The last advance from that Scandinavian ice flow to have reached this far south, covered much of Northwest Middlesex and finally forced the proto-Thames to take roughly its present course.

The original land surface was some 350 to 400 feet above the current sea level. The surface had sandy deposits from an ancient sea, laid over sedimentary clay (this is the Blue London Clay). All the erosion down from this higher land surface and sorting action by these changes of water flow and direction, formed what is known as the Thames River Gravel Terraces. The ice sheet which stopped around present day Finchley, deposited Boulder clay to form Dollis Hill and Hanger Hill. Its torrent of meltwater gushed through the Finchley Gap and south towards the new course of the Thames, and proceeded to carve out the Brent Valley in the process. Upon the valley sides there can be seen other terraces of Brickearth; laid over and sometimes interlayered with the clays. These deposits were brought in by the winds during the periglacial periods, suggesting that wide flat marshes were then part of the landscape, which the new river Brent proceeded to cut down. The steepness of the valley sides is witness to the very much lower mean sea levels caused by the glaciation locking up so much water upon the land masses, thus causing the river water to flow rapidly seaward and so erode its bed quickly downwards.

Since Roman times and perhaps earlier, however, the isostatic rebound from the weight of previous ice sheets, and its interplay with the eustatic change in sea level, means that the old valley of river Brent, together with that of the Thames, has been silting up again. Thus along much of the Brent's present day course one can make out the water meadows of rich alluvium, which is augmented by frequent floods.

So extensive have the changes to this landscape been that what little evidence there is of man's presence before the ice came has inevitably shown signs of transportation here by water and reveals nothing specifically local. Likewise, later evidence of occupation, even since the arrival of the Romans, may lie next to the original banks of the Brent but have been buried under centuries of silt.

Earliest recorded reference and etymology

A letter from the Bishop of London in AD 705 suggesting a meeting at Breguntford, now Brentford, is the earliest record of this place and of the river.

The name may have very ancient origins cognate with the name of the Celtic goddess Brigant. However this does not imply (as suggested in some texts) that it was named after such a deity. Rather it appears that it was the usual practice to name natural features after their most notable characteristic or quality A deity associated with the site or feature might have been so named subsequently.


A possible origin of the name is that Brig belongs to the root for stream, as in Brigstow (modern-day Bristol). Br is a common prefix for many rivers e.g. Br-ad-field, Br-ad-ford, Br-ane, Br-ant, Br-ay, Br-ay-an, Br-et-on, Br-it-on, Br-id-y, Br-ide and of course Br-ent, which serves as the name to more rivers than just this one river of Middlesex. Note also, in these examples the presence of aid, en, ad, ane, ay, and especially ant and ent which are all derived from the Celtic for stream or water. So, for instance: Br-ay-an translates to river-river-river and Brent as simply meaning river-river. This renaming and adding to the existing names given to natural features of the same synonym but in the new vernacular of succeeding peoples was not restricted to rivers. For example, in Cumbria there is Tor-pen-how-hill, which translates as hill-hill-hill-hill.

Alternatively, if the first recorded instance of Brentford as Breguntford is broken into Breogh-ant this could be a variant of Braoch, Breoch or Breogh for boarder or division of land and ant for water or stream. Or the unt in Bregunt may be a synonym of aon i.e., land or country, with a 'T' sound added at the end due to Epenthesis. Soon after this, it became known as the river Brigant. This reminds one of the Brigantes or the people who dwell in Border-water-land. They were a tribe bordered by both sea to the east and between the great rivers Humber and Tyne. (A tribe of the same name was also known on the European mainland also similarly bounded.) Referring back to the prefix 'Br': maybe it was the dividing aspect that a river presented that this prefix had back then one and the same meaning of both border and river? However, can the river Brent be considered a border in the sense that the quality it possessed of dividing the land, was notable enough to be given such a descriptive title? The Brent river valley in AD 705 would have looked very different to today. Before modern day dredging the river was wider and shallower. Before the construction of its weirs, the Brent reservoir and Grand Union Canal (and its Paddington Branch, which takes much of the Brent's waters) the river would have flooded more frequently than it does today. The alluvial valley floor would therefore have been swamp. On Google Earth, the signs of many of the old drainage channels that turned the marsh into water meadow are still visible. Bordering these marshes would have been dense thickets of thorn and willow (hence the modern place names of Elthorne [the sheltering tree.from Helethorne with the 'h' being lost to elision], and Spelthorne (the tree of speech).

By the Middle Ages malaria had reached Britain, It went on to be a great problem here in the south. There were hot spots of this disease along the course of the river Thames as well as at Romney Marsh, so one might expect that the Brent Valley could also have harboured the disease, thus living near it may have been too unhealthy to encourage many settlements. Only at places where the river gravel beds afforded a firm river bed was fording a safe and practical proposition. Some such fording places were the Roman road crossing in Brentford itself, Green Lanes in Hanwell (a reminder that this was an old droving route, the word 'green' signifying that livestock could graze whilst on their last journey), and Hanwell Bridge on the Uxbridge Road. With only a few fordable places along the river's course it would obviously have been easier to defend, and this suggests that it may have been an important border.

Another conjecture: The original parish of Hanwell was larger than today and stretched for some three and a half miles north from the Brent's confluence with the river Thames but was only some half a mile wide, thus separating the parishes of Norwood on the east bank of the Brent and Ealing towards the west. To the north it bordered Greenford and Perivale. One of the possible etymologies given for this ancient parish of Hanwell is 'Han' as Saxon for boundary stone and 'well' as Saxon for fresh water or spring. The Rectory Cottage to the parish church of St Mary has a large stone of about a ton in its garden. A large land owner and historian also put forward the observation that this appeared to line up with what he maintained as traces of the parish being divided up into the Roman Centuria unit of land area, indicating that they to used this stone as a datum. However , the position of the field boundaries and roads still wait to be statistically analysed to test this hypothesis. Nevertheless, a cursory inspection of the old ordnance survey maps, blended with an appreciation of how hedges and boundary paths drift with time and use, strongly suggests that they approximated to dimensions of the quintarial limes of the Roman field system by a degree that far exceeds what would be expected by chance alone. Also, as already mentioned, the original parish is very narrow in the east-west direction. You will recall that the letter of AD 705 AD suggested a meeting at Brentford; this was to discuss a dispute between the East Saxons and the West Saxons. Thus the location was recognised as a convenient half way point or boundary. Other later historically important meetings are also recorded here. Going back a little further, evidence of the West Saxons successfully overrunning the Chilterns to the north west can be seen in the number of place names which end in ham ton and worth But then they stop, as if the parish of Hanwell and the course of the Brent are the boundary between the invading West Saxons and the last vestiges of Romano-British London which lasted until the end of the 5th century.

It has also been suggested that Han came from the Saxon han for cockerel. This would seem rather too broad a noun to serve as a place name but the spelling that appears in the Domesday Book is Hannewelle. Could Hannewelle be derived from Han-créd -welle noting especially the stress placed on the e. The other sounds being dropped (see: Elision) to make it easier to say and a touch more euphonic. Han-créd or rather the modern synonym cock-crow was a term used until recently in both town and country to signify the boarder between night and day, and is neither one nor the other. Guns and other mechanisms are 'cocked' etc., etc. The suffix of 'Hat' is used today to divide computer hackers and before them: gun-slinger, witches etc., etc. This use of some nouns appears to be a feature of human language (also present in ancient Greek). Could 'cock' in this instance have been be used in the same way?

As partly touched upon, the course of the river Brent still denotes the boundary of many part of the human landscape it passes through including the boundary of Middlesex and Hertfordshire -which is the border of the old Hundred of Gore In the Victorian era and the romantic period, one tended fancifully to suggest links to the druids, or to ancient deities.

The river's course

From Barnet to Brent Cross

The River Brent rises in low hills and fields of the London Borough of Barnet in north London, with several tributaries. The main tributary is the Dollis Brook, around 10 km or 6 miles long, which rises in what was Barnet Common, Arkley, and passes eastward through Duck Island (Barnet). The name Dollis is believed by some to be connected with commoners' rights at Barnet, and to be cognate with "dole". It marks the boundary between the ancient parish of Totteridge and Chipping Barnet. The Dollis turns south and flows down between Totteridge and the Finchley side of Whetstone.

A tributary of the Dollis, Folly Brook, meets the Dollis not far from Woodside Park tube station.

From here the Dollis flows south as a boundary between Mill Hill, and the ancient parish of Finchley. The tributary, Mutton Brook, rises in East Finchley at Cherry Tree Wood. It flows westward from there, underground, until it comes out shortly after The Bishop's Avenue. Just west of Henley’s Corner, Mutton Brook joins the Dollis to form the Brent, though some people maintain the name Dollis Brook as far as the Welsh Harp.

A small stream called Decoy Brook that rises somewhere in Temple Fortune runs parallel to Golders Green Road to join the Brent River, at Brent Bridge. Another, Clitterhouse Brook, rises at two locations on the Western slopes of Hampstead Heath. One brook feeds the Leg of Mutton Pond on West Heath, and the lower duck pond of Golders Hill Park. On the bank of the stream by Leg of Mutton Pond lies the site of a stone age encampment, which was excavated by the Hendon and District Archaeological Society in the 1970s. Another brook feeds the upper duck pond in Golders Hill Park and then flows to merge with the other branch at the lower duck pond. From Golders Hill Park the stream flows underground approximately in parallel with Dunstan Road to Childs Hill Park. At Granville Road, at the south end of the park a laundry industry emerged to use the clean water of the stream as did a nursery industry, now all disappeared. From Granville Road the stream flows underground to emerge at Clitterhouse Playing Fields and joins the Brent at Brent Cross shopping centre. The River Brent then flows alongside the A406 North Circular Road to Brent Cross, and then into the Brent Reservoir, where it is joined by another tributory, the Silk Stream.

From Brent Cross to Brentford

From here, still closely following the North Circular Road, the river passes Stonebridge Park, south of Wembley, and under an aqueduct carrying the Paddington arm of the Grand Union Canal. From Stonebridge Park the river turns westward, and flows under the A40 Western Avenue and through Brent River Park for 5 km or 3 miles until it reaches Greenford. This part of the river, as it passes through the southern boundary of Greenford Golf Course, was dredged deeper in the 1960s and a control weir built, to reduce the risk of flooding, especially of Costons Lane, along which there is a flood protection wall. Previously, Ruslip Road East would also regularly become impassable.

It then swings south again at Greenford Bridge to Hanwell, a mile away across the fields. The River Brent continues SE-ward past St. Mary's Church. It flows under the Great Western Railway at Wharncliffe Viaduct, a high spanned railway viaduct carrying the main line railway from Paddington to the west of England.

Within about 500m, the River Brent is joined from the west by the main line of the Grand Union Canal at the foot of a flight of locks. From here, the Brent is canalised and navigable — the river and canal pass through Osterley and a further three locks before joining the tidal River Thames at Brentford tidal lock, a mile upstream of Kew Bridge.

Notable floods

The earliest flood record is 1682. A very violent storm of rain, accompanied with thunder and lightning, caused a sudden flood, which did great damage to the town of Brentford. The whole place was overflown; boats rowed up and down the streets, and several houses and other buildings were carried away by the force of the waters.

1841 saw the waters of the Brent Reservoir overflow the top of the dam which caused a breech. A waves of frothing and roaring water swept down the river's course taking all before it. People died.

In the summer of 1976 Britain experienced its worst drought since records began; with Water Companies declaring it would take six or seven years for their empty, dry reservoirs to fill again. However, in August the following year, torrential rain not only filled but overwhelmed the Brent reservoir again, forcing the sluice gate to be opened to their fullest extent. It carried on raining heavily throughout the night. Even before the river broke its banks, the drains had started to overflow with sewerage. People awoke during the night to find their homes being flooded. Commuters set for to work in the morning to find the North London streets grid-locked due to wide spread flooding of the Brent river. Trains could not run. Hundreds ended up homeless and hundreds of shops and businesses had to close to clear up the mess. Roads that were unaffected by the water and sewage were awash with the dozens and dozens of news-crews covering the mayhem.

In literature and poetry

Poet Laureate Sir John Betjeman in his poem Middlesex.

Gentle Brent, I used to know you
Wandering Wembley-wards at will,
Now what change your waters show you
In the meadowlands you fill!
Recollect the elm-trees misty
And the footpaths climbing twisty
Under cedar-shaded palings,
Low laburnum-leaned-on railings
Out of Northolt on and upward to the heights of Harrow hill.

See also

External links


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